1/*
2** 2001-09-15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
20** features recently added to SQLite. We do not anticipate changes
21** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are supposed to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32*/
33#ifndef SQLITE3_H
34#define SQLITE3_H
35#include <stdarg.h> /* Needed for the definition of va_list */
36
37/*
38** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44
45/*
46** Facilitate override of interface linkage and calling conventions.
47** Be aware that these macros may not be used within this particular
48** translation of the amalgamation and its associated header file.
49**
50** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51** compiler that the target identifier should have external linkage.
52**
53** The SQLITE_CDECL macro is used to set the calling convention for
54** public functions that accept a variable number of arguments.
55**
56** The SQLITE_APICALL macro is used to set the calling convention for
57** public functions that accept a fixed number of arguments.
58**
59** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60**
61** The SQLITE_CALLBACK macro is used to set the calling convention for
62** function pointers.
63**
64** The SQLITE_SYSAPI macro is used to set the calling convention for
65** functions provided by the operating system.
66**
67** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68** SQLITE_SYSAPI macros are used only when building for environments
69** that require non-default calling conventions.
70*/
71#ifndef SQLITE_EXTERN
72# define SQLITE_EXTERN extern
73#endif
74#ifndef SQLITE_API
75# define SQLITE_API
76#endif
77#ifndef SQLITE_CDECL
78# define SQLITE_CDECL
79#endif
80#ifndef SQLITE_APICALL
81# define SQLITE_APICALL
82#endif
83#ifndef SQLITE_STDCALL
84# define SQLITE_STDCALL SQLITE_APICALL
85#endif
86#ifndef SQLITE_CALLBACK
87# define SQLITE_CALLBACK
88#endif
89#ifndef SQLITE_SYSAPI
90# define SQLITE_SYSAPI
91#endif
92
93/*
94** These no-op macros are used in front of interfaces to mark those
95** interfaces as either deprecated or experimental. New applications
96** should not use deprecated interfaces - they are supported for backwards
97** compatibility only. Application writers should be aware that
98** experimental interfaces are subject to change in point releases.
99**
100** These macros used to resolve to various kinds of compiler magic that
101** would generate warning messages when they were used. But that
102** compiler magic ended up generating such a flurry of bug reports
103** that we have taken it all out and gone back to using simple
104** noop macros.
105*/
106#define SQLITE_DEPRECATED
107#define SQLITE_EXPERIMENTAL
108
109/*
110** Ensure these symbols were not defined by some previous header file.
111*/
112#ifdef SQLITE_VERSION
113# undef SQLITE_VERSION
114#endif
115#ifdef SQLITE_VERSION_NUMBER
116# undef SQLITE_VERSION_NUMBER
117#endif
118
119/*
120** CAPI3REF: Compile-Time Library Version Numbers
121**
122** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123** evaluates to a string literal that is the SQLite version in the
124** format "X.Y.Z" where X is the major version number (always 3 for
125** SQLite3) and Y is the minor version number and Z is the release number.)^
126** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128** numbers used in [SQLITE_VERSION].)^
129** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130** be larger than the release from which it is derived. Either Y will
131** be held constant and Z will be incremented or else Y will be incremented
132** and Z will be reset to zero.
133**
134** Since [version 3.6.18] ([dateof:3.6.18]),
135** SQLite source code has been stored in the
136** <a href="http://www.fossil-scm.org/">Fossil configuration management
137** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138** a string which identifies a particular check-in of SQLite
139** within its configuration management system. ^The SQLITE_SOURCE_ID
140** string contains the date and time of the check-in (UTC) and a SHA1
141** or SHA3-256 hash of the entire source tree. If the source code has
142** been edited in any way since it was last checked in, then the last
143** four hexadecimal digits of the hash may be modified.
144**
145** See also: [sqlite3_libversion()],
146** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147** [sqlite_version()] and [sqlite_source_id()].
148*/
149#define SQLITE_VERSION "3.43.1"
150#define SQLITE_VERSION_NUMBER 3043001
151#define SQLITE_SOURCE_ID "2023-09-11 12:01:27 2d3a40c05c49e1a49264912b1a05bc2143ac0e7c3df588276ce80a4cbc9bd1b0"
152
153/*
154** CAPI3REF: Run-Time Library Version Numbers
155** KEYWORDS: sqlite3_version sqlite3_sourceid
156**
157** These interfaces provide the same information as the [SQLITE_VERSION],
158** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159** but are associated with the library instead of the header file. ^(Cautious
160** programmers might include assert() statements in their application to
161** verify that values returned by these interfaces match the macros in
162** the header, and thus ensure that the application is
163** compiled with matching library and header files.
164**
165** <blockquote><pre>
166** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169** </pre></blockquote>)^
170**
171** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172** macro. ^The sqlite3_libversion() function returns a pointer to the
173** to the sqlite3_version[] string constant. The sqlite3_libversion()
174** function is provided for use in DLLs since DLL users usually do not have
175** direct access to string constants within the DLL. ^The
176** sqlite3_libversion_number() function returns an integer equal to
177** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178** a pointer to a string constant whose value is the same as the
179** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180** using an edited copy of [the amalgamation], then the last four characters
181** of the hash might be different from [SQLITE_SOURCE_ID].)^
182**
183** See also: [sqlite_version()] and [sqlite_source_id()].
184*/
185SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186SQLITE_API const char *sqlite3_libversion(void);
187SQLITE_API const char *sqlite3_sourceid(void);
188SQLITE_API int sqlite3_libversion_number(void);
189
190/*
191** CAPI3REF: Run-Time Library Compilation Options Diagnostics
192**
193** ^The sqlite3_compileoption_used() function returns 0 or 1
194** indicating whether the specified option was defined at
195** compile time. ^The SQLITE_ prefix may be omitted from the
196** option name passed to sqlite3_compileoption_used().
197**
198** ^The sqlite3_compileoption_get() function allows iterating
199** over the list of options that were defined at compile time by
200** returning the N-th compile time option string. ^If N is out of range,
201** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202** prefix is omitted from any strings returned by
203** sqlite3_compileoption_get().
204**
205** ^Support for the diagnostic functions sqlite3_compileoption_used()
206** and sqlite3_compileoption_get() may be omitted by specifying the
207** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
208**
209** See also: SQL functions [sqlite_compileoption_used()] and
210** [sqlite_compileoption_get()] and the [compile_options pragma].
211*/
212#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214SQLITE_API const char *sqlite3_compileoption_get(int N);
215#else
216# define sqlite3_compileoption_used(X) 0
217# define sqlite3_compileoption_get(X) ((void*)0)
218#endif
219
220/*
221** CAPI3REF: Test To See If The Library Is Threadsafe
222**
223** ^The sqlite3_threadsafe() function returns zero if and only if
224** SQLite was compiled with mutexing code omitted due to the
225** [SQLITE_THREADSAFE] compile-time option being set to 0.
226**
227** SQLite can be compiled with or without mutexes. When
228** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229** are enabled and SQLite is threadsafe. When the
230** [SQLITE_THREADSAFE] macro is 0,
231** the mutexes are omitted. Without the mutexes, it is not safe
232** to use SQLite concurrently from more than one thread.
233**
234** Enabling mutexes incurs a measurable performance penalty.
235** So if speed is of utmost importance, it makes sense to disable
236** the mutexes. But for maximum safety, mutexes should be enabled.
237** ^The default behavior is for mutexes to be enabled.
238**
239** This interface can be used by an application to make sure that the
240** version of SQLite that it is linking against was compiled with
241** the desired setting of the [SQLITE_THREADSAFE] macro.
242**
243** This interface only reports on the compile-time mutex setting
244** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246** can be fully or partially disabled using a call to [sqlite3_config()]
247** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249** sqlite3_threadsafe() function shows only the compile-time setting of
250** thread safety, not any run-time changes to that setting made by
251** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252** is unchanged by calls to sqlite3_config().)^
253**
254** See the [threading mode] documentation for additional information.
255*/
256SQLITE_API int sqlite3_threadsafe(void);
257
258/*
259** CAPI3REF: Database Connection Handle
260** KEYWORDS: {database connection} {database connections}
261**
262** Each open SQLite database is represented by a pointer to an instance of
263** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266** and [sqlite3_close_v2()] are its destructors. There are many other
267** interfaces (such as
268** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269** [sqlite3_busy_timeout()] to name but three) that are methods on an
270** sqlite3 object.
271*/
272typedef struct sqlite3 sqlite3;
273
274/*
275** CAPI3REF: 64-Bit Integer Types
276** KEYWORDS: sqlite_int64 sqlite_uint64
277**
278** Because there is no cross-platform way to specify 64-bit integer types
279** SQLite includes typedefs for 64-bit signed and unsigned integers.
280**
281** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283** compatibility only.
284**
285** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287** sqlite3_uint64 and sqlite_uint64 types can store integer values
288** between 0 and +18446744073709551615 inclusive.
289*/
290#ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292# ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
294# else
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
296# endif
297#elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
300#else
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
303#endif
304typedef sqlite_int64 sqlite3_int64;
305typedef sqlite_uint64 sqlite3_uint64;
306
307/*
308** If compiling for a processor that lacks floating point support,
309** substitute integer for floating-point.
310*/
311#ifdef SQLITE_OMIT_FLOATING_POINT
312# define double sqlite3_int64
313#endif
314
315/*
316** CAPI3REF: Closing A Database Connection
317** DESTRUCTOR: sqlite3
318**
319** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320** for the [sqlite3] object.
321** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322** the [sqlite3] object is successfully destroyed and all associated
323** resources are deallocated.
324**
325** Ideally, applications should [sqlite3_finalize | finalize] all
326** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328** with the [sqlite3] object prior to attempting to close the object.
329** ^If the database connection is associated with unfinalized prepared
330** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331** sqlite3_close() will leave the database connection open and return
332** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335** connection immediately, it marks the database connection as an unusable
336** "zombie" and makes arrangements to automatically deallocate the database
337** connection after all prepared statements are finalized, all BLOB handles
338** are closed, and all backups have finished. The sqlite3_close_v2() interface
339** is intended for use with host languages that are garbage collected, and
340** where the order in which destructors are called is arbitrary.
341**
342** ^If an [sqlite3] object is destroyed while a transaction is open,
343** the transaction is automatically rolled back.
344**
345** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346** must be either a NULL
347** pointer or an [sqlite3] object pointer obtained
348** from [sqlite3_open()], [sqlite3_open16()], or
349** [sqlite3_open_v2()], and not previously closed.
350** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351** argument is a harmless no-op.
352*/
353SQLITE_API int sqlite3_close(sqlite3*);
354SQLITE_API int sqlite3_close_v2(sqlite3*);
355
356/*
357** The type for a callback function.
358** This is legacy and deprecated. It is included for historical
359** compatibility and is not documented.
360*/
361typedef int (*sqlite3_callback)(void*,int,char**, char**);
362
363/*
364** CAPI3REF: One-Step Query Execution Interface
365** METHOD: sqlite3
366**
367** The sqlite3_exec() interface is a convenience wrapper around
368** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369** that allows an application to run multiple statements of SQL
370** without having to use a lot of C code.
371**
372** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373** semicolon-separate SQL statements passed into its 2nd argument,
374** in the context of the [database connection] passed in as its 1st
375** argument. ^If the callback function of the 3rd argument to
376** sqlite3_exec() is not NULL, then it is invoked for each result row
377** coming out of the evaluated SQL statements. ^The 4th argument to
378** sqlite3_exec() is relayed through to the 1st argument of each
379** callback invocation. ^If the callback pointer to sqlite3_exec()
380** is NULL, then no callback is ever invoked and result rows are
381** ignored.
382**
383** ^If an error occurs while evaluating the SQL statements passed into
384** sqlite3_exec(), then execution of the current statement stops and
385** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386** is not NULL then any error message is written into memory obtained
387** from [sqlite3_malloc()] and passed back through the 5th parameter.
388** To avoid memory leaks, the application should invoke [sqlite3_free()]
389** on error message strings returned through the 5th parameter of
390** sqlite3_exec() after the error message string is no longer needed.
391** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393** NULL before returning.
394**
395** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396** routine returns SQLITE_ABORT without invoking the callback again and
397** without running any subsequent SQL statements.
398**
399** ^The 2nd argument to the sqlite3_exec() callback function is the
400** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401** callback is an array of pointers to strings obtained as if from
402** [sqlite3_column_text()], one for each column. ^If an element of a
403** result row is NULL then the corresponding string pointer for the
404** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405** sqlite3_exec() callback is an array of pointers to strings where each
406** entry represents the name of corresponding result column as obtained
407** from [sqlite3_column_name()].
408**
409** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410** to an empty string, or a pointer that contains only whitespace and/or
411** SQL comments, then no SQL statements are evaluated and the database
412** is not changed.
413**
414** Restrictions:
415**
416** <ul>
417** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418** is a valid and open [database connection].
419** <li> The application must not close the [database connection] specified by
420** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421** <li> The application must not modify the SQL statement text passed into
422** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
423** </ul>
424*/
425SQLITE_API int sqlite3_exec(
426 sqlite3*, /* An open database */
427 const char *sql, /* SQL to be evaluated */
428 int (*callback)(void*,int,char**,char**), /* Callback function */
429 void *, /* 1st argument to callback */
430 char **errmsg /* Error msg written here */
431);
432
433/*
434** CAPI3REF: Result Codes
435** KEYWORDS: {result code definitions}
436**
437** Many SQLite functions return an integer result code from the set shown
438** here in order to indicate success or failure.
439**
440** New error codes may be added in future versions of SQLite.
441**
442** See also: [extended result code definitions]
443*/
444#define SQLITE_OK 0 /* Successful result */
445/* beginning-of-error-codes */
446#define SQLITE_ERROR 1 /* Generic error */
447#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
448#define SQLITE_PERM 3 /* Access permission denied */
449#define SQLITE_ABORT 4 /* Callback routine requested an abort */
450#define SQLITE_BUSY 5 /* The database file is locked */
451#define SQLITE_LOCKED 6 /* A table in the database is locked */
452#define SQLITE_NOMEM 7 /* A malloc() failed */
453#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
454#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
455#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
456#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
457#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
458#define SQLITE_FULL 13 /* Insertion failed because database is full */
459#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
460#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
461#define SQLITE_EMPTY 16 /* Internal use only */
462#define SQLITE_SCHEMA 17 /* The database schema changed */
463#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
464#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
465#define SQLITE_MISMATCH 20 /* Data type mismatch */
466#define SQLITE_MISUSE 21 /* Library used incorrectly */
467#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
468#define SQLITE_AUTH 23 /* Authorization denied */
469#define SQLITE_FORMAT 24 /* Not used */
470#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
471#define SQLITE_NOTADB 26 /* File opened that is not a database file */
472#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
473#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
474#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
475#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
476/* end-of-error-codes */
477
478/*
479** CAPI3REF: Extended Result Codes
480** KEYWORDS: {extended result code definitions}
481**
482** In its default configuration, SQLite API routines return one of 30 integer
483** [result codes]. However, experience has shown that many of
484** these result codes are too coarse-grained. They do not provide as
485** much information about problems as programmers might like. In an effort to
486** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
487** and later) include
488** support for additional result codes that provide more detailed information
489** about errors. These [extended result codes] are enabled or disabled
490** on a per database connection basis using the
491** [sqlite3_extended_result_codes()] API. Or, the extended code for
492** the most recent error can be obtained using
493** [sqlite3_extended_errcode()].
494*/
495#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
496#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
497#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
498#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
499#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
500#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
501#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
502#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
503#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
504#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
505#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
506#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
507#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
508#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
509#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
510#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
511#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
512#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
513#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
514#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
515#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
516#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
517#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
518#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
519#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
520#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
521#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
522#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
523#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
524#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
525#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
526#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
527#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
528#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
529#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
530#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
531#define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
532#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
533#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
534#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
535#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
536#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
537#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
538#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
539#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
540#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
541#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
542#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
543#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
544#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
545#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
546#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
547#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
548#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
549#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
550#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
551#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
552#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
553#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
554#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
555#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
556#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
557#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
558#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
559#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
560#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
561#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
562#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
563#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
564#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
565#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
566#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
567#define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
568#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
569#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
570#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
571#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
572
573/*
574** CAPI3REF: Flags For File Open Operations
575**
576** These bit values are intended for use in the
577** 3rd parameter to the [sqlite3_open_v2()] interface and
578** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
579**
580** Only those flags marked as "Ok for sqlite3_open_v2()" may be
581** used as the third argument to the [sqlite3_open_v2()] interface.
582** The other flags have historically been ignored by sqlite3_open_v2(),
583** though future versions of SQLite might change so that an error is
584** raised if any of the disallowed bits are passed into sqlite3_open_v2().
585** Applications should not depend on the historical behavior.
586**
587** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
588** [sqlite3_open_v2()] does *not* cause the underlying database file
589** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
590** [sqlite3_open_v2()] has historically be a no-op and might become an
591** error in future versions of SQLite.
592*/
593#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
594#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
595#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
596#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
597#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
598#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
599#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
600#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
601#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
602#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
603#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
604#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
605#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
606#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
607#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
608#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
609#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
610#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
611#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
612#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
613#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
614#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
615
616/* Reserved: 0x00F00000 */
617/* Legacy compatibility: */
618#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
619
620
621/*
622** CAPI3REF: Device Characteristics
623**
624** The xDeviceCharacteristics method of the [sqlite3_io_methods]
625** object returns an integer which is a vector of these
626** bit values expressing I/O characteristics of the mass storage
627** device that holds the file that the [sqlite3_io_methods]
628** refers to.
629**
630** The SQLITE_IOCAP_ATOMIC property means that all writes of
631** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
632** mean that writes of blocks that are nnn bytes in size and
633** are aligned to an address which is an integer multiple of
634** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
635** that when data is appended to a file, the data is appended
636** first then the size of the file is extended, never the other
637** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
638** information is written to disk in the same order as calls
639** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
640** after reboot following a crash or power loss, the only bytes in a
641** file that were written at the application level might have changed
642** and that adjacent bytes, even bytes within the same sector are
643** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
644** flag indicates that a file cannot be deleted when open. The
645** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
646** read-only media and cannot be changed even by processes with
647** elevated privileges.
648**
649** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
650** filesystem supports doing multiple write operations atomically when those
651** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
652** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
653*/
654#define SQLITE_IOCAP_ATOMIC 0x00000001
655#define SQLITE_IOCAP_ATOMIC512 0x00000002
656#define SQLITE_IOCAP_ATOMIC1K 0x00000004
657#define SQLITE_IOCAP_ATOMIC2K 0x00000008
658#define SQLITE_IOCAP_ATOMIC4K 0x00000010
659#define SQLITE_IOCAP_ATOMIC8K 0x00000020
660#define SQLITE_IOCAP_ATOMIC16K 0x00000040
661#define SQLITE_IOCAP_ATOMIC32K 0x00000080
662#define SQLITE_IOCAP_ATOMIC64K 0x00000100
663#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
664#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
665#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
666#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
667#define SQLITE_IOCAP_IMMUTABLE 0x00002000
668#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
669
670/*
671** CAPI3REF: File Locking Levels
672**
673** SQLite uses one of these integer values as the second
674** argument to calls it makes to the xLock() and xUnlock() methods
675** of an [sqlite3_io_methods] object. These values are ordered from
676** lest restrictive to most restrictive.
677**
678** The argument to xLock() is always SHARED or higher. The argument to
679** xUnlock is either SHARED or NONE.
680*/
681#define SQLITE_LOCK_NONE 0 /* xUnlock() only */
682#define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
683#define SQLITE_LOCK_RESERVED 2 /* xLock() only */
684#define SQLITE_LOCK_PENDING 3 /* xLock() only */
685#define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
686
687/*
688** CAPI3REF: Synchronization Type Flags
689**
690** When SQLite invokes the xSync() method of an
691** [sqlite3_io_methods] object it uses a combination of
692** these integer values as the second argument.
693**
694** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
695** sync operation only needs to flush data to mass storage. Inode
696** information need not be flushed. If the lower four bits of the flag
697** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
698** If the lower four bits equal SQLITE_SYNC_FULL, that means
699** to use Mac OS X style fullsync instead of fsync().
700**
701** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
702** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
703** settings. The [synchronous pragma] determines when calls to the
704** xSync VFS method occur and applies uniformly across all platforms.
705** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
706** energetic or rigorous or forceful the sync operations are and
707** only make a difference on Mac OSX for the default SQLite code.
708** (Third-party VFS implementations might also make the distinction
709** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
710** operating systems natively supported by SQLite, only Mac OSX
711** cares about the difference.)
712*/
713#define SQLITE_SYNC_NORMAL 0x00002
714#define SQLITE_SYNC_FULL 0x00003
715#define SQLITE_SYNC_DATAONLY 0x00010
716
717/*
718** CAPI3REF: OS Interface Open File Handle
719**
720** An [sqlite3_file] object represents an open file in the
721** [sqlite3_vfs | OS interface layer]. Individual OS interface
722** implementations will
723** want to subclass this object by appending additional fields
724** for their own use. The pMethods entry is a pointer to an
725** [sqlite3_io_methods] object that defines methods for performing
726** I/O operations on the open file.
727*/
728typedef struct sqlite3_file sqlite3_file;
729struct sqlite3_file {
730 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
731};
732
733/*
734** CAPI3REF: OS Interface File Virtual Methods Object
735**
736** Every file opened by the [sqlite3_vfs.xOpen] method populates an
737** [sqlite3_file] object (or, more commonly, a subclass of the
738** [sqlite3_file] object) with a pointer to an instance of this object.
739** This object defines the methods used to perform various operations
740** against the open file represented by the [sqlite3_file] object.
741**
742** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
743** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
744** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
745** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
746** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
747** to NULL.
748**
749** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
750** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
751** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
752** flag may be ORed in to indicate that only the data of the file
753** and not its inode needs to be synced.
754**
755** The integer values to xLock() and xUnlock() are one of
756** <ul>
757** <li> [SQLITE_LOCK_NONE],
758** <li> [SQLITE_LOCK_SHARED],
759** <li> [SQLITE_LOCK_RESERVED],
760** <li> [SQLITE_LOCK_PENDING], or
761** <li> [SQLITE_LOCK_EXCLUSIVE].
762** </ul>
763** xLock() upgrades the database file lock. In other words, xLock() moves the
764** database file lock in the direction NONE toward EXCLUSIVE. The argument to
765** xLock() is always on of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
766** SQLITE_LOCK_NONE. If the database file lock is already at or above the
767** requested lock, then the call to xLock() is a no-op.
768** xUnlock() downgrades the database file lock to either SHARED or NONE.
769* If the lock is already at or below the requested lock state, then the call
770** to xUnlock() is a no-op.
771** The xCheckReservedLock() method checks whether any database connection,
772** either in this process or in some other process, is holding a RESERVED,
773** PENDING, or EXCLUSIVE lock on the file. It returns true
774** if such a lock exists and false otherwise.
775**
776** The xFileControl() method is a generic interface that allows custom
777** VFS implementations to directly control an open file using the
778** [sqlite3_file_control()] interface. The second "op" argument is an
779** integer opcode. The third argument is a generic pointer intended to
780** point to a structure that may contain arguments or space in which to
781** write return values. Potential uses for xFileControl() might be
782** functions to enable blocking locks with timeouts, to change the
783** locking strategy (for example to use dot-file locks), to inquire
784** about the status of a lock, or to break stale locks. The SQLite
785** core reserves all opcodes less than 100 for its own use.
786** A [file control opcodes | list of opcodes] less than 100 is available.
787** Applications that define a custom xFileControl method should use opcodes
788** greater than 100 to avoid conflicts. VFS implementations should
789** return [SQLITE_NOTFOUND] for file control opcodes that they do not
790** recognize.
791**
792** The xSectorSize() method returns the sector size of the
793** device that underlies the file. The sector size is the
794** minimum write that can be performed without disturbing
795** other bytes in the file. The xDeviceCharacteristics()
796** method returns a bit vector describing behaviors of the
797** underlying device:
798**
799** <ul>
800** <li> [SQLITE_IOCAP_ATOMIC]
801** <li> [SQLITE_IOCAP_ATOMIC512]
802** <li> [SQLITE_IOCAP_ATOMIC1K]
803** <li> [SQLITE_IOCAP_ATOMIC2K]
804** <li> [SQLITE_IOCAP_ATOMIC4K]
805** <li> [SQLITE_IOCAP_ATOMIC8K]
806** <li> [SQLITE_IOCAP_ATOMIC16K]
807** <li> [SQLITE_IOCAP_ATOMIC32K]
808** <li> [SQLITE_IOCAP_ATOMIC64K]
809** <li> [SQLITE_IOCAP_SAFE_APPEND]
810** <li> [SQLITE_IOCAP_SEQUENTIAL]
811** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
812** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
813** <li> [SQLITE_IOCAP_IMMUTABLE]
814** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
815** </ul>
816**
817** The SQLITE_IOCAP_ATOMIC property means that all writes of
818** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
819** mean that writes of blocks that are nnn bytes in size and
820** are aligned to an address which is an integer multiple of
821** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
822** that when data is appended to a file, the data is appended
823** first then the size of the file is extended, never the other
824** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
825** information is written to disk in the same order as calls
826** to xWrite().
827**
828** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
829** in the unread portions of the buffer with zeros. A VFS that
830** fails to zero-fill short reads might seem to work. However,
831** failure to zero-fill short reads will eventually lead to
832** database corruption.
833*/
834typedef struct sqlite3_io_methods sqlite3_io_methods;
835struct sqlite3_io_methods {
836 int iVersion;
837 int (*xClose)(sqlite3_file*);
838 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
839 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
840 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
841 int (*xSync)(sqlite3_file*, int flags);
842 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
843 int (*xLock)(sqlite3_file*, int);
844 int (*xUnlock)(sqlite3_file*, int);
845 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
846 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
847 int (*xSectorSize)(sqlite3_file*);
848 int (*xDeviceCharacteristics)(sqlite3_file*);
849 /* Methods above are valid for version 1 */
850 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
851 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
852 void (*xShmBarrier)(sqlite3_file*);
853 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
854 /* Methods above are valid for version 2 */
855 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
856 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
857 /* Methods above are valid for version 3 */
858 /* Additional methods may be added in future releases */
859};
860
861/*
862** CAPI3REF: Standard File Control Opcodes
863** KEYWORDS: {file control opcodes} {file control opcode}
864**
865** These integer constants are opcodes for the xFileControl method
866** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
867** interface.
868**
869** <ul>
870** <li>[[SQLITE_FCNTL_LOCKSTATE]]
871** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
872** opcode causes the xFileControl method to write the current state of
873** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
874** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
875** into an integer that the pArg argument points to.
876** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
877**
878** <li>[[SQLITE_FCNTL_SIZE_HINT]]
879** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
880** layer a hint of how large the database file will grow to be during the
881** current transaction. This hint is not guaranteed to be accurate but it
882** is often close. The underlying VFS might choose to preallocate database
883** file space based on this hint in order to help writes to the database
884** file run faster.
885**
886** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
887** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
888** implements [sqlite3_deserialize()] to set an upper bound on the size
889** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
890** If the integer pointed to is negative, then it is filled in with the
891** current limit. Otherwise the limit is set to the larger of the value
892** of the integer pointed to and the current database size. The integer
893** pointed to is set to the new limit.
894**
895** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
896** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
897** extends and truncates the database file in chunks of a size specified
898** by the user. The fourth argument to [sqlite3_file_control()] should
899** point to an integer (type int) containing the new chunk-size to use
900** for the nominated database. Allocating database file space in large
901** chunks (say 1MB at a time), may reduce file-system fragmentation and
902** improve performance on some systems.
903**
904** <li>[[SQLITE_FCNTL_FILE_POINTER]]
905** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
906** to the [sqlite3_file] object associated with a particular database
907** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
908**
909** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
910** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
911** to the [sqlite3_file] object associated with the journal file (either
912** the [rollback journal] or the [write-ahead log]) for a particular database
913** connection. See also [SQLITE_FCNTL_FILE_POINTER].
914**
915** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
916** No longer in use.
917**
918** <li>[[SQLITE_FCNTL_SYNC]]
919** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
920** sent to the VFS immediately before the xSync method is invoked on a
921** database file descriptor. Or, if the xSync method is not invoked
922** because the user has configured SQLite with
923** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
924** of the xSync method. In most cases, the pointer argument passed with
925** this file-control is NULL. However, if the database file is being synced
926** as part of a multi-database commit, the argument points to a nul-terminated
927** string containing the transactions super-journal file name. VFSes that
928** do not need this signal should silently ignore this opcode. Applications
929** should not call [sqlite3_file_control()] with this opcode as doing so may
930** disrupt the operation of the specialized VFSes that do require it.
931**
932** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
933** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
934** and sent to the VFS after a transaction has been committed immediately
935** but before the database is unlocked. VFSes that do not need this signal
936** should silently ignore this opcode. Applications should not call
937** [sqlite3_file_control()] with this opcode as doing so may disrupt the
938** operation of the specialized VFSes that do require it.
939**
940** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
941** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
942** retry counts and intervals for certain disk I/O operations for the
943** windows [VFS] in order to provide robustness in the presence of
944** anti-virus programs. By default, the windows VFS will retry file read,
945** file write, and file delete operations up to 10 times, with a delay
946** of 25 milliseconds before the first retry and with the delay increasing
947** by an additional 25 milliseconds with each subsequent retry. This
948** opcode allows these two values (10 retries and 25 milliseconds of delay)
949** to be adjusted. The values are changed for all database connections
950** within the same process. The argument is a pointer to an array of two
951** integers where the first integer is the new retry count and the second
952** integer is the delay. If either integer is negative, then the setting
953** is not changed but instead the prior value of that setting is written
954** into the array entry, allowing the current retry settings to be
955** interrogated. The zDbName parameter is ignored.
956**
957** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
958** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
959** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
960** write ahead log ([WAL file]) and shared memory
961** files used for transaction control
962** are automatically deleted when the latest connection to the database
963** closes. Setting persistent WAL mode causes those files to persist after
964** close. Persisting the files is useful when other processes that do not
965** have write permission on the directory containing the database file want
966** to read the database file, as the WAL and shared memory files must exist
967** in order for the database to be readable. The fourth parameter to
968** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
969** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
970** WAL mode. If the integer is -1, then it is overwritten with the current
971** WAL persistence setting.
972**
973** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
974** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
975** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
976** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
977** xDeviceCharacteristics methods. The fourth parameter to
978** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
979** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
980** mode. If the integer is -1, then it is overwritten with the current
981** zero-damage mode setting.
982**
983** <li>[[SQLITE_FCNTL_OVERWRITE]]
984** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
985** a write transaction to indicate that, unless it is rolled back for some
986** reason, the entire database file will be overwritten by the current
987** transaction. This is used by VACUUM operations.
988**
989** <li>[[SQLITE_FCNTL_VFSNAME]]
990** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
991** all [VFSes] in the VFS stack. The names are of all VFS shims and the
992** final bottom-level VFS are written into memory obtained from
993** [sqlite3_malloc()] and the result is stored in the char* variable
994** that the fourth parameter of [sqlite3_file_control()] points to.
995** The caller is responsible for freeing the memory when done. As with
996** all file-control actions, there is no guarantee that this will actually
997** do anything. Callers should initialize the char* variable to a NULL
998** pointer in case this file-control is not implemented. This file-control
999** is intended for diagnostic use only.
1000**
1001** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1002** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1003** [VFSes] currently in use. ^(The argument X in
1004** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1005** of type "[sqlite3_vfs] **". This opcodes will set *X
1006** to a pointer to the top-level VFS.)^
1007** ^When there are multiple VFS shims in the stack, this opcode finds the
1008** upper-most shim only.
1009**
1010** <li>[[SQLITE_FCNTL_PRAGMA]]
1011** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1012** file control is sent to the open [sqlite3_file] object corresponding
1013** to the database file to which the pragma statement refers. ^The argument
1014** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1015** pointers to strings (char**) in which the second element of the array
1016** is the name of the pragma and the third element is the argument to the
1017** pragma or NULL if the pragma has no argument. ^The handler for an
1018** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1019** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1020** or the equivalent and that string will become the result of the pragma or
1021** the error message if the pragma fails. ^If the
1022** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1023** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1024** file control returns [SQLITE_OK], then the parser assumes that the
1025** VFS has handled the PRAGMA itself and the parser generates a no-op
1026** prepared statement if result string is NULL, or that returns a copy
1027** of the result string if the string is non-NULL.
1028** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1029** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1030** that the VFS encountered an error while handling the [PRAGMA] and the
1031** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1032** file control occurs at the beginning of pragma statement analysis and so
1033** it is able to override built-in [PRAGMA] statements.
1034**
1035** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1036** ^The [SQLITE_FCNTL_BUSYHANDLER]
1037** file-control may be invoked by SQLite on the database file handle
1038** shortly after it is opened in order to provide a custom VFS with access
1039** to the connection's busy-handler callback. The argument is of type (void**)
1040** - an array of two (void *) values. The first (void *) actually points
1041** to a function of type (int (*)(void *)). In order to invoke the connection's
1042** busy-handler, this function should be invoked with the second (void *) in
1043** the array as the only argument. If it returns non-zero, then the operation
1044** should be retried. If it returns zero, the custom VFS should abandon the
1045** current operation.
1046**
1047** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1048** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1049** to have SQLite generate a
1050** temporary filename using the same algorithm that is followed to generate
1051** temporary filenames for TEMP tables and other internal uses. The
1052** argument should be a char** which will be filled with the filename
1053** written into memory obtained from [sqlite3_malloc()]. The caller should
1054** invoke [sqlite3_free()] on the result to avoid a memory leak.
1055**
1056** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1057** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1058** maximum number of bytes that will be used for memory-mapped I/O.
1059** The argument is a pointer to a value of type sqlite3_int64 that
1060** is an advisory maximum number of bytes in the file to memory map. The
1061** pointer is overwritten with the old value. The limit is not changed if
1062** the value originally pointed to is negative, and so the current limit
1063** can be queried by passing in a pointer to a negative number. This
1064** file-control is used internally to implement [PRAGMA mmap_size].
1065**
1066** <li>[[SQLITE_FCNTL_TRACE]]
1067** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1068** to the VFS about what the higher layers of the SQLite stack are doing.
1069** This file control is used by some VFS activity tracing [shims].
1070** The argument is a zero-terminated string. Higher layers in the
1071** SQLite stack may generate instances of this file control if
1072** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1073**
1074** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1075** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1076** pointer to an integer and it writes a boolean into that integer depending
1077** on whether or not the file has been renamed, moved, or deleted since it
1078** was first opened.
1079**
1080** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1081** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1082** underlying native file handle associated with a file handle. This file
1083** control interprets its argument as a pointer to a native file handle and
1084** writes the resulting value there.
1085**
1086** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1087** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1088** opcode causes the xFileControl method to swap the file handle with the one
1089** pointed to by the pArg argument. This capability is used during testing
1090** and only needs to be supported when SQLITE_TEST is defined.
1091**
1092** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1093** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1094** be advantageous to block on the next WAL lock if the lock is not immediately
1095** available. The WAL subsystem issues this signal during rare
1096** circumstances in order to fix a problem with priority inversion.
1097** Applications should <em>not</em> use this file-control.
1098**
1099** <li>[[SQLITE_FCNTL_ZIPVFS]]
1100** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1101** VFS should return SQLITE_NOTFOUND for this opcode.
1102**
1103** <li>[[SQLITE_FCNTL_RBU]]
1104** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1105** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1106** this opcode.
1107**
1108** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1109** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1110** the file descriptor is placed in "batch write mode", which
1111** means all subsequent write operations will be deferred and done
1112** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1113** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1114** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1115** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1116** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1117** no VFS interface calls on the same [sqlite3_file] file descriptor
1118** except for calls to the xWrite method and the xFileControl method
1119** with [SQLITE_FCNTL_SIZE_HINT].
1120**
1121** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1122** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1123** operations since the previous successful call to
1124** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1125** This file control returns [SQLITE_OK] if and only if the writes were
1126** all performed successfully and have been committed to persistent storage.
1127** ^Regardless of whether or not it is successful, this file control takes
1128** the file descriptor out of batch write mode so that all subsequent
1129** write operations are independent.
1130** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1131** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1132**
1133** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1134** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1135** operations since the previous successful call to
1136** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1137** ^This file control takes the file descriptor out of batch write mode
1138** so that all subsequent write operations are independent.
1139** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1140** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1141**
1142** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1143** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1144** to block for up to M milliseconds before failing when attempting to
1145** obtain a file lock using the xLock or xShmLock methods of the VFS.
1146** The parameter is a pointer to a 32-bit signed integer that contains
1147** the value that M is to be set to. Before returning, the 32-bit signed
1148** integer is overwritten with the previous value of M.
1149**
1150** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1151** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1152** a database file. The argument is a pointer to a 32-bit unsigned integer.
1153** The "data version" for the pager is written into the pointer. The
1154** "data version" changes whenever any change occurs to the corresponding
1155** database file, either through SQL statements on the same database
1156** connection or through transactions committed by separate database
1157** connections possibly in other processes. The [sqlite3_total_changes()]
1158** interface can be used to find if any database on the connection has changed,
1159** but that interface responds to changes on TEMP as well as MAIN and does
1160** not provide a mechanism to detect changes to MAIN only. Also, the
1161** [sqlite3_total_changes()] interface responds to internal changes only and
1162** omits changes made by other database connections. The
1163** [PRAGMA data_version] command provides a mechanism to detect changes to
1164** a single attached database that occur due to other database connections,
1165** but omits changes implemented by the database connection on which it is
1166** called. This file control is the only mechanism to detect changes that
1167** happen either internally or externally and that are associated with
1168** a particular attached database.
1169**
1170** <li>[[SQLITE_FCNTL_CKPT_START]]
1171** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1172** in wal mode before the client starts to copy pages from the wal
1173** file to the database file.
1174**
1175** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1176** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1177** in wal mode after the client has finished copying pages from the wal
1178** file to the database file, but before the *-shm file is updated to
1179** record the fact that the pages have been checkpointed.
1180**
1181** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1182** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1183** whether or not there is a database client in another process with a wal-mode
1184** transaction open on the database or not. It is only available on unix.The
1185** (void*) argument passed with this file-control should be a pointer to a
1186** value of type (int). The integer value is set to 1 if the database is a wal
1187** mode database and there exists at least one client in another process that
1188** currently has an SQL transaction open on the database. It is set to 0 if
1189** the database is not a wal-mode db, or if there is no such connection in any
1190** other process. This opcode cannot be used to detect transactions opened
1191** by clients within the current process, only within other processes.
1192**
1193** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1194** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1195** [checksum VFS shim] only.
1196**
1197** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1198** If there is currently no transaction open on the database, and the
1199** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1200** purges the contents of the in-memory page cache. If there is an open
1201** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1202** </ul>
1203*/
1204#define SQLITE_FCNTL_LOCKSTATE 1
1205#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1206#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1207#define SQLITE_FCNTL_LAST_ERRNO 4
1208#define SQLITE_FCNTL_SIZE_HINT 5
1209#define SQLITE_FCNTL_CHUNK_SIZE 6
1210#define SQLITE_FCNTL_FILE_POINTER 7
1211#define SQLITE_FCNTL_SYNC_OMITTED 8
1212#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1213#define SQLITE_FCNTL_PERSIST_WAL 10
1214#define SQLITE_FCNTL_OVERWRITE 11
1215#define SQLITE_FCNTL_VFSNAME 12
1216#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1217#define SQLITE_FCNTL_PRAGMA 14
1218#define SQLITE_FCNTL_BUSYHANDLER 15
1219#define SQLITE_FCNTL_TEMPFILENAME 16
1220#define SQLITE_FCNTL_MMAP_SIZE 18
1221#define SQLITE_FCNTL_TRACE 19
1222#define SQLITE_FCNTL_HAS_MOVED 20
1223#define SQLITE_FCNTL_SYNC 21
1224#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1225#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1226#define SQLITE_FCNTL_WAL_BLOCK 24
1227#define SQLITE_FCNTL_ZIPVFS 25
1228#define SQLITE_FCNTL_RBU 26
1229#define SQLITE_FCNTL_VFS_POINTER 27
1230#define SQLITE_FCNTL_JOURNAL_POINTER 28
1231#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1232#define SQLITE_FCNTL_PDB 30
1233#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1234#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1235#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1236#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1237#define SQLITE_FCNTL_DATA_VERSION 35
1238#define SQLITE_FCNTL_SIZE_LIMIT 36
1239#define SQLITE_FCNTL_CKPT_DONE 37
1240#define SQLITE_FCNTL_RESERVE_BYTES 38
1241#define SQLITE_FCNTL_CKPT_START 39
1242#define SQLITE_FCNTL_EXTERNAL_READER 40
1243#define SQLITE_FCNTL_CKSM_FILE 41
1244#define SQLITE_FCNTL_RESET_CACHE 42
1245
1246/* deprecated names */
1247#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1248#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1249#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1250
1251
1252/*
1253** CAPI3REF: Mutex Handle
1254**
1255** The mutex module within SQLite defines [sqlite3_mutex] to be an
1256** abstract type for a mutex object. The SQLite core never looks
1257** at the internal representation of an [sqlite3_mutex]. It only
1258** deals with pointers to the [sqlite3_mutex] object.
1259**
1260** Mutexes are created using [sqlite3_mutex_alloc()].
1261*/
1262typedef struct sqlite3_mutex sqlite3_mutex;
1263
1264/*
1265** CAPI3REF: Loadable Extension Thunk
1266**
1267** A pointer to the opaque sqlite3_api_routines structure is passed as
1268** the third parameter to entry points of [loadable extensions]. This
1269** structure must be typedefed in order to work around compiler warnings
1270** on some platforms.
1271*/
1272typedef struct sqlite3_api_routines sqlite3_api_routines;
1273
1274/*
1275** CAPI3REF: File Name
1276**
1277** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1278** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1279** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1280** may also be passed to special APIs such as:
1281**
1282** <ul>
1283** <li> sqlite3_filename_database()
1284** <li> sqlite3_filename_journal()
1285** <li> sqlite3_filename_wal()
1286** <li> sqlite3_uri_parameter()
1287** <li> sqlite3_uri_boolean()
1288** <li> sqlite3_uri_int64()
1289** <li> sqlite3_uri_key()
1290** </ul>
1291*/
1292typedef const char *sqlite3_filename;
1293
1294/*
1295** CAPI3REF: OS Interface Object
1296**
1297** An instance of the sqlite3_vfs object defines the interface between
1298** the SQLite core and the underlying operating system. The "vfs"
1299** in the name of the object stands for "virtual file system". See
1300** the [VFS | VFS documentation] for further information.
1301**
1302** The VFS interface is sometimes extended by adding new methods onto
1303** the end. Each time such an extension occurs, the iVersion field
1304** is incremented. The iVersion value started out as 1 in
1305** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1306** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1307** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1308** may be appended to the sqlite3_vfs object and the iVersion value
1309** may increase again in future versions of SQLite.
1310** Note that due to an oversight, the structure
1311** of the sqlite3_vfs object changed in the transition from
1312** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1313** and yet the iVersion field was not increased.
1314**
1315** The szOsFile field is the size of the subclassed [sqlite3_file]
1316** structure used by this VFS. mxPathname is the maximum length of
1317** a pathname in this VFS.
1318**
1319** Registered sqlite3_vfs objects are kept on a linked list formed by
1320** the pNext pointer. The [sqlite3_vfs_register()]
1321** and [sqlite3_vfs_unregister()] interfaces manage this list
1322** in a thread-safe way. The [sqlite3_vfs_find()] interface
1323** searches the list. Neither the application code nor the VFS
1324** implementation should use the pNext pointer.
1325**
1326** The pNext field is the only field in the sqlite3_vfs
1327** structure that SQLite will ever modify. SQLite will only access
1328** or modify this field while holding a particular static mutex.
1329** The application should never modify anything within the sqlite3_vfs
1330** object once the object has been registered.
1331**
1332** The zName field holds the name of the VFS module. The name must
1333** be unique across all VFS modules.
1334**
1335** [[sqlite3_vfs.xOpen]]
1336** ^SQLite guarantees that the zFilename parameter to xOpen
1337** is either a NULL pointer or string obtained
1338** from xFullPathname() with an optional suffix added.
1339** ^If a suffix is added to the zFilename parameter, it will
1340** consist of a single "-" character followed by no more than
1341** 11 alphanumeric and/or "-" characters.
1342** ^SQLite further guarantees that
1343** the string will be valid and unchanged until xClose() is
1344** called. Because of the previous sentence,
1345** the [sqlite3_file] can safely store a pointer to the
1346** filename if it needs to remember the filename for some reason.
1347** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1348** must invent its own temporary name for the file. ^Whenever the
1349** xFilename parameter is NULL it will also be the case that the
1350** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1351**
1352** The flags argument to xOpen() includes all bits set in
1353** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1354** or [sqlite3_open16()] is used, then flags includes at least
1355** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1356** If xOpen() opens a file read-only then it sets *pOutFlags to
1357** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1358**
1359** ^(SQLite will also add one of the following flags to the xOpen()
1360** call, depending on the object being opened:
1361**
1362** <ul>
1363** <li> [SQLITE_OPEN_MAIN_DB]
1364** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1365** <li> [SQLITE_OPEN_TEMP_DB]
1366** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1367** <li> [SQLITE_OPEN_TRANSIENT_DB]
1368** <li> [SQLITE_OPEN_SUBJOURNAL]
1369** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1370** <li> [SQLITE_OPEN_WAL]
1371** </ul>)^
1372**
1373** The file I/O implementation can use the object type flags to
1374** change the way it deals with files. For example, an application
1375** that does not care about crash recovery or rollback might make
1376** the open of a journal file a no-op. Writes to this journal would
1377** also be no-ops, and any attempt to read the journal would return
1378** SQLITE_IOERR. Or the implementation might recognize that a database
1379** file will be doing page-aligned sector reads and writes in a random
1380** order and set up its I/O subsystem accordingly.
1381**
1382** SQLite might also add one of the following flags to the xOpen method:
1383**
1384** <ul>
1385** <li> [SQLITE_OPEN_DELETEONCLOSE]
1386** <li> [SQLITE_OPEN_EXCLUSIVE]
1387** </ul>
1388**
1389** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1390** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1391** will be set for TEMP databases and their journals, transient
1392** databases, and subjournals.
1393**
1394** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1395** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1396** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1397** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1398** SQLITE_OPEN_CREATE, is used to indicate that file should always
1399** be created, and that it is an error if it already exists.
1400** It is <i>not</i> used to indicate the file should be opened
1401** for exclusive access.
1402**
1403** ^At least szOsFile bytes of memory are allocated by SQLite
1404** to hold the [sqlite3_file] structure passed as the third
1405** argument to xOpen. The xOpen method does not have to
1406** allocate the structure; it should just fill it in. Note that
1407** the xOpen method must set the sqlite3_file.pMethods to either
1408** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1409** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1410** element will be valid after xOpen returns regardless of the success
1411** or failure of the xOpen call.
1412**
1413** [[sqlite3_vfs.xAccess]]
1414** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1415** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1416** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1417** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1418** flag is never actually used and is not implemented in the built-in
1419** VFSes of SQLite. The file is named by the second argument and can be a
1420** directory. The xAccess method returns [SQLITE_OK] on success or some
1421** non-zero error code if there is an I/O error or if the name of
1422** the file given in the second argument is illegal. If SQLITE_OK
1423** is returned, then non-zero or zero is written into *pResOut to indicate
1424** whether or not the file is accessible.
1425**
1426** ^SQLite will always allocate at least mxPathname+1 bytes for the
1427** output buffer xFullPathname. The exact size of the output buffer
1428** is also passed as a parameter to both methods. If the output buffer
1429** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1430** handled as a fatal error by SQLite, vfs implementations should endeavor
1431** to prevent this by setting mxPathname to a sufficiently large value.
1432**
1433** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1434** interfaces are not strictly a part of the filesystem, but they are
1435** included in the VFS structure for completeness.
1436** The xRandomness() function attempts to return nBytes bytes
1437** of good-quality randomness into zOut. The return value is
1438** the actual number of bytes of randomness obtained.
1439** The xSleep() method causes the calling thread to sleep for at
1440** least the number of microseconds given. ^The xCurrentTime()
1441** method returns a Julian Day Number for the current date and time as
1442** a floating point value.
1443** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1444** Day Number multiplied by 86400000 (the number of milliseconds in
1445** a 24-hour day).
1446** ^SQLite will use the xCurrentTimeInt64() method to get the current
1447** date and time if that method is available (if iVersion is 2 or
1448** greater and the function pointer is not NULL) and will fall back
1449** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1450**
1451** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1452** are not used by the SQLite core. These optional interfaces are provided
1453** by some VFSes to facilitate testing of the VFS code. By overriding
1454** system calls with functions under its control, a test program can
1455** simulate faults and error conditions that would otherwise be difficult
1456** or impossible to induce. The set of system calls that can be overridden
1457** varies from one VFS to another, and from one version of the same VFS to the
1458** next. Applications that use these interfaces must be prepared for any
1459** or all of these interfaces to be NULL or for their behavior to change
1460** from one release to the next. Applications must not attempt to access
1461** any of these methods if the iVersion of the VFS is less than 3.
1462*/
1463typedef struct sqlite3_vfs sqlite3_vfs;
1464typedef void (*sqlite3_syscall_ptr)(void);
1465struct sqlite3_vfs {
1466 int iVersion; /* Structure version number (currently 3) */
1467 int szOsFile; /* Size of subclassed sqlite3_file */
1468 int mxPathname; /* Maximum file pathname length */
1469 sqlite3_vfs *pNext; /* Next registered VFS */
1470 const char *zName; /* Name of this virtual file system */
1471 void *pAppData; /* Pointer to application-specific data */
1472 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1473 int flags, int *pOutFlags);
1474 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1475 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1476 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1477 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1478 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1479 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1480 void (*xDlClose)(sqlite3_vfs*, void*);
1481 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1482 int (*xSleep)(sqlite3_vfs*, int microseconds);
1483 int (*xCurrentTime)(sqlite3_vfs*, double*);
1484 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1485 /*
1486 ** The methods above are in version 1 of the sqlite_vfs object
1487 ** definition. Those that follow are added in version 2 or later
1488 */
1489 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1490 /*
1491 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1492 ** Those below are for version 3 and greater.
1493 */
1494 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1495 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1496 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1497 /*
1498 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1499 ** New fields may be appended in future versions. The iVersion
1500 ** value will increment whenever this happens.
1501 */
1502};
1503
1504/*
1505** CAPI3REF: Flags for the xAccess VFS method
1506**
1507** These integer constants can be used as the third parameter to
1508** the xAccess method of an [sqlite3_vfs] object. They determine
1509** what kind of permissions the xAccess method is looking for.
1510** With SQLITE_ACCESS_EXISTS, the xAccess method
1511** simply checks whether the file exists.
1512** With SQLITE_ACCESS_READWRITE, the xAccess method
1513** checks whether the named directory is both readable and writable
1514** (in other words, if files can be added, removed, and renamed within
1515** the directory).
1516** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1517** [temp_store_directory pragma], though this could change in a future
1518** release of SQLite.
1519** With SQLITE_ACCESS_READ, the xAccess method
1520** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1521** currently unused, though it might be used in a future release of
1522** SQLite.
1523*/
1524#define SQLITE_ACCESS_EXISTS 0
1525#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1526#define SQLITE_ACCESS_READ 2 /* Unused */
1527
1528/*
1529** CAPI3REF: Flags for the xShmLock VFS method
1530**
1531** These integer constants define the various locking operations
1532** allowed by the xShmLock method of [sqlite3_io_methods]. The
1533** following are the only legal combinations of flags to the
1534** xShmLock method:
1535**
1536** <ul>
1537** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1538** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1539** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1540** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1541** </ul>
1542**
1543** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1544** was given on the corresponding lock.
1545**
1546** The xShmLock method can transition between unlocked and SHARED or
1547** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1548** and EXCLUSIVE.
1549*/
1550#define SQLITE_SHM_UNLOCK 1
1551#define SQLITE_SHM_LOCK 2
1552#define SQLITE_SHM_SHARED 4
1553#define SQLITE_SHM_EXCLUSIVE 8
1554
1555/*
1556** CAPI3REF: Maximum xShmLock index
1557**
1558** The xShmLock method on [sqlite3_io_methods] may use values
1559** between 0 and this upper bound as its "offset" argument.
1560** The SQLite core will never attempt to acquire or release a
1561** lock outside of this range
1562*/
1563#define SQLITE_SHM_NLOCK 8
1564
1565
1566/*
1567** CAPI3REF: Initialize The SQLite Library
1568**
1569** ^The sqlite3_initialize() routine initializes the
1570** SQLite library. ^The sqlite3_shutdown() routine
1571** deallocates any resources that were allocated by sqlite3_initialize().
1572** These routines are designed to aid in process initialization and
1573** shutdown on embedded systems. Workstation applications using
1574** SQLite normally do not need to invoke either of these routines.
1575**
1576** A call to sqlite3_initialize() is an "effective" call if it is
1577** the first time sqlite3_initialize() is invoked during the lifetime of
1578** the process, or if it is the first time sqlite3_initialize() is invoked
1579** following a call to sqlite3_shutdown(). ^(Only an effective call
1580** of sqlite3_initialize() does any initialization. All other calls
1581** are harmless no-ops.)^
1582**
1583** A call to sqlite3_shutdown() is an "effective" call if it is the first
1584** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1585** an effective call to sqlite3_shutdown() does any deinitialization.
1586** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1587**
1588** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1589** is not. The sqlite3_shutdown() interface must only be called from a
1590** single thread. All open [database connections] must be closed and all
1591** other SQLite resources must be deallocated prior to invoking
1592** sqlite3_shutdown().
1593**
1594** Among other things, ^sqlite3_initialize() will invoke
1595** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1596** will invoke sqlite3_os_end().
1597**
1598** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1599** ^If for some reason, sqlite3_initialize() is unable to initialize
1600** the library (perhaps it is unable to allocate a needed resource such
1601** as a mutex) it returns an [error code] other than [SQLITE_OK].
1602**
1603** ^The sqlite3_initialize() routine is called internally by many other
1604** SQLite interfaces so that an application usually does not need to
1605** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1606** calls sqlite3_initialize() so the SQLite library will be automatically
1607** initialized when [sqlite3_open()] is called if it has not be initialized
1608** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1609** compile-time option, then the automatic calls to sqlite3_initialize()
1610** are omitted and the application must call sqlite3_initialize() directly
1611** prior to using any other SQLite interface. For maximum portability,
1612** it is recommended that applications always invoke sqlite3_initialize()
1613** directly prior to using any other SQLite interface. Future releases
1614** of SQLite may require this. In other words, the behavior exhibited
1615** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1616** default behavior in some future release of SQLite.
1617**
1618** The sqlite3_os_init() routine does operating-system specific
1619** initialization of the SQLite library. The sqlite3_os_end()
1620** routine undoes the effect of sqlite3_os_init(). Typical tasks
1621** performed by these routines include allocation or deallocation
1622** of static resources, initialization of global variables,
1623** setting up a default [sqlite3_vfs] module, or setting up
1624** a default configuration using [sqlite3_config()].
1625**
1626** The application should never invoke either sqlite3_os_init()
1627** or sqlite3_os_end() directly. The application should only invoke
1628** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1629** interface is called automatically by sqlite3_initialize() and
1630** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1631** implementations for sqlite3_os_init() and sqlite3_os_end()
1632** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1633** When [custom builds | built for other platforms]
1634** (using the [SQLITE_OS_OTHER=1] compile-time
1635** option) the application must supply a suitable implementation for
1636** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1637** implementation of sqlite3_os_init() or sqlite3_os_end()
1638** must return [SQLITE_OK] on success and some other [error code] upon
1639** failure.
1640*/
1641SQLITE_API int sqlite3_initialize(void);
1642SQLITE_API int sqlite3_shutdown(void);
1643SQLITE_API int sqlite3_os_init(void);
1644SQLITE_API int sqlite3_os_end(void);
1645
1646/*
1647** CAPI3REF: Configuring The SQLite Library
1648**
1649** The sqlite3_config() interface is used to make global configuration
1650** changes to SQLite in order to tune SQLite to the specific needs of
1651** the application. The default configuration is recommended for most
1652** applications and so this routine is usually not necessary. It is
1653** provided to support rare applications with unusual needs.
1654**
1655** <b>The sqlite3_config() interface is not threadsafe. The application
1656** must ensure that no other SQLite interfaces are invoked by other
1657** threads while sqlite3_config() is running.</b>
1658**
1659** The first argument to sqlite3_config() is an integer
1660** [configuration option] that determines
1661** what property of SQLite is to be configured. Subsequent arguments
1662** vary depending on the [configuration option]
1663** in the first argument.
1664**
1665** For most configuration options, the sqlite3_config() interface
1666** may only be invoked prior to library initialization using
1667** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1668** The exceptional configuration options that may be invoked at any time
1669** are called "anytime configuration options".
1670** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1671** [sqlite3_shutdown()] with a first argument that is not an anytime
1672** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1673** Note, however, that ^sqlite3_config() can be called as part of the
1674** implementation of an application-defined [sqlite3_os_init()].
1675**
1676** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1677** ^If the option is unknown or SQLite is unable to set the option
1678** then this routine returns a non-zero [error code].
1679*/
1680SQLITE_API int sqlite3_config(int, ...);
1681
1682/*
1683** CAPI3REF: Configure database connections
1684** METHOD: sqlite3
1685**
1686** The sqlite3_db_config() interface is used to make configuration
1687** changes to a [database connection]. The interface is similar to
1688** [sqlite3_config()] except that the changes apply to a single
1689** [database connection] (specified in the first argument).
1690**
1691** The second argument to sqlite3_db_config(D,V,...) is the
1692** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1693** that indicates what aspect of the [database connection] is being configured.
1694** Subsequent arguments vary depending on the configuration verb.
1695**
1696** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1697** the call is considered successful.
1698*/
1699SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1700
1701/*
1702** CAPI3REF: Memory Allocation Routines
1703**
1704** An instance of this object defines the interface between SQLite
1705** and low-level memory allocation routines.
1706**
1707** This object is used in only one place in the SQLite interface.
1708** A pointer to an instance of this object is the argument to
1709** [sqlite3_config()] when the configuration option is
1710** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1711** By creating an instance of this object
1712** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1713** during configuration, an application can specify an alternative
1714** memory allocation subsystem for SQLite to use for all of its
1715** dynamic memory needs.
1716**
1717** Note that SQLite comes with several [built-in memory allocators]
1718** that are perfectly adequate for the overwhelming majority of applications
1719** and that this object is only useful to a tiny minority of applications
1720** with specialized memory allocation requirements. This object is
1721** also used during testing of SQLite in order to specify an alternative
1722** memory allocator that simulates memory out-of-memory conditions in
1723** order to verify that SQLite recovers gracefully from such
1724** conditions.
1725**
1726** The xMalloc, xRealloc, and xFree methods must work like the
1727** malloc(), realloc() and free() functions from the standard C library.
1728** ^SQLite guarantees that the second argument to
1729** xRealloc is always a value returned by a prior call to xRoundup.
1730**
1731** xSize should return the allocated size of a memory allocation
1732** previously obtained from xMalloc or xRealloc. The allocated size
1733** is always at least as big as the requested size but may be larger.
1734**
1735** The xRoundup method returns what would be the allocated size of
1736** a memory allocation given a particular requested size. Most memory
1737** allocators round up memory allocations at least to the next multiple
1738** of 8. Some allocators round up to a larger multiple or to a power of 2.
1739** Every memory allocation request coming in through [sqlite3_malloc()]
1740** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1741** that causes the corresponding memory allocation to fail.
1742**
1743** The xInit method initializes the memory allocator. For example,
1744** it might allocate any required mutexes or initialize internal data
1745** structures. The xShutdown method is invoked (indirectly) by
1746** [sqlite3_shutdown()] and should deallocate any resources acquired
1747** by xInit. The pAppData pointer is used as the only parameter to
1748** xInit and xShutdown.
1749**
1750** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1751** the xInit method, so the xInit method need not be threadsafe. The
1752** xShutdown method is only called from [sqlite3_shutdown()] so it does
1753** not need to be threadsafe either. For all other methods, SQLite
1754** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1755** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1756** it is by default) and so the methods are automatically serialized.
1757** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1758** methods must be threadsafe or else make their own arrangements for
1759** serialization.
1760**
1761** SQLite will never invoke xInit() more than once without an intervening
1762** call to xShutdown().
1763*/
1764typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1765struct sqlite3_mem_methods {
1766 void *(*xMalloc)(int); /* Memory allocation function */
1767 void (*xFree)(void*); /* Free a prior allocation */
1768 void *(*xRealloc)(void*,int); /* Resize an allocation */
1769 int (*xSize)(void*); /* Return the size of an allocation */
1770 int (*xRoundup)(int); /* Round up request size to allocation size */
1771 int (*xInit)(void*); /* Initialize the memory allocator */
1772 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1773 void *pAppData; /* Argument to xInit() and xShutdown() */
1774};
1775
1776/*
1777** CAPI3REF: Configuration Options
1778** KEYWORDS: {configuration option}
1779**
1780** These constants are the available integer configuration options that
1781** can be passed as the first argument to the [sqlite3_config()] interface.
1782**
1783** Most of the configuration options for sqlite3_config()
1784** will only work if invoked prior to [sqlite3_initialize()] or after
1785** [sqlite3_shutdown()]. The few exceptions to this rule are called
1786** "anytime configuration options".
1787** ^Calling [sqlite3_config()] with a first argument that is not an
1788** anytime configuration option in between calls to [sqlite3_initialize()] and
1789** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1790**
1791** The set of anytime configuration options can change (by insertions
1792** and/or deletions) from one release of SQLite to the next.
1793** As of SQLite version 3.42.0, the complete set of anytime configuration
1794** options is:
1795** <ul>
1796** <li> SQLITE_CONFIG_LOG
1797** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1798** </ul>
1799**
1800** New configuration options may be added in future releases of SQLite.
1801** Existing configuration options might be discontinued. Applications
1802** should check the return code from [sqlite3_config()] to make sure that
1803** the call worked. The [sqlite3_config()] interface will return a
1804** non-zero [error code] if a discontinued or unsupported configuration option
1805** is invoked.
1806**
1807** <dl>
1808** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1809** <dd>There are no arguments to this option. ^This option sets the
1810** [threading mode] to Single-thread. In other words, it disables
1811** all mutexing and puts SQLite into a mode where it can only be used
1812** by a single thread. ^If SQLite is compiled with
1813** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1814** it is not possible to change the [threading mode] from its default
1815** value of Single-thread and so [sqlite3_config()] will return
1816** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1817** configuration option.</dd>
1818**
1819** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1820** <dd>There are no arguments to this option. ^This option sets the
1821** [threading mode] to Multi-thread. In other words, it disables
1822** mutexing on [database connection] and [prepared statement] objects.
1823** The application is responsible for serializing access to
1824** [database connections] and [prepared statements]. But other mutexes
1825** are enabled so that SQLite will be safe to use in a multi-threaded
1826** environment as long as no two threads attempt to use the same
1827** [database connection] at the same time. ^If SQLite is compiled with
1828** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1829** it is not possible to set the Multi-thread [threading mode] and
1830** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1831** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1832**
1833** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1834** <dd>There are no arguments to this option. ^This option sets the
1835** [threading mode] to Serialized. In other words, this option enables
1836** all mutexes including the recursive
1837** mutexes on [database connection] and [prepared statement] objects.
1838** In this mode (which is the default when SQLite is compiled with
1839** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1840** to [database connections] and [prepared statements] so that the
1841** application is free to use the same [database connection] or the
1842** same [prepared statement] in different threads at the same time.
1843** ^If SQLite is compiled with
1844** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1845** it is not possible to set the Serialized [threading mode] and
1846** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1847** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1848**
1849** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1850** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1851** a pointer to an instance of the [sqlite3_mem_methods] structure.
1852** The argument specifies
1853** alternative low-level memory allocation routines to be used in place of
1854** the memory allocation routines built into SQLite.)^ ^SQLite makes
1855** its own private copy of the content of the [sqlite3_mem_methods] structure
1856** before the [sqlite3_config()] call returns.</dd>
1857**
1858** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1859** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1860** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1861** The [sqlite3_mem_methods]
1862** structure is filled with the currently defined memory allocation routines.)^
1863** This option can be used to overload the default memory allocation
1864** routines with a wrapper that simulations memory allocation failure or
1865** tracks memory usage, for example. </dd>
1866**
1867** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1868** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1869** type int, interpreted as a boolean, which if true provides a hint to
1870** SQLite that it should avoid large memory allocations if possible.
1871** SQLite will run faster if it is free to make large memory allocations,
1872** but some application might prefer to run slower in exchange for
1873** guarantees about memory fragmentation that are possible if large
1874** allocations are avoided. This hint is normally off.
1875** </dd>
1876**
1877** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1878** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1879** interpreted as a boolean, which enables or disables the collection of
1880** memory allocation statistics. ^(When memory allocation statistics are
1881** disabled, the following SQLite interfaces become non-operational:
1882** <ul>
1883** <li> [sqlite3_hard_heap_limit64()]
1884** <li> [sqlite3_memory_used()]
1885** <li> [sqlite3_memory_highwater()]
1886** <li> [sqlite3_soft_heap_limit64()]
1887** <li> [sqlite3_status64()]
1888** </ul>)^
1889** ^Memory allocation statistics are enabled by default unless SQLite is
1890** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1891** allocation statistics are disabled by default.
1892** </dd>
1893**
1894** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1895** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1896** </dd>
1897**
1898** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1899** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1900** that SQLite can use for the database page cache with the default page
1901** cache implementation.
1902** This configuration option is a no-op if an application-defined page
1903** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1904** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1905** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1906** and the number of cache lines (N).
1907** The sz argument should be the size of the largest database page
1908** (a power of two between 512 and 65536) plus some extra bytes for each
1909** page header. ^The number of extra bytes needed by the page header
1910** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1911** ^It is harmless, apart from the wasted memory,
1912** for the sz parameter to be larger than necessary. The pMem
1913** argument must be either a NULL pointer or a pointer to an 8-byte
1914** aligned block of memory of at least sz*N bytes, otherwise
1915** subsequent behavior is undefined.
1916** ^When pMem is not NULL, SQLite will strive to use the memory provided
1917** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1918** a page cache line is larger than sz bytes or if all of the pMem buffer
1919** is exhausted.
1920** ^If pMem is NULL and N is non-zero, then each database connection
1921** does an initial bulk allocation for page cache memory
1922** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1923** of -1024*N bytes if N is negative, . ^If additional
1924** page cache memory is needed beyond what is provided by the initial
1925** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1926** additional cache line. </dd>
1927**
1928** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1929** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1930** that SQLite will use for all of its dynamic memory allocation needs
1931** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1932** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1933** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1934** [SQLITE_ERROR] if invoked otherwise.
1935** ^There are three arguments to SQLITE_CONFIG_HEAP:
1936** An 8-byte aligned pointer to the memory,
1937** the number of bytes in the memory buffer, and the minimum allocation size.
1938** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1939** to using its default memory allocator (the system malloc() implementation),
1940** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1941** memory pointer is not NULL then the alternative memory
1942** allocator is engaged to handle all of SQLites memory allocation needs.
1943** The first pointer (the memory pointer) must be aligned to an 8-byte
1944** boundary or subsequent behavior of SQLite will be undefined.
1945** The minimum allocation size is capped at 2**12. Reasonable values
1946** for the minimum allocation size are 2**5 through 2**8.</dd>
1947**
1948** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1949** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1950** pointer to an instance of the [sqlite3_mutex_methods] structure.
1951** The argument specifies alternative low-level mutex routines to be used
1952** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1953** the content of the [sqlite3_mutex_methods] structure before the call to
1954** [sqlite3_config()] returns. ^If SQLite is compiled with
1955** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1956** the entire mutexing subsystem is omitted from the build and hence calls to
1957** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1958** return [SQLITE_ERROR].</dd>
1959**
1960** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1961** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1962** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1963** [sqlite3_mutex_methods]
1964** structure is filled with the currently defined mutex routines.)^
1965** This option can be used to overload the default mutex allocation
1966** routines with a wrapper used to track mutex usage for performance
1967** profiling or testing, for example. ^If SQLite is compiled with
1968** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1969** the entire mutexing subsystem is omitted from the build and hence calls to
1970** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1971** return [SQLITE_ERROR].</dd>
1972**
1973** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1974** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1975** the default size of lookaside memory on each [database connection].
1976** The first argument is the
1977** size of each lookaside buffer slot and the second is the number of
1978** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1979** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1980** option to [sqlite3_db_config()] can be used to change the lookaside
1981** configuration on individual connections.)^ </dd>
1982**
1983** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1984** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1985** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1986** the interface to a custom page cache implementation.)^
1987** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1988**
1989** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1990** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1991** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1992** the current page cache implementation into that object.)^ </dd>
1993**
1994** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1995** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1996** global [error log].
1997** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1998** function with a call signature of void(*)(void*,int,const char*),
1999** and a pointer to void. ^If the function pointer is not NULL, it is
2000** invoked by [sqlite3_log()] to process each logging event. ^If the
2001** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2002** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2003** passed through as the first parameter to the application-defined logger
2004** function whenever that function is invoked. ^The second parameter to
2005** the logger function is a copy of the first parameter to the corresponding
2006** [sqlite3_log()] call and is intended to be a [result code] or an
2007** [extended result code]. ^The third parameter passed to the logger is
2008** log message after formatting via [sqlite3_snprintf()].
2009** The SQLite logging interface is not reentrant; the logger function
2010** supplied by the application must not invoke any SQLite interface.
2011** In a multi-threaded application, the application-defined logger
2012** function must be threadsafe. </dd>
2013**
2014** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2015** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2016** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2017** then URI handling is globally disabled.)^ ^If URI handling is globally
2018** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2019** [sqlite3_open16()] or
2020** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2021** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2022** connection is opened. ^If it is globally disabled, filenames are
2023** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2024** database connection is opened. ^(By default, URI handling is globally
2025** disabled. The default value may be changed by compiling with the
2026** [SQLITE_USE_URI] symbol defined.)^
2027**
2028** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2029** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2030** argument which is interpreted as a boolean in order to enable or disable
2031** the use of covering indices for full table scans in the query optimizer.
2032** ^The default setting is determined
2033** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2034** if that compile-time option is omitted.
2035** The ability to disable the use of covering indices for full table scans
2036** is because some incorrectly coded legacy applications might malfunction
2037** when the optimization is enabled. Providing the ability to
2038** disable the optimization allows the older, buggy application code to work
2039** without change even with newer versions of SQLite.
2040**
2041** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2042** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2043** <dd> These options are obsolete and should not be used by new code.
2044** They are retained for backwards compatibility but are now no-ops.
2045** </dd>
2046**
2047** [[SQLITE_CONFIG_SQLLOG]]
2048** <dt>SQLITE_CONFIG_SQLLOG
2049** <dd>This option is only available if sqlite is compiled with the
2050** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2051** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2052** The second should be of type (void*). The callback is invoked by the library
2053** in three separate circumstances, identified by the value passed as the
2054** fourth parameter. If the fourth parameter is 0, then the database connection
2055** passed as the second argument has just been opened. The third argument
2056** points to a buffer containing the name of the main database file. If the
2057** fourth parameter is 1, then the SQL statement that the third parameter
2058** points to has just been executed. Or, if the fourth parameter is 2, then
2059** the connection being passed as the second parameter is being closed. The
2060** third parameter is passed NULL In this case. An example of using this
2061** configuration option can be seen in the "test_sqllog.c" source file in
2062** the canonical SQLite source tree.</dd>
2063**
2064** [[SQLITE_CONFIG_MMAP_SIZE]]
2065** <dt>SQLITE_CONFIG_MMAP_SIZE
2066** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2067** that are the default mmap size limit (the default setting for
2068** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2069** ^The default setting can be overridden by each database connection using
2070** either the [PRAGMA mmap_size] command, or by using the
2071** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2072** will be silently truncated if necessary so that it does not exceed the
2073** compile-time maximum mmap size set by the
2074** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2075** ^If either argument to this option is negative, then that argument is
2076** changed to its compile-time default.
2077**
2078** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2079** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2080** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2081** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2082** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2083** that specifies the maximum size of the created heap.
2084**
2085** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2086** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2087** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2088** is a pointer to an integer and writes into that integer the number of extra
2089** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2090** The amount of extra space required can change depending on the compiler,
2091** target platform, and SQLite version.
2092**
2093** [[SQLITE_CONFIG_PMASZ]]
2094** <dt>SQLITE_CONFIG_PMASZ
2095** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2096** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2097** sorter to that integer. The default minimum PMA Size is set by the
2098** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2099** to help with sort operations when multithreaded sorting
2100** is enabled (using the [PRAGMA threads] command) and the amount of content
2101** to be sorted exceeds the page size times the minimum of the
2102** [PRAGMA cache_size] setting and this value.
2103**
2104** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2105** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2106** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2107** becomes the [statement journal] spill-to-disk threshold.
2108** [Statement journals] are held in memory until their size (in bytes)
2109** exceeds this threshold, at which point they are written to disk.
2110** Or if the threshold is -1, statement journals are always held
2111** exclusively in memory.
2112** Since many statement journals never become large, setting the spill
2113** threshold to a value such as 64KiB can greatly reduce the amount of
2114** I/O required to support statement rollback.
2115** The default value for this setting is controlled by the
2116** [SQLITE_STMTJRNL_SPILL] compile-time option.
2117**
2118** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2119** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2120** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2121** of type (int) - the new value of the sorter-reference size threshold.
2122** Usually, when SQLite uses an external sort to order records according
2123** to an ORDER BY clause, all fields required by the caller are present in the
2124** sorted records. However, if SQLite determines based on the declared type
2125** of a table column that its values are likely to be very large - larger
2126** than the configured sorter-reference size threshold - then a reference
2127** is stored in each sorted record and the required column values loaded
2128** from the database as records are returned in sorted order. The default
2129** value for this option is to never use this optimization. Specifying a
2130** negative value for this option restores the default behaviour.
2131** This option is only available if SQLite is compiled with the
2132** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2133**
2134** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2135** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2136** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2137** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2138** database created using [sqlite3_deserialize()]. This default maximum
2139** size can be adjusted up or down for individual databases using the
2140** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2141** configuration setting is never used, then the default maximum is determined
2142** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2143** compile-time option is not set, then the default maximum is 1073741824.
2144** </dl>
2145*/
2146#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2147#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2148#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2149#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2150#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2151#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2152#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2153#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2154#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2155#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2156#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2157/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2158#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2159#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2160#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2161#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2162#define SQLITE_CONFIG_URI 17 /* int */
2163#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2164#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2165#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2166#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2167#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2168#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2169#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2170#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2171#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2172#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2173#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2174#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2175
2176/*
2177** CAPI3REF: Database Connection Configuration Options
2178**
2179** These constants are the available integer configuration options that
2180** can be passed as the second argument to the [sqlite3_db_config()] interface.
2181**
2182** New configuration options may be added in future releases of SQLite.
2183** Existing configuration options might be discontinued. Applications
2184** should check the return code from [sqlite3_db_config()] to make sure that
2185** the call worked. ^The [sqlite3_db_config()] interface will return a
2186** non-zero [error code] if a discontinued or unsupported configuration option
2187** is invoked.
2188**
2189** <dl>
2190** [[SQLITE_DBCONFIG_LOOKASIDE]]
2191** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2192** <dd> ^This option takes three additional arguments that determine the
2193** [lookaside memory allocator] configuration for the [database connection].
2194** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2195** pointer to a memory buffer to use for lookaside memory.
2196** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2197** may be NULL in which case SQLite will allocate the
2198** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2199** size of each lookaside buffer slot. ^The third argument is the number of
2200** slots. The size of the buffer in the first argument must be greater than
2201** or equal to the product of the second and third arguments. The buffer
2202** must be aligned to an 8-byte boundary. ^If the second argument to
2203** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2204** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2205** configuration for a database connection can only be changed when that
2206** connection is not currently using lookaside memory, or in other words
2207** when the "current value" returned by
2208** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero.
2209** Any attempt to change the lookaside memory configuration when lookaside
2210** memory is in use leaves the configuration unchanged and returns
2211** [SQLITE_BUSY].)^</dd>
2212**
2213** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2214** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2215** <dd> ^This option is used to enable or disable the enforcement of
2216** [foreign key constraints]. There should be two additional arguments.
2217** The first argument is an integer which is 0 to disable FK enforcement,
2218** positive to enable FK enforcement or negative to leave FK enforcement
2219** unchanged. The second parameter is a pointer to an integer into which
2220** is written 0 or 1 to indicate whether FK enforcement is off or on
2221** following this call. The second parameter may be a NULL pointer, in
2222** which case the FK enforcement setting is not reported back. </dd>
2223**
2224** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2225** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2226** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2227** There should be two additional arguments.
2228** The first argument is an integer which is 0 to disable triggers,
2229** positive to enable triggers or negative to leave the setting unchanged.
2230** The second parameter is a pointer to an integer into which
2231** is written 0 or 1 to indicate whether triggers are disabled or enabled
2232** following this call. The second parameter may be a NULL pointer, in
2233** which case the trigger setting is not reported back.
2234**
2235** <p>Originally this option disabled all triggers. ^(However, since
2236** SQLite version 3.35.0, TEMP triggers are still allowed even if
2237** this option is off. So, in other words, this option now only disables
2238** triggers in the main database schema or in the schemas of ATTACH-ed
2239** databases.)^ </dd>
2240**
2241** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2242** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2243** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2244** There should be two additional arguments.
2245** The first argument is an integer which is 0 to disable views,
2246** positive to enable views or negative to leave the setting unchanged.
2247** The second parameter is a pointer to an integer into which
2248** is written 0 or 1 to indicate whether views are disabled or enabled
2249** following this call. The second parameter may be a NULL pointer, in
2250** which case the view setting is not reported back.
2251**
2252** <p>Originally this option disabled all views. ^(However, since
2253** SQLite version 3.35.0, TEMP views are still allowed even if
2254** this option is off. So, in other words, this option now only disables
2255** views in the main database schema or in the schemas of ATTACH-ed
2256** databases.)^ </dd>
2257**
2258** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2259** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2260** <dd> ^This option is used to enable or disable the
2261** [fts3_tokenizer()] function which is part of the
2262** [FTS3] full-text search engine extension.
2263** There should be two additional arguments.
2264** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2265** positive to enable fts3_tokenizer() or negative to leave the setting
2266** unchanged.
2267** The second parameter is a pointer to an integer into which
2268** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2269** following this call. The second parameter may be a NULL pointer, in
2270** which case the new setting is not reported back. </dd>
2271**
2272** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2273** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2274** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2275** interface independently of the [load_extension()] SQL function.
2276** The [sqlite3_enable_load_extension()] API enables or disables both the
2277** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2278** There should be two additional arguments.
2279** When the first argument to this interface is 1, then only the C-API is
2280** enabled and the SQL function remains disabled. If the first argument to
2281** this interface is 0, then both the C-API and the SQL function are disabled.
2282** If the first argument is -1, then no changes are made to state of either the
2283** C-API or the SQL function.
2284** The second parameter is a pointer to an integer into which
2285** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2286** is disabled or enabled following this call. The second parameter may
2287** be a NULL pointer, in which case the new setting is not reported back.
2288** </dd>
2289**
2290** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2291** <dd> ^This option is used to change the name of the "main" database
2292** schema. ^The sole argument is a pointer to a constant UTF8 string
2293** which will become the new schema name in place of "main". ^SQLite
2294** does not make a copy of the new main schema name string, so the application
2295** must ensure that the argument passed into this DBCONFIG option is unchanged
2296** until after the database connection closes.
2297** </dd>
2298**
2299** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2300** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2301** <dd> Usually, when a database in wal mode is closed or detached from a
2302** database handle, SQLite checks if this will mean that there are now no
2303** connections at all to the database. If so, it performs a checkpoint
2304** operation before closing the connection. This option may be used to
2305** override this behaviour. The first parameter passed to this operation
2306** is an integer - positive to disable checkpoints-on-close, or zero (the
2307** default) to enable them, and negative to leave the setting unchanged.
2308** The second parameter is a pointer to an integer
2309** into which is written 0 or 1 to indicate whether checkpoints-on-close
2310** have been disabled - 0 if they are not disabled, 1 if they are.
2311** </dd>
2312**
2313** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2314** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2315** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2316** a single SQL query statement will always use the same algorithm regardless
2317** of values of [bound parameters].)^ The QPSG disables some query optimizations
2318** that look at the values of bound parameters, which can make some queries
2319** slower. But the QPSG has the advantage of more predictable behavior. With
2320** the QPSG active, SQLite will always use the same query plan in the field as
2321** was used during testing in the lab.
2322** The first argument to this setting is an integer which is 0 to disable
2323** the QPSG, positive to enable QPSG, or negative to leave the setting
2324** unchanged. The second parameter is a pointer to an integer into which
2325** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2326** following this call.
2327** </dd>
2328**
2329** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2330** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2331** include output for any operations performed by trigger programs. This
2332** option is used to set or clear (the default) a flag that governs this
2333** behavior. The first parameter passed to this operation is an integer -
2334** positive to enable output for trigger programs, or zero to disable it,
2335** or negative to leave the setting unchanged.
2336** The second parameter is a pointer to an integer into which is written
2337** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2338** it is not disabled, 1 if it is.
2339** </dd>
2340**
2341** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2342** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2343** [VACUUM] in order to reset a database back to an empty database
2344** with no schema and no content. The following process works even for
2345** a badly corrupted database file:
2346** <ol>
2347** <li> If the database connection is newly opened, make sure it has read the
2348** database schema by preparing then discarding some query against the
2349** database, or calling sqlite3_table_column_metadata(), ignoring any
2350** errors. This step is only necessary if the application desires to keep
2351** the database in WAL mode after the reset if it was in WAL mode before
2352** the reset.
2353** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2354** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2355** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2356** </ol>
2357** Because resetting a database is destructive and irreversible, the
2358** process requires the use of this obscure API and multiple steps to
2359** help ensure that it does not happen by accident. Because this
2360** feature must be capable of resetting corrupt databases, and
2361** shutting down virtual tables may require access to that corrupt
2362** storage, the library must abandon any installed virtual tables
2363** without calling their xDestroy() methods.
2364**
2365** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2366** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2367** "defensive" flag for a database connection. When the defensive
2368** flag is enabled, language features that allow ordinary SQL to
2369** deliberately corrupt the database file are disabled. The disabled
2370** features include but are not limited to the following:
2371** <ul>
2372** <li> The [PRAGMA writable_schema=ON] statement.
2373** <li> The [PRAGMA journal_mode=OFF] statement.
2374** <li> The [PRAGMA schema_version=N] statement.
2375** <li> Writes to the [sqlite_dbpage] virtual table.
2376** <li> Direct writes to [shadow tables].
2377** </ul>
2378** </dd>
2379**
2380** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2381** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2382** "writable_schema" flag. This has the same effect and is logically equivalent
2383** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2384** The first argument to this setting is an integer which is 0 to disable
2385** the writable_schema, positive to enable writable_schema, or negative to
2386** leave the setting unchanged. The second parameter is a pointer to an
2387** integer into which is written 0 or 1 to indicate whether the writable_schema
2388** is enabled or disabled following this call.
2389** </dd>
2390**
2391** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2392** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2393** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2394** the legacy behavior of the [ALTER TABLE RENAME] command such it
2395** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2396** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2397** additional information. This feature can also be turned on and off
2398** using the [PRAGMA legacy_alter_table] statement.
2399** </dd>
2400**
2401** [[SQLITE_DBCONFIG_DQS_DML]]
2402** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2403** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2404** the legacy [double-quoted string literal] misfeature for DML statements
2405** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2406** default value of this setting is determined by the [-DSQLITE_DQS]
2407** compile-time option.
2408** </dd>
2409**
2410** [[SQLITE_DBCONFIG_DQS_DDL]]
2411** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2412** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2413** the legacy [double-quoted string literal] misfeature for DDL statements,
2414** such as CREATE TABLE and CREATE INDEX. The
2415** default value of this setting is determined by the [-DSQLITE_DQS]
2416** compile-time option.
2417** </dd>
2418**
2419** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2420** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2421** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2422** assume that database schemas are untainted by malicious content.
2423** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2424** takes additional defensive steps to protect the application from harm
2425** including:
2426** <ul>
2427** <li> Prohibit the use of SQL functions inside triggers, views,
2428** CHECK constraints, DEFAULT clauses, expression indexes,
2429** partial indexes, or generated columns
2430** unless those functions are tagged with [SQLITE_INNOCUOUS].
2431** <li> Prohibit the use of virtual tables inside of triggers or views
2432** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2433** </ul>
2434** This setting defaults to "on" for legacy compatibility, however
2435** all applications are advised to turn it off if possible. This setting
2436** can also be controlled using the [PRAGMA trusted_schema] statement.
2437** </dd>
2438**
2439** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2440** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2441** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2442** the legacy file format flag. When activated, this flag causes all newly
2443** created database file to have a schema format version number (the 4-byte
2444** integer found at offset 44 into the database header) of 1. This in turn
2445** means that the resulting database file will be readable and writable by
2446** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2447** newly created databases are generally not understandable by SQLite versions
2448** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2449** is now scarcely any need to generate database files that are compatible
2450** all the way back to version 3.0.0, and so this setting is of little
2451** practical use, but is provided so that SQLite can continue to claim the
2452** ability to generate new database files that are compatible with version
2453** 3.0.0.
2454** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2455** the [VACUUM] command will fail with an obscure error when attempting to
2456** process a table with generated columns and a descending index. This is
2457** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2458** either generated columns or descending indexes.
2459** </dd>
2460**
2461** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2462** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2463** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2464** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2465** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2466** statistics. For statistics to be collected, the flag must be set on
2467** the database handle both when the SQL statement is prepared and when it
2468** is stepped. The flag is set (collection of statistics is enabled)
2469** by default. This option takes two arguments: an integer and a pointer to
2470** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2471** leave unchanged the statement scanstatus option. If the second argument
2472** is not NULL, then the value of the statement scanstatus setting after
2473** processing the first argument is written into the integer that the second
2474** argument points to.
2475** </dd>
2476**
2477** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2478** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2479** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2480** in which tables and indexes are scanned so that the scans start at the end
2481** and work toward the beginning rather than starting at the beginning and
2482** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2483** same as setting [PRAGMA reverse_unordered_selects]. This option takes
2484** two arguments which are an integer and a pointer to an integer. The first
2485** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2486** reverse scan order flag, respectively. If the second argument is not NULL,
2487** then 0 or 1 is written into the integer that the second argument points to
2488** depending on if the reverse scan order flag is set after processing the
2489** first argument.
2490** </dd>
2491**
2492** </dl>
2493*/
2494#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2495#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2496#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2497#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2498#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2499#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2500#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2501#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2502#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2503#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2504#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2505#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2506#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2507#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2508#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2509#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2510#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2511#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2512#define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2513#define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2514#define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */
2515
2516/*
2517** CAPI3REF: Enable Or Disable Extended Result Codes
2518** METHOD: sqlite3
2519**
2520** ^The sqlite3_extended_result_codes() routine enables or disables the
2521** [extended result codes] feature of SQLite. ^The extended result
2522** codes are disabled by default for historical compatibility.
2523*/
2524SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2525
2526/*
2527** CAPI3REF: Last Insert Rowid
2528** METHOD: sqlite3
2529**
2530** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2531** has a unique 64-bit signed
2532** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2533** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2534** names are not also used by explicitly declared columns. ^If
2535** the table has a column of type [INTEGER PRIMARY KEY] then that column
2536** is another alias for the rowid.
2537**
2538** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2539** the most recent successful [INSERT] into a rowid table or [virtual table]
2540** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2541** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2542** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2543** zero.
2544**
2545** As well as being set automatically as rows are inserted into database
2546** tables, the value returned by this function may be set explicitly by
2547** [sqlite3_set_last_insert_rowid()]
2548**
2549** Some virtual table implementations may INSERT rows into rowid tables as
2550** part of committing a transaction (e.g. to flush data accumulated in memory
2551** to disk). In this case subsequent calls to this function return the rowid
2552** associated with these internal INSERT operations, which leads to
2553** unintuitive results. Virtual table implementations that do write to rowid
2554** tables in this way can avoid this problem by restoring the original
2555** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2556** control to the user.
2557**
2558** ^(If an [INSERT] occurs within a trigger then this routine will
2559** return the [rowid] of the inserted row as long as the trigger is
2560** running. Once the trigger program ends, the value returned
2561** by this routine reverts to what it was before the trigger was fired.)^
2562**
2563** ^An [INSERT] that fails due to a constraint violation is not a
2564** successful [INSERT] and does not change the value returned by this
2565** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2566** and INSERT OR ABORT make no changes to the return value of this
2567** routine when their insertion fails. ^(When INSERT OR REPLACE
2568** encounters a constraint violation, it does not fail. The
2569** INSERT continues to completion after deleting rows that caused
2570** the constraint problem so INSERT OR REPLACE will always change
2571** the return value of this interface.)^
2572**
2573** ^For the purposes of this routine, an [INSERT] is considered to
2574** be successful even if it is subsequently rolled back.
2575**
2576** This function is accessible to SQL statements via the
2577** [last_insert_rowid() SQL function].
2578**
2579** If a separate thread performs a new [INSERT] on the same
2580** database connection while the [sqlite3_last_insert_rowid()]
2581** function is running and thus changes the last insert [rowid],
2582** then the value returned by [sqlite3_last_insert_rowid()] is
2583** unpredictable and might not equal either the old or the new
2584** last insert [rowid].
2585*/
2586SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2587
2588/*
2589** CAPI3REF: Set the Last Insert Rowid value.
2590** METHOD: sqlite3
2591**
2592** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2593** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2594** without inserting a row into the database.
2595*/
2596SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2597
2598/*
2599** CAPI3REF: Count The Number Of Rows Modified
2600** METHOD: sqlite3
2601**
2602** ^These functions return the number of rows modified, inserted or
2603** deleted by the most recently completed INSERT, UPDATE or DELETE
2604** statement on the database connection specified by the only parameter.
2605** The two functions are identical except for the type of the return value
2606** and that if the number of rows modified by the most recent INSERT, UPDATE
2607** or DELETE is greater than the maximum value supported by type "int", then
2608** the return value of sqlite3_changes() is undefined. ^Executing any other
2609** type of SQL statement does not modify the value returned by these functions.
2610**
2611** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2612** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2613** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2614**
2615** Changes to a view that are intercepted by
2616** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2617** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2618** DELETE statement run on a view is always zero. Only changes made to real
2619** tables are counted.
2620**
2621** Things are more complicated if the sqlite3_changes() function is
2622** executed while a trigger program is running. This may happen if the
2623** program uses the [changes() SQL function], or if some other callback
2624** function invokes sqlite3_changes() directly. Essentially:
2625**
2626** <ul>
2627** <li> ^(Before entering a trigger program the value returned by
2628** sqlite3_changes() function is saved. After the trigger program
2629** has finished, the original value is restored.)^
2630**
2631** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2632** statement sets the value returned by sqlite3_changes()
2633** upon completion as normal. Of course, this value will not include
2634** any changes performed by sub-triggers, as the sqlite3_changes()
2635** value will be saved and restored after each sub-trigger has run.)^
2636** </ul>
2637**
2638** ^This means that if the changes() SQL function (or similar) is used
2639** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2640** returns the value as set when the calling statement began executing.
2641** ^If it is used by the second or subsequent such statement within a trigger
2642** program, the value returned reflects the number of rows modified by the
2643** previous INSERT, UPDATE or DELETE statement within the same trigger.
2644**
2645** If a separate thread makes changes on the same database connection
2646** while [sqlite3_changes()] is running then the value returned
2647** is unpredictable and not meaningful.
2648**
2649** See also:
2650** <ul>
2651** <li> the [sqlite3_total_changes()] interface
2652** <li> the [count_changes pragma]
2653** <li> the [changes() SQL function]
2654** <li> the [data_version pragma]
2655** </ul>
2656*/
2657SQLITE_API int sqlite3_changes(sqlite3*);
2658SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2659
2660/*
2661** CAPI3REF: Total Number Of Rows Modified
2662** METHOD: sqlite3
2663**
2664** ^These functions return the total number of rows inserted, modified or
2665** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2666** since the database connection was opened, including those executed as
2667** part of trigger programs. The two functions are identical except for the
2668** type of the return value and that if the number of rows modified by the
2669** connection exceeds the maximum value supported by type "int", then
2670** the return value of sqlite3_total_changes() is undefined. ^Executing
2671** any other type of SQL statement does not affect the value returned by
2672** sqlite3_total_changes().
2673**
2674** ^Changes made as part of [foreign key actions] are included in the
2675** count, but those made as part of REPLACE constraint resolution are
2676** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2677** are not counted.
2678**
2679** The [sqlite3_total_changes(D)] interface only reports the number
2680** of rows that changed due to SQL statement run against database
2681** connection D. Any changes by other database connections are ignored.
2682** To detect changes against a database file from other database
2683** connections use the [PRAGMA data_version] command or the
2684** [SQLITE_FCNTL_DATA_VERSION] [file control].
2685**
2686** If a separate thread makes changes on the same database connection
2687** while [sqlite3_total_changes()] is running then the value
2688** returned is unpredictable and not meaningful.
2689**
2690** See also:
2691** <ul>
2692** <li> the [sqlite3_changes()] interface
2693** <li> the [count_changes pragma]
2694** <li> the [changes() SQL function]
2695** <li> the [data_version pragma]
2696** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2697** </ul>
2698*/
2699SQLITE_API int sqlite3_total_changes(sqlite3*);
2700SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2701
2702/*
2703** CAPI3REF: Interrupt A Long-Running Query
2704** METHOD: sqlite3
2705**
2706** ^This function causes any pending database operation to abort and
2707** return at its earliest opportunity. This routine is typically
2708** called in response to a user action such as pressing "Cancel"
2709** or Ctrl-C where the user wants a long query operation to halt
2710** immediately.
2711**
2712** ^It is safe to call this routine from a thread different from the
2713** thread that is currently running the database operation. But it
2714** is not safe to call this routine with a [database connection] that
2715** is closed or might close before sqlite3_interrupt() returns.
2716**
2717** ^If an SQL operation is very nearly finished at the time when
2718** sqlite3_interrupt() is called, then it might not have an opportunity
2719** to be interrupted and might continue to completion.
2720**
2721** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2722** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2723** that is inside an explicit transaction, then the entire transaction
2724** will be rolled back automatically.
2725**
2726** ^The sqlite3_interrupt(D) call is in effect until all currently running
2727** SQL statements on [database connection] D complete. ^Any new SQL statements
2728** that are started after the sqlite3_interrupt() call and before the
2729** running statement count reaches zero are interrupted as if they had been
2730** running prior to the sqlite3_interrupt() call. ^New SQL statements
2731** that are started after the running statement count reaches zero are
2732** not effected by the sqlite3_interrupt().
2733** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2734** SQL statements is a no-op and has no effect on SQL statements
2735** that are started after the sqlite3_interrupt() call returns.
2736**
2737** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2738** or not an interrupt is currently in effect for [database connection] D.
2739** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2740*/
2741SQLITE_API void sqlite3_interrupt(sqlite3*);
2742SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2743
2744/*
2745** CAPI3REF: Determine If An SQL Statement Is Complete
2746**
2747** These routines are useful during command-line input to determine if the
2748** currently entered text seems to form a complete SQL statement or
2749** if additional input is needed before sending the text into
2750** SQLite for parsing. ^These routines return 1 if the input string
2751** appears to be a complete SQL statement. ^A statement is judged to be
2752** complete if it ends with a semicolon token and is not a prefix of a
2753** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2754** string literals or quoted identifier names or comments are not
2755** independent tokens (they are part of the token in which they are
2756** embedded) and thus do not count as a statement terminator. ^Whitespace
2757** and comments that follow the final semicolon are ignored.
2758**
2759** ^These routines return 0 if the statement is incomplete. ^If a
2760** memory allocation fails, then SQLITE_NOMEM is returned.
2761**
2762** ^These routines do not parse the SQL statements thus
2763** will not detect syntactically incorrect SQL.
2764**
2765** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2766** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2767** automatically by sqlite3_complete16(). If that initialization fails,
2768** then the return value from sqlite3_complete16() will be non-zero
2769** regardless of whether or not the input SQL is complete.)^
2770**
2771** The input to [sqlite3_complete()] must be a zero-terminated
2772** UTF-8 string.
2773**
2774** The input to [sqlite3_complete16()] must be a zero-terminated
2775** UTF-16 string in native byte order.
2776*/
2777SQLITE_API int sqlite3_complete(const char *sql);
2778SQLITE_API int sqlite3_complete16(const void *sql);
2779
2780/*
2781** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2782** KEYWORDS: {busy-handler callback} {busy handler}
2783** METHOD: sqlite3
2784**
2785** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2786** that might be invoked with argument P whenever
2787** an attempt is made to access a database table associated with
2788** [database connection] D when another thread
2789** or process has the table locked.
2790** The sqlite3_busy_handler() interface is used to implement
2791** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2792**
2793** ^If the busy callback is NULL, then [SQLITE_BUSY]
2794** is returned immediately upon encountering the lock. ^If the busy callback
2795** is not NULL, then the callback might be invoked with two arguments.
2796**
2797** ^The first argument to the busy handler is a copy of the void* pointer which
2798** is the third argument to sqlite3_busy_handler(). ^The second argument to
2799** the busy handler callback is the number of times that the busy handler has
2800** been invoked previously for the same locking event. ^If the
2801** busy callback returns 0, then no additional attempts are made to
2802** access the database and [SQLITE_BUSY] is returned
2803** to the application.
2804** ^If the callback returns non-zero, then another attempt
2805** is made to access the database and the cycle repeats.
2806**
2807** The presence of a busy handler does not guarantee that it will be invoked
2808** when there is lock contention. ^If SQLite determines that invoking the busy
2809** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2810** to the application instead of invoking the
2811** busy handler.
2812** Consider a scenario where one process is holding a read lock that
2813** it is trying to promote to a reserved lock and
2814** a second process is holding a reserved lock that it is trying
2815** to promote to an exclusive lock. The first process cannot proceed
2816** because it is blocked by the second and the second process cannot
2817** proceed because it is blocked by the first. If both processes
2818** invoke the busy handlers, neither will make any progress. Therefore,
2819** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2820** will induce the first process to release its read lock and allow
2821** the second process to proceed.
2822**
2823** ^The default busy callback is NULL.
2824**
2825** ^(There can only be a single busy handler defined for each
2826** [database connection]. Setting a new busy handler clears any
2827** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2828** or evaluating [PRAGMA busy_timeout=N] will change the
2829** busy handler and thus clear any previously set busy handler.
2830**
2831** The busy callback should not take any actions which modify the
2832** database connection that invoked the busy handler. In other words,
2833** the busy handler is not reentrant. Any such actions
2834** result in undefined behavior.
2835**
2836** A busy handler must not close the database connection
2837** or [prepared statement] that invoked the busy handler.
2838*/
2839SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2840
2841/*
2842** CAPI3REF: Set A Busy Timeout
2843** METHOD: sqlite3
2844**
2845** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2846** for a specified amount of time when a table is locked. ^The handler
2847** will sleep multiple times until at least "ms" milliseconds of sleeping
2848** have accumulated. ^After at least "ms" milliseconds of sleeping,
2849** the handler returns 0 which causes [sqlite3_step()] to return
2850** [SQLITE_BUSY].
2851**
2852** ^Calling this routine with an argument less than or equal to zero
2853** turns off all busy handlers.
2854**
2855** ^(There can only be a single busy handler for a particular
2856** [database connection] at any given moment. If another busy handler
2857** was defined (using [sqlite3_busy_handler()]) prior to calling
2858** this routine, that other busy handler is cleared.)^
2859**
2860** See also: [PRAGMA busy_timeout]
2861*/
2862SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2863
2864/*
2865** CAPI3REF: Convenience Routines For Running Queries
2866** METHOD: sqlite3
2867**
2868** This is a legacy interface that is preserved for backwards compatibility.
2869** Use of this interface is not recommended.
2870**
2871** Definition: A <b>result table</b> is memory data structure created by the
2872** [sqlite3_get_table()] interface. A result table records the
2873** complete query results from one or more queries.
2874**
2875** The table conceptually has a number of rows and columns. But
2876** these numbers are not part of the result table itself. These
2877** numbers are obtained separately. Let N be the number of rows
2878** and M be the number of columns.
2879**
2880** A result table is an array of pointers to zero-terminated UTF-8 strings.
2881** There are (N+1)*M elements in the array. The first M pointers point
2882** to zero-terminated strings that contain the names of the columns.
2883** The remaining entries all point to query results. NULL values result
2884** in NULL pointers. All other values are in their UTF-8 zero-terminated
2885** string representation as returned by [sqlite3_column_text()].
2886**
2887** A result table might consist of one or more memory allocations.
2888** It is not safe to pass a result table directly to [sqlite3_free()].
2889** A result table should be deallocated using [sqlite3_free_table()].
2890**
2891** ^(As an example of the result table format, suppose a query result
2892** is as follows:
2893**
2894** <blockquote><pre>
2895** Name | Age
2896** -----------------------
2897** Alice | 43
2898** Bob | 28
2899** Cindy | 21
2900** </pre></blockquote>
2901**
2902** There are two columns (M==2) and three rows (N==3). Thus the
2903** result table has 8 entries. Suppose the result table is stored
2904** in an array named azResult. Then azResult holds this content:
2905**
2906** <blockquote><pre>
2907** azResult&#91;0] = "Name";
2908** azResult&#91;1] = "Age";
2909** azResult&#91;2] = "Alice";
2910** azResult&#91;3] = "43";
2911** azResult&#91;4] = "Bob";
2912** azResult&#91;5] = "28";
2913** azResult&#91;6] = "Cindy";
2914** azResult&#91;7] = "21";
2915** </pre></blockquote>)^
2916**
2917** ^The sqlite3_get_table() function evaluates one or more
2918** semicolon-separated SQL statements in the zero-terminated UTF-8
2919** string of its 2nd parameter and returns a result table to the
2920** pointer given in its 3rd parameter.
2921**
2922** After the application has finished with the result from sqlite3_get_table(),
2923** it must pass the result table pointer to sqlite3_free_table() in order to
2924** release the memory that was malloced. Because of the way the
2925** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2926** function must not try to call [sqlite3_free()] directly. Only
2927** [sqlite3_free_table()] is able to release the memory properly and safely.
2928**
2929** The sqlite3_get_table() interface is implemented as a wrapper around
2930** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2931** to any internal data structures of SQLite. It uses only the public
2932** interface defined here. As a consequence, errors that occur in the
2933** wrapper layer outside of the internal [sqlite3_exec()] call are not
2934** reflected in subsequent calls to [sqlite3_errcode()] or
2935** [sqlite3_errmsg()].
2936*/
2937SQLITE_API int sqlite3_get_table(
2938 sqlite3 *db, /* An open database */
2939 const char *zSql, /* SQL to be evaluated */
2940 char ***pazResult, /* Results of the query */
2941 int *pnRow, /* Number of result rows written here */
2942 int *pnColumn, /* Number of result columns written here */
2943 char **pzErrmsg /* Error msg written here */
2944);
2945SQLITE_API void sqlite3_free_table(char **result);
2946
2947/*
2948** CAPI3REF: Formatted String Printing Functions
2949**
2950** These routines are work-alikes of the "printf()" family of functions
2951** from the standard C library.
2952** These routines understand most of the common formatting options from
2953** the standard library printf()
2954** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2955** See the [built-in printf()] documentation for details.
2956**
2957** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2958** results into memory obtained from [sqlite3_malloc64()].
2959** The strings returned by these two routines should be
2960** released by [sqlite3_free()]. ^Both routines return a
2961** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2962** memory to hold the resulting string.
2963**
2964** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2965** the standard C library. The result is written into the
2966** buffer supplied as the second parameter whose size is given by
2967** the first parameter. Note that the order of the
2968** first two parameters is reversed from snprintf().)^ This is an
2969** historical accident that cannot be fixed without breaking
2970** backwards compatibility. ^(Note also that sqlite3_snprintf()
2971** returns a pointer to its buffer instead of the number of
2972** characters actually written into the buffer.)^ We admit that
2973** the number of characters written would be a more useful return
2974** value but we cannot change the implementation of sqlite3_snprintf()
2975** now without breaking compatibility.
2976**
2977** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2978** guarantees that the buffer is always zero-terminated. ^The first
2979** parameter "n" is the total size of the buffer, including space for
2980** the zero terminator. So the longest string that can be completely
2981** written will be n-1 characters.
2982**
2983** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2984**
2985** See also: [built-in printf()], [printf() SQL function]
2986*/
2987SQLITE_API char *sqlite3_mprintf(const char*,...);
2988SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2989SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2990SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2991
2992/*
2993** CAPI3REF: Memory Allocation Subsystem
2994**
2995** The SQLite core uses these three routines for all of its own
2996** internal memory allocation needs. "Core" in the previous sentence
2997** does not include operating-system specific [VFS] implementation. The
2998** Windows VFS uses native malloc() and free() for some operations.
2999**
3000** ^The sqlite3_malloc() routine returns a pointer to a block
3001** of memory at least N bytes in length, where N is the parameter.
3002** ^If sqlite3_malloc() is unable to obtain sufficient free
3003** memory, it returns a NULL pointer. ^If the parameter N to
3004** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3005** a NULL pointer.
3006**
3007** ^The sqlite3_malloc64(N) routine works just like
3008** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3009** of a signed 32-bit integer.
3010**
3011** ^Calling sqlite3_free() with a pointer previously returned
3012** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3013** that it might be reused. ^The sqlite3_free() routine is
3014** a no-op if is called with a NULL pointer. Passing a NULL pointer
3015** to sqlite3_free() is harmless. After being freed, memory
3016** should neither be read nor written. Even reading previously freed
3017** memory might result in a segmentation fault or other severe error.
3018** Memory corruption, a segmentation fault, or other severe error
3019** might result if sqlite3_free() is called with a non-NULL pointer that
3020** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3021**
3022** ^The sqlite3_realloc(X,N) interface attempts to resize a
3023** prior memory allocation X to be at least N bytes.
3024** ^If the X parameter to sqlite3_realloc(X,N)
3025** is a NULL pointer then its behavior is identical to calling
3026** sqlite3_malloc(N).
3027** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3028** negative then the behavior is exactly the same as calling
3029** sqlite3_free(X).
3030** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3031** of at least N bytes in size or NULL if insufficient memory is available.
3032** ^If M is the size of the prior allocation, then min(N,M) bytes
3033** of the prior allocation are copied into the beginning of buffer returned
3034** by sqlite3_realloc(X,N) and the prior allocation is freed.
3035** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3036** prior allocation is not freed.
3037**
3038** ^The sqlite3_realloc64(X,N) interfaces works the same as
3039** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3040** of a 32-bit signed integer.
3041**
3042** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3043** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3044** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3045** ^The value returned by sqlite3_msize(X) might be larger than the number
3046** of bytes requested when X was allocated. ^If X is a NULL pointer then
3047** sqlite3_msize(X) returns zero. If X points to something that is not
3048** the beginning of memory allocation, or if it points to a formerly
3049** valid memory allocation that has now been freed, then the behavior
3050** of sqlite3_msize(X) is undefined and possibly harmful.
3051**
3052** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3053** sqlite3_malloc64(), and sqlite3_realloc64()
3054** is always aligned to at least an 8 byte boundary, or to a
3055** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3056** option is used.
3057**
3058** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3059** must be either NULL or else pointers obtained from a prior
3060** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3061** not yet been released.
3062**
3063** The application must not read or write any part of
3064** a block of memory after it has been released using
3065** [sqlite3_free()] or [sqlite3_realloc()].
3066*/
3067SQLITE_API void *sqlite3_malloc(int);
3068SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3069SQLITE_API void *sqlite3_realloc(void*, int);
3070SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3071SQLITE_API void sqlite3_free(void*);
3072SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3073
3074/*
3075** CAPI3REF: Memory Allocator Statistics
3076**
3077** SQLite provides these two interfaces for reporting on the status
3078** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3079** routines, which form the built-in memory allocation subsystem.
3080**
3081** ^The [sqlite3_memory_used()] routine returns the number of bytes
3082** of memory currently outstanding (malloced but not freed).
3083** ^The [sqlite3_memory_highwater()] routine returns the maximum
3084** value of [sqlite3_memory_used()] since the high-water mark
3085** was last reset. ^The values returned by [sqlite3_memory_used()] and
3086** [sqlite3_memory_highwater()] include any overhead
3087** added by SQLite in its implementation of [sqlite3_malloc()],
3088** but not overhead added by the any underlying system library
3089** routines that [sqlite3_malloc()] may call.
3090**
3091** ^The memory high-water mark is reset to the current value of
3092** [sqlite3_memory_used()] if and only if the parameter to
3093** [sqlite3_memory_highwater()] is true. ^The value returned
3094** by [sqlite3_memory_highwater(1)] is the high-water mark
3095** prior to the reset.
3096*/
3097SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3098SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3099
3100/*
3101** CAPI3REF: Pseudo-Random Number Generator
3102**
3103** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3104** select random [ROWID | ROWIDs] when inserting new records into a table that
3105** already uses the largest possible [ROWID]. The PRNG is also used for
3106** the built-in random() and randomblob() SQL functions. This interface allows
3107** applications to access the same PRNG for other purposes.
3108**
3109** ^A call to this routine stores N bytes of randomness into buffer P.
3110** ^The P parameter can be a NULL pointer.
3111**
3112** ^If this routine has not been previously called or if the previous
3113** call had N less than one or a NULL pointer for P, then the PRNG is
3114** seeded using randomness obtained from the xRandomness method of
3115** the default [sqlite3_vfs] object.
3116** ^If the previous call to this routine had an N of 1 or more and a
3117** non-NULL P then the pseudo-randomness is generated
3118** internally and without recourse to the [sqlite3_vfs] xRandomness
3119** method.
3120*/
3121SQLITE_API void sqlite3_randomness(int N, void *P);
3122
3123/*
3124** CAPI3REF: Compile-Time Authorization Callbacks
3125** METHOD: sqlite3
3126** KEYWORDS: {authorizer callback}
3127**
3128** ^This routine registers an authorizer callback with a particular
3129** [database connection], supplied in the first argument.
3130** ^The authorizer callback is invoked as SQL statements are being compiled
3131** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3132** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3133** and [sqlite3_prepare16_v3()]. ^At various
3134** points during the compilation process, as logic is being created
3135** to perform various actions, the authorizer callback is invoked to
3136** see if those actions are allowed. ^The authorizer callback should
3137** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3138** specific action but allow the SQL statement to continue to be
3139** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3140** rejected with an error. ^If the authorizer callback returns
3141** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3142** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3143** the authorizer will fail with an error message.
3144**
3145** When the callback returns [SQLITE_OK], that means the operation
3146** requested is ok. ^When the callback returns [SQLITE_DENY], the
3147** [sqlite3_prepare_v2()] or equivalent call that triggered the
3148** authorizer will fail with an error message explaining that
3149** access is denied.
3150**
3151** ^The first parameter to the authorizer callback is a copy of the third
3152** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3153** to the callback is an integer [SQLITE_COPY | action code] that specifies
3154** the particular action to be authorized. ^The third through sixth parameters
3155** to the callback are either NULL pointers or zero-terminated strings
3156** that contain additional details about the action to be authorized.
3157** Applications must always be prepared to encounter a NULL pointer in any
3158** of the third through the sixth parameters of the authorization callback.
3159**
3160** ^If the action code is [SQLITE_READ]
3161** and the callback returns [SQLITE_IGNORE] then the
3162** [prepared statement] statement is constructed to substitute
3163** a NULL value in place of the table column that would have
3164** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3165** return can be used to deny an untrusted user access to individual
3166** columns of a table.
3167** ^When a table is referenced by a [SELECT] but no column values are
3168** extracted from that table (for example in a query like
3169** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3170** is invoked once for that table with a column name that is an empty string.
3171** ^If the action code is [SQLITE_DELETE] and the callback returns
3172** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3173** [truncate optimization] is disabled and all rows are deleted individually.
3174**
3175** An authorizer is used when [sqlite3_prepare | preparing]
3176** SQL statements from an untrusted source, to ensure that the SQL statements
3177** do not try to access data they are not allowed to see, or that they do not
3178** try to execute malicious statements that damage the database. For
3179** example, an application may allow a user to enter arbitrary
3180** SQL queries for evaluation by a database. But the application does
3181** not want the user to be able to make arbitrary changes to the
3182** database. An authorizer could then be put in place while the
3183** user-entered SQL is being [sqlite3_prepare | prepared] that
3184** disallows everything except [SELECT] statements.
3185**
3186** Applications that need to process SQL from untrusted sources
3187** might also consider lowering resource limits using [sqlite3_limit()]
3188** and limiting database size using the [max_page_count] [PRAGMA]
3189** in addition to using an authorizer.
3190**
3191** ^(Only a single authorizer can be in place on a database connection
3192** at a time. Each call to sqlite3_set_authorizer overrides the
3193** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3194** The authorizer is disabled by default.
3195**
3196** The authorizer callback must not do anything that will modify
3197** the database connection that invoked the authorizer callback.
3198** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3199** database connections for the meaning of "modify" in this paragraph.
3200**
3201** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3202** statement might be re-prepared during [sqlite3_step()] due to a
3203** schema change. Hence, the application should ensure that the
3204** correct authorizer callback remains in place during the [sqlite3_step()].
3205**
3206** ^Note that the authorizer callback is invoked only during
3207** [sqlite3_prepare()] or its variants. Authorization is not
3208** performed during statement evaluation in [sqlite3_step()], unless
3209** as stated in the previous paragraph, sqlite3_step() invokes
3210** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3211*/
3212SQLITE_API int sqlite3_set_authorizer(
3213 sqlite3*,
3214 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3215 void *pUserData
3216);
3217
3218/*
3219** CAPI3REF: Authorizer Return Codes
3220**
3221** The [sqlite3_set_authorizer | authorizer callback function] must
3222** return either [SQLITE_OK] or one of these two constants in order
3223** to signal SQLite whether or not the action is permitted. See the
3224** [sqlite3_set_authorizer | authorizer documentation] for additional
3225** information.
3226**
3227** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3228** returned from the [sqlite3_vtab_on_conflict()] interface.
3229*/
3230#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3231#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3232
3233/*
3234** CAPI3REF: Authorizer Action Codes
3235**
3236** The [sqlite3_set_authorizer()] interface registers a callback function
3237** that is invoked to authorize certain SQL statement actions. The
3238** second parameter to the callback is an integer code that specifies
3239** what action is being authorized. These are the integer action codes that
3240** the authorizer callback may be passed.
3241**
3242** These action code values signify what kind of operation is to be
3243** authorized. The 3rd and 4th parameters to the authorization
3244** callback function will be parameters or NULL depending on which of these
3245** codes is used as the second parameter. ^(The 5th parameter to the
3246** authorizer callback is the name of the database ("main", "temp",
3247** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3248** is the name of the inner-most trigger or view that is responsible for
3249** the access attempt or NULL if this access attempt is directly from
3250** top-level SQL code.
3251*/
3252/******************************************* 3rd ************ 4th ***********/
3253#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3254#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3255#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3256#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3257#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3258#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3259#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3260#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3261#define SQLITE_DELETE 9 /* Table Name NULL */
3262#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3263#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3264#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3265#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3266#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3267#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3268#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3269#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3270#define SQLITE_INSERT 18 /* Table Name NULL */
3271#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3272#define SQLITE_READ 20 /* Table Name Column Name */
3273#define SQLITE_SELECT 21 /* NULL NULL */
3274#define SQLITE_TRANSACTION 22 /* Operation NULL */
3275#define SQLITE_UPDATE 23 /* Table Name Column Name */
3276#define SQLITE_ATTACH 24 /* Filename NULL */
3277#define SQLITE_DETACH 25 /* Database Name NULL */
3278#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3279#define SQLITE_REINDEX 27 /* Index Name NULL */
3280#define SQLITE_ANALYZE 28 /* Table Name NULL */
3281#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3282#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3283#define SQLITE_FUNCTION 31 /* NULL Function Name */
3284#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3285#define SQLITE_COPY 0 /* No longer used */
3286#define SQLITE_RECURSIVE 33 /* NULL NULL */
3287
3288/*
3289** CAPI3REF: Tracing And Profiling Functions
3290** METHOD: sqlite3
3291**
3292** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3293** instead of the routines described here.
3294**
3295** These routines register callback functions that can be used for
3296** tracing and profiling the execution of SQL statements.
3297**
3298** ^The callback function registered by sqlite3_trace() is invoked at
3299** various times when an SQL statement is being run by [sqlite3_step()].
3300** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3301** SQL statement text as the statement first begins executing.
3302** ^(Additional sqlite3_trace() callbacks might occur
3303** as each triggered subprogram is entered. The callbacks for triggers
3304** contain a UTF-8 SQL comment that identifies the trigger.)^
3305**
3306** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3307** the length of [bound parameter] expansion in the output of sqlite3_trace().
3308**
3309** ^The callback function registered by sqlite3_profile() is invoked
3310** as each SQL statement finishes. ^The profile callback contains
3311** the original statement text and an estimate of wall-clock time
3312** of how long that statement took to run. ^The profile callback
3313** time is in units of nanoseconds, however the current implementation
3314** is only capable of millisecond resolution so the six least significant
3315** digits in the time are meaningless. Future versions of SQLite
3316** might provide greater resolution on the profiler callback. Invoking
3317** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3318** profile callback.
3319*/
3320SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3321 void(*xTrace)(void*,const char*), void*);
3322SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3323 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3324
3325/*
3326** CAPI3REF: SQL Trace Event Codes
3327** KEYWORDS: SQLITE_TRACE
3328**
3329** These constants identify classes of events that can be monitored
3330** using the [sqlite3_trace_v2()] tracing logic. The M argument
3331** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3332** the following constants. ^The first argument to the trace callback
3333** is one of the following constants.
3334**
3335** New tracing constants may be added in future releases.
3336**
3337** ^A trace callback has four arguments: xCallback(T,C,P,X).
3338** ^The T argument is one of the integer type codes above.
3339** ^The C argument is a copy of the context pointer passed in as the
3340** fourth argument to [sqlite3_trace_v2()].
3341** The P and X arguments are pointers whose meanings depend on T.
3342**
3343** <dl>
3344** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3345** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3346** first begins running and possibly at other times during the
3347** execution of the prepared statement, such as at the start of each
3348** trigger subprogram. ^The P argument is a pointer to the
3349** [prepared statement]. ^The X argument is a pointer to a string which
3350** is the unexpanded SQL text of the prepared statement or an SQL comment
3351** that indicates the invocation of a trigger. ^The callback can compute
3352** the same text that would have been returned by the legacy [sqlite3_trace()]
3353** interface by using the X argument when X begins with "--" and invoking
3354** [sqlite3_expanded_sql(P)] otherwise.
3355**
3356** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3357** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3358** information as is provided by the [sqlite3_profile()] callback.
3359** ^The P argument is a pointer to the [prepared statement] and the
3360** X argument points to a 64-bit integer which is approximately
3361** the number of nanoseconds that the prepared statement took to run.
3362** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3363**
3364** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3365** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3366** statement generates a single row of result.
3367** ^The P argument is a pointer to the [prepared statement] and the
3368** X argument is unused.
3369**
3370** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3371** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3372** connection closes.
3373** ^The P argument is a pointer to the [database connection] object
3374** and the X argument is unused.
3375** </dl>
3376*/
3377#define SQLITE_TRACE_STMT 0x01
3378#define SQLITE_TRACE_PROFILE 0x02
3379#define SQLITE_TRACE_ROW 0x04
3380#define SQLITE_TRACE_CLOSE 0x08
3381
3382/*
3383** CAPI3REF: SQL Trace Hook
3384** METHOD: sqlite3
3385**
3386** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3387** function X against [database connection] D, using property mask M
3388** and context pointer P. ^If the X callback is
3389** NULL or if the M mask is zero, then tracing is disabled. The
3390** M argument should be the bitwise OR-ed combination of
3391** zero or more [SQLITE_TRACE] constants.
3392**
3393** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3394** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3395** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3396** database connection may have at most one trace callback.
3397**
3398** ^The X callback is invoked whenever any of the events identified by
3399** mask M occur. ^The integer return value from the callback is currently
3400** ignored, though this may change in future releases. Callback
3401** implementations should return zero to ensure future compatibility.
3402**
3403** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3404** ^The T argument is one of the [SQLITE_TRACE]
3405** constants to indicate why the callback was invoked.
3406** ^The C argument is a copy of the context pointer.
3407** The P and X arguments are pointers whose meanings depend on T.
3408**
3409** The sqlite3_trace_v2() interface is intended to replace the legacy
3410** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3411** are deprecated.
3412*/
3413SQLITE_API int sqlite3_trace_v2(
3414 sqlite3*,
3415 unsigned uMask,
3416 int(*xCallback)(unsigned,void*,void*,void*),
3417 void *pCtx
3418);
3419
3420/*
3421** CAPI3REF: Query Progress Callbacks
3422** METHOD: sqlite3
3423**
3424** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3425** function X to be invoked periodically during long running calls to
3426** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3427** database connection D. An example use for this
3428** interface is to keep a GUI updated during a large query.
3429**
3430** ^The parameter P is passed through as the only parameter to the
3431** callback function X. ^The parameter N is the approximate number of
3432** [virtual machine instructions] that are evaluated between successive
3433** invocations of the callback X. ^If N is less than one then the progress
3434** handler is disabled.
3435**
3436** ^Only a single progress handler may be defined at one time per
3437** [database connection]; setting a new progress handler cancels the
3438** old one. ^Setting parameter X to NULL disables the progress handler.
3439** ^The progress handler is also disabled by setting N to a value less
3440** than 1.
3441**
3442** ^If the progress callback returns non-zero, the operation is
3443** interrupted. This feature can be used to implement a
3444** "Cancel" button on a GUI progress dialog box.
3445**
3446** The progress handler callback must not do anything that will modify
3447** the database connection that invoked the progress handler.
3448** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3449** database connections for the meaning of "modify" in this paragraph.
3450**
3451** The progress handler callback would originally only be invoked from the
3452** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3453** and similar because those routines might force a reparse of the schema
3454** which involves running the bytecode engine. However, beginning with
3455** SQLite version 3.41.0, the progress handler callback might also be
3456** invoked directly from [sqlite3_prepare()] while analyzing and generating
3457** code for complex queries.
3458*/
3459SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3460
3461/*
3462** CAPI3REF: Opening A New Database Connection
3463** CONSTRUCTOR: sqlite3
3464**
3465** ^These routines open an SQLite database file as specified by the
3466** filename argument. ^The filename argument is interpreted as UTF-8 for
3467** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3468** order for sqlite3_open16(). ^(A [database connection] handle is usually
3469** returned in *ppDb, even if an error occurs. The only exception is that
3470** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3471** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3472** object.)^ ^(If the database is opened (and/or created) successfully, then
3473** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3474** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3475** an English language description of the error following a failure of any
3476** of the sqlite3_open() routines.
3477**
3478** ^The default encoding will be UTF-8 for databases created using
3479** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3480** created using sqlite3_open16() will be UTF-16 in the native byte order.
3481**
3482** Whether or not an error occurs when it is opened, resources
3483** associated with the [database connection] handle should be released by
3484** passing it to [sqlite3_close()] when it is no longer required.
3485**
3486** The sqlite3_open_v2() interface works like sqlite3_open()
3487** except that it accepts two additional parameters for additional control
3488** over the new database connection. ^(The flags parameter to
3489** sqlite3_open_v2() must include, at a minimum, one of the following
3490** three flag combinations:)^
3491**
3492** <dl>
3493** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3494** <dd>The database is opened in read-only mode. If the database does
3495** not already exist, an error is returned.</dd>)^
3496**
3497** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3498** <dd>The database is opened for reading and writing if possible, or
3499** reading only if the file is write protected by the operating
3500** system. In either case the database must already exist, otherwise
3501** an error is returned. For historical reasons, if opening in
3502** read-write mode fails due to OS-level permissions, an attempt is
3503** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3504** used to determine whether the database is actually
3505** read-write.</dd>)^
3506**
3507** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3508** <dd>The database is opened for reading and writing, and is created if
3509** it does not already exist. This is the behavior that is always used for
3510** sqlite3_open() and sqlite3_open16().</dd>)^
3511** </dl>
3512**
3513** In addition to the required flags, the following optional flags are
3514** also supported:
3515**
3516** <dl>
3517** ^(<dt>[SQLITE_OPEN_URI]</dt>
3518** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3519**
3520** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3521** <dd>The database will be opened as an in-memory database. The database
3522** is named by the "filename" argument for the purposes of cache-sharing,
3523** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3524** </dd>)^
3525**
3526** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3527** <dd>The new database connection will use the "multi-thread"
3528** [threading mode].)^ This means that separate threads are allowed
3529** to use SQLite at the same time, as long as each thread is using
3530** a different [database connection].
3531**
3532** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3533** <dd>The new database connection will use the "serialized"
3534** [threading mode].)^ This means the multiple threads can safely
3535** attempt to use the same database connection at the same time.
3536** (Mutexes will block any actual concurrency, but in this mode
3537** there is no harm in trying.)
3538**
3539** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3540** <dd>The database is opened [shared cache] enabled, overriding
3541** the default shared cache setting provided by
3542** [sqlite3_enable_shared_cache()].)^
3543** The [use of shared cache mode is discouraged] and hence shared cache
3544** capabilities may be omitted from many builds of SQLite. In such cases,
3545** this option is a no-op.
3546**
3547** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3548** <dd>The database is opened [shared cache] disabled, overriding
3549** the default shared cache setting provided by
3550** [sqlite3_enable_shared_cache()].)^
3551**
3552** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3553** <dd>The database connection comes up in "extended result code mode".
3554** In other words, the database behaves has if
3555** [sqlite3_extended_result_codes(db,1)] where called on the database
3556** connection as soon as the connection is created. In addition to setting
3557** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3558** to return an extended result code.</dd>
3559**
3560** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3561** <dd>The database filename is not allowed to contain a symbolic link</dd>
3562** </dl>)^
3563**
3564** If the 3rd parameter to sqlite3_open_v2() is not one of the
3565** required combinations shown above optionally combined with other
3566** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3567** then the behavior is undefined. Historic versions of SQLite
3568** have silently ignored surplus bits in the flags parameter to
3569** sqlite3_open_v2(), however that behavior might not be carried through
3570** into future versions of SQLite and so applications should not rely
3571** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3572** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3573** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3574** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3575** by sqlite3_open_v2().
3576**
3577** ^The fourth parameter to sqlite3_open_v2() is the name of the
3578** [sqlite3_vfs] object that defines the operating system interface that
3579** the new database connection should use. ^If the fourth parameter is
3580** a NULL pointer then the default [sqlite3_vfs] object is used.
3581**
3582** ^If the filename is ":memory:", then a private, temporary in-memory database
3583** is created for the connection. ^This in-memory database will vanish when
3584** the database connection is closed. Future versions of SQLite might
3585** make use of additional special filenames that begin with the ":" character.
3586** It is recommended that when a database filename actually does begin with
3587** a ":" character you should prefix the filename with a pathname such as
3588** "./" to avoid ambiguity.
3589**
3590** ^If the filename is an empty string, then a private, temporary
3591** on-disk database will be created. ^This private database will be
3592** automatically deleted as soon as the database connection is closed.
3593**
3594** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3595**
3596** ^If [URI filename] interpretation is enabled, and the filename argument
3597** begins with "file:", then the filename is interpreted as a URI. ^URI
3598** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3599** set in the third argument to sqlite3_open_v2(), or if it has
3600** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3601** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3602** URI filename interpretation is turned off
3603** by default, but future releases of SQLite might enable URI filename
3604** interpretation by default. See "[URI filenames]" for additional
3605** information.
3606**
3607** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3608** authority, then it must be either an empty string or the string
3609** "localhost". ^If the authority is not an empty string or "localhost", an
3610** error is returned to the caller. ^The fragment component of a URI, if
3611** present, is ignored.
3612**
3613** ^SQLite uses the path component of the URI as the name of the disk file
3614** which contains the database. ^If the path begins with a '/' character,
3615** then it is interpreted as an absolute path. ^If the path does not begin
3616** with a '/' (meaning that the authority section is omitted from the URI)
3617** then the path is interpreted as a relative path.
3618** ^(On windows, the first component of an absolute path
3619** is a drive specification (e.g. "C:").)^
3620**
3621** [[core URI query parameters]]
3622** The query component of a URI may contain parameters that are interpreted
3623** either by SQLite itself, or by a [VFS | custom VFS implementation].
3624** SQLite and its built-in [VFSes] interpret the
3625** following query parameters:
3626**
3627** <ul>
3628** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3629** a VFS object that provides the operating system interface that should
3630** be used to access the database file on disk. ^If this option is set to
3631** an empty string the default VFS object is used. ^Specifying an unknown
3632** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3633** present, then the VFS specified by the option takes precedence over
3634** the value passed as the fourth parameter to sqlite3_open_v2().
3635**
3636** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3637** "rwc", or "memory". Attempting to set it to any other value is
3638** an error)^.
3639** ^If "ro" is specified, then the database is opened for read-only
3640** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3641** third argument to sqlite3_open_v2(). ^If the mode option is set to
3642** "rw", then the database is opened for read-write (but not create)
3643** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3644** been set. ^Value "rwc" is equivalent to setting both
3645** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3646** set to "memory" then a pure [in-memory database] that never reads
3647** or writes from disk is used. ^It is an error to specify a value for
3648** the mode parameter that is less restrictive than that specified by
3649** the flags passed in the third parameter to sqlite3_open_v2().
3650**
3651** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3652** "private". ^Setting it to "shared" is equivalent to setting the
3653** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3654** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3655** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3656** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3657** a URI filename, its value overrides any behavior requested by setting
3658** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3659**
3660** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3661** [powersafe overwrite] property does or does not apply to the
3662** storage media on which the database file resides.
3663**
3664** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3665** which if set disables file locking in rollback journal modes. This
3666** is useful for accessing a database on a filesystem that does not
3667** support locking. Caution: Database corruption might result if two
3668** or more processes write to the same database and any one of those
3669** processes uses nolock=1.
3670**
3671** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3672** parameter that indicates that the database file is stored on
3673** read-only media. ^When immutable is set, SQLite assumes that the
3674** database file cannot be changed, even by a process with higher
3675** privilege, and so the database is opened read-only and all locking
3676** and change detection is disabled. Caution: Setting the immutable
3677** property on a database file that does in fact change can result
3678** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3679** See also: [SQLITE_IOCAP_IMMUTABLE].
3680**
3681** </ul>
3682**
3683** ^Specifying an unknown parameter in the query component of a URI is not an
3684** error. Future versions of SQLite might understand additional query
3685** parameters. See "[query parameters with special meaning to SQLite]" for
3686** additional information.
3687**
3688** [[URI filename examples]] <h3>URI filename examples</h3>
3689**
3690** <table border="1" align=center cellpadding=5>
3691** <tr><th> URI filenames <th> Results
3692** <tr><td> file:data.db <td>
3693** Open the file "data.db" in the current directory.
3694** <tr><td> file:/home/fred/data.db<br>
3695** file:///home/fred/data.db <br>
3696** file://localhost/home/fred/data.db <br> <td>
3697** Open the database file "/home/fred/data.db".
3698** <tr><td> file://darkstar/home/fred/data.db <td>
3699** An error. "darkstar" is not a recognized authority.
3700** <tr><td style="white-space:nowrap">
3701** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3702** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3703** C:. Note that the %20 escaping in this example is not strictly
3704** necessary - space characters can be used literally
3705** in URI filenames.
3706** <tr><td> file:data.db?mode=ro&cache=private <td>
3707** Open file "data.db" in the current directory for read-only access.
3708** Regardless of whether or not shared-cache mode is enabled by
3709** default, use a private cache.
3710** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3711** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3712** that uses dot-files in place of posix advisory locking.
3713** <tr><td> file:data.db?mode=readonly <td>
3714** An error. "readonly" is not a valid option for the "mode" parameter.
3715** Use "ro" instead: "file:data.db?mode=ro".
3716** </table>
3717**
3718** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3719** query components of a URI. A hexadecimal escape sequence consists of a
3720** percent sign - "%" - followed by exactly two hexadecimal digits
3721** specifying an octet value. ^Before the path or query components of a
3722** URI filename are interpreted, they are encoded using UTF-8 and all
3723** hexadecimal escape sequences replaced by a single byte containing the
3724** corresponding octet. If this process generates an invalid UTF-8 encoding,
3725** the results are undefined.
3726**
3727** <b>Note to Windows users:</b> The encoding used for the filename argument
3728** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3729** codepage is currently defined. Filenames containing international
3730** characters must be converted to UTF-8 prior to passing them into
3731** sqlite3_open() or sqlite3_open_v2().
3732**
3733** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3734** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3735** features that require the use of temporary files may fail.
3736**
3737** See also: [sqlite3_temp_directory]
3738*/
3739SQLITE_API int sqlite3_open(
3740 const char *filename, /* Database filename (UTF-8) */
3741 sqlite3 **ppDb /* OUT: SQLite db handle */
3742);
3743SQLITE_API int sqlite3_open16(
3744 const void *filename, /* Database filename (UTF-16) */
3745 sqlite3 **ppDb /* OUT: SQLite db handle */
3746);
3747SQLITE_API int sqlite3_open_v2(
3748 const char *filename, /* Database filename (UTF-8) */
3749 sqlite3 **ppDb, /* OUT: SQLite db handle */
3750 int flags, /* Flags */
3751 const char *zVfs /* Name of VFS module to use */
3752);
3753
3754/*
3755** CAPI3REF: Obtain Values For URI Parameters
3756**
3757** These are utility routines, useful to [VFS|custom VFS implementations],
3758** that check if a database file was a URI that contained a specific query
3759** parameter, and if so obtains the value of that query parameter.
3760**
3761** The first parameter to these interfaces (hereafter referred to
3762** as F) must be one of:
3763** <ul>
3764** <li> A database filename pointer created by the SQLite core and
3765** passed into the xOpen() method of a VFS implementation, or
3766** <li> A filename obtained from [sqlite3_db_filename()], or
3767** <li> A new filename constructed using [sqlite3_create_filename()].
3768** </ul>
3769** If the F parameter is not one of the above, then the behavior is
3770** undefined and probably undesirable. Older versions of SQLite were
3771** more tolerant of invalid F parameters than newer versions.
3772**
3773** If F is a suitable filename (as described in the previous paragraph)
3774** and if P is the name of the query parameter, then
3775** sqlite3_uri_parameter(F,P) returns the value of the P
3776** parameter if it exists or a NULL pointer if P does not appear as a
3777** query parameter on F. If P is a query parameter of F and it
3778** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3779** a pointer to an empty string.
3780**
3781** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3782** parameter and returns true (1) or false (0) according to the value
3783** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3784** value of query parameter P is one of "yes", "true", or "on" in any
3785** case or if the value begins with a non-zero number. The
3786** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3787** query parameter P is one of "no", "false", or "off" in any case or
3788** if the value begins with a numeric zero. If P is not a query
3789** parameter on F or if the value of P does not match any of the
3790** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3791**
3792** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3793** 64-bit signed integer and returns that integer, or D if P does not
3794** exist. If the value of P is something other than an integer, then
3795** zero is returned.
3796**
3797** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3798** the value) of the N-th query parameter for filename F, or a NULL
3799** pointer if N is less than zero or greater than the number of query
3800** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3801** the name of the first query parameter, 1 for the second parameter, and
3802** so forth.
3803**
3804** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3805** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3806** is not a database file pathname pointer that the SQLite core passed
3807** into the xOpen VFS method, then the behavior of this routine is undefined
3808** and probably undesirable.
3809**
3810** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3811** parameter can also be the name of a rollback journal file or WAL file
3812** in addition to the main database file. Prior to version 3.31.0, these
3813** routines would only work if F was the name of the main database file.
3814** When the F parameter is the name of the rollback journal or WAL file,
3815** it has access to all the same query parameters as were found on the
3816** main database file.
3817**
3818** See the [URI filename] documentation for additional information.
3819*/
3820SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
3821SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
3822SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
3823SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
3824
3825/*
3826** CAPI3REF: Translate filenames
3827**
3828** These routines are available to [VFS|custom VFS implementations] for
3829** translating filenames between the main database file, the journal file,
3830** and the WAL file.
3831**
3832** If F is the name of an sqlite database file, journal file, or WAL file
3833** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3834** returns the name of the corresponding database file.
3835**
3836** If F is the name of an sqlite database file, journal file, or WAL file
3837** passed by the SQLite core into the VFS, or if F is a database filename
3838** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3839** returns the name of the corresponding rollback journal file.
3840**
3841** If F is the name of an sqlite database file, journal file, or WAL file
3842** that was passed by the SQLite core into the VFS, or if F is a database
3843** filename obtained from [sqlite3_db_filename()], then
3844** sqlite3_filename_wal(F) returns the name of the corresponding
3845** WAL file.
3846**
3847** In all of the above, if F is not the name of a database, journal or WAL
3848** filename passed into the VFS from the SQLite core and F is not the
3849** return value from [sqlite3_db_filename()], then the result is
3850** undefined and is likely a memory access violation.
3851*/
3852SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
3853SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
3854SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
3855
3856/*
3857** CAPI3REF: Database File Corresponding To A Journal
3858**
3859** ^If X is the name of a rollback or WAL-mode journal file that is
3860** passed into the xOpen method of [sqlite3_vfs], then
3861** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3862** object that represents the main database file.
3863**
3864** This routine is intended for use in custom [VFS] implementations
3865** only. It is not a general-purpose interface.
3866** The argument sqlite3_file_object(X) must be a filename pointer that
3867** has been passed into [sqlite3_vfs].xOpen method where the
3868** flags parameter to xOpen contains one of the bits
3869** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3870** of this routine results in undefined and probably undesirable
3871** behavior.
3872*/
3873SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3874
3875/*
3876** CAPI3REF: Create and Destroy VFS Filenames
3877**
3878** These interfaces are provided for use by [VFS shim] implementations and
3879** are not useful outside of that context.
3880**
3881** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3882** database filename D with corresponding journal file J and WAL file W and
3883** with N URI parameters key/values pairs in the array P. The result from
3884** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3885** is safe to pass to routines like:
3886** <ul>
3887** <li> [sqlite3_uri_parameter()],
3888** <li> [sqlite3_uri_boolean()],
3889** <li> [sqlite3_uri_int64()],
3890** <li> [sqlite3_uri_key()],
3891** <li> [sqlite3_filename_database()],
3892** <li> [sqlite3_filename_journal()], or
3893** <li> [sqlite3_filename_wal()].
3894** </ul>
3895** If a memory allocation error occurs, sqlite3_create_filename() might
3896** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3897** must be released by a corresponding call to sqlite3_free_filename(Y).
3898**
3899** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3900** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3901** to a key and value for a query parameter. The P parameter may be a NULL
3902** pointer if N is zero. None of the 2*N pointers in the P array may be
3903** NULL pointers and key pointers should not be empty strings.
3904** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3905** be NULL pointers, though they can be empty strings.
3906**
3907** The sqlite3_free_filename(Y) routine releases a memory allocation
3908** previously obtained from sqlite3_create_filename(). Invoking
3909** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3910**
3911** If the Y parameter to sqlite3_free_filename(Y) is anything other
3912** than a NULL pointer or a pointer previously acquired from
3913** sqlite3_create_filename(), then bad things such as heap
3914** corruption or segfaults may occur. The value Y should not be
3915** used again after sqlite3_free_filename(Y) has been called. This means
3916** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3917** then the corresponding [sqlite3_module.xClose() method should also be
3918** invoked prior to calling sqlite3_free_filename(Y).
3919*/
3920SQLITE_API sqlite3_filename sqlite3_create_filename(
3921 const char *zDatabase,
3922 const char *zJournal,
3923 const char *zWal,
3924 int nParam,
3925 const char **azParam
3926);
3927SQLITE_API void sqlite3_free_filename(sqlite3_filename);
3928
3929/*
3930** CAPI3REF: Error Codes And Messages
3931** METHOD: sqlite3
3932**
3933** ^If the most recent sqlite3_* API call associated with
3934** [database connection] D failed, then the sqlite3_errcode(D) interface
3935** returns the numeric [result code] or [extended result code] for that
3936** API call.
3937** ^The sqlite3_extended_errcode()
3938** interface is the same except that it always returns the
3939** [extended result code] even when extended result codes are
3940** disabled.
3941**
3942** The values returned by sqlite3_errcode() and/or
3943** sqlite3_extended_errcode() might change with each API call.
3944** Except, there are some interfaces that are guaranteed to never
3945** change the value of the error code. The error-code preserving
3946** interfaces include the following:
3947**
3948** <ul>
3949** <li> sqlite3_errcode()
3950** <li> sqlite3_extended_errcode()
3951** <li> sqlite3_errmsg()
3952** <li> sqlite3_errmsg16()
3953** <li> sqlite3_error_offset()
3954** </ul>
3955**
3956** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3957** text that describes the error, as either UTF-8 or UTF-16 respectively.
3958** ^(Memory to hold the error message string is managed internally.
3959** The application does not need to worry about freeing the result.
3960** However, the error string might be overwritten or deallocated by
3961** subsequent calls to other SQLite interface functions.)^
3962**
3963** ^The sqlite3_errstr() interface returns the English-language text
3964** that describes the [result code], as UTF-8.
3965** ^(Memory to hold the error message string is managed internally
3966** and must not be freed by the application)^.
3967**
3968** ^If the most recent error references a specific token in the input
3969** SQL, the sqlite3_error_offset() interface returns the byte offset
3970** of the start of that token. ^The byte offset returned by
3971** sqlite3_error_offset() assumes that the input SQL is UTF8.
3972** ^If the most recent error does not reference a specific token in the input
3973** SQL, then the sqlite3_error_offset() function returns -1.
3974**
3975** When the serialized [threading mode] is in use, it might be the
3976** case that a second error occurs on a separate thread in between
3977** the time of the first error and the call to these interfaces.
3978** When that happens, the second error will be reported since these
3979** interfaces always report the most recent result. To avoid
3980** this, each thread can obtain exclusive use of the [database connection] D
3981** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3982** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3983** all calls to the interfaces listed here are completed.
3984**
3985** If an interface fails with SQLITE_MISUSE, that means the interface
3986** was invoked incorrectly by the application. In that case, the
3987** error code and message may or may not be set.
3988*/
3989SQLITE_API int sqlite3_errcode(sqlite3 *db);
3990SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3991SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3992SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3993SQLITE_API const char *sqlite3_errstr(int);
3994SQLITE_API int sqlite3_error_offset(sqlite3 *db);
3995
3996/*
3997** CAPI3REF: Prepared Statement Object
3998** KEYWORDS: {prepared statement} {prepared statements}
3999**
4000** An instance of this object represents a single SQL statement that
4001** has been compiled into binary form and is ready to be evaluated.
4002**
4003** Think of each SQL statement as a separate computer program. The
4004** original SQL text is source code. A prepared statement object
4005** is the compiled object code. All SQL must be converted into a
4006** prepared statement before it can be run.
4007**
4008** The life-cycle of a prepared statement object usually goes like this:
4009**
4010** <ol>
4011** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4012** <li> Bind values to [parameters] using the sqlite3_bind_*()
4013** interfaces.
4014** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4015** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4016** to step 2. Do this zero or more times.
4017** <li> Destroy the object using [sqlite3_finalize()].
4018** </ol>
4019*/
4020typedef struct sqlite3_stmt sqlite3_stmt;
4021
4022/*
4023** CAPI3REF: Run-time Limits
4024** METHOD: sqlite3
4025**
4026** ^(This interface allows the size of various constructs to be limited
4027** on a connection by connection basis. The first parameter is the
4028** [database connection] whose limit is to be set or queried. The
4029** second parameter is one of the [limit categories] that define a
4030** class of constructs to be size limited. The third parameter is the
4031** new limit for that construct.)^
4032**
4033** ^If the new limit is a negative number, the limit is unchanged.
4034** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4035** [limits | hard upper bound]
4036** set at compile-time by a C preprocessor macro called
4037** [limits | SQLITE_MAX_<i>NAME</i>].
4038** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4039** ^Attempts to increase a limit above its hard upper bound are
4040** silently truncated to the hard upper bound.
4041**
4042** ^Regardless of whether or not the limit was changed, the
4043** [sqlite3_limit()] interface returns the prior value of the limit.
4044** ^Hence, to find the current value of a limit without changing it,
4045** simply invoke this interface with the third parameter set to -1.
4046**
4047** Run-time limits are intended for use in applications that manage
4048** both their own internal database and also databases that are controlled
4049** by untrusted external sources. An example application might be a
4050** web browser that has its own databases for storing history and
4051** separate databases controlled by JavaScript applications downloaded
4052** off the Internet. The internal databases can be given the
4053** large, default limits. Databases managed by external sources can
4054** be given much smaller limits designed to prevent a denial of service
4055** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4056** interface to further control untrusted SQL. The size of the database
4057** created by an untrusted script can be contained using the
4058** [max_page_count] [PRAGMA].
4059**
4060** New run-time limit categories may be added in future releases.
4061*/
4062SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4063
4064/*
4065** CAPI3REF: Run-Time Limit Categories
4066** KEYWORDS: {limit category} {*limit categories}
4067**
4068** These constants define various performance limits
4069** that can be lowered at run-time using [sqlite3_limit()].
4070** The synopsis of the meanings of the various limits is shown below.
4071** Additional information is available at [limits | Limits in SQLite].
4072**
4073** <dl>
4074** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4075** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4076**
4077** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4078** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4079**
4080** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4081** <dd>The maximum number of columns in a table definition or in the
4082** result set of a [SELECT] or the maximum number of columns in an index
4083** or in an ORDER BY or GROUP BY clause.</dd>)^
4084**
4085** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4086** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4087**
4088** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4089** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4090**
4091** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4092** <dd>The maximum number of instructions in a virtual machine program
4093** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4094** the equivalent tries to allocate space for more than this many opcodes
4095** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4096**
4097** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4098** <dd>The maximum number of arguments on a function.</dd>)^
4099**
4100** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4101** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4102**
4103** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4104** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4105** <dd>The maximum length of the pattern argument to the [LIKE] or
4106** [GLOB] operators.</dd>)^
4107**
4108** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4109** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4110** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4111**
4112** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4113** <dd>The maximum depth of recursion for triggers.</dd>)^
4114**
4115** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4116** <dd>The maximum number of auxiliary worker threads that a single
4117** [prepared statement] may start.</dd>)^
4118** </dl>
4119*/
4120#define SQLITE_LIMIT_LENGTH 0
4121#define SQLITE_LIMIT_SQL_LENGTH 1
4122#define SQLITE_LIMIT_COLUMN 2
4123#define SQLITE_LIMIT_EXPR_DEPTH 3
4124#define SQLITE_LIMIT_COMPOUND_SELECT 4
4125#define SQLITE_LIMIT_VDBE_OP 5
4126#define SQLITE_LIMIT_FUNCTION_ARG 6
4127#define SQLITE_LIMIT_ATTACHED 7
4128#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4129#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4130#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4131#define SQLITE_LIMIT_WORKER_THREADS 11
4132
4133/*
4134** CAPI3REF: Prepare Flags
4135**
4136** These constants define various flags that can be passed into
4137** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4138** [sqlite3_prepare16_v3()] interfaces.
4139**
4140** New flags may be added in future releases of SQLite.
4141**
4142** <dl>
4143** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4144** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4145** that the prepared statement will be retained for a long time and
4146** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4147** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4148** be used just once or at most a few times and then destroyed using
4149** [sqlite3_finalize()] relatively soon. The current implementation acts
4150** on this hint by avoiding the use of [lookaside memory] so as not to
4151** deplete the limited store of lookaside memory. Future versions of
4152** SQLite may act on this hint differently.
4153**
4154** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4155** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4156** to be required for any prepared statement that wanted to use the
4157** [sqlite3_normalized_sql()] interface. However, the
4158** [sqlite3_normalized_sql()] interface is now available to all
4159** prepared statements, regardless of whether or not they use this
4160** flag.
4161**
4162** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4163** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4164** to return an error (error code SQLITE_ERROR) if the statement uses
4165** any virtual tables.
4166** </dl>
4167*/
4168#define SQLITE_PREPARE_PERSISTENT 0x01
4169#define SQLITE_PREPARE_NORMALIZE 0x02
4170#define SQLITE_PREPARE_NO_VTAB 0x04
4171
4172/*
4173** CAPI3REF: Compiling An SQL Statement
4174** KEYWORDS: {SQL statement compiler}
4175** METHOD: sqlite3
4176** CONSTRUCTOR: sqlite3_stmt
4177**
4178** To execute an SQL statement, it must first be compiled into a byte-code
4179** program using one of these routines. Or, in other words, these routines
4180** are constructors for the [prepared statement] object.
4181**
4182** The preferred routine to use is [sqlite3_prepare_v2()]. The
4183** [sqlite3_prepare()] interface is legacy and should be avoided.
4184** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4185** for special purposes.
4186**
4187** The use of the UTF-8 interfaces is preferred, as SQLite currently
4188** does all parsing using UTF-8. The UTF-16 interfaces are provided
4189** as a convenience. The UTF-16 interfaces work by converting the
4190** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4191**
4192** The first argument, "db", is a [database connection] obtained from a
4193** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4194** [sqlite3_open16()]. The database connection must not have been closed.
4195**
4196** The second argument, "zSql", is the statement to be compiled, encoded
4197** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4198** and sqlite3_prepare_v3()
4199** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4200** and sqlite3_prepare16_v3() use UTF-16.
4201**
4202** ^If the nByte argument is negative, then zSql is read up to the
4203** first zero terminator. ^If nByte is positive, then it is the
4204** number of bytes read from zSql. ^If nByte is zero, then no prepared
4205** statement is generated.
4206** If the caller knows that the supplied string is nul-terminated, then
4207** there is a small performance advantage to passing an nByte parameter that
4208** is the number of bytes in the input string <i>including</i>
4209** the nul-terminator.
4210**
4211** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4212** past the end of the first SQL statement in zSql. These routines only
4213** compile the first statement in zSql, so *pzTail is left pointing to
4214** what remains uncompiled.
4215**
4216** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4217** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4218** to NULL. ^If the input text contains no SQL (if the input is an empty
4219** string or a comment) then *ppStmt is set to NULL.
4220** The calling procedure is responsible for deleting the compiled
4221** SQL statement using [sqlite3_finalize()] after it has finished with it.
4222** ppStmt may not be NULL.
4223**
4224** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4225** otherwise an [error code] is returned.
4226**
4227** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4228** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4229** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4230** are retained for backwards compatibility, but their use is discouraged.
4231** ^In the "vX" interfaces, the prepared statement
4232** that is returned (the [sqlite3_stmt] object) contains a copy of the
4233** original SQL text. This causes the [sqlite3_step()] interface to
4234** behave differently in three ways:
4235**
4236** <ol>
4237** <li>
4238** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4239** always used to do, [sqlite3_step()] will automatically recompile the SQL
4240** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4241** retries will occur before sqlite3_step() gives up and returns an error.
4242** </li>
4243**
4244** <li>
4245** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4246** [error codes] or [extended error codes]. ^The legacy behavior was that
4247** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4248** and the application would have to make a second call to [sqlite3_reset()]
4249** in order to find the underlying cause of the problem. With the "v2" prepare
4250** interfaces, the underlying reason for the error is returned immediately.
4251** </li>
4252**
4253** <li>
4254** ^If the specific value bound to a [parameter | host parameter] in the
4255** WHERE clause might influence the choice of query plan for a statement,
4256** then the statement will be automatically recompiled, as if there had been
4257** a schema change, on the first [sqlite3_step()] call following any change
4258** to the [sqlite3_bind_text | bindings] of that [parameter].
4259** ^The specific value of a WHERE-clause [parameter] might influence the
4260** choice of query plan if the parameter is the left-hand side of a [LIKE]
4261** or [GLOB] operator or if the parameter is compared to an indexed column
4262** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4263** </li>
4264** </ol>
4265**
4266** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4267** the extra prepFlags parameter, which is a bit array consisting of zero or
4268** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4269** sqlite3_prepare_v2() interface works exactly the same as
4270** sqlite3_prepare_v3() with a zero prepFlags parameter.
4271*/
4272SQLITE_API int sqlite3_prepare(
4273 sqlite3 *db, /* Database handle */
4274 const char *zSql, /* SQL statement, UTF-8 encoded */
4275 int nByte, /* Maximum length of zSql in bytes. */
4276 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4277 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4278);
4279SQLITE_API int sqlite3_prepare_v2(
4280 sqlite3 *db, /* Database handle */
4281 const char *zSql, /* SQL statement, UTF-8 encoded */
4282 int nByte, /* Maximum length of zSql in bytes. */
4283 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4284 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4285);
4286SQLITE_API int sqlite3_prepare_v3(
4287 sqlite3 *db, /* Database handle */
4288 const char *zSql, /* SQL statement, UTF-8 encoded */
4289 int nByte, /* Maximum length of zSql in bytes. */
4290 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4291 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4292 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4293);
4294SQLITE_API int sqlite3_prepare16(
4295 sqlite3 *db, /* Database handle */
4296 const void *zSql, /* SQL statement, UTF-16 encoded */
4297 int nByte, /* Maximum length of zSql in bytes. */
4298 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4299 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4300);
4301SQLITE_API int sqlite3_prepare16_v2(
4302 sqlite3 *db, /* Database handle */
4303 const void *zSql, /* SQL statement, UTF-16 encoded */
4304 int nByte, /* Maximum length of zSql in bytes. */
4305 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4306 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4307);
4308SQLITE_API int sqlite3_prepare16_v3(
4309 sqlite3 *db, /* Database handle */
4310 const void *zSql, /* SQL statement, UTF-16 encoded */
4311 int nByte, /* Maximum length of zSql in bytes. */
4312 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4313 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4314 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4315);
4316
4317/*
4318** CAPI3REF: Retrieving Statement SQL
4319** METHOD: sqlite3_stmt
4320**
4321** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4322** SQL text used to create [prepared statement] P if P was
4323** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4324** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4325** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4326** string containing the SQL text of prepared statement P with
4327** [bound parameters] expanded.
4328** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4329** string containing the normalized SQL text of prepared statement P. The
4330** semantics used to normalize a SQL statement are unspecified and subject
4331** to change. At a minimum, literal values will be replaced with suitable
4332** placeholders.
4333**
4334** ^(For example, if a prepared statement is created using the SQL
4335** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4336** and parameter :xyz is unbound, then sqlite3_sql() will return
4337** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4338** will return "SELECT 2345,NULL".)^
4339**
4340** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4341** is available to hold the result, or if the result would exceed the
4342** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4343**
4344** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4345** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4346** option causes sqlite3_expanded_sql() to always return NULL.
4347**
4348** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4349** are managed by SQLite and are automatically freed when the prepared
4350** statement is finalized.
4351** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4352** is obtained from [sqlite3_malloc()] and must be freed by the application
4353** by passing it to [sqlite3_free()].
4354**
4355** ^The sqlite3_normalized_sql() interface is only available if
4356** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4357*/
4358SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4359SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4360#ifdef SQLITE_ENABLE_NORMALIZE
4361SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4362#endif
4363
4364/*
4365** CAPI3REF: Determine If An SQL Statement Writes The Database
4366** METHOD: sqlite3_stmt
4367**
4368** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4369** and only if the [prepared statement] X makes no direct changes to
4370** the content of the database file.
4371**
4372** Note that [application-defined SQL functions] or
4373** [virtual tables] might change the database indirectly as a side effect.
4374** ^(For example, if an application defines a function "eval()" that
4375** calls [sqlite3_exec()], then the following SQL statement would
4376** change the database file through side-effects:
4377**
4378** <blockquote><pre>
4379** SELECT eval('DELETE FROM t1') FROM t2;
4380** </pre></blockquote>
4381**
4382** But because the [SELECT] statement does not change the database file
4383** directly, sqlite3_stmt_readonly() would still return true.)^
4384**
4385** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4386** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4387** since the statements themselves do not actually modify the database but
4388** rather they control the timing of when other statements modify the
4389** database. ^The [ATTACH] and [DETACH] statements also cause
4390** sqlite3_stmt_readonly() to return true since, while those statements
4391** change the configuration of a database connection, they do not make
4392** changes to the content of the database files on disk.
4393** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4394** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4395** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4396** sqlite3_stmt_readonly() returns false for those commands.
4397**
4398** ^This routine returns false if there is any possibility that the
4399** statement might change the database file. ^A false return does
4400** not guarantee that the statement will change the database file.
4401** ^For example, an UPDATE statement might have a WHERE clause that
4402** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4403** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4404** read-only no-op if the table already exists, but
4405** sqlite3_stmt_readonly() still returns false for such a statement.
4406**
4407** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4408** statement, then sqlite3_stmt_readonly(X) returns the same value as
4409** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4410*/
4411SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4412
4413/*
4414** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4415** METHOD: sqlite3_stmt
4416**
4417** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4418** prepared statement S is an EXPLAIN statement, or 2 if the
4419** statement S is an EXPLAIN QUERY PLAN.
4420** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4421** an ordinary statement or a NULL pointer.
4422*/
4423SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4424
4425/*
4426** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4427** METHOD: sqlite3_stmt
4428**
4429** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4430** setting for [prepared statement] S. If E is zero, then S becomes
4431** a normal prepared statement. If E is 1, then S behaves as if
4432** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4433** its SQL text began with "[EXPLAIN QUERY PLAN]".
4434**
4435** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4436** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4437** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4438**
4439** Because of the potential need to reprepare, a call to
4440** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4441** reprepared because it was created using [sqlite3_prepare()] instead of
4442** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4443** hence has no saved SQL text with which to reprepare.
4444**
4445** Changing the explain setting for a prepared statement does not change
4446** the original SQL text for the statement. Hence, if the SQL text originally
4447** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4448** is called to convert the statement into an ordinary statement, the EXPLAIN
4449** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4450** output, even though the statement now acts like a normal SQL statement.
4451**
4452** This routine returns SQLITE_OK if the explain mode is successfully
4453** changed, or an error code if the explain mode could not be changed.
4454** The explain mode cannot be changed while a statement is active.
4455** Hence, it is good practice to call [sqlite3_reset(S)]
4456** immediately prior to calling sqlite3_stmt_explain(S,E).
4457*/
4458SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4459
4460/*
4461** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4462** METHOD: sqlite3_stmt
4463**
4464** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4465** [prepared statement] S has been stepped at least once using
4466** [sqlite3_step(S)] but has neither run to completion (returned
4467** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4468** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4469** interface returns false if S is a NULL pointer. If S is not a
4470** NULL pointer and is not a pointer to a valid [prepared statement]
4471** object, then the behavior is undefined and probably undesirable.
4472**
4473** This interface can be used in combination [sqlite3_next_stmt()]
4474** to locate all prepared statements associated with a database
4475** connection that are in need of being reset. This can be used,
4476** for example, in diagnostic routines to search for prepared
4477** statements that are holding a transaction open.
4478*/
4479SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4480
4481/*
4482** CAPI3REF: Dynamically Typed Value Object
4483** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4484**
4485** SQLite uses the sqlite3_value object to represent all values
4486** that can be stored in a database table. SQLite uses dynamic typing
4487** for the values it stores. ^Values stored in sqlite3_value objects
4488** can be integers, floating point values, strings, BLOBs, or NULL.
4489**
4490** An sqlite3_value object may be either "protected" or "unprotected".
4491** Some interfaces require a protected sqlite3_value. Other interfaces
4492** will accept either a protected or an unprotected sqlite3_value.
4493** Every interface that accepts sqlite3_value arguments specifies
4494** whether or not it requires a protected sqlite3_value. The
4495** [sqlite3_value_dup()] interface can be used to construct a new
4496** protected sqlite3_value from an unprotected sqlite3_value.
4497**
4498** The terms "protected" and "unprotected" refer to whether or not
4499** a mutex is held. An internal mutex is held for a protected
4500** sqlite3_value object but no mutex is held for an unprotected
4501** sqlite3_value object. If SQLite is compiled to be single-threaded
4502** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4503** or if SQLite is run in one of reduced mutex modes
4504** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4505** then there is no distinction between protected and unprotected
4506** sqlite3_value objects and they can be used interchangeably. However,
4507** for maximum code portability it is recommended that applications
4508** still make the distinction between protected and unprotected
4509** sqlite3_value objects even when not strictly required.
4510**
4511** ^The sqlite3_value objects that are passed as parameters into the
4512** implementation of [application-defined SQL functions] are protected.
4513** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4514** are protected.
4515** ^The sqlite3_value object returned by
4516** [sqlite3_column_value()] is unprotected.
4517** Unprotected sqlite3_value objects may only be used as arguments
4518** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4519** [sqlite3_value_dup()].
4520** The [sqlite3_value_blob | sqlite3_value_type()] family of
4521** interfaces require protected sqlite3_value objects.
4522*/
4523typedef struct sqlite3_value sqlite3_value;
4524
4525/*
4526** CAPI3REF: SQL Function Context Object
4527**
4528** The context in which an SQL function executes is stored in an
4529** sqlite3_context object. ^A pointer to an sqlite3_context object
4530** is always first parameter to [application-defined SQL functions].
4531** The application-defined SQL function implementation will pass this
4532** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4533** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4534** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4535** and/or [sqlite3_set_auxdata()].
4536*/
4537typedef struct sqlite3_context sqlite3_context;
4538
4539/*
4540** CAPI3REF: Binding Values To Prepared Statements
4541** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4542** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4543** METHOD: sqlite3_stmt
4544**
4545** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4546** literals may be replaced by a [parameter] that matches one of following
4547** templates:
4548**
4549** <ul>
4550** <li> ?
4551** <li> ?NNN
4552** <li> :VVV
4553** <li> @VVV
4554** <li> $VVV
4555** </ul>
4556**
4557** In the templates above, NNN represents an integer literal,
4558** and VVV represents an alphanumeric identifier.)^ ^The values of these
4559** parameters (also called "host parameter names" or "SQL parameters")
4560** can be set using the sqlite3_bind_*() routines defined here.
4561**
4562** ^The first argument to the sqlite3_bind_*() routines is always
4563** a pointer to the [sqlite3_stmt] object returned from
4564** [sqlite3_prepare_v2()] or its variants.
4565**
4566** ^The second argument is the index of the SQL parameter to be set.
4567** ^The leftmost SQL parameter has an index of 1. ^When the same named
4568** SQL parameter is used more than once, second and subsequent
4569** occurrences have the same index as the first occurrence.
4570** ^The index for named parameters can be looked up using the
4571** [sqlite3_bind_parameter_index()] API if desired. ^The index
4572** for "?NNN" parameters is the value of NNN.
4573** ^The NNN value must be between 1 and the [sqlite3_limit()]
4574** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4575**
4576** ^The third argument is the value to bind to the parameter.
4577** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4578** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4579** is ignored and the end result is the same as sqlite3_bind_null().
4580** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4581** it should be a pointer to well-formed UTF8 text.
4582** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4583** it should be a pointer to well-formed UTF16 text.
4584** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4585** it should be a pointer to a well-formed unicode string that is
4586** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4587** otherwise.
4588**
4589** [[byte-order determination rules]] ^The byte-order of
4590** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4591** found in first character, which is removed, or in the absence of a BOM
4592** the byte order is the native byte order of the host
4593** machine for sqlite3_bind_text16() or the byte order specified in
4594** the 6th parameter for sqlite3_bind_text64().)^
4595** ^If UTF16 input text contains invalid unicode
4596** characters, then SQLite might change those invalid characters
4597** into the unicode replacement character: U+FFFD.
4598**
4599** ^(In those routines that have a fourth argument, its value is the
4600** number of bytes in the parameter. To be clear: the value is the
4601** number of <u>bytes</u> in the value, not the number of characters.)^
4602** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4603** is negative, then the length of the string is
4604** the number of bytes up to the first zero terminator.
4605** If the fourth parameter to sqlite3_bind_blob() is negative, then
4606** the behavior is undefined.
4607** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4608** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4609** that parameter must be the byte offset
4610** where the NUL terminator would occur assuming the string were NUL
4611** terminated. If any NUL characters occurs at byte offsets less than
4612** the value of the fourth parameter then the resulting string value will
4613** contain embedded NULs. The result of expressions involving strings
4614** with embedded NULs is undefined.
4615**
4616** ^The fifth argument to the BLOB and string binding interfaces controls
4617** or indicates the lifetime of the object referenced by the third parameter.
4618** These three options exist:
4619** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4620** with it may be passed. ^It is called to dispose of the BLOB or string even
4621** if the call to the bind API fails, except the destructor is not called if
4622** the third parameter is a NULL pointer or the fourth parameter is negative.
4623** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4624** the application remains responsible for disposing of the object. ^In this
4625** case, the object and the provided pointer to it must remain valid until
4626** either the prepared statement is finalized or the same SQL parameter is
4627** bound to something else, whichever occurs sooner.
4628** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4629** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4630** object and pointer to it must remain valid until then. ^SQLite will then
4631** manage the lifetime of its private copy.
4632**
4633** ^The sixth argument to sqlite3_bind_text64() must be one of
4634** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4635** to specify the encoding of the text in the third parameter. If
4636** the sixth argument to sqlite3_bind_text64() is not one of the
4637** allowed values shown above, or if the text encoding is different
4638** from the encoding specified by the sixth parameter, then the behavior
4639** is undefined.
4640**
4641** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4642** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4643** (just an integer to hold its size) while it is being processed.
4644** Zeroblobs are intended to serve as placeholders for BLOBs whose
4645** content is later written using
4646** [sqlite3_blob_open | incremental BLOB I/O] routines.
4647** ^A negative value for the zeroblob results in a zero-length BLOB.
4648**
4649** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4650** [prepared statement] S to have an SQL value of NULL, but to also be
4651** associated with the pointer P of type T. ^D is either a NULL pointer or
4652** a pointer to a destructor function for P. ^SQLite will invoke the
4653** destructor D with a single argument of P when it is finished using
4654** P. The T parameter should be a static string, preferably a string
4655** literal. The sqlite3_bind_pointer() routine is part of the
4656** [pointer passing interface] added for SQLite 3.20.0.
4657**
4658** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4659** for the [prepared statement] or with a prepared statement for which
4660** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4661** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4662** routine is passed a [prepared statement] that has been finalized, the
4663** result is undefined and probably harmful.
4664**
4665** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4666** ^Unbound parameters are interpreted as NULL.
4667**
4668** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4669** [error code] if anything goes wrong.
4670** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4671** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4672** [SQLITE_MAX_LENGTH].
4673** ^[SQLITE_RANGE] is returned if the parameter
4674** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4675**
4676** See also: [sqlite3_bind_parameter_count()],
4677** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4678*/
4679SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4680SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4681 void(*)(void*));
4682SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4683SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4684SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4685SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4686SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4687SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4688SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4689 void(*)(void*), unsigned char encoding);
4690SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4691SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4692SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4693SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4694
4695/*
4696** CAPI3REF: Number Of SQL Parameters
4697** METHOD: sqlite3_stmt
4698**
4699** ^This routine can be used to find the number of [SQL parameters]
4700** in a [prepared statement]. SQL parameters are tokens of the
4701** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4702** placeholders for values that are [sqlite3_bind_blob | bound]
4703** to the parameters at a later time.
4704**
4705** ^(This routine actually returns the index of the largest (rightmost)
4706** parameter. For all forms except ?NNN, this will correspond to the
4707** number of unique parameters. If parameters of the ?NNN form are used,
4708** there may be gaps in the list.)^
4709**
4710** See also: [sqlite3_bind_blob|sqlite3_bind()],
4711** [sqlite3_bind_parameter_name()], and
4712** [sqlite3_bind_parameter_index()].
4713*/
4714SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4715
4716/*
4717** CAPI3REF: Name Of A Host Parameter
4718** METHOD: sqlite3_stmt
4719**
4720** ^The sqlite3_bind_parameter_name(P,N) interface returns
4721** the name of the N-th [SQL parameter] in the [prepared statement] P.
4722** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4723** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4724** respectively.
4725** In other words, the initial ":" or "$" or "@" or "?"
4726** is included as part of the name.)^
4727** ^Parameters of the form "?" without a following integer have no name
4728** and are referred to as "nameless" or "anonymous parameters".
4729**
4730** ^The first host parameter has an index of 1, not 0.
4731**
4732** ^If the value N is out of range or if the N-th parameter is
4733** nameless, then NULL is returned. ^The returned string is
4734** always in UTF-8 encoding even if the named parameter was
4735** originally specified as UTF-16 in [sqlite3_prepare16()],
4736** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4737**
4738** See also: [sqlite3_bind_blob|sqlite3_bind()],
4739** [sqlite3_bind_parameter_count()], and
4740** [sqlite3_bind_parameter_index()].
4741*/
4742SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4743
4744/*
4745** CAPI3REF: Index Of A Parameter With A Given Name
4746** METHOD: sqlite3_stmt
4747**
4748** ^Return the index of an SQL parameter given its name. ^The
4749** index value returned is suitable for use as the second
4750** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4751** is returned if no matching parameter is found. ^The parameter
4752** name must be given in UTF-8 even if the original statement
4753** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4754** [sqlite3_prepare16_v3()].
4755**
4756** See also: [sqlite3_bind_blob|sqlite3_bind()],
4757** [sqlite3_bind_parameter_count()], and
4758** [sqlite3_bind_parameter_name()].
4759*/
4760SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4761
4762/*
4763** CAPI3REF: Reset All Bindings On A Prepared Statement
4764** METHOD: sqlite3_stmt
4765**
4766** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4767** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4768** ^Use this routine to reset all host parameters to NULL.
4769*/
4770SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4771
4772/*
4773** CAPI3REF: Number Of Columns In A Result Set
4774** METHOD: sqlite3_stmt
4775**
4776** ^Return the number of columns in the result set returned by the
4777** [prepared statement]. ^If this routine returns 0, that means the
4778** [prepared statement] returns no data (for example an [UPDATE]).
4779** ^However, just because this routine returns a positive number does not
4780** mean that one or more rows of data will be returned. ^A SELECT statement
4781** will always have a positive sqlite3_column_count() but depending on the
4782** WHERE clause constraints and the table content, it might return no rows.
4783**
4784** See also: [sqlite3_data_count()]
4785*/
4786SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4787
4788/*
4789** CAPI3REF: Column Names In A Result Set
4790** METHOD: sqlite3_stmt
4791**
4792** ^These routines return the name assigned to a particular column
4793** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4794** interface returns a pointer to a zero-terminated UTF-8 string
4795** and sqlite3_column_name16() returns a pointer to a zero-terminated
4796** UTF-16 string. ^The first parameter is the [prepared statement]
4797** that implements the [SELECT] statement. ^The second parameter is the
4798** column number. ^The leftmost column is number 0.
4799**
4800** ^The returned string pointer is valid until either the [prepared statement]
4801** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4802** reprepared by the first call to [sqlite3_step()] for a particular run
4803** or until the next call to
4804** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4805**
4806** ^If sqlite3_malloc() fails during the processing of either routine
4807** (for example during a conversion from UTF-8 to UTF-16) then a
4808** NULL pointer is returned.
4809**
4810** ^The name of a result column is the value of the "AS" clause for
4811** that column, if there is an AS clause. If there is no AS clause
4812** then the name of the column is unspecified and may change from
4813** one release of SQLite to the next.
4814*/
4815SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4816SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4817
4818/*
4819** CAPI3REF: Source Of Data In A Query Result
4820** METHOD: sqlite3_stmt
4821**
4822** ^These routines provide a means to determine the database, table, and
4823** table column that is the origin of a particular result column in
4824** [SELECT] statement.
4825** ^The name of the database or table or column can be returned as
4826** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4827** the database name, the _table_ routines return the table name, and
4828** the origin_ routines return the column name.
4829** ^The returned string is valid until the [prepared statement] is destroyed
4830** using [sqlite3_finalize()] or until the statement is automatically
4831** reprepared by the first call to [sqlite3_step()] for a particular run
4832** or until the same information is requested
4833** again in a different encoding.
4834**
4835** ^The names returned are the original un-aliased names of the
4836** database, table, and column.
4837**
4838** ^The first argument to these interfaces is a [prepared statement].
4839** ^These functions return information about the Nth result column returned by
4840** the statement, where N is the second function argument.
4841** ^The left-most column is column 0 for these routines.
4842**
4843** ^If the Nth column returned by the statement is an expression or
4844** subquery and is not a column value, then all of these functions return
4845** NULL. ^These routines might also return NULL if a memory allocation error
4846** occurs. ^Otherwise, they return the name of the attached database, table,
4847** or column that query result column was extracted from.
4848**
4849** ^As with all other SQLite APIs, those whose names end with "16" return
4850** UTF-16 encoded strings and the other functions return UTF-8.
4851**
4852** ^These APIs are only available if the library was compiled with the
4853** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4854**
4855** If two or more threads call one or more
4856** [sqlite3_column_database_name | column metadata interfaces]
4857** for the same [prepared statement] and result column
4858** at the same time then the results are undefined.
4859*/
4860SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4861SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4862SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4863SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4864SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4865SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4866
4867/*
4868** CAPI3REF: Declared Datatype Of A Query Result
4869** METHOD: sqlite3_stmt
4870**
4871** ^(The first parameter is a [prepared statement].
4872** If this statement is a [SELECT] statement and the Nth column of the
4873** returned result set of that [SELECT] is a table column (not an
4874** expression or subquery) then the declared type of the table
4875** column is returned.)^ ^If the Nth column of the result set is an
4876** expression or subquery, then a NULL pointer is returned.
4877** ^The returned string is always UTF-8 encoded.
4878**
4879** ^(For example, given the database schema:
4880**
4881** CREATE TABLE t1(c1 VARIANT);
4882**
4883** and the following statement to be compiled:
4884**
4885** SELECT c1 + 1, c1 FROM t1;
4886**
4887** this routine would return the string "VARIANT" for the second result
4888** column (i==1), and a NULL pointer for the first result column (i==0).)^
4889**
4890** ^SQLite uses dynamic run-time typing. ^So just because a column
4891** is declared to contain a particular type does not mean that the
4892** data stored in that column is of the declared type. SQLite is
4893** strongly typed, but the typing is dynamic not static. ^Type
4894** is associated with individual values, not with the containers
4895** used to hold those values.
4896*/
4897SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4898SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4899
4900/*
4901** CAPI3REF: Evaluate An SQL Statement
4902** METHOD: sqlite3_stmt
4903**
4904** After a [prepared statement] has been prepared using any of
4905** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4906** or [sqlite3_prepare16_v3()] or one of the legacy
4907** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4908** must be called one or more times to evaluate the statement.
4909**
4910** The details of the behavior of the sqlite3_step() interface depend
4911** on whether the statement was prepared using the newer "vX" interfaces
4912** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4913** [sqlite3_prepare16_v2()] or the older legacy
4914** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4915** new "vX" interface is recommended for new applications but the legacy
4916** interface will continue to be supported.
4917**
4918** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4919** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4920** ^With the "v2" interface, any of the other [result codes] or
4921** [extended result codes] might be returned as well.
4922**
4923** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4924** database locks it needs to do its job. ^If the statement is a [COMMIT]
4925** or occurs outside of an explicit transaction, then you can retry the
4926** statement. If the statement is not a [COMMIT] and occurs within an
4927** explicit transaction then you should rollback the transaction before
4928** continuing.
4929**
4930** ^[SQLITE_DONE] means that the statement has finished executing
4931** successfully. sqlite3_step() should not be called again on this virtual
4932** machine without first calling [sqlite3_reset()] to reset the virtual
4933** machine back to its initial state.
4934**
4935** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4936** is returned each time a new row of data is ready for processing by the
4937** caller. The values may be accessed using the [column access functions].
4938** sqlite3_step() is called again to retrieve the next row of data.
4939**
4940** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4941** violation) has occurred. sqlite3_step() should not be called again on
4942** the VM. More information may be found by calling [sqlite3_errmsg()].
4943** ^With the legacy interface, a more specific error code (for example,
4944** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4945** can be obtained by calling [sqlite3_reset()] on the
4946** [prepared statement]. ^In the "v2" interface,
4947** the more specific error code is returned directly by sqlite3_step().
4948**
4949** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4950** Perhaps it was called on a [prepared statement] that has
4951** already been [sqlite3_finalize | finalized] or on one that had
4952** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4953** be the case that the same database connection is being used by two or
4954** more threads at the same moment in time.
4955**
4956** For all versions of SQLite up to and including 3.6.23.1, a call to
4957** [sqlite3_reset()] was required after sqlite3_step() returned anything
4958** other than [SQLITE_ROW] before any subsequent invocation of
4959** sqlite3_step(). Failure to reset the prepared statement using
4960** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4961** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4962** sqlite3_step() began
4963** calling [sqlite3_reset()] automatically in this circumstance rather
4964** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4965** break because any application that ever receives an SQLITE_MISUSE error
4966** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4967** can be used to restore the legacy behavior.
4968**
4969** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4970** API always returns a generic error code, [SQLITE_ERROR], following any
4971** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4972** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4973** specific [error codes] that better describes the error.
4974** We admit that this is a goofy design. The problem has been fixed
4975** with the "v2" interface. If you prepare all of your SQL statements
4976** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4977** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4978** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4979** then the more specific [error codes] are returned directly
4980** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4981*/
4982SQLITE_API int sqlite3_step(sqlite3_stmt*);
4983
4984/*
4985** CAPI3REF: Number of columns in a result set
4986** METHOD: sqlite3_stmt
4987**
4988** ^The sqlite3_data_count(P) interface returns the number of columns in the
4989** current row of the result set of [prepared statement] P.
4990** ^If prepared statement P does not have results ready to return
4991** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4992** interfaces) then sqlite3_data_count(P) returns 0.
4993** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4994** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4995** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4996** will return non-zero if previous call to [sqlite3_step](P) returned
4997** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4998** where it always returns zero since each step of that multi-step
4999** pragma returns 0 columns of data.
5000**
5001** See also: [sqlite3_column_count()]
5002*/
5003SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5004
5005/*
5006** CAPI3REF: Fundamental Datatypes
5007** KEYWORDS: SQLITE_TEXT
5008**
5009** ^(Every value in SQLite has one of five fundamental datatypes:
5010**
5011** <ul>
5012** <li> 64-bit signed integer
5013** <li> 64-bit IEEE floating point number
5014** <li> string
5015** <li> BLOB
5016** <li> NULL
5017** </ul>)^
5018**
5019** These constants are codes for each of those types.
5020**
5021** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5022** for a completely different meaning. Software that links against both
5023** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5024** SQLITE_TEXT.
5025*/
5026#define SQLITE_INTEGER 1
5027#define SQLITE_FLOAT 2
5028#define SQLITE_BLOB 4
5029#define SQLITE_NULL 5
5030#ifdef SQLITE_TEXT
5031# undef SQLITE_TEXT
5032#else
5033# define SQLITE_TEXT 3
5034#endif
5035#define SQLITE3_TEXT 3
5036
5037/*
5038** CAPI3REF: Result Values From A Query
5039** KEYWORDS: {column access functions}
5040** METHOD: sqlite3_stmt
5041**
5042** <b>Summary:</b>
5043** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5044** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
5045** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
5046** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
5047** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
5048** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
5049** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
5050** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
5051** [sqlite3_value|unprotected sqlite3_value] object.
5052** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5053** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
5054** or a UTF-8 TEXT result in bytes
5055** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
5056** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5057** TEXT in bytes
5058** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
5059** datatype of the result
5060** </table></blockquote>
5061**
5062** <b>Details:</b>
5063**
5064** ^These routines return information about a single column of the current
5065** result row of a query. ^In every case the first argument is a pointer
5066** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5067** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5068** and the second argument is the index of the column for which information
5069** should be returned. ^The leftmost column of the result set has the index 0.
5070** ^The number of columns in the result can be determined using
5071** [sqlite3_column_count()].
5072**
5073** If the SQL statement does not currently point to a valid row, or if the
5074** column index is out of range, the result is undefined.
5075** These routines may only be called when the most recent call to
5076** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5077** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5078** If any of these routines are called after [sqlite3_reset()] or
5079** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5080** something other than [SQLITE_ROW], the results are undefined.
5081** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5082** are called from a different thread while any of these routines
5083** are pending, then the results are undefined.
5084**
5085** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5086** each return the value of a result column in a specific data format. If
5087** the result column is not initially in the requested format (for example,
5088** if the query returns an integer but the sqlite3_column_text() interface
5089** is used to extract the value) then an automatic type conversion is performed.
5090**
5091** ^The sqlite3_column_type() routine returns the
5092** [SQLITE_INTEGER | datatype code] for the initial data type
5093** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5094** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5095** The return value of sqlite3_column_type() can be used to decide which
5096** of the first six interface should be used to extract the column value.
5097** The value returned by sqlite3_column_type() is only meaningful if no
5098** automatic type conversions have occurred for the value in question.
5099** After a type conversion, the result of calling sqlite3_column_type()
5100** is undefined, though harmless. Future
5101** versions of SQLite may change the behavior of sqlite3_column_type()
5102** following a type conversion.
5103**
5104** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5105** or sqlite3_column_bytes16() interfaces can be used to determine the size
5106** of that BLOB or string.
5107**
5108** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5109** routine returns the number of bytes in that BLOB or string.
5110** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5111** the string to UTF-8 and then returns the number of bytes.
5112** ^If the result is a numeric value then sqlite3_column_bytes() uses
5113** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5114** the number of bytes in that string.
5115** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5116**
5117** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5118** routine returns the number of bytes in that BLOB or string.
5119** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5120** the string to UTF-16 and then returns the number of bytes.
5121** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5122** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5123** the number of bytes in that string.
5124** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5125**
5126** ^The values returned by [sqlite3_column_bytes()] and
5127** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5128** of the string. ^For clarity: the values returned by
5129** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5130** bytes in the string, not the number of characters.
5131**
5132** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5133** even empty strings, are always zero-terminated. ^The return
5134** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5135**
5136** ^Strings returned by sqlite3_column_text16() always have the endianness
5137** which is native to the platform, regardless of the text encoding set
5138** for the database.
5139**
5140** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5141** [unprotected sqlite3_value] object. In a multithreaded environment,
5142** an unprotected sqlite3_value object may only be used safely with
5143** [sqlite3_bind_value()] and [sqlite3_result_value()].
5144** If the [unprotected sqlite3_value] object returned by
5145** [sqlite3_column_value()] is used in any other way, including calls
5146** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5147** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5148** Hence, the sqlite3_column_value() interface
5149** is normally only useful within the implementation of
5150** [application-defined SQL functions] or [virtual tables], not within
5151** top-level application code.
5152**
5153** These routines may attempt to convert the datatype of the result.
5154** ^For example, if the internal representation is FLOAT and a text result
5155** is requested, [sqlite3_snprintf()] is used internally to perform the
5156** conversion automatically. ^(The following table details the conversions
5157** that are applied:
5158**
5159** <blockquote>
5160** <table border="1">
5161** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5162**
5163** <tr><td> NULL <td> INTEGER <td> Result is 0
5164** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5165** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5166** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5167** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5168** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5169** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5170** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5171** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5172** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5173** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5174** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5175** <tr><td> TEXT <td> BLOB <td> No change
5176** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5177** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5178** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5179** </table>
5180** </blockquote>)^
5181**
5182** Note that when type conversions occur, pointers returned by prior
5183** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5184** sqlite3_column_text16() may be invalidated.
5185** Type conversions and pointer invalidations might occur
5186** in the following cases:
5187**
5188** <ul>
5189** <li> The initial content is a BLOB and sqlite3_column_text() or
5190** sqlite3_column_text16() is called. A zero-terminator might
5191** need to be added to the string.</li>
5192** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5193** sqlite3_column_text16() is called. The content must be converted
5194** to UTF-16.</li>
5195** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5196** sqlite3_column_text() is called. The content must be converted
5197** to UTF-8.</li>
5198** </ul>
5199**
5200** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5201** not invalidate a prior pointer, though of course the content of the buffer
5202** that the prior pointer references will have been modified. Other kinds
5203** of conversion are done in place when it is possible, but sometimes they
5204** are not possible and in those cases prior pointers are invalidated.
5205**
5206** The safest policy is to invoke these routines
5207** in one of the following ways:
5208**
5209** <ul>
5210** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5211** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5212** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5213** </ul>
5214**
5215** In other words, you should call sqlite3_column_text(),
5216** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5217** into the desired format, then invoke sqlite3_column_bytes() or
5218** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5219** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5220** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5221** with calls to sqlite3_column_bytes().
5222**
5223** ^The pointers returned are valid until a type conversion occurs as
5224** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5225** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5226** and BLOBs is freed automatically. Do not pass the pointers returned
5227** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5228** [sqlite3_free()].
5229**
5230** As long as the input parameters are correct, these routines will only
5231** fail if an out-of-memory error occurs during a format conversion.
5232** Only the following subset of interfaces are subject to out-of-memory
5233** errors:
5234**
5235** <ul>
5236** <li> sqlite3_column_blob()
5237** <li> sqlite3_column_text()
5238** <li> sqlite3_column_text16()
5239** <li> sqlite3_column_bytes()
5240** <li> sqlite3_column_bytes16()
5241** </ul>
5242**
5243** If an out-of-memory error occurs, then the return value from these
5244** routines is the same as if the column had contained an SQL NULL value.
5245** Valid SQL NULL returns can be distinguished from out-of-memory errors
5246** by invoking the [sqlite3_errcode()] immediately after the suspect
5247** return value is obtained and before any
5248** other SQLite interface is called on the same [database connection].
5249*/
5250SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5251SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5252SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5253SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5254SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5255SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5256SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5257SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5258SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5259SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5260
5261/*
5262** CAPI3REF: Destroy A Prepared Statement Object
5263** DESTRUCTOR: sqlite3_stmt
5264**
5265** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5266** ^If the most recent evaluation of the statement encountered no errors
5267** or if the statement is never been evaluated, then sqlite3_finalize() returns
5268** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5269** sqlite3_finalize(S) returns the appropriate [error code] or
5270** [extended error code].
5271**
5272** ^The sqlite3_finalize(S) routine can be called at any point during
5273** the life cycle of [prepared statement] S:
5274** before statement S is ever evaluated, after
5275** one or more calls to [sqlite3_reset()], or after any call
5276** to [sqlite3_step()] regardless of whether or not the statement has
5277** completed execution.
5278**
5279** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5280**
5281** The application must finalize every [prepared statement] in order to avoid
5282** resource leaks. It is a grievous error for the application to try to use
5283** a prepared statement after it has been finalized. Any use of a prepared
5284** statement after it has been finalized can result in undefined and
5285** undesirable behavior such as segfaults and heap corruption.
5286*/
5287SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5288
5289/*
5290** CAPI3REF: Reset A Prepared Statement Object
5291** METHOD: sqlite3_stmt
5292**
5293** The sqlite3_reset() function is called to reset a [prepared statement]
5294** object back to its initial state, ready to be re-executed.
5295** ^Any SQL statement variables that had values bound to them using
5296** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5297** Use [sqlite3_clear_bindings()] to reset the bindings.
5298**
5299** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5300** back to the beginning of its program.
5301**
5302** ^The return code from [sqlite3_reset(S)] indicates whether or not
5303** the previous evaluation of prepared statement S completed successfully.
5304** ^If [sqlite3_step(S)] has never before been called on S or if
5305** [sqlite3_step(S)] has not been called since the previous call
5306** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5307** [SQLITE_OK].
5308**
5309** ^If the most recent call to [sqlite3_step(S)] for the
5310** [prepared statement] S indicated an error, then
5311** [sqlite3_reset(S)] returns an appropriate [error code].
5312** ^The [sqlite3_reset(S)] interface might also return an [error code]
5313** if there were no prior errors but the process of resetting
5314** the prepared statement caused a new error. ^For example, if an
5315** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5316** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5317** the overall statement might still fail and the [sqlite3_reset(S)] call
5318** might return SQLITE_BUSY if locking constraints prevent the
5319** database change from committing. Therefore, it is important that
5320** applications check the return code from [sqlite3_reset(S)] even if
5321** no prior call to [sqlite3_step(S)] indicated a problem.
5322**
5323** ^The [sqlite3_reset(S)] interface does not change the values
5324** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5325*/
5326SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5327
5328/*
5329** CAPI3REF: Create Or Redefine SQL Functions
5330** KEYWORDS: {function creation routines}
5331** METHOD: sqlite3
5332**
5333** ^These functions (collectively known as "function creation routines")
5334** are used to add SQL functions or aggregates or to redefine the behavior
5335** of existing SQL functions or aggregates. The only differences between
5336** the three "sqlite3_create_function*" routines are the text encoding
5337** expected for the second parameter (the name of the function being
5338** created) and the presence or absence of a destructor callback for
5339** the application data pointer. Function sqlite3_create_window_function()
5340** is similar, but allows the user to supply the extra callback functions
5341** needed by [aggregate window functions].
5342**
5343** ^The first parameter is the [database connection] to which the SQL
5344** function is to be added. ^If an application uses more than one database
5345** connection then application-defined SQL functions must be added
5346** to each database connection separately.
5347**
5348** ^The second parameter is the name of the SQL function to be created or
5349** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5350** representation, exclusive of the zero-terminator. ^Note that the name
5351** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5352** ^Any attempt to create a function with a longer name
5353** will result in [SQLITE_MISUSE] being returned.
5354**
5355** ^The third parameter (nArg)
5356** is the number of arguments that the SQL function or
5357** aggregate takes. ^If this parameter is -1, then the SQL function or
5358** aggregate may take any number of arguments between 0 and the limit
5359** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5360** parameter is less than -1 or greater than 127 then the behavior is
5361** undefined.
5362**
5363** ^The fourth parameter, eTextRep, specifies what
5364** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5365** its parameters. The application should set this parameter to
5366** [SQLITE_UTF16LE] if the function implementation invokes
5367** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5368** implementation invokes [sqlite3_value_text16be()] on an input, or
5369** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5370** otherwise. ^The same SQL function may be registered multiple times using
5371** different preferred text encodings, with different implementations for
5372** each encoding.
5373** ^When multiple implementations of the same function are available, SQLite
5374** will pick the one that involves the least amount of data conversion.
5375**
5376** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5377** to signal that the function will always return the same result given
5378** the same inputs within a single SQL statement. Most SQL functions are
5379** deterministic. The built-in [random()] SQL function is an example of a
5380** function that is not deterministic. The SQLite query planner is able to
5381** perform additional optimizations on deterministic functions, so use
5382** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5383**
5384** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5385** flag, which if present prevents the function from being invoked from
5386** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5387** index expressions, or the WHERE clause of partial indexes.
5388**
5389** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5390** all application-defined SQL functions that do not need to be
5391** used inside of triggers, view, CHECK constraints, or other elements of
5392** the database schema. This flags is especially recommended for SQL
5393** functions that have side effects or reveal internal application state.
5394** Without this flag, an attacker might be able to modify the schema of
5395** a database file to include invocations of the function with parameters
5396** chosen by the attacker, which the application will then execute when
5397** the database file is opened and read.
5398**
5399** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5400** function can gain access to this pointer using [sqlite3_user_data()].)^
5401**
5402** ^The sixth, seventh and eighth parameters passed to the three
5403** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5404** pointers to C-language functions that implement the SQL function or
5405** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5406** callback only; NULL pointers must be passed as the xStep and xFinal
5407** parameters. ^An aggregate SQL function requires an implementation of xStep
5408** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5409** SQL function or aggregate, pass NULL pointers for all three function
5410** callbacks.
5411**
5412** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5413** and xInverse) passed to sqlite3_create_window_function are pointers to
5414** C-language callbacks that implement the new function. xStep and xFinal
5415** must both be non-NULL. xValue and xInverse may either both be NULL, in
5416** which case a regular aggregate function is created, or must both be
5417** non-NULL, in which case the new function may be used as either an aggregate
5418** or aggregate window function. More details regarding the implementation
5419** of aggregate window functions are
5420** [user-defined window functions|available here].
5421**
5422** ^(If the final parameter to sqlite3_create_function_v2() or
5423** sqlite3_create_window_function() is not NULL, then it is destructor for
5424** the application data pointer. The destructor is invoked when the function
5425** is deleted, either by being overloaded or when the database connection
5426** closes.)^ ^The destructor is also invoked if the call to
5427** sqlite3_create_function_v2() fails. ^When the destructor callback is
5428** invoked, it is passed a single argument which is a copy of the application
5429** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5430**
5431** ^It is permitted to register multiple implementations of the same
5432** functions with the same name but with either differing numbers of
5433** arguments or differing preferred text encodings. ^SQLite will use
5434** the implementation that most closely matches the way in which the
5435** SQL function is used. ^A function implementation with a non-negative
5436** nArg parameter is a better match than a function implementation with
5437** a negative nArg. ^A function where the preferred text encoding
5438** matches the database encoding is a better
5439** match than a function where the encoding is different.
5440** ^A function where the encoding difference is between UTF16le and UTF16be
5441** is a closer match than a function where the encoding difference is
5442** between UTF8 and UTF16.
5443**
5444** ^Built-in functions may be overloaded by new application-defined functions.
5445**
5446** ^An application-defined function is permitted to call other
5447** SQLite interfaces. However, such calls must not
5448** close the database connection nor finalize or reset the prepared
5449** statement in which the function is running.
5450*/
5451SQLITE_API int sqlite3_create_function(
5452 sqlite3 *db,
5453 const char *zFunctionName,
5454 int nArg,
5455 int eTextRep,
5456 void *pApp,
5457 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5458 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5459 void (*xFinal)(sqlite3_context*)
5460);
5461SQLITE_API int sqlite3_create_function16(
5462 sqlite3 *db,
5463 const void *zFunctionName,
5464 int nArg,
5465 int eTextRep,
5466 void *pApp,
5467 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5468 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5469 void (*xFinal)(sqlite3_context*)
5470);
5471SQLITE_API int sqlite3_create_function_v2(
5472 sqlite3 *db,
5473 const char *zFunctionName,
5474 int nArg,
5475 int eTextRep,
5476 void *pApp,
5477 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5478 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5479 void (*xFinal)(sqlite3_context*),
5480 void(*xDestroy)(void*)
5481);
5482SQLITE_API int sqlite3_create_window_function(
5483 sqlite3 *db,
5484 const char *zFunctionName,
5485 int nArg,
5486 int eTextRep,
5487 void *pApp,
5488 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5489 void (*xFinal)(sqlite3_context*),
5490 void (*xValue)(sqlite3_context*),
5491 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5492 void(*xDestroy)(void*)
5493);
5494
5495/*
5496** CAPI3REF: Text Encodings
5497**
5498** These constant define integer codes that represent the various
5499** text encodings supported by SQLite.
5500*/
5501#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5502#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5503#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5504#define SQLITE_UTF16 4 /* Use native byte order */
5505#define SQLITE_ANY 5 /* Deprecated */
5506#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5507
5508/*
5509** CAPI3REF: Function Flags
5510**
5511** These constants may be ORed together with the
5512** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5513** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5514** [sqlite3_create_function_v2()].
5515**
5516** <dl>
5517** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5518** The SQLITE_DETERMINISTIC flag means that the new function always gives
5519** the same output when the input parameters are the same.
5520** The [abs|abs() function] is deterministic, for example, but
5521** [randomblob|randomblob()] is not. Functions must
5522** be deterministic in order to be used in certain contexts such as
5523** with the WHERE clause of [partial indexes] or in [generated columns].
5524** SQLite might also optimize deterministic functions by factoring them
5525** out of inner loops.
5526** </dd>
5527**
5528** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5529** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5530** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5531** schema structures such as [CHECK constraints], [DEFAULT clauses],
5532** [expression indexes], [partial indexes], or [generated columns].
5533** <p>
5534** The SQLITE_DIRECTONLY flag is recommended for any
5535** [application-defined SQL function]
5536** that has side-effects or that could potentially leak sensitive information.
5537** This will prevent attacks in which an application is tricked
5538** into using a database file that has had its schema surreptitiously
5539** modified to invoke the application-defined function in ways that are
5540** harmful.
5541** <p>
5542** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5543** [application-defined SQL functions], regardless of whether or not they
5544** are security sensitive, as doing so prevents those functions from being used
5545** inside of the database schema, and thus ensures that the database
5546** can be inspected and modified using generic tools (such as the [CLI])
5547** that do not have access to the application-defined functions.
5548** </dd>
5549**
5550** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5551** The SQLITE_INNOCUOUS flag means that the function is unlikely
5552** to cause problems even if misused. An innocuous function should have
5553** no side effects and should not depend on any values other than its
5554** input parameters. The [abs|abs() function] is an example of an
5555** innocuous function.
5556** The [load_extension() SQL function] is not innocuous because of its
5557** side effects.
5558** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5559** exactly the same. The [random|random() function] is an example of a
5560** function that is innocuous but not deterministic.
5561** <p>Some heightened security settings
5562** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5563** disable the use of SQL functions inside views and triggers and in
5564** schema structures such as [CHECK constraints], [DEFAULT clauses],
5565** [expression indexes], [partial indexes], and [generated columns] unless
5566** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5567** are innocuous. Developers are advised to avoid using the
5568** SQLITE_INNOCUOUS flag for application-defined functions unless the
5569** function has been carefully audited and found to be free of potentially
5570** security-adverse side-effects and information-leaks.
5571** </dd>
5572**
5573** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5574** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5575** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5576** Specifying this flag makes no difference for scalar or aggregate user
5577** functions. However, if it is not specified for a user-defined window
5578** function, then any sub-types belonging to arguments passed to the window
5579** function may be discarded before the window function is called (i.e.
5580** sqlite3_value_subtype() will always return 0).
5581** </dd>
5582** </dl>
5583*/
5584#define SQLITE_DETERMINISTIC 0x000000800
5585#define SQLITE_DIRECTONLY 0x000080000
5586#define SQLITE_SUBTYPE 0x000100000
5587#define SQLITE_INNOCUOUS 0x000200000
5588
5589/*
5590** CAPI3REF: Deprecated Functions
5591** DEPRECATED
5592**
5593** These functions are [deprecated]. In order to maintain
5594** backwards compatibility with older code, these functions continue
5595** to be supported. However, new applications should avoid
5596** the use of these functions. To encourage programmers to avoid
5597** these functions, we will not explain what they do.
5598*/
5599#ifndef SQLITE_OMIT_DEPRECATED
5600SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5601SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5602SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5603SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5604SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5605SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5606 void*,sqlite3_int64);
5607#endif
5608
5609/*
5610** CAPI3REF: Obtaining SQL Values
5611** METHOD: sqlite3_value
5612**
5613** <b>Summary:</b>
5614** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5615** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5616** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5617** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5618** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5619** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5620** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5621** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5622** the native byteorder
5623** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5624** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5625** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5626** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5627** or a UTF-8 TEXT in bytes
5628** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5629** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5630** TEXT in bytes
5631** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5632** datatype of the value
5633** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5634** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5635** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5636** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5637** against a virtual table.
5638** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5639** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5640** </table></blockquote>
5641**
5642** <b>Details:</b>
5643**
5644** These routines extract type, size, and content information from
5645** [protected sqlite3_value] objects. Protected sqlite3_value objects
5646** are used to pass parameter information into the functions that
5647** implement [application-defined SQL functions] and [virtual tables].
5648**
5649** These routines work only with [protected sqlite3_value] objects.
5650** Any attempt to use these routines on an [unprotected sqlite3_value]
5651** is not threadsafe.
5652**
5653** ^These routines work just like the corresponding [column access functions]
5654** except that these routines take a single [protected sqlite3_value] object
5655** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5656**
5657** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5658** in the native byte-order of the host machine. ^The
5659** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5660** extract UTF-16 strings as big-endian and little-endian respectively.
5661**
5662** ^If [sqlite3_value] object V was initialized
5663** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5664** and if X and Y are strings that compare equal according to strcmp(X,Y),
5665** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5666** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5667** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5668**
5669** ^(The sqlite3_value_type(V) interface returns the
5670** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5671** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5672** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5673** Other interfaces might change the datatype for an sqlite3_value object.
5674** For example, if the datatype is initially SQLITE_INTEGER and
5675** sqlite3_value_text(V) is called to extract a text value for that
5676** integer, then subsequent calls to sqlite3_value_type(V) might return
5677** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5678** occurs is undefined and may change from one release of SQLite to the next.
5679**
5680** ^(The sqlite3_value_numeric_type() interface attempts to apply
5681** numeric affinity to the value. This means that an attempt is
5682** made to convert the value to an integer or floating point. If
5683** such a conversion is possible without loss of information (in other
5684** words, if the value is a string that looks like a number)
5685** then the conversion is performed. Otherwise no conversion occurs.
5686** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5687**
5688** ^Within the [xUpdate] method of a [virtual table], the
5689** sqlite3_value_nochange(X) interface returns true if and only if
5690** the column corresponding to X is unchanged by the UPDATE operation
5691** that the xUpdate method call was invoked to implement and if
5692** and the prior [xColumn] method call that was invoked to extracted
5693** the value for that column returned without setting a result (probably
5694** because it queried [sqlite3_vtab_nochange()] and found that the column
5695** was unchanging). ^Within an [xUpdate] method, any value for which
5696** sqlite3_value_nochange(X) is true will in all other respects appear
5697** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5698** than within an [xUpdate] method call for an UPDATE statement, then
5699** the return value is arbitrary and meaningless.
5700**
5701** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5702** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5703** interfaces. ^If X comes from an SQL literal value, or a table column,
5704** or an expression, then sqlite3_value_frombind(X) returns zero.
5705**
5706** Please pay particular attention to the fact that the pointer returned
5707** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5708** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5709** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5710** or [sqlite3_value_text16()].
5711**
5712** These routines must be called from the same thread as
5713** the SQL function that supplied the [sqlite3_value*] parameters.
5714**
5715** As long as the input parameter is correct, these routines can only
5716** fail if an out-of-memory error occurs during a format conversion.
5717** Only the following subset of interfaces are subject to out-of-memory
5718** errors:
5719**
5720** <ul>
5721** <li> sqlite3_value_blob()
5722** <li> sqlite3_value_text()
5723** <li> sqlite3_value_text16()
5724** <li> sqlite3_value_text16le()
5725** <li> sqlite3_value_text16be()
5726** <li> sqlite3_value_bytes()
5727** <li> sqlite3_value_bytes16()
5728** </ul>
5729**
5730** If an out-of-memory error occurs, then the return value from these
5731** routines is the same as if the column had contained an SQL NULL value.
5732** Valid SQL NULL returns can be distinguished from out-of-memory errors
5733** by invoking the [sqlite3_errcode()] immediately after the suspect
5734** return value is obtained and before any
5735** other SQLite interface is called on the same [database connection].
5736*/
5737SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5738SQLITE_API double sqlite3_value_double(sqlite3_value*);
5739SQLITE_API int sqlite3_value_int(sqlite3_value*);
5740SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5741SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5742SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5743SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5744SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5745SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5746SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5747SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5748SQLITE_API int sqlite3_value_type(sqlite3_value*);
5749SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5750SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5751SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5752
5753/*
5754** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
5755** METHOD: sqlite3_value
5756**
5757** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
5758** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
5759** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
5760** returns something other than SQLITE_TEXT, then the return value from
5761** sqlite3_value_encoding(X) is meaningless. ^Calls to
5762** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
5763** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
5764** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
5765** thus change the return from subsequent calls to sqlite3_value_encoding(X).
5766**
5767** This routine is intended for used by applications that test and validate
5768** the SQLite implementation. This routine is inquiring about the opaque
5769** internal state of an [sqlite3_value] object. Ordinary applications should
5770** not need to know what the internal state of an sqlite3_value object is and
5771** hence should not need to use this interface.
5772*/
5773SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
5774
5775/*
5776** CAPI3REF: Finding The Subtype Of SQL Values
5777** METHOD: sqlite3_value
5778**
5779** The sqlite3_value_subtype(V) function returns the subtype for
5780** an [application-defined SQL function] argument V. The subtype
5781** information can be used to pass a limited amount of context from
5782** one SQL function to another. Use the [sqlite3_result_subtype()]
5783** routine to set the subtype for the return value of an SQL function.
5784*/
5785SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5786
5787/*
5788** CAPI3REF: Copy And Free SQL Values
5789** METHOD: sqlite3_value
5790**
5791** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5792** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5793** is a [protected sqlite3_value] object even if the input is not.
5794** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5795** memory allocation fails. ^If V is a [pointer value], then the result
5796** of sqlite3_value_dup(V) is a NULL value.
5797**
5798** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5799** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5800** then sqlite3_value_free(V) is a harmless no-op.
5801*/
5802SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5803SQLITE_API void sqlite3_value_free(sqlite3_value*);
5804
5805/*
5806** CAPI3REF: Obtain Aggregate Function Context
5807** METHOD: sqlite3_context
5808**
5809** Implementations of aggregate SQL functions use this
5810** routine to allocate memory for storing their state.
5811**
5812** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5813** for a particular aggregate function, SQLite allocates
5814** N bytes of memory, zeroes out that memory, and returns a pointer
5815** to the new memory. ^On second and subsequent calls to
5816** sqlite3_aggregate_context() for the same aggregate function instance,
5817** the same buffer is returned. Sqlite3_aggregate_context() is normally
5818** called once for each invocation of the xStep callback and then one
5819** last time when the xFinal callback is invoked. ^(When no rows match
5820** an aggregate query, the xStep() callback of the aggregate function
5821** implementation is never called and xFinal() is called exactly once.
5822** In those cases, sqlite3_aggregate_context() might be called for the
5823** first time from within xFinal().)^
5824**
5825** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5826** when first called if N is less than or equal to zero or if a memory
5827** allocation error occurs.
5828**
5829** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5830** determined by the N parameter on first successful call. Changing the
5831** value of N in any subsequent call to sqlite3_aggregate_context() within
5832** the same aggregate function instance will not resize the memory
5833** allocation.)^ Within the xFinal callback, it is customary to set
5834** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5835** pointless memory allocations occur.
5836**
5837** ^SQLite automatically frees the memory allocated by
5838** sqlite3_aggregate_context() when the aggregate query concludes.
5839**
5840** The first parameter must be a copy of the
5841** [sqlite3_context | SQL function context] that is the first parameter
5842** to the xStep or xFinal callback routine that implements the aggregate
5843** function.
5844**
5845** This routine must be called from the same thread in which
5846** the aggregate SQL function is running.
5847*/
5848SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5849
5850/*
5851** CAPI3REF: User Data For Functions
5852** METHOD: sqlite3_context
5853**
5854** ^The sqlite3_user_data() interface returns a copy of
5855** the pointer that was the pUserData parameter (the 5th parameter)
5856** of the [sqlite3_create_function()]
5857** and [sqlite3_create_function16()] routines that originally
5858** registered the application defined function.
5859**
5860** This routine must be called from the same thread in which
5861** the application-defined function is running.
5862*/
5863SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5864
5865/*
5866** CAPI3REF: Database Connection For Functions
5867** METHOD: sqlite3_context
5868**
5869** ^The sqlite3_context_db_handle() interface returns a copy of
5870** the pointer to the [database connection] (the 1st parameter)
5871** of the [sqlite3_create_function()]
5872** and [sqlite3_create_function16()] routines that originally
5873** registered the application defined function.
5874*/
5875SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5876
5877/*
5878** CAPI3REF: Function Auxiliary Data
5879** METHOD: sqlite3_context
5880**
5881** These functions may be used by (non-aggregate) SQL functions to
5882** associate metadata with argument values. If the same value is passed to
5883** multiple invocations of the same SQL function during query execution, under
5884** some circumstances the associated metadata may be preserved. An example
5885** of where this might be useful is in a regular-expression matching
5886** function. The compiled version of the regular expression can be stored as
5887** metadata associated with the pattern string.
5888** Then as long as the pattern string remains the same,
5889** the compiled regular expression can be reused on multiple
5890** invocations of the same function.
5891**
5892** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5893** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5894** value to the application-defined function. ^N is zero for the left-most
5895** function argument. ^If there is no metadata
5896** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5897** returns a NULL pointer.
5898**
5899** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5900** argument of the application-defined function. ^Subsequent
5901** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5902** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5903** NULL if the metadata has been discarded.
5904** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5905** SQLite will invoke the destructor function X with parameter P exactly
5906** once, when the metadata is discarded.
5907** SQLite is free to discard the metadata at any time, including: <ul>
5908** <li> ^(when the corresponding function parameter changes)^, or
5909** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5910** SQL statement)^, or
5911** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5912** parameter)^, or
5913** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5914** allocation error occurs.)^ </ul>
5915**
5916** Note the last bullet in particular. The destructor X in
5917** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5918** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5919** should be called near the end of the function implementation and the
5920** function implementation should not make any use of P after
5921** sqlite3_set_auxdata() has been called.
5922**
5923** ^(In practice, metadata is preserved between function calls for
5924** function parameters that are compile-time constants, including literal
5925** values and [parameters] and expressions composed from the same.)^
5926**
5927** The value of the N parameter to these interfaces should be non-negative.
5928** Future enhancements may make use of negative N values to define new
5929** kinds of function caching behavior.
5930**
5931** These routines must be called from the same thread in which
5932** the SQL function is running.
5933*/
5934SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5935SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5936
5937
5938/*
5939** CAPI3REF: Constants Defining Special Destructor Behavior
5940**
5941** These are special values for the destructor that is passed in as the
5942** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5943** argument is SQLITE_STATIC, it means that the content pointer is constant
5944** and will never change. It does not need to be destroyed. ^The
5945** SQLITE_TRANSIENT value means that the content will likely change in
5946** the near future and that SQLite should make its own private copy of
5947** the content before returning.
5948**
5949** The typedef is necessary to work around problems in certain
5950** C++ compilers.
5951*/
5952typedef void (*sqlite3_destructor_type)(void*);
5953#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5954#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5955
5956/*
5957** CAPI3REF: Setting The Result Of An SQL Function
5958** METHOD: sqlite3_context
5959**
5960** These routines are used by the xFunc or xFinal callbacks that
5961** implement SQL functions and aggregates. See
5962** [sqlite3_create_function()] and [sqlite3_create_function16()]
5963** for additional information.
5964**
5965** These functions work very much like the [parameter binding] family of
5966** functions used to bind values to host parameters in prepared statements.
5967** Refer to the [SQL parameter] documentation for additional information.
5968**
5969** ^The sqlite3_result_blob() interface sets the result from
5970** an application-defined function to be the BLOB whose content is pointed
5971** to by the second parameter and which is N bytes long where N is the
5972** third parameter.
5973**
5974** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5975** interfaces set the result of the application-defined function to be
5976** a BLOB containing all zero bytes and N bytes in size.
5977**
5978** ^The sqlite3_result_double() interface sets the result from
5979** an application-defined function to be a floating point value specified
5980** by its 2nd argument.
5981**
5982** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5983** cause the implemented SQL function to throw an exception.
5984** ^SQLite uses the string pointed to by the
5985** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5986** as the text of an error message. ^SQLite interprets the error
5987** message string from sqlite3_result_error() as UTF-8. ^SQLite
5988** interprets the string from sqlite3_result_error16() as UTF-16 using
5989** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5990** ^If the third parameter to sqlite3_result_error()
5991** or sqlite3_result_error16() is negative then SQLite takes as the error
5992** message all text up through the first zero character.
5993** ^If the third parameter to sqlite3_result_error() or
5994** sqlite3_result_error16() is non-negative then SQLite takes that many
5995** bytes (not characters) from the 2nd parameter as the error message.
5996** ^The sqlite3_result_error() and sqlite3_result_error16()
5997** routines make a private copy of the error message text before
5998** they return. Hence, the calling function can deallocate or
5999** modify the text after they return without harm.
6000** ^The sqlite3_result_error_code() function changes the error code
6001** returned by SQLite as a result of an error in a function. ^By default,
6002** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6003** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6004**
6005** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6006** error indicating that a string or BLOB is too long to represent.
6007**
6008** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6009** error indicating that a memory allocation failed.
6010**
6011** ^The sqlite3_result_int() interface sets the return value
6012** of the application-defined function to be the 32-bit signed integer
6013** value given in the 2nd argument.
6014** ^The sqlite3_result_int64() interface sets the return value
6015** of the application-defined function to be the 64-bit signed integer
6016** value given in the 2nd argument.
6017**
6018** ^The sqlite3_result_null() interface sets the return value
6019** of the application-defined function to be NULL.
6020**
6021** ^The sqlite3_result_text(), sqlite3_result_text16(),
6022** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6023** set the return value of the application-defined function to be
6024** a text string which is represented as UTF-8, UTF-16 native byte order,
6025** UTF-16 little endian, or UTF-16 big endian, respectively.
6026** ^The sqlite3_result_text64() interface sets the return value of an
6027** application-defined function to be a text string in an encoding
6028** specified by the fifth (and last) parameter, which must be one
6029** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6030** ^SQLite takes the text result from the application from
6031** the 2nd parameter of the sqlite3_result_text* interfaces.
6032** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6033** other than sqlite3_result_text64() is negative, then SQLite computes
6034** the string length itself by searching the 2nd parameter for the first
6035** zero character.
6036** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6037** is non-negative, then as many bytes (not characters) of the text
6038** pointed to by the 2nd parameter are taken as the application-defined
6039** function result. If the 3rd parameter is non-negative, then it
6040** must be the byte offset into the string where the NUL terminator would
6041** appear if the string where NUL terminated. If any NUL characters occur
6042** in the string at a byte offset that is less than the value of the 3rd
6043** parameter, then the resulting string will contain embedded NULs and the
6044** result of expressions operating on strings with embedded NULs is undefined.
6045** ^If the 4th parameter to the sqlite3_result_text* interfaces
6046** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6047** function as the destructor on the text or BLOB result when it has
6048** finished using that result.
6049** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6050** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6051** assumes that the text or BLOB result is in constant space and does not
6052** copy the content of the parameter nor call a destructor on the content
6053** when it has finished using that result.
6054** ^If the 4th parameter to the sqlite3_result_text* interfaces
6055** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6056** then SQLite makes a copy of the result into space obtained
6057** from [sqlite3_malloc()] before it returns.
6058**
6059** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6060** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6061** when the encoding is not UTF8, if the input UTF16 begins with a
6062** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6063** string and the rest of the string is interpreted according to the
6064** byte-order specified by the BOM. ^The byte-order specified by
6065** the BOM at the beginning of the text overrides the byte-order
6066** specified by the interface procedure. ^So, for example, if
6067** sqlite3_result_text16le() is invoked with text that begins
6068** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6069** first two bytes of input are skipped and the remaining input
6070** is interpreted as UTF16BE text.
6071**
6072** ^For UTF16 input text to the sqlite3_result_text16(),
6073** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6074** sqlite3_result_text64() routines, if the text contains invalid
6075** UTF16 characters, the invalid characters might be converted
6076** into the unicode replacement character, U+FFFD.
6077**
6078** ^The sqlite3_result_value() interface sets the result of
6079** the application-defined function to be a copy of the
6080** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6081** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6082** so that the [sqlite3_value] specified in the parameter may change or
6083** be deallocated after sqlite3_result_value() returns without harm.
6084** ^A [protected sqlite3_value] object may always be used where an
6085** [unprotected sqlite3_value] object is required, so either
6086** kind of [sqlite3_value] object can be used with this interface.
6087**
6088** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6089** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6090** also associates the host-language pointer P or type T with that
6091** NULL value such that the pointer can be retrieved within an
6092** [application-defined SQL function] using [sqlite3_value_pointer()].
6093** ^If the D parameter is not NULL, then it is a pointer to a destructor
6094** for the P parameter. ^SQLite invokes D with P as its only argument
6095** when SQLite is finished with P. The T parameter should be a static
6096** string and preferably a string literal. The sqlite3_result_pointer()
6097** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6098**
6099** If these routines are called from within the different thread
6100** than the one containing the application-defined function that received
6101** the [sqlite3_context] pointer, the results are undefined.
6102*/
6103SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6104SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6105 sqlite3_uint64,void(*)(void*));
6106SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6107SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6108SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6109SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6110SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6111SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6112SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6113SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6114SQLITE_API void sqlite3_result_null(sqlite3_context*);
6115SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6116SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6117 void(*)(void*), unsigned char encoding);
6118SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6119SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6120SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6121SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6122SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6123SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6124SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6125
6126
6127/*
6128** CAPI3REF: Setting The Subtype Of An SQL Function
6129** METHOD: sqlite3_context
6130**
6131** The sqlite3_result_subtype(C,T) function causes the subtype of
6132** the result from the [application-defined SQL function] with
6133** [sqlite3_context] C to be the value T. Only the lower 8 bits
6134** of the subtype T are preserved in current versions of SQLite;
6135** higher order bits are discarded.
6136** The number of subtype bytes preserved by SQLite might increase
6137** in future releases of SQLite.
6138*/
6139SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6140
6141/*
6142** CAPI3REF: Define New Collating Sequences
6143** METHOD: sqlite3
6144**
6145** ^These functions add, remove, or modify a [collation] associated
6146** with the [database connection] specified as the first argument.
6147**
6148** ^The name of the collation is a UTF-8 string
6149** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6150** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6151** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6152** considered to be the same name.
6153**
6154** ^(The third argument (eTextRep) must be one of the constants:
6155** <ul>
6156** <li> [SQLITE_UTF8],
6157** <li> [SQLITE_UTF16LE],
6158** <li> [SQLITE_UTF16BE],
6159** <li> [SQLITE_UTF16], or
6160** <li> [SQLITE_UTF16_ALIGNED].
6161** </ul>)^
6162** ^The eTextRep argument determines the encoding of strings passed
6163** to the collating function callback, xCompare.
6164** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6165** force strings to be UTF16 with native byte order.
6166** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6167** on an even byte address.
6168**
6169** ^The fourth argument, pArg, is an application data pointer that is passed
6170** through as the first argument to the collating function callback.
6171**
6172** ^The fifth argument, xCompare, is a pointer to the collating function.
6173** ^Multiple collating functions can be registered using the same name but
6174** with different eTextRep parameters and SQLite will use whichever
6175** function requires the least amount of data transformation.
6176** ^If the xCompare argument is NULL then the collating function is
6177** deleted. ^When all collating functions having the same name are deleted,
6178** that collation is no longer usable.
6179**
6180** ^The collating function callback is invoked with a copy of the pArg
6181** application data pointer and with two strings in the encoding specified
6182** by the eTextRep argument. The two integer parameters to the collating
6183** function callback are the length of the two strings, in bytes. The collating
6184** function must return an integer that is negative, zero, or positive
6185** if the first string is less than, equal to, or greater than the second,
6186** respectively. A collating function must always return the same answer
6187** given the same inputs. If two or more collating functions are registered
6188** to the same collation name (using different eTextRep values) then all
6189** must give an equivalent answer when invoked with equivalent strings.
6190** The collating function must obey the following properties for all
6191** strings A, B, and C:
6192**
6193** <ol>
6194** <li> If A==B then B==A.
6195** <li> If A==B and B==C then A==C.
6196** <li> If A&lt;B THEN B&gt;A.
6197** <li> If A&lt;B and B&lt;C then A&lt;C.
6198** </ol>
6199**
6200** If a collating function fails any of the above constraints and that
6201** collating function is registered and used, then the behavior of SQLite
6202** is undefined.
6203**
6204** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6205** with the addition that the xDestroy callback is invoked on pArg when
6206** the collating function is deleted.
6207** ^Collating functions are deleted when they are overridden by later
6208** calls to the collation creation functions or when the
6209** [database connection] is closed using [sqlite3_close()].
6210**
6211** ^The xDestroy callback is <u>not</u> called if the
6212** sqlite3_create_collation_v2() function fails. Applications that invoke
6213** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6214** check the return code and dispose of the application data pointer
6215** themselves rather than expecting SQLite to deal with it for them.
6216** This is different from every other SQLite interface. The inconsistency
6217** is unfortunate but cannot be changed without breaking backwards
6218** compatibility.
6219**
6220** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6221*/
6222SQLITE_API int sqlite3_create_collation(
6223 sqlite3*,
6224 const char *zName,
6225 int eTextRep,
6226 void *pArg,
6227 int(*xCompare)(void*,int,const void*,int,const void*)
6228);
6229SQLITE_API int sqlite3_create_collation_v2(
6230 sqlite3*,
6231 const char *zName,
6232 int eTextRep,
6233 void *pArg,
6234 int(*xCompare)(void*,int,const void*,int,const void*),
6235 void(*xDestroy)(void*)
6236);
6237SQLITE_API int sqlite3_create_collation16(
6238 sqlite3*,
6239 const void *zName,
6240 int eTextRep,
6241 void *pArg,
6242 int(*xCompare)(void*,int,const void*,int,const void*)
6243);
6244
6245/*
6246** CAPI3REF: Collation Needed Callbacks
6247** METHOD: sqlite3
6248**
6249** ^To avoid having to register all collation sequences before a database
6250** can be used, a single callback function may be registered with the
6251** [database connection] to be invoked whenever an undefined collation
6252** sequence is required.
6253**
6254** ^If the function is registered using the sqlite3_collation_needed() API,
6255** then it is passed the names of undefined collation sequences as strings
6256** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6257** the names are passed as UTF-16 in machine native byte order.
6258** ^A call to either function replaces the existing collation-needed callback.
6259**
6260** ^(When the callback is invoked, the first argument passed is a copy
6261** of the second argument to sqlite3_collation_needed() or
6262** sqlite3_collation_needed16(). The second argument is the database
6263** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6264** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6265** sequence function required. The fourth parameter is the name of the
6266** required collation sequence.)^
6267**
6268** The callback function should register the desired collation using
6269** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6270** [sqlite3_create_collation_v2()].
6271*/
6272SQLITE_API int sqlite3_collation_needed(
6273 sqlite3*,
6274 void*,
6275 void(*)(void*,sqlite3*,int eTextRep,const char*)
6276);
6277SQLITE_API int sqlite3_collation_needed16(
6278 sqlite3*,
6279 void*,
6280 void(*)(void*,sqlite3*,int eTextRep,const void*)
6281);
6282
6283#ifdef SQLITE_ENABLE_CEROD
6284/*
6285** Specify the activation key for a CEROD database. Unless
6286** activated, none of the CEROD routines will work.
6287*/
6288SQLITE_API void sqlite3_activate_cerod(
6289 const char *zPassPhrase /* Activation phrase */
6290);
6291#endif
6292
6293/*
6294** CAPI3REF: Suspend Execution For A Short Time
6295**
6296** The sqlite3_sleep() function causes the current thread to suspend execution
6297** for at least a number of milliseconds specified in its parameter.
6298**
6299** If the operating system does not support sleep requests with
6300** millisecond time resolution, then the time will be rounded up to
6301** the nearest second. The number of milliseconds of sleep actually
6302** requested from the operating system is returned.
6303**
6304** ^SQLite implements this interface by calling the xSleep()
6305** method of the default [sqlite3_vfs] object. If the xSleep() method
6306** of the default VFS is not implemented correctly, or not implemented at
6307** all, then the behavior of sqlite3_sleep() may deviate from the description
6308** in the previous paragraphs.
6309**
6310** If a negative argument is passed to sqlite3_sleep() the results vary by
6311** VFS and operating system. Some system treat a negative argument as an
6312** instruction to sleep forever. Others understand it to mean do not sleep
6313** at all. ^In SQLite version 3.42.0 and later, a negative
6314** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6315** down into the xSleep method of the VFS.
6316*/
6317SQLITE_API int sqlite3_sleep(int);
6318
6319/*
6320** CAPI3REF: Name Of The Folder Holding Temporary Files
6321**
6322** ^(If this global variable is made to point to a string which is
6323** the name of a folder (a.k.a. directory), then all temporary files
6324** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6325** will be placed in that directory.)^ ^If this variable
6326** is a NULL pointer, then SQLite performs a search for an appropriate
6327** temporary file directory.
6328**
6329** Applications are strongly discouraged from using this global variable.
6330** It is required to set a temporary folder on Windows Runtime (WinRT).
6331** But for all other platforms, it is highly recommended that applications
6332** neither read nor write this variable. This global variable is a relic
6333** that exists for backwards compatibility of legacy applications and should
6334** be avoided in new projects.
6335**
6336** It is not safe to read or modify this variable in more than one
6337** thread at a time. It is not safe to read or modify this variable
6338** if a [database connection] is being used at the same time in a separate
6339** thread.
6340** It is intended that this variable be set once
6341** as part of process initialization and before any SQLite interface
6342** routines have been called and that this variable remain unchanged
6343** thereafter.
6344**
6345** ^The [temp_store_directory pragma] may modify this variable and cause
6346** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6347** the [temp_store_directory pragma] always assumes that any string
6348** that this variable points to is held in memory obtained from
6349** [sqlite3_malloc] and the pragma may attempt to free that memory
6350** using [sqlite3_free].
6351** Hence, if this variable is modified directly, either it should be
6352** made NULL or made to point to memory obtained from [sqlite3_malloc]
6353** or else the use of the [temp_store_directory pragma] should be avoided.
6354** Except when requested by the [temp_store_directory pragma], SQLite
6355** does not free the memory that sqlite3_temp_directory points to. If
6356** the application wants that memory to be freed, it must do
6357** so itself, taking care to only do so after all [database connection]
6358** objects have been destroyed.
6359**
6360** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6361** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6362** features that require the use of temporary files may fail. Here is an
6363** example of how to do this using C++ with the Windows Runtime:
6364**
6365** <blockquote><pre>
6366** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6367** &nbsp; TemporaryFolder->Path->Data();
6368** char zPathBuf&#91;MAX_PATH + 1&#93;;
6369** memset(zPathBuf, 0, sizeof(zPathBuf));
6370** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6371** &nbsp; NULL, NULL);
6372** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6373** </pre></blockquote>
6374*/
6375SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6376
6377/*
6378** CAPI3REF: Name Of The Folder Holding Database Files
6379**
6380** ^(If this global variable is made to point to a string which is
6381** the name of a folder (a.k.a. directory), then all database files
6382** specified with a relative pathname and created or accessed by
6383** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6384** to be relative to that directory.)^ ^If this variable is a NULL
6385** pointer, then SQLite assumes that all database files specified
6386** with a relative pathname are relative to the current directory
6387** for the process. Only the windows VFS makes use of this global
6388** variable; it is ignored by the unix VFS.
6389**
6390** Changing the value of this variable while a database connection is
6391** open can result in a corrupt database.
6392**
6393** It is not safe to read or modify this variable in more than one
6394** thread at a time. It is not safe to read or modify this variable
6395** if a [database connection] is being used at the same time in a separate
6396** thread.
6397** It is intended that this variable be set once
6398** as part of process initialization and before any SQLite interface
6399** routines have been called and that this variable remain unchanged
6400** thereafter.
6401**
6402** ^The [data_store_directory pragma] may modify this variable and cause
6403** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6404** the [data_store_directory pragma] always assumes that any string
6405** that this variable points to is held in memory obtained from
6406** [sqlite3_malloc] and the pragma may attempt to free that memory
6407** using [sqlite3_free].
6408** Hence, if this variable is modified directly, either it should be
6409** made NULL or made to point to memory obtained from [sqlite3_malloc]
6410** or else the use of the [data_store_directory pragma] should be avoided.
6411*/
6412SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6413
6414/*
6415** CAPI3REF: Win32 Specific Interface
6416**
6417** These interfaces are available only on Windows. The
6418** [sqlite3_win32_set_directory] interface is used to set the value associated
6419** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6420** zValue, depending on the value of the type parameter. The zValue parameter
6421** should be NULL to cause the previous value to be freed via [sqlite3_free];
6422** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6423** prior to being used. The [sqlite3_win32_set_directory] interface returns
6424** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6425** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6426** [sqlite3_data_directory] variable is intended to act as a replacement for
6427** the current directory on the sub-platforms of Win32 where that concept is
6428** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6429** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6430** sqlite3_win32_set_directory interface except the string parameter must be
6431** UTF-8 or UTF-16, respectively.
6432*/
6433SQLITE_API int sqlite3_win32_set_directory(
6434 unsigned long type, /* Identifier for directory being set or reset */
6435 void *zValue /* New value for directory being set or reset */
6436);
6437SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6438SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6439
6440/*
6441** CAPI3REF: Win32 Directory Types
6442**
6443** These macros are only available on Windows. They define the allowed values
6444** for the type argument to the [sqlite3_win32_set_directory] interface.
6445*/
6446#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6447#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6448
6449/*
6450** CAPI3REF: Test For Auto-Commit Mode
6451** KEYWORDS: {autocommit mode}
6452** METHOD: sqlite3
6453**
6454** ^The sqlite3_get_autocommit() interface returns non-zero or
6455** zero if the given database connection is or is not in autocommit mode,
6456** respectively. ^Autocommit mode is on by default.
6457** ^Autocommit mode is disabled by a [BEGIN] statement.
6458** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6459**
6460** If certain kinds of errors occur on a statement within a multi-statement
6461** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6462** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6463** transaction might be rolled back automatically. The only way to
6464** find out whether SQLite automatically rolled back the transaction after
6465** an error is to use this function.
6466**
6467** If another thread changes the autocommit status of the database
6468** connection while this routine is running, then the return value
6469** is undefined.
6470*/
6471SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6472
6473/*
6474** CAPI3REF: Find The Database Handle Of A Prepared Statement
6475** METHOD: sqlite3_stmt
6476**
6477** ^The sqlite3_db_handle interface returns the [database connection] handle
6478** to which a [prepared statement] belongs. ^The [database connection]
6479** returned by sqlite3_db_handle is the same [database connection]
6480** that was the first argument
6481** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6482** create the statement in the first place.
6483*/
6484SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6485
6486/*
6487** CAPI3REF: Return The Schema Name For A Database Connection
6488** METHOD: sqlite3
6489**
6490** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6491** for the N-th database on database connection D, or a NULL pointer of N is
6492** out of range. An N value of 0 means the main database file. An N of 1 is
6493** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6494** databases.
6495**
6496** Space to hold the string that is returned by sqlite3_db_name() is managed
6497** by SQLite itself. The string might be deallocated by any operation that
6498** changes the schema, including [ATTACH] or [DETACH] or calls to
6499** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6500** occur on a different thread. Applications that need to
6501** remember the string long-term should make their own copy. Applications that
6502** are accessing the same database connection simultaneously on multiple
6503** threads should mutex-protect calls to this API and should make their own
6504** private copy of the result prior to releasing the mutex.
6505*/
6506SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6507
6508/*
6509** CAPI3REF: Return The Filename For A Database Connection
6510** METHOD: sqlite3
6511**
6512** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6513** associated with database N of connection D.
6514** ^If there is no attached database N on the database
6515** connection D, or if database N is a temporary or in-memory database, then
6516** this function will return either a NULL pointer or an empty string.
6517**
6518** ^The string value returned by this routine is owned and managed by
6519** the database connection. ^The value will be valid until the database N
6520** is [DETACH]-ed or until the database connection closes.
6521**
6522** ^The filename returned by this function is the output of the
6523** xFullPathname method of the [VFS]. ^In other words, the filename
6524** will be an absolute pathname, even if the filename used
6525** to open the database originally was a URI or relative pathname.
6526**
6527** If the filename pointer returned by this routine is not NULL, then it
6528** can be used as the filename input parameter to these routines:
6529** <ul>
6530** <li> [sqlite3_uri_parameter()]
6531** <li> [sqlite3_uri_boolean()]
6532** <li> [sqlite3_uri_int64()]
6533** <li> [sqlite3_filename_database()]
6534** <li> [sqlite3_filename_journal()]
6535** <li> [sqlite3_filename_wal()]
6536** </ul>
6537*/
6538SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6539
6540/*
6541** CAPI3REF: Determine if a database is read-only
6542** METHOD: sqlite3
6543**
6544** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6545** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6546** the name of a database on connection D.
6547*/
6548SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6549
6550/*
6551** CAPI3REF: Determine the transaction state of a database
6552** METHOD: sqlite3
6553**
6554** ^The sqlite3_txn_state(D,S) interface returns the current
6555** [transaction state] of schema S in database connection D. ^If S is NULL,
6556** then the highest transaction state of any schema on database connection D
6557** is returned. Transaction states are (in order of lowest to highest):
6558** <ol>
6559** <li value="0"> SQLITE_TXN_NONE
6560** <li value="1"> SQLITE_TXN_READ
6561** <li value="2"> SQLITE_TXN_WRITE
6562** </ol>
6563** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6564** a valid schema, then -1 is returned.
6565*/
6566SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6567
6568/*
6569** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
6570** KEYWORDS: {transaction state}
6571**
6572** These constants define the current transaction state of a database file.
6573** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6574** constants in order to describe the transaction state of schema S
6575** in [database connection] D.
6576**
6577** <dl>
6578** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6579** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6580** pending.</dd>
6581**
6582** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6583** <dd>The SQLITE_TXN_READ state means that the database is currently
6584** in a read transaction. Content has been read from the database file
6585** but nothing in the database file has changed. The transaction state
6586** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6587** no other conflicting concurrent write transactions. The transaction
6588** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6589** [COMMIT].</dd>
6590**
6591** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6592** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6593** in a write transaction. Content has been written to the database file
6594** but has not yet committed. The transaction state will change to
6595** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6596*/
6597#define SQLITE_TXN_NONE 0
6598#define SQLITE_TXN_READ 1
6599#define SQLITE_TXN_WRITE 2
6600
6601/*
6602** CAPI3REF: Find the next prepared statement
6603** METHOD: sqlite3
6604**
6605** ^This interface returns a pointer to the next [prepared statement] after
6606** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6607** then this interface returns a pointer to the first prepared statement
6608** associated with the database connection pDb. ^If no prepared statement
6609** satisfies the conditions of this routine, it returns NULL.
6610**
6611** The [database connection] pointer D in a call to
6612** [sqlite3_next_stmt(D,S)] must refer to an open database
6613** connection and in particular must not be a NULL pointer.
6614*/
6615SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6616
6617/*
6618** CAPI3REF: Commit And Rollback Notification Callbacks
6619** METHOD: sqlite3
6620**
6621** ^The sqlite3_commit_hook() interface registers a callback
6622** function to be invoked whenever a transaction is [COMMIT | committed].
6623** ^Any callback set by a previous call to sqlite3_commit_hook()
6624** for the same database connection is overridden.
6625** ^The sqlite3_rollback_hook() interface registers a callback
6626** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6627** ^Any callback set by a previous call to sqlite3_rollback_hook()
6628** for the same database connection is overridden.
6629** ^The pArg argument is passed through to the callback.
6630** ^If the callback on a commit hook function returns non-zero,
6631** then the commit is converted into a rollback.
6632**
6633** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6634** return the P argument from the previous call of the same function
6635** on the same [database connection] D, or NULL for
6636** the first call for each function on D.
6637**
6638** The commit and rollback hook callbacks are not reentrant.
6639** The callback implementation must not do anything that will modify
6640** the database connection that invoked the callback. Any actions
6641** to modify the database connection must be deferred until after the
6642** completion of the [sqlite3_step()] call that triggered the commit
6643** or rollback hook in the first place.
6644** Note that running any other SQL statements, including SELECT statements,
6645** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6646** the database connections for the meaning of "modify" in this paragraph.
6647**
6648** ^Registering a NULL function disables the callback.
6649**
6650** ^When the commit hook callback routine returns zero, the [COMMIT]
6651** operation is allowed to continue normally. ^If the commit hook
6652** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6653** ^The rollback hook is invoked on a rollback that results from a commit
6654** hook returning non-zero, just as it would be with any other rollback.
6655**
6656** ^For the purposes of this API, a transaction is said to have been
6657** rolled back if an explicit "ROLLBACK" statement is executed, or
6658** an error or constraint causes an implicit rollback to occur.
6659** ^The rollback callback is not invoked if a transaction is
6660** automatically rolled back because the database connection is closed.
6661**
6662** See also the [sqlite3_update_hook()] interface.
6663*/
6664SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6665SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6666
6667/*
6668** CAPI3REF: Autovacuum Compaction Amount Callback
6669** METHOD: sqlite3
6670**
6671** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6672** function C that is invoked prior to each autovacuum of the database
6673** file. ^The callback is passed a copy of the generic data pointer (P),
6674** the schema-name of the attached database that is being autovacuumed,
6675** the size of the database file in pages, the number of free pages,
6676** and the number of bytes per page, respectively. The callback should
6677** return the number of free pages that should be removed by the
6678** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6679** ^If the value returned is greater than or equal to the number of
6680** free pages, then a complete autovacuum happens.
6681**
6682** <p>^If there are multiple ATTACH-ed database files that are being
6683** modified as part of a transaction commit, then the autovacuum pages
6684** callback is invoked separately for each file.
6685**
6686** <p><b>The callback is not reentrant.</b> The callback function should
6687** not attempt to invoke any other SQLite interface. If it does, bad
6688** things may happen, including segmentation faults and corrupt database
6689** files. The callback function should be a simple function that
6690** does some arithmetic on its input parameters and returns a result.
6691**
6692** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6693** destructor for the P parameter. ^If X is not NULL, then X(P) is
6694** invoked whenever the database connection closes or when the callback
6695** is overwritten by another invocation of sqlite3_autovacuum_pages().
6696**
6697** <p>^There is only one autovacuum pages callback per database connection.
6698** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6699** previous invocations for that database connection. ^If the callback
6700** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6701** then the autovacuum steps callback is cancelled. The return value
6702** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6703** be some other error code if something goes wrong. The current
6704** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6705** return codes might be added in future releases.
6706**
6707** <p>If no autovacuum pages callback is specified (the usual case) or
6708** a NULL pointer is provided for the callback,
6709** then the default behavior is to vacuum all free pages. So, in other
6710** words, the default behavior is the same as if the callback function
6711** were something like this:
6712**
6713** <blockquote><pre>
6714** &nbsp; unsigned int demonstration_autovac_pages_callback(
6715** &nbsp; void *pClientData,
6716** &nbsp; const char *zSchema,
6717** &nbsp; unsigned int nDbPage,
6718** &nbsp; unsigned int nFreePage,
6719** &nbsp; unsigned int nBytePerPage
6720** &nbsp; ){
6721** &nbsp; return nFreePage;
6722** &nbsp; }
6723** </pre></blockquote>
6724*/
6725SQLITE_API int sqlite3_autovacuum_pages(
6726 sqlite3 *db,
6727 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6728 void*,
6729 void(*)(void*)
6730);
6731
6732
6733/*
6734** CAPI3REF: Data Change Notification Callbacks
6735** METHOD: sqlite3
6736**
6737** ^The sqlite3_update_hook() interface registers a callback function
6738** with the [database connection] identified by the first argument
6739** to be invoked whenever a row is updated, inserted or deleted in
6740** a [rowid table].
6741** ^Any callback set by a previous call to this function
6742** for the same database connection is overridden.
6743**
6744** ^The second argument is a pointer to the function to invoke when a
6745** row is updated, inserted or deleted in a rowid table.
6746** ^The first argument to the callback is a copy of the third argument
6747** to sqlite3_update_hook().
6748** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6749** or [SQLITE_UPDATE], depending on the operation that caused the callback
6750** to be invoked.
6751** ^The third and fourth arguments to the callback contain pointers to the
6752** database and table name containing the affected row.
6753** ^The final callback parameter is the [rowid] of the row.
6754** ^In the case of an update, this is the [rowid] after the update takes place.
6755**
6756** ^(The update hook is not invoked when internal system tables are
6757** modified (i.e. sqlite_sequence).)^
6758** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6759**
6760** ^In the current implementation, the update hook
6761** is not invoked when conflicting rows are deleted because of an
6762** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6763** invoked when rows are deleted using the [truncate optimization].
6764** The exceptions defined in this paragraph might change in a future
6765** release of SQLite.
6766**
6767** The update hook implementation must not do anything that will modify
6768** the database connection that invoked the update hook. Any actions
6769** to modify the database connection must be deferred until after the
6770** completion of the [sqlite3_step()] call that triggered the update hook.
6771** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6772** database connections for the meaning of "modify" in this paragraph.
6773**
6774** ^The sqlite3_update_hook(D,C,P) function
6775** returns the P argument from the previous call
6776** on the same [database connection] D, or NULL for
6777** the first call on D.
6778**
6779** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6780** and [sqlite3_preupdate_hook()] interfaces.
6781*/
6782SQLITE_API void *sqlite3_update_hook(
6783 sqlite3*,
6784 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6785 void*
6786);
6787
6788/*
6789** CAPI3REF: Enable Or Disable Shared Pager Cache
6790**
6791** ^(This routine enables or disables the sharing of the database cache
6792** and schema data structures between [database connection | connections]
6793** to the same database. Sharing is enabled if the argument is true
6794** and disabled if the argument is false.)^
6795**
6796** This interface is omitted if SQLite is compiled with
6797** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
6798** compile-time option is recommended because the
6799** [use of shared cache mode is discouraged].
6800**
6801** ^Cache sharing is enabled and disabled for an entire process.
6802** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6803** In prior versions of SQLite,
6804** sharing was enabled or disabled for each thread separately.
6805**
6806** ^(The cache sharing mode set by this interface effects all subsequent
6807** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6808** Existing database connections continue to use the sharing mode
6809** that was in effect at the time they were opened.)^
6810**
6811** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6812** successfully. An [error code] is returned otherwise.)^
6813**
6814** ^Shared cache is disabled by default. It is recommended that it stay
6815** that way. In other words, do not use this routine. This interface
6816** continues to be provided for historical compatibility, but its use is
6817** discouraged. Any use of shared cache is discouraged. If shared cache
6818** must be used, it is recommended that shared cache only be enabled for
6819** individual database connections using the [sqlite3_open_v2()] interface
6820** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6821**
6822** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6823** and will always return SQLITE_MISUSE. On those systems,
6824** shared cache mode should be enabled per-database connection via
6825** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6826**
6827** This interface is threadsafe on processors where writing a
6828** 32-bit integer is atomic.
6829**
6830** See Also: [SQLite Shared-Cache Mode]
6831*/
6832SQLITE_API int sqlite3_enable_shared_cache(int);
6833
6834/*
6835** CAPI3REF: Attempt To Free Heap Memory
6836**
6837** ^The sqlite3_release_memory() interface attempts to free N bytes
6838** of heap memory by deallocating non-essential memory allocations
6839** held by the database library. Memory used to cache database
6840** pages to improve performance is an example of non-essential memory.
6841** ^sqlite3_release_memory() returns the number of bytes actually freed,
6842** which might be more or less than the amount requested.
6843** ^The sqlite3_release_memory() routine is a no-op returning zero
6844** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6845**
6846** See also: [sqlite3_db_release_memory()]
6847*/
6848SQLITE_API int sqlite3_release_memory(int);
6849
6850/*
6851** CAPI3REF: Free Memory Used By A Database Connection
6852** METHOD: sqlite3
6853**
6854** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6855** memory as possible from database connection D. Unlike the
6856** [sqlite3_release_memory()] interface, this interface is in effect even
6857** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6858** omitted.
6859**
6860** See also: [sqlite3_release_memory()]
6861*/
6862SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6863
6864/*
6865** CAPI3REF: Impose A Limit On Heap Size
6866**
6867** These interfaces impose limits on the amount of heap memory that will be
6868** by all database connections within a single process.
6869**
6870** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6871** soft limit on the amount of heap memory that may be allocated by SQLite.
6872** ^SQLite strives to keep heap memory utilization below the soft heap
6873** limit by reducing the number of pages held in the page cache
6874** as heap memory usages approaches the limit.
6875** ^The soft heap limit is "soft" because even though SQLite strives to stay
6876** below the limit, it will exceed the limit rather than generate
6877** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6878** is advisory only.
6879**
6880** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6881** N bytes on the amount of memory that will be allocated. ^The
6882** sqlite3_hard_heap_limit64(N) interface is similar to
6883** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6884** when the hard heap limit is reached.
6885**
6886** ^The return value from both sqlite3_soft_heap_limit64() and
6887** sqlite3_hard_heap_limit64() is the size of
6888** the heap limit prior to the call, or negative in the case of an
6889** error. ^If the argument N is negative
6890** then no change is made to the heap limit. Hence, the current
6891** size of heap limits can be determined by invoking
6892** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6893**
6894** ^Setting the heap limits to zero disables the heap limiter mechanism.
6895**
6896** ^The soft heap limit may not be greater than the hard heap limit.
6897** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6898** is invoked with a value of N that is greater than the hard heap limit,
6899** the soft heap limit is set to the value of the hard heap limit.
6900** ^The soft heap limit is automatically enabled whenever the hard heap
6901** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6902** the soft heap limit is outside the range of 1..N, then the soft heap
6903** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6904** hard heap limit is enabled makes the soft heap limit equal to the
6905** hard heap limit.
6906**
6907** The memory allocation limits can also be adjusted using
6908** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
6909**
6910** ^(The heap limits are not enforced in the current implementation
6911** if one or more of following conditions are true:
6912**
6913** <ul>
6914** <li> The limit value is set to zero.
6915** <li> Memory accounting is disabled using a combination of the
6916** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6917** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6918** <li> An alternative page cache implementation is specified using
6919** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6920** <li> The page cache allocates from its own memory pool supplied
6921** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6922** from the heap.
6923** </ul>)^
6924**
6925** The circumstances under which SQLite will enforce the heap limits may
6926** changes in future releases of SQLite.
6927*/
6928SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6929SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
6930
6931/*
6932** CAPI3REF: Deprecated Soft Heap Limit Interface
6933** DEPRECATED
6934**
6935** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6936** interface. This routine is provided for historical compatibility
6937** only. All new applications should use the
6938** [sqlite3_soft_heap_limit64()] interface rather than this one.
6939*/
6940SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6941
6942
6943/*
6944** CAPI3REF: Extract Metadata About A Column Of A Table
6945** METHOD: sqlite3
6946**
6947** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6948** information about column C of table T in database D
6949** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6950** interface returns SQLITE_OK and fills in the non-NULL pointers in
6951** the final five arguments with appropriate values if the specified
6952** column exists. ^The sqlite3_table_column_metadata() interface returns
6953** SQLITE_ERROR if the specified column does not exist.
6954** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6955** NULL pointer, then this routine simply checks for the existence of the
6956** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6957** does not. If the table name parameter T in a call to
6958** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6959** undefined behavior.
6960**
6961** ^The column is identified by the second, third and fourth parameters to
6962** this function. ^(The second parameter is either the name of the database
6963** (i.e. "main", "temp", or an attached database) containing the specified
6964** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6965** for the table using the same algorithm used by the database engine to
6966** resolve unqualified table references.
6967**
6968** ^The third and fourth parameters to this function are the table and column
6969** name of the desired column, respectively.
6970**
6971** ^Metadata is returned by writing to the memory locations passed as the 5th
6972** and subsequent parameters to this function. ^Any of these arguments may be
6973** NULL, in which case the corresponding element of metadata is omitted.
6974**
6975** ^(<blockquote>
6976** <table border="1">
6977** <tr><th> Parameter <th> Output<br>Type <th> Description
6978**
6979** <tr><td> 5th <td> const char* <td> Data type
6980** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6981** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6982** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6983** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6984** </table>
6985** </blockquote>)^
6986**
6987** ^The memory pointed to by the character pointers returned for the
6988** declaration type and collation sequence is valid until the next
6989** call to any SQLite API function.
6990**
6991** ^If the specified table is actually a view, an [error code] is returned.
6992**
6993** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6994** is not a [WITHOUT ROWID] table and an
6995** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6996** parameters are set for the explicitly declared column. ^(If there is no
6997** [INTEGER PRIMARY KEY] column, then the outputs
6998** for the [rowid] are set as follows:
6999**
7000** <pre>
7001** data type: "INTEGER"
7002** collation sequence: "BINARY"
7003** not null: 0
7004** primary key: 1
7005** auto increment: 0
7006** </pre>)^
7007**
7008** ^This function causes all database schemas to be read from disk and
7009** parsed, if that has not already been done, and returns an error if
7010** any errors are encountered while loading the schema.
7011*/
7012SQLITE_API int sqlite3_table_column_metadata(
7013 sqlite3 *db, /* Connection handle */
7014 const char *zDbName, /* Database name or NULL */
7015 const char *zTableName, /* Table name */
7016 const char *zColumnName, /* Column name */
7017 char const **pzDataType, /* OUTPUT: Declared data type */
7018 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7019 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7020 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7021 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7022);
7023
7024/*
7025** CAPI3REF: Load An Extension
7026** METHOD: sqlite3
7027**
7028** ^This interface loads an SQLite extension library from the named file.
7029**
7030** ^The sqlite3_load_extension() interface attempts to load an
7031** [SQLite extension] library contained in the file zFile. If
7032** the file cannot be loaded directly, attempts are made to load
7033** with various operating-system specific extensions added.
7034** So for example, if "samplelib" cannot be loaded, then names like
7035** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7036** be tried also.
7037**
7038** ^The entry point is zProc.
7039** ^(zProc may be 0, in which case SQLite will try to come up with an
7040** entry point name on its own. It first tries "sqlite3_extension_init".
7041** If that does not work, it constructs a name "sqlite3_X_init" where the
7042** X is consists of the lower-case equivalent of all ASCII alphabetic
7043** characters in the filename from the last "/" to the first following
7044** "." and omitting any initial "lib".)^
7045** ^The sqlite3_load_extension() interface returns
7046** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7047** ^If an error occurs and pzErrMsg is not 0, then the
7048** [sqlite3_load_extension()] interface shall attempt to
7049** fill *pzErrMsg with error message text stored in memory
7050** obtained from [sqlite3_malloc()]. The calling function
7051** should free this memory by calling [sqlite3_free()].
7052**
7053** ^Extension loading must be enabled using
7054** [sqlite3_enable_load_extension()] or
7055** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7056** prior to calling this API,
7057** otherwise an error will be returned.
7058**
7059** <b>Security warning:</b> It is recommended that the
7060** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7061** interface. The use of the [sqlite3_enable_load_extension()] interface
7062** should be avoided. This will keep the SQL function [load_extension()]
7063** disabled and prevent SQL injections from giving attackers
7064** access to extension loading capabilities.
7065**
7066** See also the [load_extension() SQL function].
7067*/
7068SQLITE_API int sqlite3_load_extension(
7069 sqlite3 *db, /* Load the extension into this database connection */
7070 const char *zFile, /* Name of the shared library containing extension */
7071 const char *zProc, /* Entry point. Derived from zFile if 0 */
7072 char **pzErrMsg /* Put error message here if not 0 */
7073);
7074
7075/*
7076** CAPI3REF: Enable Or Disable Extension Loading
7077** METHOD: sqlite3
7078**
7079** ^So as not to open security holes in older applications that are
7080** unprepared to deal with [extension loading], and as a means of disabling
7081** [extension loading] while evaluating user-entered SQL, the following API
7082** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7083**
7084** ^Extension loading is off by default.
7085** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7086** to turn extension loading on and call it with onoff==0 to turn
7087** it back off again.
7088**
7089** ^This interface enables or disables both the C-API
7090** [sqlite3_load_extension()] and the SQL function [load_extension()].
7091** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7092** to enable or disable only the C-API.)^
7093**
7094** <b>Security warning:</b> It is recommended that extension loading
7095** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7096** rather than this interface, so the [load_extension()] SQL function
7097** remains disabled. This will prevent SQL injections from giving attackers
7098** access to extension loading capabilities.
7099*/
7100SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7101
7102/*
7103** CAPI3REF: Automatically Load Statically Linked Extensions
7104**
7105** ^This interface causes the xEntryPoint() function to be invoked for
7106** each new [database connection] that is created. The idea here is that
7107** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7108** that is to be automatically loaded into all new database connections.
7109**
7110** ^(Even though the function prototype shows that xEntryPoint() takes
7111** no arguments and returns void, SQLite invokes xEntryPoint() with three
7112** arguments and expects an integer result as if the signature of the
7113** entry point where as follows:
7114**
7115** <blockquote><pre>
7116** &nbsp; int xEntryPoint(
7117** &nbsp; sqlite3 *db,
7118** &nbsp; const char **pzErrMsg,
7119** &nbsp; const struct sqlite3_api_routines *pThunk
7120** &nbsp; );
7121** </pre></blockquote>)^
7122**
7123** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7124** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7125** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7126** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7127** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7128** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7129** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7130**
7131** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7132** on the list of automatic extensions is a harmless no-op. ^No entry point
7133** will be called more than once for each database connection that is opened.
7134**
7135** See also: [sqlite3_reset_auto_extension()]
7136** and [sqlite3_cancel_auto_extension()]
7137*/
7138SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7139
7140/*
7141** CAPI3REF: Cancel Automatic Extension Loading
7142**
7143** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7144** initialization routine X that was registered using a prior call to
7145** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7146** routine returns 1 if initialization routine X was successfully
7147** unregistered and it returns 0 if X was not on the list of initialization
7148** routines.
7149*/
7150SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7151
7152/*
7153** CAPI3REF: Reset Automatic Extension Loading
7154**
7155** ^This interface disables all automatic extensions previously
7156** registered using [sqlite3_auto_extension()].
7157*/
7158SQLITE_API void sqlite3_reset_auto_extension(void);
7159
7160/*
7161** Structures used by the virtual table interface
7162*/
7163typedef struct sqlite3_vtab sqlite3_vtab;
7164typedef struct sqlite3_index_info sqlite3_index_info;
7165typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7166typedef struct sqlite3_module sqlite3_module;
7167
7168/*
7169** CAPI3REF: Virtual Table Object
7170** KEYWORDS: sqlite3_module {virtual table module}
7171**
7172** This structure, sometimes called a "virtual table module",
7173** defines the implementation of a [virtual table].
7174** This structure consists mostly of methods for the module.
7175**
7176** ^A virtual table module is created by filling in a persistent
7177** instance of this structure and passing a pointer to that instance
7178** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7179** ^The registration remains valid until it is replaced by a different
7180** module or until the [database connection] closes. The content
7181** of this structure must not change while it is registered with
7182** any database connection.
7183*/
7184struct sqlite3_module {
7185 int iVersion;
7186 int (*xCreate)(sqlite3*, void *pAux,
7187 int argc, const char *const*argv,
7188 sqlite3_vtab **ppVTab, char**);
7189 int (*xConnect)(sqlite3*, void *pAux,
7190 int argc, const char *const*argv,
7191 sqlite3_vtab **ppVTab, char**);
7192 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7193 int (*xDisconnect)(sqlite3_vtab *pVTab);
7194 int (*xDestroy)(sqlite3_vtab *pVTab);
7195 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7196 int (*xClose)(sqlite3_vtab_cursor*);
7197 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7198 int argc, sqlite3_value **argv);
7199 int (*xNext)(sqlite3_vtab_cursor*);
7200 int (*xEof)(sqlite3_vtab_cursor*);
7201 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7202 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7203 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7204 int (*xBegin)(sqlite3_vtab *pVTab);
7205 int (*xSync)(sqlite3_vtab *pVTab);
7206 int (*xCommit)(sqlite3_vtab *pVTab);
7207 int (*xRollback)(sqlite3_vtab *pVTab);
7208 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7209 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7210 void **ppArg);
7211 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7212 /* The methods above are in version 1 of the sqlite_module object. Those
7213 ** below are for version 2 and greater. */
7214 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7215 int (*xRelease)(sqlite3_vtab *pVTab, int);
7216 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7217 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7218 ** Those below are for version 3 and greater. */
7219 int (*xShadowName)(const char*);
7220};
7221
7222/*
7223** CAPI3REF: Virtual Table Indexing Information
7224** KEYWORDS: sqlite3_index_info
7225**
7226** The sqlite3_index_info structure and its substructures is used as part
7227** of the [virtual table] interface to
7228** pass information into and receive the reply from the [xBestIndex]
7229** method of a [virtual table module]. The fields under **Inputs** are the
7230** inputs to xBestIndex and are read-only. xBestIndex inserts its
7231** results into the **Outputs** fields.
7232**
7233** ^(The aConstraint[] array records WHERE clause constraints of the form:
7234**
7235** <blockquote>column OP expr</blockquote>
7236**
7237** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7238** stored in aConstraint[].op using one of the
7239** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7240** ^(The index of the column is stored in
7241** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7242** expr on the right-hand side can be evaluated (and thus the constraint
7243** is usable) and false if it cannot.)^
7244**
7245** ^The optimizer automatically inverts terms of the form "expr OP column"
7246** and makes other simplifications to the WHERE clause in an attempt to
7247** get as many WHERE clause terms into the form shown above as possible.
7248** ^The aConstraint[] array only reports WHERE clause terms that are
7249** relevant to the particular virtual table being queried.
7250**
7251** ^Information about the ORDER BY clause is stored in aOrderBy[].
7252** ^Each term of aOrderBy records a column of the ORDER BY clause.
7253**
7254** The colUsed field indicates which columns of the virtual table may be
7255** required by the current scan. Virtual table columns are numbered from
7256** zero in the order in which they appear within the CREATE TABLE statement
7257** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7258** the corresponding bit is set within the colUsed mask if the column may be
7259** required by SQLite. If the table has at least 64 columns and any column
7260** to the right of the first 63 is required, then bit 63 of colUsed is also
7261** set. In other words, column iCol may be required if the expression
7262** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7263** non-zero.
7264**
7265** The [xBestIndex] method must fill aConstraintUsage[] with information
7266** about what parameters to pass to xFilter. ^If argvIndex>0 then
7267** the right-hand side of the corresponding aConstraint[] is evaluated
7268** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7269** is true, then the constraint is assumed to be fully handled by the
7270** virtual table and might not be checked again by the byte code.)^ ^(The
7271** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7272** is left in its default setting of false, the constraint will always be
7273** checked separately in byte code. If the omit flag is change to true, then
7274** the constraint may or may not be checked in byte code. In other words,
7275** when the omit flag is true there is no guarantee that the constraint will
7276** not be checked again using byte code.)^
7277**
7278** ^The idxNum and idxStr values are recorded and passed into the
7279** [xFilter] method.
7280** ^[sqlite3_free()] is used to free idxStr if and only if
7281** needToFreeIdxStr is true.
7282**
7283** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7284** the correct order to satisfy the ORDER BY clause so that no separate
7285** sorting step is required.
7286**
7287** ^The estimatedCost value is an estimate of the cost of a particular
7288** strategy. A cost of N indicates that the cost of the strategy is similar
7289** to a linear scan of an SQLite table with N rows. A cost of log(N)
7290** indicates that the expense of the operation is similar to that of a
7291** binary search on a unique indexed field of an SQLite table with N rows.
7292**
7293** ^The estimatedRows value is an estimate of the number of rows that
7294** will be returned by the strategy.
7295**
7296** The xBestIndex method may optionally populate the idxFlags field with a
7297** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7298** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7299** assumes that the strategy may visit at most one row.
7300**
7301** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7302** SQLite also assumes that if a call to the xUpdate() method is made as
7303** part of the same statement to delete or update a virtual table row and the
7304** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7305** any database changes. In other words, if the xUpdate() returns
7306** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7307** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7308** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7309** the xUpdate method are automatically rolled back by SQLite.
7310**
7311** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7312** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7313** If a virtual table extension is
7314** used with an SQLite version earlier than 3.8.2, the results of attempting
7315** to read or write the estimatedRows field are undefined (but are likely
7316** to include crashing the application). The estimatedRows field should
7317** therefore only be used if [sqlite3_libversion_number()] returns a
7318** value greater than or equal to 3008002. Similarly, the idxFlags field
7319** was added for [version 3.9.0] ([dateof:3.9.0]).
7320** It may therefore only be used if
7321** sqlite3_libversion_number() returns a value greater than or equal to
7322** 3009000.
7323*/
7324struct sqlite3_index_info {
7325 /* Inputs */
7326 int nConstraint; /* Number of entries in aConstraint */
7327 struct sqlite3_index_constraint {
7328 int iColumn; /* Column constrained. -1 for ROWID */
7329 unsigned char op; /* Constraint operator */
7330 unsigned char usable; /* True if this constraint is usable */
7331 int iTermOffset; /* Used internally - xBestIndex should ignore */
7332 } *aConstraint; /* Table of WHERE clause constraints */
7333 int nOrderBy; /* Number of terms in the ORDER BY clause */
7334 struct sqlite3_index_orderby {
7335 int iColumn; /* Column number */
7336 unsigned char desc; /* True for DESC. False for ASC. */
7337 } *aOrderBy; /* The ORDER BY clause */
7338 /* Outputs */
7339 struct sqlite3_index_constraint_usage {
7340 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7341 unsigned char omit; /* Do not code a test for this constraint */
7342 } *aConstraintUsage;
7343 int idxNum; /* Number used to identify the index */
7344 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7345 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7346 int orderByConsumed; /* True if output is already ordered */
7347 double estimatedCost; /* Estimated cost of using this index */
7348 /* Fields below are only available in SQLite 3.8.2 and later */
7349 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7350 /* Fields below are only available in SQLite 3.9.0 and later */
7351 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7352 /* Fields below are only available in SQLite 3.10.0 and later */
7353 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7354};
7355
7356/*
7357** CAPI3REF: Virtual Table Scan Flags
7358**
7359** Virtual table implementations are allowed to set the
7360** [sqlite3_index_info].idxFlags field to some combination of
7361** these bits.
7362*/
7363#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7364
7365/*
7366** CAPI3REF: Virtual Table Constraint Operator Codes
7367**
7368** These macros define the allowed values for the
7369** [sqlite3_index_info].aConstraint[].op field. Each value represents
7370** an operator that is part of a constraint term in the WHERE clause of
7371** a query that uses a [virtual table].
7372**
7373** ^The left-hand operand of the operator is given by the corresponding
7374** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7375** operand is the rowid.
7376** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7377** operators have no left-hand operand, and so for those operators the
7378** corresponding aConstraint[].iColumn is meaningless and should not be
7379** used.
7380**
7381** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7382** value 255 are reserved to represent functions that are overloaded
7383** by the [xFindFunction|xFindFunction method] of the virtual table
7384** implementation.
7385**
7386** The right-hand operands for each constraint might be accessible using
7387** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7388** operand is only available if it appears as a single constant literal
7389** in the input SQL. If the right-hand operand is another column or an
7390** expression (even a constant expression) or a parameter, then the
7391** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7392** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7393** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7394** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7395** always return SQLITE_NOTFOUND.
7396**
7397** The collating sequence to be used for comparison can be found using
7398** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7399** tables, the collating sequence of constraints does not matter (for example
7400** because the constraints are numeric) and so the sqlite3_vtab_collation()
7401** interface is not commonly needed.
7402*/
7403#define SQLITE_INDEX_CONSTRAINT_EQ 2
7404#define SQLITE_INDEX_CONSTRAINT_GT 4
7405#define SQLITE_INDEX_CONSTRAINT_LE 8
7406#define SQLITE_INDEX_CONSTRAINT_LT 16
7407#define SQLITE_INDEX_CONSTRAINT_GE 32
7408#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7409#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7410#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7411#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7412#define SQLITE_INDEX_CONSTRAINT_NE 68
7413#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7414#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7415#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7416#define SQLITE_INDEX_CONSTRAINT_IS 72
7417#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7418#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7419#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7420
7421/*
7422** CAPI3REF: Register A Virtual Table Implementation
7423** METHOD: sqlite3
7424**
7425** ^These routines are used to register a new [virtual table module] name.
7426** ^Module names must be registered before
7427** creating a new [virtual table] using the module and before using a
7428** preexisting [virtual table] for the module.
7429**
7430** ^The module name is registered on the [database connection] specified
7431** by the first parameter. ^The name of the module is given by the
7432** second parameter. ^The third parameter is a pointer to
7433** the implementation of the [virtual table module]. ^The fourth
7434** parameter is an arbitrary client data pointer that is passed through
7435** into the [xCreate] and [xConnect] methods of the virtual table module
7436** when a new virtual table is be being created or reinitialized.
7437**
7438** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7439** is a pointer to a destructor for the pClientData. ^SQLite will
7440** invoke the destructor function (if it is not NULL) when SQLite
7441** no longer needs the pClientData pointer. ^The destructor will also
7442** be invoked if the call to sqlite3_create_module_v2() fails.
7443** ^The sqlite3_create_module()
7444** interface is equivalent to sqlite3_create_module_v2() with a NULL
7445** destructor.
7446**
7447** ^If the third parameter (the pointer to the sqlite3_module object) is
7448** NULL then no new module is created and any existing modules with the
7449** same name are dropped.
7450**
7451** See also: [sqlite3_drop_modules()]
7452*/
7453SQLITE_API int sqlite3_create_module(
7454 sqlite3 *db, /* SQLite connection to register module with */
7455 const char *zName, /* Name of the module */
7456 const sqlite3_module *p, /* Methods for the module */
7457 void *pClientData /* Client data for xCreate/xConnect */
7458);
7459SQLITE_API int sqlite3_create_module_v2(
7460 sqlite3 *db, /* SQLite connection to register module with */
7461 const char *zName, /* Name of the module */
7462 const sqlite3_module *p, /* Methods for the module */
7463 void *pClientData, /* Client data for xCreate/xConnect */
7464 void(*xDestroy)(void*) /* Module destructor function */
7465);
7466
7467/*
7468** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7469** METHOD: sqlite3
7470**
7471** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7472** table modules from database connection D except those named on list L.
7473** The L parameter must be either NULL or a pointer to an array of pointers
7474** to strings where the array is terminated by a single NULL pointer.
7475** ^If the L parameter is NULL, then all virtual table modules are removed.
7476**
7477** See also: [sqlite3_create_module()]
7478*/
7479SQLITE_API int sqlite3_drop_modules(
7480 sqlite3 *db, /* Remove modules from this connection */
7481 const char **azKeep /* Except, do not remove the ones named here */
7482);
7483
7484/*
7485** CAPI3REF: Virtual Table Instance Object
7486** KEYWORDS: sqlite3_vtab
7487**
7488** Every [virtual table module] implementation uses a subclass
7489** of this object to describe a particular instance
7490** of the [virtual table]. Each subclass will
7491** be tailored to the specific needs of the module implementation.
7492** The purpose of this superclass is to define certain fields that are
7493** common to all module implementations.
7494**
7495** ^Virtual tables methods can set an error message by assigning a
7496** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7497** take care that any prior string is freed by a call to [sqlite3_free()]
7498** prior to assigning a new string to zErrMsg. ^After the error message
7499** is delivered up to the client application, the string will be automatically
7500** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7501*/
7502struct sqlite3_vtab {
7503 const sqlite3_module *pModule; /* The module for this virtual table */
7504 int nRef; /* Number of open cursors */
7505 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7506 /* Virtual table implementations will typically add additional fields */
7507};
7508
7509/*
7510** CAPI3REF: Virtual Table Cursor Object
7511** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7512**
7513** Every [virtual table module] implementation uses a subclass of the
7514** following structure to describe cursors that point into the
7515** [virtual table] and are used
7516** to loop through the virtual table. Cursors are created using the
7517** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7518** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7519** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7520** of the module. Each module implementation will define
7521** the content of a cursor structure to suit its own needs.
7522**
7523** This superclass exists in order to define fields of the cursor that
7524** are common to all implementations.
7525*/
7526struct sqlite3_vtab_cursor {
7527 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7528 /* Virtual table implementations will typically add additional fields */
7529};
7530
7531/*
7532** CAPI3REF: Declare The Schema Of A Virtual Table
7533**
7534** ^The [xCreate] and [xConnect] methods of a
7535** [virtual table module] call this interface
7536** to declare the format (the names and datatypes of the columns) of
7537** the virtual tables they implement.
7538*/
7539SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7540
7541/*
7542** CAPI3REF: Overload A Function For A Virtual Table
7543** METHOD: sqlite3
7544**
7545** ^(Virtual tables can provide alternative implementations of functions
7546** using the [xFindFunction] method of the [virtual table module].
7547** But global versions of those functions
7548** must exist in order to be overloaded.)^
7549**
7550** ^(This API makes sure a global version of a function with a particular
7551** name and number of parameters exists. If no such function exists
7552** before this API is called, a new function is created.)^ ^The implementation
7553** of the new function always causes an exception to be thrown. So
7554** the new function is not good for anything by itself. Its only
7555** purpose is to be a placeholder function that can be overloaded
7556** by a [virtual table].
7557*/
7558SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7559
7560/*
7561** CAPI3REF: A Handle To An Open BLOB
7562** KEYWORDS: {BLOB handle} {BLOB handles}
7563**
7564** An instance of this object represents an open BLOB on which
7565** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7566** ^Objects of this type are created by [sqlite3_blob_open()]
7567** and destroyed by [sqlite3_blob_close()].
7568** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7569** can be used to read or write small subsections of the BLOB.
7570** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7571*/
7572typedef struct sqlite3_blob sqlite3_blob;
7573
7574/*
7575** CAPI3REF: Open A BLOB For Incremental I/O
7576** METHOD: sqlite3
7577** CONSTRUCTOR: sqlite3_blob
7578**
7579** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7580** in row iRow, column zColumn, table zTable in database zDb;
7581** in other words, the same BLOB that would be selected by:
7582**
7583** <pre>
7584** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7585** </pre>)^
7586**
7587** ^(Parameter zDb is not the filename that contains the database, but
7588** rather the symbolic name of the database. For attached databases, this is
7589** the name that appears after the AS keyword in the [ATTACH] statement.
7590** For the main database file, the database name is "main". For TEMP
7591** tables, the database name is "temp".)^
7592**
7593** ^If the flags parameter is non-zero, then the BLOB is opened for read
7594** and write access. ^If the flags parameter is zero, the BLOB is opened for
7595** read-only access.
7596**
7597** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7598** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7599** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7600** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7601** on *ppBlob after this function it returns.
7602**
7603** This function fails with SQLITE_ERROR if any of the following are true:
7604** <ul>
7605** <li> ^(Database zDb does not exist)^,
7606** <li> ^(Table zTable does not exist within database zDb)^,
7607** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7608** <li> ^(Column zColumn does not exist)^,
7609** <li> ^(Row iRow is not present in the table)^,
7610** <li> ^(The specified column of row iRow contains a value that is not
7611** a TEXT or BLOB value)^,
7612** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7613** constraint and the blob is being opened for read/write access)^,
7614** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7615** column zColumn is part of a [child key] definition and the blob is
7616** being opened for read/write access)^.
7617** </ul>
7618**
7619** ^Unless it returns SQLITE_MISUSE, this function sets the
7620** [database connection] error code and message accessible via
7621** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7622**
7623** A BLOB referenced by sqlite3_blob_open() may be read using the
7624** [sqlite3_blob_read()] interface and modified by using
7625** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7626** different row of the same table using the [sqlite3_blob_reopen()]
7627** interface. However, the column, table, or database of a [BLOB handle]
7628** cannot be changed after the [BLOB handle] is opened.
7629**
7630** ^(If the row that a BLOB handle points to is modified by an
7631** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7632** then the BLOB handle is marked as "expired".
7633** This is true if any column of the row is changed, even a column
7634** other than the one the BLOB handle is open on.)^
7635** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7636** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7637** ^(Changes written into a BLOB prior to the BLOB expiring are not
7638** rolled back by the expiration of the BLOB. Such changes will eventually
7639** commit if the transaction continues to completion.)^
7640**
7641** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7642** the opened blob. ^The size of a blob may not be changed by this
7643** interface. Use the [UPDATE] SQL command to change the size of a
7644** blob.
7645**
7646** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7647** and the built-in [zeroblob] SQL function may be used to create a
7648** zero-filled blob to read or write using the incremental-blob interface.
7649**
7650** To avoid a resource leak, every open [BLOB handle] should eventually
7651** be released by a call to [sqlite3_blob_close()].
7652**
7653** See also: [sqlite3_blob_close()],
7654** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7655** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7656*/
7657SQLITE_API int sqlite3_blob_open(
7658 sqlite3*,
7659 const char *zDb,
7660 const char *zTable,
7661 const char *zColumn,
7662 sqlite3_int64 iRow,
7663 int flags,
7664 sqlite3_blob **ppBlob
7665);
7666
7667/*
7668** CAPI3REF: Move a BLOB Handle to a New Row
7669** METHOD: sqlite3_blob
7670**
7671** ^This function is used to move an existing [BLOB handle] so that it points
7672** to a different row of the same database table. ^The new row is identified
7673** by the rowid value passed as the second argument. Only the row can be
7674** changed. ^The database, table and column on which the blob handle is open
7675** remain the same. Moving an existing [BLOB handle] to a new row is
7676** faster than closing the existing handle and opening a new one.
7677**
7678** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7679** it must exist and there must be either a blob or text value stored in
7680** the nominated column.)^ ^If the new row is not present in the table, or if
7681** it does not contain a blob or text value, or if another error occurs, an
7682** SQLite error code is returned and the blob handle is considered aborted.
7683** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7684** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7685** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7686** always returns zero.
7687**
7688** ^This function sets the database handle error code and message.
7689*/
7690SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7691
7692/*
7693** CAPI3REF: Close A BLOB Handle
7694** DESTRUCTOR: sqlite3_blob
7695**
7696** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7697** unconditionally. Even if this routine returns an error code, the
7698** handle is still closed.)^
7699**
7700** ^If the blob handle being closed was opened for read-write access, and if
7701** the database is in auto-commit mode and there are no other open read-write
7702** blob handles or active write statements, the current transaction is
7703** committed. ^If an error occurs while committing the transaction, an error
7704** code is returned and the transaction rolled back.
7705**
7706** Calling this function with an argument that is not a NULL pointer or an
7707** open blob handle results in undefined behaviour. ^Calling this routine
7708** with a null pointer (such as would be returned by a failed call to
7709** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7710** is passed a valid open blob handle, the values returned by the
7711** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7712*/
7713SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7714
7715/*
7716** CAPI3REF: Return The Size Of An Open BLOB
7717** METHOD: sqlite3_blob
7718**
7719** ^Returns the size in bytes of the BLOB accessible via the
7720** successfully opened [BLOB handle] in its only argument. ^The
7721** incremental blob I/O routines can only read or overwriting existing
7722** blob content; they cannot change the size of a blob.
7723**
7724** This routine only works on a [BLOB handle] which has been created
7725** by a prior successful call to [sqlite3_blob_open()] and which has not
7726** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7727** to this routine results in undefined and probably undesirable behavior.
7728*/
7729SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7730
7731/*
7732** CAPI3REF: Read Data From A BLOB Incrementally
7733** METHOD: sqlite3_blob
7734**
7735** ^(This function is used to read data from an open [BLOB handle] into a
7736** caller-supplied buffer. N bytes of data are copied into buffer Z
7737** from the open BLOB, starting at offset iOffset.)^
7738**
7739** ^If offset iOffset is less than N bytes from the end of the BLOB,
7740** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7741** less than zero, [SQLITE_ERROR] is returned and no data is read.
7742** ^The size of the blob (and hence the maximum value of N+iOffset)
7743** can be determined using the [sqlite3_blob_bytes()] interface.
7744**
7745** ^An attempt to read from an expired [BLOB handle] fails with an
7746** error code of [SQLITE_ABORT].
7747**
7748** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7749** Otherwise, an [error code] or an [extended error code] is returned.)^
7750**
7751** This routine only works on a [BLOB handle] which has been created
7752** by a prior successful call to [sqlite3_blob_open()] and which has not
7753** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7754** to this routine results in undefined and probably undesirable behavior.
7755**
7756** See also: [sqlite3_blob_write()].
7757*/
7758SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7759
7760/*
7761** CAPI3REF: Write Data Into A BLOB Incrementally
7762** METHOD: sqlite3_blob
7763**
7764** ^(This function is used to write data into an open [BLOB handle] from a
7765** caller-supplied buffer. N bytes of data are copied from the buffer Z
7766** into the open BLOB, starting at offset iOffset.)^
7767**
7768** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7769** Otherwise, an [error code] or an [extended error code] is returned.)^
7770** ^Unless SQLITE_MISUSE is returned, this function sets the
7771** [database connection] error code and message accessible via
7772** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7773**
7774** ^If the [BLOB handle] passed as the first argument was not opened for
7775** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7776** this function returns [SQLITE_READONLY].
7777**
7778** This function may only modify the contents of the BLOB; it is
7779** not possible to increase the size of a BLOB using this API.
7780** ^If offset iOffset is less than N bytes from the end of the BLOB,
7781** [SQLITE_ERROR] is returned and no data is written. The size of the
7782** BLOB (and hence the maximum value of N+iOffset) can be determined
7783** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7784** than zero [SQLITE_ERROR] is returned and no data is written.
7785**
7786** ^An attempt to write to an expired [BLOB handle] fails with an
7787** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7788** before the [BLOB handle] expired are not rolled back by the
7789** expiration of the handle, though of course those changes might
7790** have been overwritten by the statement that expired the BLOB handle
7791** or by other independent statements.
7792**
7793** This routine only works on a [BLOB handle] which has been created
7794** by a prior successful call to [sqlite3_blob_open()] and which has not
7795** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7796** to this routine results in undefined and probably undesirable behavior.
7797**
7798** See also: [sqlite3_blob_read()].
7799*/
7800SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7801
7802/*
7803** CAPI3REF: Virtual File System Objects
7804**
7805** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7806** that SQLite uses to interact
7807** with the underlying operating system. Most SQLite builds come with a
7808** single default VFS that is appropriate for the host computer.
7809** New VFSes can be registered and existing VFSes can be unregistered.
7810** The following interfaces are provided.
7811**
7812** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7813** ^Names are case sensitive.
7814** ^Names are zero-terminated UTF-8 strings.
7815** ^If there is no match, a NULL pointer is returned.
7816** ^If zVfsName is NULL then the default VFS is returned.
7817**
7818** ^New VFSes are registered with sqlite3_vfs_register().
7819** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7820** ^The same VFS can be registered multiple times without injury.
7821** ^To make an existing VFS into the default VFS, register it again
7822** with the makeDflt flag set. If two different VFSes with the
7823** same name are registered, the behavior is undefined. If a
7824** VFS is registered with a name that is NULL or an empty string,
7825** then the behavior is undefined.
7826**
7827** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7828** ^(If the default VFS is unregistered, another VFS is chosen as
7829** the default. The choice for the new VFS is arbitrary.)^
7830*/
7831SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7832SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7833SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7834
7835/*
7836** CAPI3REF: Mutexes
7837**
7838** The SQLite core uses these routines for thread
7839** synchronization. Though they are intended for internal
7840** use by SQLite, code that links against SQLite is
7841** permitted to use any of these routines.
7842**
7843** The SQLite source code contains multiple implementations
7844** of these mutex routines. An appropriate implementation
7845** is selected automatically at compile-time. The following
7846** implementations are available in the SQLite core:
7847**
7848** <ul>
7849** <li> SQLITE_MUTEX_PTHREADS
7850** <li> SQLITE_MUTEX_W32
7851** <li> SQLITE_MUTEX_NOOP
7852** </ul>
7853**
7854** The SQLITE_MUTEX_NOOP implementation is a set of routines
7855** that does no real locking and is appropriate for use in
7856** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7857** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7858** and Windows.
7859**
7860** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7861** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7862** implementation is included with the library. In this case the
7863** application must supply a custom mutex implementation using the
7864** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7865** before calling sqlite3_initialize() or any other public sqlite3_
7866** function that calls sqlite3_initialize().
7867**
7868** ^The sqlite3_mutex_alloc() routine allocates a new
7869** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7870** routine returns NULL if it is unable to allocate the requested
7871** mutex. The argument to sqlite3_mutex_alloc() must one of these
7872** integer constants:
7873**
7874** <ul>
7875** <li> SQLITE_MUTEX_FAST
7876** <li> SQLITE_MUTEX_RECURSIVE
7877** <li> SQLITE_MUTEX_STATIC_MAIN
7878** <li> SQLITE_MUTEX_STATIC_MEM
7879** <li> SQLITE_MUTEX_STATIC_OPEN
7880** <li> SQLITE_MUTEX_STATIC_PRNG
7881** <li> SQLITE_MUTEX_STATIC_LRU
7882** <li> SQLITE_MUTEX_STATIC_PMEM
7883** <li> SQLITE_MUTEX_STATIC_APP1
7884** <li> SQLITE_MUTEX_STATIC_APP2
7885** <li> SQLITE_MUTEX_STATIC_APP3
7886** <li> SQLITE_MUTEX_STATIC_VFS1
7887** <li> SQLITE_MUTEX_STATIC_VFS2
7888** <li> SQLITE_MUTEX_STATIC_VFS3
7889** </ul>
7890**
7891** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7892** cause sqlite3_mutex_alloc() to create
7893** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7894** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7895** The mutex implementation does not need to make a distinction
7896** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7897** not want to. SQLite will only request a recursive mutex in
7898** cases where it really needs one. If a faster non-recursive mutex
7899** implementation is available on the host platform, the mutex subsystem
7900** might return such a mutex in response to SQLITE_MUTEX_FAST.
7901**
7902** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7903** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7904** a pointer to a static preexisting mutex. ^Nine static mutexes are
7905** used by the current version of SQLite. Future versions of SQLite
7906** may add additional static mutexes. Static mutexes are for internal
7907** use by SQLite only. Applications that use SQLite mutexes should
7908** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7909** SQLITE_MUTEX_RECURSIVE.
7910**
7911** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7912** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7913** returns a different mutex on every call. ^For the static
7914** mutex types, the same mutex is returned on every call that has
7915** the same type number.
7916**
7917** ^The sqlite3_mutex_free() routine deallocates a previously
7918** allocated dynamic mutex. Attempting to deallocate a static
7919** mutex results in undefined behavior.
7920**
7921** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7922** to enter a mutex. ^If another thread is already within the mutex,
7923** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7924** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7925** upon successful entry. ^(Mutexes created using
7926** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7927** In such cases, the
7928** mutex must be exited an equal number of times before another thread
7929** can enter.)^ If the same thread tries to enter any mutex other
7930** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7931**
7932** ^(Some systems (for example, Windows 95) do not support the operation
7933** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7934** will always return SQLITE_BUSY. The SQLite core only ever uses
7935** sqlite3_mutex_try() as an optimization so this is acceptable
7936** behavior.)^
7937**
7938** ^The sqlite3_mutex_leave() routine exits a mutex that was
7939** previously entered by the same thread. The behavior
7940** is undefined if the mutex is not currently entered by the
7941** calling thread or is not currently allocated.
7942**
7943** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
7944** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
7945** then any of the four routines behaves as a no-op.
7946**
7947** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7948*/
7949SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7950SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7951SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7952SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7953SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7954
7955/*
7956** CAPI3REF: Mutex Methods Object
7957**
7958** An instance of this structure defines the low-level routines
7959** used to allocate and use mutexes.
7960**
7961** Usually, the default mutex implementations provided by SQLite are
7962** sufficient, however the application has the option of substituting a custom
7963** implementation for specialized deployments or systems for which SQLite
7964** does not provide a suitable implementation. In this case, the application
7965** creates and populates an instance of this structure to pass
7966** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7967** Additionally, an instance of this structure can be used as an
7968** output variable when querying the system for the current mutex
7969** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7970**
7971** ^The xMutexInit method defined by this structure is invoked as
7972** part of system initialization by the sqlite3_initialize() function.
7973** ^The xMutexInit routine is called by SQLite exactly once for each
7974** effective call to [sqlite3_initialize()].
7975**
7976** ^The xMutexEnd method defined by this structure is invoked as
7977** part of system shutdown by the sqlite3_shutdown() function. The
7978** implementation of this method is expected to release all outstanding
7979** resources obtained by the mutex methods implementation, especially
7980** those obtained by the xMutexInit method. ^The xMutexEnd()
7981** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7982**
7983** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7984** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7985** xMutexNotheld) implement the following interfaces (respectively):
7986**
7987** <ul>
7988** <li> [sqlite3_mutex_alloc()] </li>
7989** <li> [sqlite3_mutex_free()] </li>
7990** <li> [sqlite3_mutex_enter()] </li>
7991** <li> [sqlite3_mutex_try()] </li>
7992** <li> [sqlite3_mutex_leave()] </li>
7993** <li> [sqlite3_mutex_held()] </li>
7994** <li> [sqlite3_mutex_notheld()] </li>
7995** </ul>)^
7996**
7997** The only difference is that the public sqlite3_XXX functions enumerated
7998** above silently ignore any invocations that pass a NULL pointer instead
7999** of a valid mutex handle. The implementations of the methods defined
8000** by this structure are not required to handle this case. The results
8001** of passing a NULL pointer instead of a valid mutex handle are undefined
8002** (i.e. it is acceptable to provide an implementation that segfaults if
8003** it is passed a NULL pointer).
8004**
8005** The xMutexInit() method must be threadsafe. It must be harmless to
8006** invoke xMutexInit() multiple times within the same process and without
8007** intervening calls to xMutexEnd(). Second and subsequent calls to
8008** xMutexInit() must be no-ops.
8009**
8010** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8011** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8012** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8013** memory allocation for a fast or recursive mutex.
8014**
8015** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8016** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8017** If xMutexInit fails in any way, it is expected to clean up after itself
8018** prior to returning.
8019*/
8020typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8021struct sqlite3_mutex_methods {
8022 int (*xMutexInit)(void);
8023 int (*xMutexEnd)(void);
8024 sqlite3_mutex *(*xMutexAlloc)(int);
8025 void (*xMutexFree)(sqlite3_mutex *);
8026 void (*xMutexEnter)(sqlite3_mutex *);
8027 int (*xMutexTry)(sqlite3_mutex *);
8028 void (*xMutexLeave)(sqlite3_mutex *);
8029 int (*xMutexHeld)(sqlite3_mutex *);
8030 int (*xMutexNotheld)(sqlite3_mutex *);
8031};
8032
8033/*
8034** CAPI3REF: Mutex Verification Routines
8035**
8036** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8037** are intended for use inside assert() statements. The SQLite core
8038** never uses these routines except inside an assert() and applications
8039** are advised to follow the lead of the core. The SQLite core only
8040** provides implementations for these routines when it is compiled
8041** with the SQLITE_DEBUG flag. External mutex implementations
8042** are only required to provide these routines if SQLITE_DEBUG is
8043** defined and if NDEBUG is not defined.
8044**
8045** These routines should return true if the mutex in their argument
8046** is held or not held, respectively, by the calling thread.
8047**
8048** The implementation is not required to provide versions of these
8049** routines that actually work. If the implementation does not provide working
8050** versions of these routines, it should at least provide stubs that always
8051** return true so that one does not get spurious assertion failures.
8052**
8053** If the argument to sqlite3_mutex_held() is a NULL pointer then
8054** the routine should return 1. This seems counter-intuitive since
8055** clearly the mutex cannot be held if it does not exist. But
8056** the reason the mutex does not exist is because the build is not
8057** using mutexes. And we do not want the assert() containing the
8058** call to sqlite3_mutex_held() to fail, so a non-zero return is
8059** the appropriate thing to do. The sqlite3_mutex_notheld()
8060** interface should also return 1 when given a NULL pointer.
8061*/
8062#ifndef NDEBUG
8063SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8064SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8065#endif
8066
8067/*
8068** CAPI3REF: Mutex Types
8069**
8070** The [sqlite3_mutex_alloc()] interface takes a single argument
8071** which is one of these integer constants.
8072**
8073** The set of static mutexes may change from one SQLite release to the
8074** next. Applications that override the built-in mutex logic must be
8075** prepared to accommodate additional static mutexes.
8076*/
8077#define SQLITE_MUTEX_FAST 0
8078#define SQLITE_MUTEX_RECURSIVE 1
8079#define SQLITE_MUTEX_STATIC_MAIN 2
8080#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8081#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8082#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8083#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8084#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8085#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8086#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8087#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8088#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8089#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8090#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8091#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8092#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8093
8094/* Legacy compatibility: */
8095#define SQLITE_MUTEX_STATIC_MASTER 2
8096
8097
8098/*
8099** CAPI3REF: Retrieve the mutex for a database connection
8100** METHOD: sqlite3
8101**
8102** ^This interface returns a pointer the [sqlite3_mutex] object that
8103** serializes access to the [database connection] given in the argument
8104** when the [threading mode] is Serialized.
8105** ^If the [threading mode] is Single-thread or Multi-thread then this
8106** routine returns a NULL pointer.
8107*/
8108SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8109
8110/*
8111** CAPI3REF: Low-Level Control Of Database Files
8112** METHOD: sqlite3
8113** KEYWORDS: {file control}
8114**
8115** ^The [sqlite3_file_control()] interface makes a direct call to the
8116** xFileControl method for the [sqlite3_io_methods] object associated
8117** with a particular database identified by the second argument. ^The
8118** name of the database is "main" for the main database or "temp" for the
8119** TEMP database, or the name that appears after the AS keyword for
8120** databases that are added using the [ATTACH] SQL command.
8121** ^A NULL pointer can be used in place of "main" to refer to the
8122** main database file.
8123** ^The third and fourth parameters to this routine
8124** are passed directly through to the second and third parameters of
8125** the xFileControl method. ^The return value of the xFileControl
8126** method becomes the return value of this routine.
8127**
8128** A few opcodes for [sqlite3_file_control()] are handled directly
8129** by the SQLite core and never invoke the
8130** sqlite3_io_methods.xFileControl method.
8131** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8132** a pointer to the underlying [sqlite3_file] object to be written into
8133** the space pointed to by the 4th parameter. The
8134** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8135** the [sqlite3_file] object associated with the journal file instead of
8136** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8137** a pointer to the underlying [sqlite3_vfs] object for the file.
8138** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8139** from the pager.
8140**
8141** ^If the second parameter (zDbName) does not match the name of any
8142** open database file, then SQLITE_ERROR is returned. ^This error
8143** code is not remembered and will not be recalled by [sqlite3_errcode()]
8144** or [sqlite3_errmsg()]. The underlying xFileControl method might
8145** also return SQLITE_ERROR. There is no way to distinguish between
8146** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8147** xFileControl method.
8148**
8149** See also: [file control opcodes]
8150*/
8151SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8152
8153/*
8154** CAPI3REF: Testing Interface
8155**
8156** ^The sqlite3_test_control() interface is used to read out internal
8157** state of SQLite and to inject faults into SQLite for testing
8158** purposes. ^The first parameter is an operation code that determines
8159** the number, meaning, and operation of all subsequent parameters.
8160**
8161** This interface is not for use by applications. It exists solely
8162** for verifying the correct operation of the SQLite library. Depending
8163** on how the SQLite library is compiled, this interface might not exist.
8164**
8165** The details of the operation codes, their meanings, the parameters
8166** they take, and what they do are all subject to change without notice.
8167** Unlike most of the SQLite API, this function is not guaranteed to
8168** operate consistently from one release to the next.
8169*/
8170SQLITE_API int sqlite3_test_control(int op, ...);
8171
8172/*
8173** CAPI3REF: Testing Interface Operation Codes
8174**
8175** These constants are the valid operation code parameters used
8176** as the first argument to [sqlite3_test_control()].
8177**
8178** These parameters and their meanings are subject to change
8179** without notice. These values are for testing purposes only.
8180** Applications should not use any of these parameters or the
8181** [sqlite3_test_control()] interface.
8182*/
8183#define SQLITE_TESTCTRL_FIRST 5
8184#define SQLITE_TESTCTRL_PRNG_SAVE 5
8185#define SQLITE_TESTCTRL_PRNG_RESTORE 6
8186#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8187#define SQLITE_TESTCTRL_BITVEC_TEST 8
8188#define SQLITE_TESTCTRL_FAULT_INSTALL 9
8189#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8190#define SQLITE_TESTCTRL_PENDING_BYTE 11
8191#define SQLITE_TESTCTRL_ASSERT 12
8192#define SQLITE_TESTCTRL_ALWAYS 13
8193#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8194#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8195#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8196#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8197#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8198#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8199#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8200#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8201#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8202#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8203#define SQLITE_TESTCTRL_BYTEORDER 22
8204#define SQLITE_TESTCTRL_ISINIT 23
8205#define SQLITE_TESTCTRL_SORTER_MMAP 24
8206#define SQLITE_TESTCTRL_IMPOSTER 25
8207#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8208#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8209#define SQLITE_TESTCTRL_PRNG_SEED 28
8210#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8211#define SQLITE_TESTCTRL_SEEK_COUNT 30
8212#define SQLITE_TESTCTRL_TRACEFLAGS 31
8213#define SQLITE_TESTCTRL_TUNE 32
8214#define SQLITE_TESTCTRL_LOGEST 33
8215#define SQLITE_TESTCTRL_USELONGDOUBLE 34
8216#define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8217
8218/*
8219** CAPI3REF: SQL Keyword Checking
8220**
8221** These routines provide access to the set of SQL language keywords
8222** recognized by SQLite. Applications can uses these routines to determine
8223** whether or not a specific identifier needs to be escaped (for example,
8224** by enclosing in double-quotes) so as not to confuse the parser.
8225**
8226** The sqlite3_keyword_count() interface returns the number of distinct
8227** keywords understood by SQLite.
8228**
8229** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
8230** makes *Z point to that keyword expressed as UTF8 and writes the number
8231** of bytes in the keyword into *L. The string that *Z points to is not
8232** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8233** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8234** or L are NULL or invalid pointers then calls to
8235** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8236**
8237** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8238** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8239** if it is and zero if not.
8240**
8241** The parser used by SQLite is forgiving. It is often possible to use
8242** a keyword as an identifier as long as such use does not result in a
8243** parsing ambiguity. For example, the statement
8244** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8245** creates a new table named "BEGIN" with three columns named
8246** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8247** using keywords as identifiers. Common techniques used to avoid keyword
8248** name collisions include:
8249** <ul>
8250** <li> Put all identifier names inside double-quotes. This is the official
8251** SQL way to escape identifier names.
8252** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8253** but it is what SQL Server does and so lots of programmers use this
8254** technique.
8255** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8256** with "Z".
8257** <li> Include a digit somewhere in every identifier name.
8258** </ul>
8259**
8260** Note that the number of keywords understood by SQLite can depend on
8261** compile-time options. For example, "VACUUM" is not a keyword if
8262** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8263** new keywords may be added to future releases of SQLite.
8264*/
8265SQLITE_API int sqlite3_keyword_count(void);
8266SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8267SQLITE_API int sqlite3_keyword_check(const char*,int);
8268
8269/*
8270** CAPI3REF: Dynamic String Object
8271** KEYWORDS: {dynamic string}
8272**
8273** An instance of the sqlite3_str object contains a dynamically-sized
8274** string under construction.
8275**
8276** The lifecycle of an sqlite3_str object is as follows:
8277** <ol>
8278** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8279** <li> ^Text is appended to the sqlite3_str object using various
8280** methods, such as [sqlite3_str_appendf()].
8281** <li> ^The sqlite3_str object is destroyed and the string it created
8282** is returned using the [sqlite3_str_finish()] interface.
8283** </ol>
8284*/
8285typedef struct sqlite3_str sqlite3_str;
8286
8287/*
8288** CAPI3REF: Create A New Dynamic String Object
8289** CONSTRUCTOR: sqlite3_str
8290**
8291** ^The [sqlite3_str_new(D)] interface allocates and initializes
8292** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8293** [sqlite3_str_new()] must be freed by a subsequent call to
8294** [sqlite3_str_finish(X)].
8295**
8296** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8297** valid [sqlite3_str] object, though in the event of an out-of-memory
8298** error the returned object might be a special singleton that will
8299** silently reject new text, always return SQLITE_NOMEM from
8300** [sqlite3_str_errcode()], always return 0 for
8301** [sqlite3_str_length()], and always return NULL from
8302** [sqlite3_str_finish(X)]. It is always safe to use the value
8303** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8304** to any of the other [sqlite3_str] methods.
8305**
8306** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8307** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8308** length of the string contained in the [sqlite3_str] object will be
8309** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8310** of [SQLITE_MAX_LENGTH].
8311*/
8312SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8313
8314/*
8315** CAPI3REF: Finalize A Dynamic String
8316** DESTRUCTOR: sqlite3_str
8317**
8318** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8319** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8320** that contains the constructed string. The calling application should
8321** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8322** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8323** errors were encountered during construction of the string. ^The
8324** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8325** string in [sqlite3_str] object X is zero bytes long.
8326*/
8327SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8328
8329/*
8330** CAPI3REF: Add Content To A Dynamic String
8331** METHOD: sqlite3_str
8332**
8333** These interfaces add content to an sqlite3_str object previously obtained
8334** from [sqlite3_str_new()].
8335**
8336** ^The [sqlite3_str_appendf(X,F,...)] and
8337** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8338** functionality of SQLite to append formatted text onto the end of
8339** [sqlite3_str] object X.
8340**
8341** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8342** onto the end of the [sqlite3_str] object X. N must be non-negative.
8343** S must contain at least N non-zero bytes of content. To append a
8344** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8345** method instead.
8346**
8347** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8348** zero-terminated string S onto the end of [sqlite3_str] object X.
8349**
8350** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8351** single-byte character C onto the end of [sqlite3_str] object X.
8352** ^This method can be used, for example, to add whitespace indentation.
8353**
8354** ^The [sqlite3_str_reset(X)] method resets the string under construction
8355** inside [sqlite3_str] object X back to zero bytes in length.
8356**
8357** These methods do not return a result code. ^If an error occurs, that fact
8358** is recorded in the [sqlite3_str] object and can be recovered by a
8359** subsequent call to [sqlite3_str_errcode(X)].
8360*/
8361SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8362SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8363SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8364SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8365SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8366SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8367
8368/*
8369** CAPI3REF: Status Of A Dynamic String
8370** METHOD: sqlite3_str
8371**
8372** These interfaces return the current status of an [sqlite3_str] object.
8373**
8374** ^If any prior errors have occurred while constructing the dynamic string
8375** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8376** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8377** [SQLITE_NOMEM] following any out-of-memory error, or
8378** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8379** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8380**
8381** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8382** of the dynamic string under construction in [sqlite3_str] object X.
8383** ^The length returned by [sqlite3_str_length(X)] does not include the
8384** zero-termination byte.
8385**
8386** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8387** content of the dynamic string under construction in X. The value
8388** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8389** and might be freed or altered by any subsequent method on the same
8390** [sqlite3_str] object. Applications must not used the pointer returned
8391** [sqlite3_str_value(X)] after any subsequent method call on the same
8392** object. ^Applications may change the content of the string returned
8393** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8394** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8395** write any byte after any subsequent sqlite3_str method call.
8396*/
8397SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8398SQLITE_API int sqlite3_str_length(sqlite3_str*);
8399SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8400
8401/*
8402** CAPI3REF: SQLite Runtime Status
8403**
8404** ^These interfaces are used to retrieve runtime status information
8405** about the performance of SQLite, and optionally to reset various
8406** highwater marks. ^The first argument is an integer code for
8407** the specific parameter to measure. ^(Recognized integer codes
8408** are of the form [status parameters | SQLITE_STATUS_...].)^
8409** ^The current value of the parameter is returned into *pCurrent.
8410** ^The highest recorded value is returned in *pHighwater. ^If the
8411** resetFlag is true, then the highest record value is reset after
8412** *pHighwater is written. ^(Some parameters do not record the highest
8413** value. For those parameters
8414** nothing is written into *pHighwater and the resetFlag is ignored.)^
8415** ^(Other parameters record only the highwater mark and not the current
8416** value. For these latter parameters nothing is written into *pCurrent.)^
8417**
8418** ^The sqlite3_status() and sqlite3_status64() routines return
8419** SQLITE_OK on success and a non-zero [error code] on failure.
8420**
8421** If either the current value or the highwater mark is too large to
8422** be represented by a 32-bit integer, then the values returned by
8423** sqlite3_status() are undefined.
8424**
8425** See also: [sqlite3_db_status()]
8426*/
8427SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8428SQLITE_API int sqlite3_status64(
8429 int op,
8430 sqlite3_int64 *pCurrent,
8431 sqlite3_int64 *pHighwater,
8432 int resetFlag
8433);
8434
8435
8436/*
8437** CAPI3REF: Status Parameters
8438** KEYWORDS: {status parameters}
8439**
8440** These integer constants designate various run-time status parameters
8441** that can be returned by [sqlite3_status()].
8442**
8443** <dl>
8444** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8445** <dd>This parameter is the current amount of memory checked out
8446** using [sqlite3_malloc()], either directly or indirectly. The
8447** figure includes calls made to [sqlite3_malloc()] by the application
8448** and internal memory usage by the SQLite library. Auxiliary page-cache
8449** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8450** this parameter. The amount returned is the sum of the allocation
8451** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8452**
8453** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8454** <dd>This parameter records the largest memory allocation request
8455** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8456** internal equivalents). Only the value returned in the
8457** *pHighwater parameter to [sqlite3_status()] is of interest.
8458** The value written into the *pCurrent parameter is undefined.</dd>)^
8459**
8460** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8461** <dd>This parameter records the number of separate memory allocations
8462** currently checked out.</dd>)^
8463**
8464** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8465** <dd>This parameter returns the number of pages used out of the
8466** [pagecache memory allocator] that was configured using
8467** [SQLITE_CONFIG_PAGECACHE]. The
8468** value returned is in pages, not in bytes.</dd>)^
8469**
8470** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8471** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8472** <dd>This parameter returns the number of bytes of page cache
8473** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8474** buffer and where forced to overflow to [sqlite3_malloc()]. The
8475** returned value includes allocations that overflowed because they
8476** where too large (they were larger than the "sz" parameter to
8477** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8478** no space was left in the page cache.</dd>)^
8479**
8480** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8481** <dd>This parameter records the largest memory allocation request
8482** handed to the [pagecache memory allocator]. Only the value returned in the
8483** *pHighwater parameter to [sqlite3_status()] is of interest.
8484** The value written into the *pCurrent parameter is undefined.</dd>)^
8485**
8486** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8487** <dd>No longer used.</dd>
8488**
8489** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8490** <dd>No longer used.</dd>
8491**
8492** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8493** <dd>No longer used.</dd>
8494**
8495** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8496** <dd>The *pHighwater parameter records the deepest parser stack.
8497** The *pCurrent value is undefined. The *pHighwater value is only
8498** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8499** </dl>
8500**
8501** New status parameters may be added from time to time.
8502*/
8503#define SQLITE_STATUS_MEMORY_USED 0
8504#define SQLITE_STATUS_PAGECACHE_USED 1
8505#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8506#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8507#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8508#define SQLITE_STATUS_MALLOC_SIZE 5
8509#define SQLITE_STATUS_PARSER_STACK 6
8510#define SQLITE_STATUS_PAGECACHE_SIZE 7
8511#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8512#define SQLITE_STATUS_MALLOC_COUNT 9
8513
8514/*
8515** CAPI3REF: Database Connection Status
8516** METHOD: sqlite3
8517**
8518** ^This interface is used to retrieve runtime status information
8519** about a single [database connection]. ^The first argument is the
8520** database connection object to be interrogated. ^The second argument
8521** is an integer constant, taken from the set of
8522** [SQLITE_DBSTATUS options], that
8523** determines the parameter to interrogate. The set of
8524** [SQLITE_DBSTATUS options] is likely
8525** to grow in future releases of SQLite.
8526**
8527** ^The current value of the requested parameter is written into *pCur
8528** and the highest instantaneous value is written into *pHiwtr. ^If
8529** the resetFlg is true, then the highest instantaneous value is
8530** reset back down to the current value.
8531**
8532** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8533** non-zero [error code] on failure.
8534**
8535** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8536*/
8537SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8538
8539/*
8540** CAPI3REF: Status Parameters for database connections
8541** KEYWORDS: {SQLITE_DBSTATUS options}
8542**
8543** These constants are the available integer "verbs" that can be passed as
8544** the second argument to the [sqlite3_db_status()] interface.
8545**
8546** New verbs may be added in future releases of SQLite. Existing verbs
8547** might be discontinued. Applications should check the return code from
8548** [sqlite3_db_status()] to make sure that the call worked.
8549** The [sqlite3_db_status()] interface will return a non-zero error code
8550** if a discontinued or unsupported verb is invoked.
8551**
8552** <dl>
8553** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8554** <dd>This parameter returns the number of lookaside memory slots currently
8555** checked out.</dd>)^
8556**
8557** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8558** <dd>This parameter returns the number of malloc attempts that were
8559** satisfied using lookaside memory. Only the high-water value is meaningful;
8560** the current value is always zero.)^
8561**
8562** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8563** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8564** <dd>This parameter returns the number malloc attempts that might have
8565** been satisfied using lookaside memory but failed due to the amount of
8566** memory requested being larger than the lookaside slot size.
8567** Only the high-water value is meaningful;
8568** the current value is always zero.)^
8569**
8570** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8571** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8572** <dd>This parameter returns the number malloc attempts that might have
8573** been satisfied using lookaside memory but failed due to all lookaside
8574** memory already being in use.
8575** Only the high-water value is meaningful;
8576** the current value is always zero.)^
8577**
8578** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8579** <dd>This parameter returns the approximate number of bytes of heap
8580** memory used by all pager caches associated with the database connection.)^
8581** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8582**
8583** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8584** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8585** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8586** pager cache is shared between two or more connections the bytes of heap
8587** memory used by that pager cache is divided evenly between the attached
8588** connections.)^ In other words, if none of the pager caches associated
8589** with the database connection are shared, this request returns the same
8590** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8591** shared, the value returned by this call will be smaller than that returned
8592** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8593** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8594**
8595** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8596** <dd>This parameter returns the approximate number of bytes of heap
8597** memory used to store the schema for all databases associated
8598** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8599** ^The full amount of memory used by the schemas is reported, even if the
8600** schema memory is shared with other database connections due to
8601** [shared cache mode] being enabled.
8602** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8603**
8604** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8605** <dd>This parameter returns the approximate number of bytes of heap
8606** and lookaside memory used by all prepared statements associated with
8607** the database connection.)^
8608** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8609** </dd>
8610**
8611** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8612** <dd>This parameter returns the number of pager cache hits that have
8613** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8614** is always 0.
8615** </dd>
8616**
8617** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8618** <dd>This parameter returns the number of pager cache misses that have
8619** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8620** is always 0.
8621** </dd>
8622**
8623** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8624** <dd>This parameter returns the number of dirty cache entries that have
8625** been written to disk. Specifically, the number of pages written to the
8626** wal file in wal mode databases, or the number of pages written to the
8627** database file in rollback mode databases. Any pages written as part of
8628** transaction rollback or database recovery operations are not included.
8629** If an IO or other error occurs while writing a page to disk, the effect
8630** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8631** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8632** </dd>
8633**
8634** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8635** <dd>This parameter returns the number of dirty cache entries that have
8636** been written to disk in the middle of a transaction due to the page
8637** cache overflowing. Transactions are more efficient if they are written
8638** to disk all at once. When pages spill mid-transaction, that introduces
8639** additional overhead. This parameter can be used help identify
8640** inefficiencies that can be resolved by increasing the cache size.
8641** </dd>
8642**
8643** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8644** <dd>This parameter returns zero for the current value if and only if
8645** all foreign key constraints (deferred or immediate) have been
8646** resolved.)^ ^The highwater mark is always 0.
8647** </dd>
8648** </dl>
8649*/
8650#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8651#define SQLITE_DBSTATUS_CACHE_USED 1
8652#define SQLITE_DBSTATUS_SCHEMA_USED 2
8653#define SQLITE_DBSTATUS_STMT_USED 3
8654#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8655#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8656#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8657#define SQLITE_DBSTATUS_CACHE_HIT 7
8658#define SQLITE_DBSTATUS_CACHE_MISS 8
8659#define SQLITE_DBSTATUS_CACHE_WRITE 9
8660#define SQLITE_DBSTATUS_DEFERRED_FKS 10
8661#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8662#define SQLITE_DBSTATUS_CACHE_SPILL 12
8663#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8664
8665
8666/*
8667** CAPI3REF: Prepared Statement Status
8668** METHOD: sqlite3_stmt
8669**
8670** ^(Each prepared statement maintains various
8671** [SQLITE_STMTSTATUS counters] that measure the number
8672** of times it has performed specific operations.)^ These counters can
8673** be used to monitor the performance characteristics of the prepared
8674** statements. For example, if the number of table steps greatly exceeds
8675** the number of table searches or result rows, that would tend to indicate
8676** that the prepared statement is using a full table scan rather than
8677** an index.
8678**
8679** ^(This interface is used to retrieve and reset counter values from
8680** a [prepared statement]. The first argument is the prepared statement
8681** object to be interrogated. The second argument
8682** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8683** to be interrogated.)^
8684** ^The current value of the requested counter is returned.
8685** ^If the resetFlg is true, then the counter is reset to zero after this
8686** interface call returns.
8687**
8688** See also: [sqlite3_status()] and [sqlite3_db_status()].
8689*/
8690SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8691
8692/*
8693** CAPI3REF: Status Parameters for prepared statements
8694** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8695**
8696** These preprocessor macros define integer codes that name counter
8697** values associated with the [sqlite3_stmt_status()] interface.
8698** The meanings of the various counters are as follows:
8699**
8700** <dl>
8701** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8702** <dd>^This is the number of times that SQLite has stepped forward in
8703** a table as part of a full table scan. Large numbers for this counter
8704** may indicate opportunities for performance improvement through
8705** careful use of indices.</dd>
8706**
8707** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8708** <dd>^This is the number of sort operations that have occurred.
8709** A non-zero value in this counter may indicate an opportunity to
8710** improvement performance through careful use of indices.</dd>
8711**
8712** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8713** <dd>^This is the number of rows inserted into transient indices that
8714** were created automatically in order to help joins run faster.
8715** A non-zero value in this counter may indicate an opportunity to
8716** improvement performance by adding permanent indices that do not
8717** need to be reinitialized each time the statement is run.</dd>
8718**
8719** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8720** <dd>^This is the number of virtual machine operations executed
8721** by the prepared statement if that number is less than or equal
8722** to 2147483647. The number of virtual machine operations can be
8723** used as a proxy for the total work done by the prepared statement.
8724** If the number of virtual machine operations exceeds 2147483647
8725** then the value returned by this statement status code is undefined.
8726**
8727** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8728** <dd>^This is the number of times that the prepare statement has been
8729** automatically regenerated due to schema changes or changes to
8730** [bound parameters] that might affect the query plan.
8731**
8732** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8733** <dd>^This is the number of times that the prepared statement has
8734** been run. A single "run" for the purposes of this counter is one
8735** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8736** The counter is incremented on the first [sqlite3_step()] call of each
8737** cycle.
8738**
8739** [[SQLITE_STMTSTATUS_FILTER_MISS]]
8740** [[SQLITE_STMTSTATUS_FILTER HIT]]
8741** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
8742** SQLITE_STMTSTATUS_FILTER_MISS</dt>
8743** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
8744** step was bypassed because a Bloom filter returned not-found. The
8745** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
8746** times that the Bloom filter returned a find, and thus the join step
8747** had to be processed as normal.
8748**
8749** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8750** <dd>^This is the approximate number of bytes of heap memory
8751** used to store the prepared statement. ^This value is not actually
8752** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8753** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8754** </dd>
8755** </dl>
8756*/
8757#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8758#define SQLITE_STMTSTATUS_SORT 2
8759#define SQLITE_STMTSTATUS_AUTOINDEX 3
8760#define SQLITE_STMTSTATUS_VM_STEP 4
8761#define SQLITE_STMTSTATUS_REPREPARE 5
8762#define SQLITE_STMTSTATUS_RUN 6
8763#define SQLITE_STMTSTATUS_FILTER_MISS 7
8764#define SQLITE_STMTSTATUS_FILTER_HIT 8
8765#define SQLITE_STMTSTATUS_MEMUSED 99
8766
8767/*
8768** CAPI3REF: Custom Page Cache Object
8769**
8770** The sqlite3_pcache type is opaque. It is implemented by
8771** the pluggable module. The SQLite core has no knowledge of
8772** its size or internal structure and never deals with the
8773** sqlite3_pcache object except by holding and passing pointers
8774** to the object.
8775**
8776** See [sqlite3_pcache_methods2] for additional information.
8777*/
8778typedef struct sqlite3_pcache sqlite3_pcache;
8779
8780/*
8781** CAPI3REF: Custom Page Cache Object
8782**
8783** The sqlite3_pcache_page object represents a single page in the
8784** page cache. The page cache will allocate instances of this
8785** object. Various methods of the page cache use pointers to instances
8786** of this object as parameters or as their return value.
8787**
8788** See [sqlite3_pcache_methods2] for additional information.
8789*/
8790typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8791struct sqlite3_pcache_page {
8792 void *pBuf; /* The content of the page */
8793 void *pExtra; /* Extra information associated with the page */
8794};
8795
8796/*
8797** CAPI3REF: Application Defined Page Cache.
8798** KEYWORDS: {page cache}
8799**
8800** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8801** register an alternative page cache implementation by passing in an
8802** instance of the sqlite3_pcache_methods2 structure.)^
8803** In many applications, most of the heap memory allocated by
8804** SQLite is used for the page cache.
8805** By implementing a
8806** custom page cache using this API, an application can better control
8807** the amount of memory consumed by SQLite, the way in which
8808** that memory is allocated and released, and the policies used to
8809** determine exactly which parts of a database file are cached and for
8810** how long.
8811**
8812** The alternative page cache mechanism is an
8813** extreme measure that is only needed by the most demanding applications.
8814** The built-in page cache is recommended for most uses.
8815**
8816** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8817** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8818** the application may discard the parameter after the call to
8819** [sqlite3_config()] returns.)^
8820**
8821** [[the xInit() page cache method]]
8822** ^(The xInit() method is called once for each effective
8823** call to [sqlite3_initialize()])^
8824** (usually only once during the lifetime of the process). ^(The xInit()
8825** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8826** The intent of the xInit() method is to set up global data structures
8827** required by the custom page cache implementation.
8828** ^(If the xInit() method is NULL, then the
8829** built-in default page cache is used instead of the application defined
8830** page cache.)^
8831**
8832** [[the xShutdown() page cache method]]
8833** ^The xShutdown() method is called by [sqlite3_shutdown()].
8834** It can be used to clean up
8835** any outstanding resources before process shutdown, if required.
8836** ^The xShutdown() method may be NULL.
8837**
8838** ^SQLite automatically serializes calls to the xInit method,
8839** so the xInit method need not be threadsafe. ^The
8840** xShutdown method is only called from [sqlite3_shutdown()] so it does
8841** not need to be threadsafe either. All other methods must be threadsafe
8842** in multithreaded applications.
8843**
8844** ^SQLite will never invoke xInit() more than once without an intervening
8845** call to xShutdown().
8846**
8847** [[the xCreate() page cache methods]]
8848** ^SQLite invokes the xCreate() method to construct a new cache instance.
8849** SQLite will typically create one cache instance for each open database file,
8850** though this is not guaranteed. ^The
8851** first parameter, szPage, is the size in bytes of the pages that must
8852** be allocated by the cache. ^szPage will always a power of two. ^The
8853** second parameter szExtra is a number of bytes of extra storage
8854** associated with each page cache entry. ^The szExtra parameter will
8855** a number less than 250. SQLite will use the
8856** extra szExtra bytes on each page to store metadata about the underlying
8857** database page on disk. The value passed into szExtra depends
8858** on the SQLite version, the target platform, and how SQLite was compiled.
8859** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8860** created will be used to cache database pages of a file stored on disk, or
8861** false if it is used for an in-memory database. The cache implementation
8862** does not have to do anything special based with the value of bPurgeable;
8863** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8864** never invoke xUnpin() except to deliberately delete a page.
8865** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8866** false will always have the "discard" flag set to true.
8867** ^Hence, a cache created with bPurgeable false will
8868** never contain any unpinned pages.
8869**
8870** [[the xCachesize() page cache method]]
8871** ^(The xCachesize() method may be called at any time by SQLite to set the
8872** suggested maximum cache-size (number of pages stored by) the cache
8873** instance passed as the first argument. This is the value configured using
8874** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8875** parameter, the implementation is not required to do anything with this
8876** value; it is advisory only.
8877**
8878** [[the xPagecount() page cache methods]]
8879** The xPagecount() method must return the number of pages currently
8880** stored in the cache, both pinned and unpinned.
8881**
8882** [[the xFetch() page cache methods]]
8883** The xFetch() method locates a page in the cache and returns a pointer to
8884** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8885** The pBuf element of the returned sqlite3_pcache_page object will be a
8886** pointer to a buffer of szPage bytes used to store the content of a
8887** single database page. The pExtra element of sqlite3_pcache_page will be
8888** a pointer to the szExtra bytes of extra storage that SQLite has requested
8889** for each entry in the page cache.
8890**
8891** The page to be fetched is determined by the key. ^The minimum key value
8892** is 1. After it has been retrieved using xFetch, the page is considered
8893** to be "pinned".
8894**
8895** If the requested page is already in the page cache, then the page cache
8896** implementation must return a pointer to the page buffer with its content
8897** intact. If the requested page is not already in the cache, then the
8898** cache implementation should use the value of the createFlag
8899** parameter to help it determined what action to take:
8900**
8901** <table border=1 width=85% align=center>
8902** <tr><th> createFlag <th> Behavior when page is not already in cache
8903** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8904** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8905** Otherwise return NULL.
8906** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8907** NULL if allocating a new page is effectively impossible.
8908** </table>
8909**
8910** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8911** will only use a createFlag of 2 after a prior call with a createFlag of 1
8912** failed.)^ In between the xFetch() calls, SQLite may
8913** attempt to unpin one or more cache pages by spilling the content of
8914** pinned pages to disk and synching the operating system disk cache.
8915**
8916** [[the xUnpin() page cache method]]
8917** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8918** as its second argument. If the third parameter, discard, is non-zero,
8919** then the page must be evicted from the cache.
8920** ^If the discard parameter is
8921** zero, then the page may be discarded or retained at the discretion of
8922** page cache implementation. ^The page cache implementation
8923** may choose to evict unpinned pages at any time.
8924**
8925** The cache must not perform any reference counting. A single
8926** call to xUnpin() unpins the page regardless of the number of prior calls
8927** to xFetch().
8928**
8929** [[the xRekey() page cache methods]]
8930** The xRekey() method is used to change the key value associated with the
8931** page passed as the second argument. If the cache
8932** previously contains an entry associated with newKey, it must be
8933** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8934** to be pinned.
8935**
8936** When SQLite calls the xTruncate() method, the cache must discard all
8937** existing cache entries with page numbers (keys) greater than or equal
8938** to the value of the iLimit parameter passed to xTruncate(). If any
8939** of these pages are pinned, they are implicitly unpinned, meaning that
8940** they can be safely discarded.
8941**
8942** [[the xDestroy() page cache method]]
8943** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8944** All resources associated with the specified cache should be freed. ^After
8945** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8946** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8947** functions.
8948**
8949** [[the xShrink() page cache method]]
8950** ^SQLite invokes the xShrink() method when it wants the page cache to
8951** free up as much of heap memory as possible. The page cache implementation
8952** is not obligated to free any memory, but well-behaved implementations should
8953** do their best.
8954*/
8955typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8956struct sqlite3_pcache_methods2 {
8957 int iVersion;
8958 void *pArg;
8959 int (*xInit)(void*);
8960 void (*xShutdown)(void*);
8961 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8962 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8963 int (*xPagecount)(sqlite3_pcache*);
8964 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8965 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8966 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8967 unsigned oldKey, unsigned newKey);
8968 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8969 void (*xDestroy)(sqlite3_pcache*);
8970 void (*xShrink)(sqlite3_pcache*);
8971};
8972
8973/*
8974** This is the obsolete pcache_methods object that has now been replaced
8975** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8976** retained in the header file for backwards compatibility only.
8977*/
8978typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8979struct sqlite3_pcache_methods {
8980 void *pArg;
8981 int (*xInit)(void*);
8982 void (*xShutdown)(void*);
8983 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8984 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8985 int (*xPagecount)(sqlite3_pcache*);
8986 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8987 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8988 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8989 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8990 void (*xDestroy)(sqlite3_pcache*);
8991};
8992
8993
8994/*
8995** CAPI3REF: Online Backup Object
8996**
8997** The sqlite3_backup object records state information about an ongoing
8998** online backup operation. ^The sqlite3_backup object is created by
8999** a call to [sqlite3_backup_init()] and is destroyed by a call to
9000** [sqlite3_backup_finish()].
9001**
9002** See Also: [Using the SQLite Online Backup API]
9003*/
9004typedef struct sqlite3_backup sqlite3_backup;
9005
9006/*
9007** CAPI3REF: Online Backup API.
9008**
9009** The backup API copies the content of one database into another.
9010** It is useful either for creating backups of databases or
9011** for copying in-memory databases to or from persistent files.
9012**
9013** See Also: [Using the SQLite Online Backup API]
9014**
9015** ^SQLite holds a write transaction open on the destination database file
9016** for the duration of the backup operation.
9017** ^The source database is read-locked only while it is being read;
9018** it is not locked continuously for the entire backup operation.
9019** ^Thus, the backup may be performed on a live source database without
9020** preventing other database connections from
9021** reading or writing to the source database while the backup is underway.
9022**
9023** ^(To perform a backup operation:
9024** <ol>
9025** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9026** backup,
9027** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9028** the data between the two databases, and finally
9029** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9030** associated with the backup operation.
9031** </ol>)^
9032** There should be exactly one call to sqlite3_backup_finish() for each
9033** successful call to sqlite3_backup_init().
9034**
9035** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9036**
9037** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9038** [database connection] associated with the destination database
9039** and the database name, respectively.
9040** ^The database name is "main" for the main database, "temp" for the
9041** temporary database, or the name specified after the AS keyword in
9042** an [ATTACH] statement for an attached database.
9043** ^The S and M arguments passed to
9044** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9045** and database name of the source database, respectively.
9046** ^The source and destination [database connections] (parameters S and D)
9047** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9048** an error.
9049**
9050** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9051** there is already a read or read-write transaction open on the
9052** destination database.
9053**
9054** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9055** returned and an error code and error message are stored in the
9056** destination [database connection] D.
9057** ^The error code and message for the failed call to sqlite3_backup_init()
9058** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9059** [sqlite3_errmsg16()] functions.
9060** ^A successful call to sqlite3_backup_init() returns a pointer to an
9061** [sqlite3_backup] object.
9062** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9063** sqlite3_backup_finish() functions to perform the specified backup
9064** operation.
9065**
9066** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9067**
9068** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9069** the source and destination databases specified by [sqlite3_backup] object B.
9070** ^If N is negative, all remaining source pages are copied.
9071** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9072** are still more pages to be copied, then the function returns [SQLITE_OK].
9073** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9074** from source to destination, then it returns [SQLITE_DONE].
9075** ^If an error occurs while running sqlite3_backup_step(B,N),
9076** then an [error code] is returned. ^As well as [SQLITE_OK] and
9077** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9078** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9079** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9080**
9081** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9082** <ol>
9083** <li> the destination database was opened read-only, or
9084** <li> the destination database is using write-ahead-log journaling
9085** and the destination and source page sizes differ, or
9086** <li> the destination database is an in-memory database and the
9087** destination and source page sizes differ.
9088** </ol>)^
9089**
9090** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9091** the [sqlite3_busy_handler | busy-handler function]
9092** is invoked (if one is specified). ^If the
9093** busy-handler returns non-zero before the lock is available, then
9094** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9095** sqlite3_backup_step() can be retried later. ^If the source
9096** [database connection]
9097** is being used to write to the source database when sqlite3_backup_step()
9098** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9099** case the call to sqlite3_backup_step() can be retried later on. ^(If
9100** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9101** [SQLITE_READONLY] is returned, then
9102** there is no point in retrying the call to sqlite3_backup_step(). These
9103** errors are considered fatal.)^ The application must accept
9104** that the backup operation has failed and pass the backup operation handle
9105** to the sqlite3_backup_finish() to release associated resources.
9106**
9107** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9108** on the destination file. ^The exclusive lock is not released until either
9109** sqlite3_backup_finish() is called or the backup operation is complete
9110** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9111** sqlite3_backup_step() obtains a [shared lock] on the source database that
9112** lasts for the duration of the sqlite3_backup_step() call.
9113** ^Because the source database is not locked between calls to
9114** sqlite3_backup_step(), the source database may be modified mid-way
9115** through the backup process. ^If the source database is modified by an
9116** external process or via a database connection other than the one being
9117** used by the backup operation, then the backup will be automatically
9118** restarted by the next call to sqlite3_backup_step(). ^If the source
9119** database is modified by the using the same database connection as is used
9120** by the backup operation, then the backup database is automatically
9121** updated at the same time.
9122**
9123** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9124**
9125** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9126** application wishes to abandon the backup operation, the application
9127** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9128** ^The sqlite3_backup_finish() interfaces releases all
9129** resources associated with the [sqlite3_backup] object.
9130** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9131** active write-transaction on the destination database is rolled back.
9132** The [sqlite3_backup] object is invalid
9133** and may not be used following a call to sqlite3_backup_finish().
9134**
9135** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9136** sqlite3_backup_step() errors occurred, regardless or whether or not
9137** sqlite3_backup_step() completed.
9138** ^If an out-of-memory condition or IO error occurred during any prior
9139** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9140** sqlite3_backup_finish() returns the corresponding [error code].
9141**
9142** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9143** is not a permanent error and does not affect the return value of
9144** sqlite3_backup_finish().
9145**
9146** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9147** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9148**
9149** ^The sqlite3_backup_remaining() routine returns the number of pages still
9150** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9151** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9152** in the source database at the conclusion of the most recent
9153** sqlite3_backup_step().
9154** ^(The values returned by these functions are only updated by
9155** sqlite3_backup_step(). If the source database is modified in a way that
9156** changes the size of the source database or the number of pages remaining,
9157** those changes are not reflected in the output of sqlite3_backup_pagecount()
9158** and sqlite3_backup_remaining() until after the next
9159** sqlite3_backup_step().)^
9160**
9161** <b>Concurrent Usage of Database Handles</b>
9162**
9163** ^The source [database connection] may be used by the application for other
9164** purposes while a backup operation is underway or being initialized.
9165** ^If SQLite is compiled and configured to support threadsafe database
9166** connections, then the source database connection may be used concurrently
9167** from within other threads.
9168**
9169** However, the application must guarantee that the destination
9170** [database connection] is not passed to any other API (by any thread) after
9171** sqlite3_backup_init() is called and before the corresponding call to
9172** sqlite3_backup_finish(). SQLite does not currently check to see
9173** if the application incorrectly accesses the destination [database connection]
9174** and so no error code is reported, but the operations may malfunction
9175** nevertheless. Use of the destination database connection while a
9176** backup is in progress might also cause a mutex deadlock.
9177**
9178** If running in [shared cache mode], the application must
9179** guarantee that the shared cache used by the destination database
9180** is not accessed while the backup is running. In practice this means
9181** that the application must guarantee that the disk file being
9182** backed up to is not accessed by any connection within the process,
9183** not just the specific connection that was passed to sqlite3_backup_init().
9184**
9185** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9186** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9187** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9188** APIs are not strictly speaking threadsafe. If they are invoked at the
9189** same time as another thread is invoking sqlite3_backup_step() it is
9190** possible that they return invalid values.
9191*/
9192SQLITE_API sqlite3_backup *sqlite3_backup_init(
9193 sqlite3 *pDest, /* Destination database handle */
9194 const char *zDestName, /* Destination database name */
9195 sqlite3 *pSource, /* Source database handle */
9196 const char *zSourceName /* Source database name */
9197);
9198SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9199SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9200SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9201SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9202
9203/*
9204** CAPI3REF: Unlock Notification
9205** METHOD: sqlite3
9206**
9207** ^When running in shared-cache mode, a database operation may fail with
9208** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9209** individual tables within the shared-cache cannot be obtained. See
9210** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9211** ^This API may be used to register a callback that SQLite will invoke
9212** when the connection currently holding the required lock relinquishes it.
9213** ^This API is only available if the library was compiled with the
9214** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9215**
9216** See Also: [Using the SQLite Unlock Notification Feature].
9217**
9218** ^Shared-cache locks are released when a database connection concludes
9219** its current transaction, either by committing it or rolling it back.
9220**
9221** ^When a connection (known as the blocked connection) fails to obtain a
9222** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9223** identity of the database connection (the blocking connection) that
9224** has locked the required resource is stored internally. ^After an
9225** application receives an SQLITE_LOCKED error, it may call the
9226** sqlite3_unlock_notify() method with the blocked connection handle as
9227** the first argument to register for a callback that will be invoked
9228** when the blocking connections current transaction is concluded. ^The
9229** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9230** call that concludes the blocking connection's transaction.
9231**
9232** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9233** there is a chance that the blocking connection will have already
9234** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9235** If this happens, then the specified callback is invoked immediately,
9236** from within the call to sqlite3_unlock_notify().)^
9237**
9238** ^If the blocked connection is attempting to obtain a write-lock on a
9239** shared-cache table, and more than one other connection currently holds
9240** a read-lock on the same table, then SQLite arbitrarily selects one of
9241** the other connections to use as the blocking connection.
9242**
9243** ^(There may be at most one unlock-notify callback registered by a
9244** blocked connection. If sqlite3_unlock_notify() is called when the
9245** blocked connection already has a registered unlock-notify callback,
9246** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9247** called with a NULL pointer as its second argument, then any existing
9248** unlock-notify callback is cancelled. ^The blocked connections
9249** unlock-notify callback may also be cancelled by closing the blocked
9250** connection using [sqlite3_close()].
9251**
9252** The unlock-notify callback is not reentrant. If an application invokes
9253** any sqlite3_xxx API functions from within an unlock-notify callback, a
9254** crash or deadlock may be the result.
9255**
9256** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9257** returns SQLITE_OK.
9258**
9259** <b>Callback Invocation Details</b>
9260**
9261** When an unlock-notify callback is registered, the application provides a
9262** single void* pointer that is passed to the callback when it is invoked.
9263** However, the signature of the callback function allows SQLite to pass
9264** it an array of void* context pointers. The first argument passed to
9265** an unlock-notify callback is a pointer to an array of void* pointers,
9266** and the second is the number of entries in the array.
9267**
9268** When a blocking connection's transaction is concluded, there may be
9269** more than one blocked connection that has registered for an unlock-notify
9270** callback. ^If two or more such blocked connections have specified the
9271** same callback function, then instead of invoking the callback function
9272** multiple times, it is invoked once with the set of void* context pointers
9273** specified by the blocked connections bundled together into an array.
9274** This gives the application an opportunity to prioritize any actions
9275** related to the set of unblocked database connections.
9276**
9277** <b>Deadlock Detection</b>
9278**
9279** Assuming that after registering for an unlock-notify callback a
9280** database waits for the callback to be issued before taking any further
9281** action (a reasonable assumption), then using this API may cause the
9282** application to deadlock. For example, if connection X is waiting for
9283** connection Y's transaction to be concluded, and similarly connection
9284** Y is waiting on connection X's transaction, then neither connection
9285** will proceed and the system may remain deadlocked indefinitely.
9286**
9287** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9288** detection. ^If a given call to sqlite3_unlock_notify() would put the
9289** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9290** unlock-notify callback is registered. The system is said to be in
9291** a deadlocked state if connection A has registered for an unlock-notify
9292** callback on the conclusion of connection B's transaction, and connection
9293** B has itself registered for an unlock-notify callback when connection
9294** A's transaction is concluded. ^Indirect deadlock is also detected, so
9295** the system is also considered to be deadlocked if connection B has
9296** registered for an unlock-notify callback on the conclusion of connection
9297** C's transaction, where connection C is waiting on connection A. ^Any
9298** number of levels of indirection are allowed.
9299**
9300** <b>The "DROP TABLE" Exception</b>
9301**
9302** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9303** always appropriate to call sqlite3_unlock_notify(). There is however,
9304** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9305** SQLite checks if there are any currently executing SELECT statements
9306** that belong to the same connection. If there are, SQLITE_LOCKED is
9307** returned. In this case there is no "blocking connection", so invoking
9308** sqlite3_unlock_notify() results in the unlock-notify callback being
9309** invoked immediately. If the application then re-attempts the "DROP TABLE"
9310** or "DROP INDEX" query, an infinite loop might be the result.
9311**
9312** One way around this problem is to check the extended error code returned
9313** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9314** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9315** the special "DROP TABLE/INDEX" case, the extended error code is just
9316** SQLITE_LOCKED.)^
9317*/
9318SQLITE_API int sqlite3_unlock_notify(
9319 sqlite3 *pBlocked, /* Waiting connection */
9320 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9321 void *pNotifyArg /* Argument to pass to xNotify */
9322);
9323
9324
9325/*
9326** CAPI3REF: String Comparison
9327**
9328** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9329** and extensions to compare the contents of two buffers containing UTF-8
9330** strings in a case-independent fashion, using the same definition of "case
9331** independence" that SQLite uses internally when comparing identifiers.
9332*/
9333SQLITE_API int sqlite3_stricmp(const char *, const char *);
9334SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9335
9336/*
9337** CAPI3REF: String Globbing
9338*
9339** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9340** string X matches the [GLOB] pattern P.
9341** ^The definition of [GLOB] pattern matching used in
9342** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9343** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9344** is case sensitive.
9345**
9346** Note that this routine returns zero on a match and non-zero if the strings
9347** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9348**
9349** See also: [sqlite3_strlike()].
9350*/
9351SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9352
9353/*
9354** CAPI3REF: String LIKE Matching
9355*
9356** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9357** string X matches the [LIKE] pattern P with escape character E.
9358** ^The definition of [LIKE] pattern matching used in
9359** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9360** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9361** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9362** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9363** insensitive - equivalent upper and lower case ASCII characters match
9364** one another.
9365**
9366** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9367** only ASCII characters are case folded.
9368**
9369** Note that this routine returns zero on a match and non-zero if the strings
9370** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9371**
9372** See also: [sqlite3_strglob()].
9373*/
9374SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9375
9376/*
9377** CAPI3REF: Error Logging Interface
9378**
9379** ^The [sqlite3_log()] interface writes a message into the [error log]
9380** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9381** ^If logging is enabled, the zFormat string and subsequent arguments are
9382** used with [sqlite3_snprintf()] to generate the final output string.
9383**
9384** The sqlite3_log() interface is intended for use by extensions such as
9385** virtual tables, collating functions, and SQL functions. While there is
9386** nothing to prevent an application from calling sqlite3_log(), doing so
9387** is considered bad form.
9388**
9389** The zFormat string must not be NULL.
9390**
9391** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9392** will not use dynamically allocated memory. The log message is stored in
9393** a fixed-length buffer on the stack. If the log message is longer than
9394** a few hundred characters, it will be truncated to the length of the
9395** buffer.
9396*/
9397SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9398
9399/*
9400** CAPI3REF: Write-Ahead Log Commit Hook
9401** METHOD: sqlite3
9402**
9403** ^The [sqlite3_wal_hook()] function is used to register a callback that
9404** is invoked each time data is committed to a database in wal mode.
9405**
9406** ^(The callback is invoked by SQLite after the commit has taken place and
9407** the associated write-lock on the database released)^, so the implementation
9408** may read, write or [checkpoint] the database as required.
9409**
9410** ^The first parameter passed to the callback function when it is invoked
9411** is a copy of the third parameter passed to sqlite3_wal_hook() when
9412** registering the callback. ^The second is a copy of the database handle.
9413** ^The third parameter is the name of the database that was written to -
9414** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9415** is the number of pages currently in the write-ahead log file,
9416** including those that were just committed.
9417**
9418** The callback function should normally return [SQLITE_OK]. ^If an error
9419** code is returned, that error will propagate back up through the
9420** SQLite code base to cause the statement that provoked the callback
9421** to report an error, though the commit will have still occurred. If the
9422** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9423** that does not correspond to any valid SQLite error code, the results
9424** are undefined.
9425**
9426** A single database handle may have at most a single write-ahead log callback
9427** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9428** previously registered write-ahead log callback. ^The return value is
9429** a copy of the third parameter from the previous call, if any, or 0.
9430** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9431** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9432** overwrite any prior [sqlite3_wal_hook()] settings.
9433*/
9434SQLITE_API void *sqlite3_wal_hook(
9435 sqlite3*,
9436 int(*)(void *,sqlite3*,const char*,int),
9437 void*
9438);
9439
9440/*
9441** CAPI3REF: Configure an auto-checkpoint
9442** METHOD: sqlite3
9443**
9444** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9445** [sqlite3_wal_hook()] that causes any database on [database connection] D
9446** to automatically [checkpoint]
9447** after committing a transaction if there are N or
9448** more frames in the [write-ahead log] file. ^Passing zero or
9449** a negative value as the nFrame parameter disables automatic
9450** checkpoints entirely.
9451**
9452** ^The callback registered by this function replaces any existing callback
9453** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9454** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9455** configured by this function.
9456**
9457** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9458** from SQL.
9459**
9460** ^Checkpoints initiated by this mechanism are
9461** [sqlite3_wal_checkpoint_v2|PASSIVE].
9462**
9463** ^Every new [database connection] defaults to having the auto-checkpoint
9464** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9465** pages. The use of this interface
9466** is only necessary if the default setting is found to be suboptimal
9467** for a particular application.
9468*/
9469SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9470
9471/*
9472** CAPI3REF: Checkpoint a database
9473** METHOD: sqlite3
9474**
9475** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9476** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9477**
9478** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9479** [write-ahead log] for database X on [database connection] D to be
9480** transferred into the database file and for the write-ahead log to
9481** be reset. See the [checkpointing] documentation for addition
9482** information.
9483**
9484** This interface used to be the only way to cause a checkpoint to
9485** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9486** interface was added. This interface is retained for backwards
9487** compatibility and as a convenience for applications that need to manually
9488** start a callback but which do not need the full power (and corresponding
9489** complication) of [sqlite3_wal_checkpoint_v2()].
9490*/
9491SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9492
9493/*
9494** CAPI3REF: Checkpoint a database
9495** METHOD: sqlite3
9496**
9497** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9498** operation on database X of [database connection] D in mode M. Status
9499** information is written back into integers pointed to by L and C.)^
9500** ^(The M parameter must be a valid [checkpoint mode]:)^
9501**
9502** <dl>
9503** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9504** ^Checkpoint as many frames as possible without waiting for any database
9505** readers or writers to finish, then sync the database file if all frames
9506** in the log were checkpointed. ^The [busy-handler callback]
9507** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9508** ^On the other hand, passive mode might leave the checkpoint unfinished
9509** if there are concurrent readers or writers.
9510**
9511** <dt>SQLITE_CHECKPOINT_FULL<dd>
9512** ^This mode blocks (it invokes the
9513** [sqlite3_busy_handler|busy-handler callback]) until there is no
9514** database writer and all readers are reading from the most recent database
9515** snapshot. ^It then checkpoints all frames in the log file and syncs the
9516** database file. ^This mode blocks new database writers while it is pending,
9517** but new database readers are allowed to continue unimpeded.
9518**
9519** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9520** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9521** that after checkpointing the log file it blocks (calls the
9522** [busy-handler callback])
9523** until all readers are reading from the database file only. ^This ensures
9524** that the next writer will restart the log file from the beginning.
9525** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9526** database writer attempts while it is pending, but does not impede readers.
9527**
9528** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9529** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9530** addition that it also truncates the log file to zero bytes just prior
9531** to a successful return.
9532** </dl>
9533**
9534** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9535** the log file or to -1 if the checkpoint could not run because
9536** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9537** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9538** log file (including any that were already checkpointed before the function
9539** was called) or to -1 if the checkpoint could not run due to an error or
9540** because the database is not in WAL mode. ^Note that upon successful
9541** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9542** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9543**
9544** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9545** any other process is running a checkpoint operation at the same time, the
9546** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9547** busy-handler configured, it will not be invoked in this case.
9548**
9549** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9550** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9551** obtained immediately, and a busy-handler is configured, it is invoked and
9552** the writer lock retried until either the busy-handler returns 0 or the lock
9553** is successfully obtained. ^The busy-handler is also invoked while waiting for
9554** database readers as described above. ^If the busy-handler returns 0 before
9555** the writer lock is obtained or while waiting for database readers, the
9556** checkpoint operation proceeds from that point in the same way as
9557** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9558** without blocking any further. ^SQLITE_BUSY is returned in this case.
9559**
9560** ^If parameter zDb is NULL or points to a zero length string, then the
9561** specified operation is attempted on all WAL databases [attached] to
9562** [database connection] db. In this case the
9563** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9564** an SQLITE_BUSY error is encountered when processing one or more of the
9565** attached WAL databases, the operation is still attempted on any remaining
9566** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9567** error occurs while processing an attached database, processing is abandoned
9568** and the error code is returned to the caller immediately. ^If no error
9569** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9570** databases, SQLITE_OK is returned.
9571**
9572** ^If database zDb is the name of an attached database that is not in WAL
9573** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9574** zDb is not NULL (or a zero length string) and is not the name of any
9575** attached database, SQLITE_ERROR is returned to the caller.
9576**
9577** ^Unless it returns SQLITE_MISUSE,
9578** the sqlite3_wal_checkpoint_v2() interface
9579** sets the error information that is queried by
9580** [sqlite3_errcode()] and [sqlite3_errmsg()].
9581**
9582** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9583** from SQL.
9584*/
9585SQLITE_API int sqlite3_wal_checkpoint_v2(
9586 sqlite3 *db, /* Database handle */
9587 const char *zDb, /* Name of attached database (or NULL) */
9588 int eMode, /* SQLITE_CHECKPOINT_* value */
9589 int *pnLog, /* OUT: Size of WAL log in frames */
9590 int *pnCkpt /* OUT: Total number of frames checkpointed */
9591);
9592
9593/*
9594** CAPI3REF: Checkpoint Mode Values
9595** KEYWORDS: {checkpoint mode}
9596**
9597** These constants define all valid values for the "checkpoint mode" passed
9598** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9599** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9600** meaning of each of these checkpoint modes.
9601*/
9602#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9603#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9604#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9605#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9606
9607/*
9608** CAPI3REF: Virtual Table Interface Configuration
9609**
9610** This function may be called by either the [xConnect] or [xCreate] method
9611** of a [virtual table] implementation to configure
9612** various facets of the virtual table interface.
9613**
9614** If this interface is invoked outside the context of an xConnect or
9615** xCreate virtual table method then the behavior is undefined.
9616**
9617** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9618** [database connection] in which the virtual table is being created and
9619** which is passed in as the first argument to the [xConnect] or [xCreate]
9620** method that is invoking sqlite3_vtab_config(). The C parameter is one
9621** of the [virtual table configuration options]. The presence and meaning
9622** of parameters after C depend on which [virtual table configuration option]
9623** is used.
9624*/
9625SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9626
9627/*
9628** CAPI3REF: Virtual Table Configuration Options
9629** KEYWORDS: {virtual table configuration options}
9630** KEYWORDS: {virtual table configuration option}
9631**
9632** These macros define the various options to the
9633** [sqlite3_vtab_config()] interface that [virtual table] implementations
9634** can use to customize and optimize their behavior.
9635**
9636** <dl>
9637** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9638** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9639** <dd>Calls of the form
9640** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9641** where X is an integer. If X is zero, then the [virtual table] whose
9642** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9643** support constraints. In this configuration (which is the default) if
9644** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9645** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9646** specified as part of the users SQL statement, regardless of the actual
9647** ON CONFLICT mode specified.
9648**
9649** If X is non-zero, then the virtual table implementation guarantees
9650** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9651** any modifications to internal or persistent data structures have been made.
9652** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9653** is able to roll back a statement or database transaction, and abandon
9654** or continue processing the current SQL statement as appropriate.
9655** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9656** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9657** had been ABORT.
9658**
9659** Virtual table implementations that are required to handle OR REPLACE
9660** must do so within the [xUpdate] method. If a call to the
9661** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9662** CONFLICT policy is REPLACE, the virtual table implementation should
9663** silently replace the appropriate rows within the xUpdate callback and
9664** return SQLITE_OK. Or, if this is not possible, it may return
9665** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9666** constraint handling.
9667** </dd>
9668**
9669** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9670** <dd>Calls of the form
9671** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9672** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9673** prohibits that virtual table from being used from within triggers and
9674** views.
9675** </dd>
9676**
9677** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9678** <dd>Calls of the form
9679** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9680** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9681** identify that virtual table as being safe to use from within triggers
9682** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9683** virtual table can do no serious harm even if it is controlled by a
9684** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9685** flag unless absolutely necessary.
9686** </dd>
9687**
9688** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
9689** <dd>Calls of the form
9690** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
9691** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9692** instruct the query planner to begin at least a read transaction on
9693** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
9694** virtual table is used.
9695** </dd>
9696** </dl>
9697*/
9698#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9699#define SQLITE_VTAB_INNOCUOUS 2
9700#define SQLITE_VTAB_DIRECTONLY 3
9701#define SQLITE_VTAB_USES_ALL_SCHEMAS 4
9702
9703/*
9704** CAPI3REF: Determine The Virtual Table Conflict Policy
9705**
9706** This function may only be called from within a call to the [xUpdate] method
9707** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9708** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9709** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9710** of the SQL statement that triggered the call to the [xUpdate] method of the
9711** [virtual table].
9712*/
9713SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9714
9715/*
9716** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9717**
9718** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9719** method of a [virtual table], then it might return true if the
9720** column is being fetched as part of an UPDATE operation during which the
9721** column value will not change. The virtual table implementation can use
9722** this hint as permission to substitute a return value that is less
9723** expensive to compute and that the corresponding
9724** [xUpdate] method understands as a "no-change" value.
9725**
9726** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9727** the column is not changed by the UPDATE statement, then the xColumn
9728** method can optionally return without setting a result, without calling
9729** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9730** In that case, [sqlite3_value_nochange(X)] will return true for the
9731** same column in the [xUpdate] method.
9732**
9733** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9734** implementations should continue to give a correct answer even if the
9735** sqlite3_vtab_nochange() interface were to always return false. In the
9736** current implementation, the sqlite3_vtab_nochange() interface does always
9737** returns false for the enhanced [UPDATE FROM] statement.
9738*/
9739SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9740
9741/*
9742** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9743** METHOD: sqlite3_index_info
9744**
9745** This function may only be called from within a call to the [xBestIndex]
9746** method of a [virtual table]. This function returns a pointer to a string
9747** that is the name of the appropriate collation sequence to use for text
9748** comparisons on the constraint identified by its arguments.
9749**
9750** The first argument must be the pointer to the [sqlite3_index_info] object
9751** that is the first parameter to the xBestIndex() method. The second argument
9752** must be an index into the aConstraint[] array belonging to the
9753** sqlite3_index_info structure passed to xBestIndex.
9754**
9755** Important:
9756** The first parameter must be the same pointer that is passed into the
9757** xBestMethod() method. The first parameter may not be a pointer to a
9758** different [sqlite3_index_info] object, even an exact copy.
9759**
9760** The return value is computed as follows:
9761**
9762** <ol>
9763** <li><p> If the constraint comes from a WHERE clause expression that contains
9764** a [COLLATE operator], then the name of the collation specified by
9765** that COLLATE operator is returned.
9766** <li><p> If there is no COLLATE operator, but the column that is the subject
9767** of the constraint specifies an alternative collating sequence via
9768** a [COLLATE clause] on the column definition within the CREATE TABLE
9769** statement that was passed into [sqlite3_declare_vtab()], then the
9770** name of that alternative collating sequence is returned.
9771** <li><p> Otherwise, "BINARY" is returned.
9772** </ol>
9773*/
9774SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9775
9776/*
9777** CAPI3REF: Determine if a virtual table query is DISTINCT
9778** METHOD: sqlite3_index_info
9779**
9780** This API may only be used from within an [xBestIndex|xBestIndex method]
9781** of a [virtual table] implementation. The result of calling this
9782** interface from outside of xBestIndex() is undefined and probably harmful.
9783**
9784** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
9785** 3. The integer returned by sqlite3_vtab_distinct()
9786** gives the virtual table additional information about how the query
9787** planner wants the output to be ordered. As long as the virtual table
9788** can meet the ordering requirements of the query planner, it may set
9789** the "orderByConsumed" flag.
9790**
9791** <ol><li value="0"><p>
9792** ^If the sqlite3_vtab_distinct() interface returns 0, that means
9793** that the query planner needs the virtual table to return all rows in the
9794** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
9795** [sqlite3_index_info] object. This is the default expectation. If the
9796** virtual table outputs all rows in sorted order, then it is always safe for
9797** the xBestIndex method to set the "orderByConsumed" flag, regardless of
9798** the return value from sqlite3_vtab_distinct().
9799** <li value="1"><p>
9800** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
9801** that the query planner does not need the rows to be returned in sorted order
9802** as long as all rows with the same values in all columns identified by the
9803** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
9804** is doing a GROUP BY.
9805** <li value="2"><p>
9806** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
9807** that the query planner does not need the rows returned in any particular
9808** order, as long as rows with the same values in all "aOrderBy" columns
9809** are adjacent.)^ ^(Furthermore, only a single row for each particular
9810** combination of values in the columns identified by the "aOrderBy" field
9811** needs to be returned.)^ ^It is always ok for two or more rows with the same
9812** values in all "aOrderBy" columns to be returned, as long as all such rows
9813** are adjacent. ^The virtual table may, if it chooses, omit extra rows
9814** that have the same value for all columns identified by "aOrderBy".
9815** ^However omitting the extra rows is optional.
9816** This mode is used for a DISTINCT query.
9817** <li value="3"><p>
9818** ^(If the sqlite3_vtab_distinct() interface returns 3, that means
9819** that the query planner needs only distinct rows but it does need the
9820** rows to be sorted.)^ ^The virtual table implementation is free to omit
9821** rows that are identical in all aOrderBy columns, if it wants to, but
9822** it is not required to omit any rows. This mode is used for queries
9823** that have both DISTINCT and ORDER BY clauses.
9824** </ol>
9825**
9826** ^For the purposes of comparing virtual table output values to see if the
9827** values are same value for sorting purposes, two NULL values are considered
9828** to be the same. In other words, the comparison operator is "IS"
9829** (or "IS NOT DISTINCT FROM") and not "==".
9830**
9831** If a virtual table implementation is unable to meet the requirements
9832** specified above, then it must not set the "orderByConsumed" flag in the
9833** [sqlite3_index_info] object or an incorrect answer may result.
9834**
9835** ^A virtual table implementation is always free to return rows in any order
9836** it wants, as long as the "orderByConsumed" flag is not set. ^When the
9837** the "orderByConsumed" flag is unset, the query planner will add extra
9838** [bytecode] to ensure that the final results returned by the SQL query are
9839** ordered correctly. The use of the "orderByConsumed" flag and the
9840** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
9841** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
9842** flag might help queries against a virtual table to run faster. Being
9843** overly aggressive and setting the "orderByConsumed" flag when it is not
9844** valid to do so, on the other hand, might cause SQLite to return incorrect
9845** results.
9846*/
9847SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
9848
9849/*
9850** CAPI3REF: Identify and handle IN constraints in xBestIndex
9851**
9852** This interface may only be used from within an
9853** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
9854** The result of invoking this interface from any other context is
9855** undefined and probably harmful.
9856**
9857** ^(A constraint on a virtual table of the form
9858** "[IN operator|column IN (...)]" is
9859** communicated to the xBestIndex method as a
9860** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
9861** this constraint, it must set the corresponding
9862** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
9863** the usual mode of handling IN operators, SQLite generates [bytecode]
9864** that invokes the [xFilter|xFilter() method] once for each value
9865** on the right-hand side of the IN operator.)^ Thus the virtual table
9866** only sees a single value from the right-hand side of the IN operator
9867** at a time.
9868**
9869** In some cases, however, it would be advantageous for the virtual
9870** table to see all values on the right-hand of the IN operator all at
9871** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
9872**
9873** <ol>
9874** <li><p>
9875** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
9876** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
9877** is an [IN operator] that can be processed all at once. ^In other words,
9878** sqlite3_vtab_in() with -1 in the third argument is a mechanism
9879** by which the virtual table can ask SQLite if all-at-once processing
9880** of the IN operator is even possible.
9881**
9882** <li><p>
9883** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
9884** to SQLite that the virtual table does or does not want to process
9885** the IN operator all-at-once, respectively. ^Thus when the third
9886** parameter (F) is non-negative, this interface is the mechanism by
9887** which the virtual table tells SQLite how it wants to process the
9888** IN operator.
9889** </ol>
9890**
9891** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
9892** within the same xBestIndex method call. ^For any given P,N pair,
9893** the return value from sqlite3_vtab_in(P,N,F) will always be the same
9894** within the same xBestIndex call. ^If the interface returns true
9895** (non-zero), that means that the constraint is an IN operator
9896** that can be processed all-at-once. ^If the constraint is not an IN
9897** operator or cannot be processed all-at-once, then the interface returns
9898** false.
9899**
9900** ^(All-at-once processing of the IN operator is selected if both of the
9901** following conditions are met:
9902**
9903** <ol>
9904** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
9905** integer. This is how the virtual table tells SQLite that it wants to
9906** use the N-th constraint.
9907**
9908** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
9909** non-negative had F>=1.
9910** </ol>)^
9911**
9912** ^If either or both of the conditions above are false, then SQLite uses
9913** the traditional one-at-a-time processing strategy for the IN constraint.
9914** ^If both conditions are true, then the argvIndex-th parameter to the
9915** xFilter method will be an [sqlite3_value] that appears to be NULL,
9916** but which can be passed to [sqlite3_vtab_in_first()] and
9917** [sqlite3_vtab_in_next()] to find all values on the right-hand side
9918** of the IN constraint.
9919*/
9920SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
9921
9922/*
9923** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
9924**
9925** These interfaces are only useful from within the
9926** [xFilter|xFilter() method] of a [virtual table] implementation.
9927** The result of invoking these interfaces from any other context
9928** is undefined and probably harmful.
9929**
9930** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
9931** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
9932** xFilter method which invokes these routines, and specifically
9933** a parameter that was previously selected for all-at-once IN constraint
9934** processing use the [sqlite3_vtab_in()] interface in the
9935** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
9936** an xFilter argument that was selected for all-at-once IN constraint
9937** processing, then these routines return [SQLITE_ERROR].)^
9938**
9939** ^(Use these routines to access all values on the right-hand side
9940** of the IN constraint using code like the following:
9941**
9942** <blockquote><pre>
9943** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
9944** &nbsp; rc==SQLITE_OK && pVal;
9945** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
9946** &nbsp; ){
9947** &nbsp; // do something with pVal
9948** &nbsp; }
9949** &nbsp; if( rc!=SQLITE_OK ){
9950** &nbsp; // an error has occurred
9951** &nbsp; }
9952** </pre></blockquote>)^
9953**
9954** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
9955** routines return SQLITE_OK and set *P to point to the first or next value
9956** on the RHS of the IN constraint. ^If there are no more values on the
9957** right hand side of the IN constraint, then *P is set to NULL and these
9958** routines return [SQLITE_DONE]. ^The return value might be
9959** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
9960**
9961** The *ppOut values returned by these routines are only valid until the
9962** next call to either of these routines or until the end of the xFilter
9963** method from which these routines were called. If the virtual table
9964** implementation needs to retain the *ppOut values for longer, it must make
9965** copies. The *ppOut values are [protected sqlite3_value|protected].
9966*/
9967SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
9968SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
9969
9970/*
9971** CAPI3REF: Constraint values in xBestIndex()
9972** METHOD: sqlite3_index_info
9973**
9974** This API may only be used from within the [xBestIndex|xBestIndex method]
9975** of a [virtual table] implementation. The result of calling this interface
9976** from outside of an xBestIndex method are undefined and probably harmful.
9977**
9978** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
9979** the [xBestIndex] method of a [virtual table] implementation, with P being
9980** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
9981** J being a 0-based index into P->aConstraint[], then this routine
9982** attempts to set *V to the value of the right-hand operand of
9983** that constraint if the right-hand operand is known. ^If the
9984** right-hand operand is not known, then *V is set to a NULL pointer.
9985** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
9986** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
9987** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
9988** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
9989** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
9990** something goes wrong.
9991**
9992** The sqlite3_vtab_rhs_value() interface is usually only successful if
9993** the right-hand operand of a constraint is a literal value in the original
9994** SQL statement. If the right-hand operand is an expression or a reference
9995** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
9996** will probably return [SQLITE_NOTFOUND].
9997**
9998** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
9999** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10000** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10001**
10002** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10003** and remains valid for the duration of the xBestIndex method call.
10004** ^When xBestIndex returns, the sqlite3_value object returned by
10005** sqlite3_vtab_rhs_value() is automatically deallocated.
10006**
10007** The "_rhs_" in the name of this routine is an abbreviation for
10008** "Right-Hand Side".
10009*/
10010SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10011
10012/*
10013** CAPI3REF: Conflict resolution modes
10014** KEYWORDS: {conflict resolution mode}
10015**
10016** These constants are returned by [sqlite3_vtab_on_conflict()] to
10017** inform a [virtual table] implementation what the [ON CONFLICT] mode
10018** is for the SQL statement being evaluated.
10019**
10020** Note that the [SQLITE_IGNORE] constant is also used as a potential
10021** return value from the [sqlite3_set_authorizer()] callback and that
10022** [SQLITE_ABORT] is also a [result code].
10023*/
10024#define SQLITE_ROLLBACK 1
10025/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10026#define SQLITE_FAIL 3
10027/* #define SQLITE_ABORT 4 // Also an error code */
10028#define SQLITE_REPLACE 5
10029
10030/*
10031** CAPI3REF: Prepared Statement Scan Status Opcodes
10032** KEYWORDS: {scanstatus options}
10033**
10034** The following constants can be used for the T parameter to the
10035** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10036** different metric for sqlite3_stmt_scanstatus() to return.
10037**
10038** When the value returned to V is a string, space to hold that string is
10039** managed by the prepared statement S and will be automatically freed when
10040** S is finalized.
10041**
10042** Not all values are available for all query elements. When a value is
10043** not available, the output variable is set to -1 if the value is numeric,
10044** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10045**
10046** <dl>
10047** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10048** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10049** set to the total number of times that the X-th loop has run.</dd>
10050**
10051** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10052** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10053** to the total number of rows examined by all iterations of the X-th loop.</dd>
10054**
10055** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10056** <dd>^The "double" variable pointed to by the V parameter will be set to the
10057** query planner's estimate for the average number of rows output from each
10058** iteration of the X-th loop. If the query planner's estimates was accurate,
10059** then this value will approximate the quotient NVISIT/NLOOP and the
10060** product of this value for all prior loops with the same SELECTID will
10061** be the NLOOP value for the current loop.
10062**
10063** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10064** <dd>^The "const char *" variable pointed to by the V parameter will be set
10065** to a zero-terminated UTF-8 string containing the name of the index or table
10066** used for the X-th loop.
10067**
10068** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10069** <dd>^The "const char *" variable pointed to by the V parameter will be set
10070** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10071** description for the X-th loop.
10072**
10073** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10074** <dd>^The "int" variable pointed to by the V parameter will be set to the
10075** id for the X-th query plan element. The id value is unique within the
10076** statement. The select-id is the same value as is output in the first
10077** column of an [EXPLAIN QUERY PLAN] query.
10078**
10079** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10080** <dd>The "int" variable pointed to by the V parameter will be set to the
10081** the id of the parent of the current query element, if applicable, or
10082** to zero if the query element has no parent. This is the same value as
10083** returned in the second column of an [EXPLAIN QUERY PLAN] query.
10084**
10085** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10086** <dd>The sqlite3_int64 output value is set to the number of cycles,
10087** according to the processor time-stamp counter, that elapsed while the
10088** query element was being processed. This value is not available for
10089** all query elements - if it is unavailable the output variable is
10090** set to -1.
10091** </dl>
10092*/
10093#define SQLITE_SCANSTAT_NLOOP 0
10094#define SQLITE_SCANSTAT_NVISIT 1
10095#define SQLITE_SCANSTAT_EST 2
10096#define SQLITE_SCANSTAT_NAME 3
10097#define SQLITE_SCANSTAT_EXPLAIN 4
10098#define SQLITE_SCANSTAT_SELECTID 5
10099#define SQLITE_SCANSTAT_PARENTID 6
10100#define SQLITE_SCANSTAT_NCYCLE 7
10101
10102/*
10103** CAPI3REF: Prepared Statement Scan Status
10104** METHOD: sqlite3_stmt
10105**
10106** These interfaces return information about the predicted and measured
10107** performance for pStmt. Advanced applications can use this
10108** interface to compare the predicted and the measured performance and
10109** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10110**
10111** Since this interface is expected to be rarely used, it is only
10112** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10113** compile-time option.
10114**
10115** The "iScanStatusOp" parameter determines which status information to return.
10116** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10117** of this interface is undefined. ^The requested measurement is written into
10118** a variable pointed to by the "pOut" parameter.
10119**
10120** The "flags" parameter must be passed a mask of flags. At present only
10121** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10122** is specified, then status information is available for all elements
10123** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10124** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10125** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10126** the EXPLAIN QUERY PLAN output) are available. Invoking API
10127** sqlite3_stmt_scanstatus() is equivalent to calling
10128** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10129**
10130** Parameter "idx" identifies the specific query element to retrieve statistics
10131** for. Query elements are numbered starting from zero. A value of -1 may be
10132** to query for statistics regarding the entire query. ^If idx is out of range
10133** - less than -1 or greater than or equal to the total number of query
10134** elements used to implement the statement - a non-zero value is returned and
10135** the variable that pOut points to is unchanged.
10136**
10137** See also: [sqlite3_stmt_scanstatus_reset()]
10138*/
10139SQLITE_API int sqlite3_stmt_scanstatus(
10140 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10141 int idx, /* Index of loop to report on */
10142 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10143 void *pOut /* Result written here */
10144);
10145SQLITE_API int sqlite3_stmt_scanstatus_v2(
10146 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10147 int idx, /* Index of loop to report on */
10148 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10149 int flags, /* Mask of flags defined below */
10150 void *pOut /* Result written here */
10151);
10152
10153/*
10154** CAPI3REF: Prepared Statement Scan Status
10155** KEYWORDS: {scan status flags}
10156*/
10157#define SQLITE_SCANSTAT_COMPLEX 0x0001
10158
10159/*
10160** CAPI3REF: Zero Scan-Status Counters
10161** METHOD: sqlite3_stmt
10162**
10163** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10164**
10165** This API is only available if the library is built with pre-processor
10166** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10167*/
10168SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10169
10170/*
10171** CAPI3REF: Flush caches to disk mid-transaction
10172** METHOD: sqlite3
10173**
10174** ^If a write-transaction is open on [database connection] D when the
10175** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
10176** pages in the pager-cache that are not currently in use are written out
10177** to disk. A dirty page may be in use if a database cursor created by an
10178** active SQL statement is reading from it, or if it is page 1 of a database
10179** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10180** interface flushes caches for all schemas - "main", "temp", and
10181** any [attached] databases.
10182**
10183** ^If this function needs to obtain extra database locks before dirty pages
10184** can be flushed to disk, it does so. ^If those locks cannot be obtained
10185** immediately and there is a busy-handler callback configured, it is invoked
10186** in the usual manner. ^If the required lock still cannot be obtained, then
10187** the database is skipped and an attempt made to flush any dirty pages
10188** belonging to the next (if any) database. ^If any databases are skipped
10189** because locks cannot be obtained, but no other error occurs, this
10190** function returns SQLITE_BUSY.
10191**
10192** ^If any other error occurs while flushing dirty pages to disk (for
10193** example an IO error or out-of-memory condition), then processing is
10194** abandoned and an SQLite [error code] is returned to the caller immediately.
10195**
10196** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10197**
10198** ^This function does not set the database handle error code or message
10199** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10200*/
10201SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10202
10203/*
10204** CAPI3REF: The pre-update hook.
10205** METHOD: sqlite3
10206**
10207** ^These interfaces are only available if SQLite is compiled using the
10208** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10209**
10210** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10211** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10212** on a database table.
10213** ^At most one preupdate hook may be registered at a time on a single
10214** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10215** the previous setting.
10216** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10217** with a NULL pointer as the second parameter.
10218** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10219** the first parameter to callbacks.
10220**
10221** ^The preupdate hook only fires for changes to real database tables; the
10222** preupdate hook is not invoked for changes to [virtual tables] or to
10223** system tables like sqlite_sequence or sqlite_stat1.
10224**
10225** ^The second parameter to the preupdate callback is a pointer to
10226** the [database connection] that registered the preupdate hook.
10227** ^The third parameter to the preupdate callback is one of the constants
10228** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10229** kind of update operation that is about to occur.
10230** ^(The fourth parameter to the preupdate callback is the name of the
10231** database within the database connection that is being modified. This
10232** will be "main" for the main database or "temp" for TEMP tables or
10233** the name given after the AS keyword in the [ATTACH] statement for attached
10234** databases.)^
10235** ^The fifth parameter to the preupdate callback is the name of the
10236** table that is being modified.
10237**
10238** For an UPDATE or DELETE operation on a [rowid table], the sixth
10239** parameter passed to the preupdate callback is the initial [rowid] of the
10240** row being modified or deleted. For an INSERT operation on a rowid table,
10241** or any operation on a WITHOUT ROWID table, the value of the sixth
10242** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10243** seventh parameter is the final rowid value of the row being inserted
10244** or updated. The value of the seventh parameter passed to the callback
10245** function is not defined for operations on WITHOUT ROWID tables, or for
10246** DELETE operations on rowid tables.
10247**
10248** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10249** the previous call on the same [database connection] D, or NULL for
10250** the first call on D.
10251**
10252** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10253** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10254** provide additional information about a preupdate event. These routines
10255** may only be called from within a preupdate callback. Invoking any of
10256** these routines from outside of a preupdate callback or with a
10257** [database connection] pointer that is different from the one supplied
10258** to the preupdate callback results in undefined and probably undesirable
10259** behavior.
10260**
10261** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10262** in the row that is being inserted, updated, or deleted.
10263**
10264** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10265** a [protected sqlite3_value] that contains the value of the Nth column of
10266** the table row before it is updated. The N parameter must be between 0
10267** and one less than the number of columns or the behavior will be
10268** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10269** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10270** behavior is undefined. The [sqlite3_value] that P points to
10271** will be destroyed when the preupdate callback returns.
10272**
10273** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10274** a [protected sqlite3_value] that contains the value of the Nth column of
10275** the table row after it is updated. The N parameter must be between 0
10276** and one less than the number of columns or the behavior will be
10277** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10278** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10279** behavior is undefined. The [sqlite3_value] that P points to
10280** will be destroyed when the preupdate callback returns.
10281**
10282** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10283** callback was invoked as a result of a direct insert, update, or delete
10284** operation; or 1 for inserts, updates, or deletes invoked by top-level
10285** triggers; or 2 for changes resulting from triggers called by top-level
10286** triggers; and so forth.
10287**
10288** When the [sqlite3_blob_write()] API is used to update a blob column,
10289** the pre-update hook is invoked with SQLITE_DELETE. This is because the
10290** in this case the new values are not available. In this case, when a
10291** callback made with op==SQLITE_DELETE is actually a write using the
10292** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10293** the index of the column being written. In other cases, where the
10294** pre-update hook is being invoked for some other reason, including a
10295** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10296**
10297** See also: [sqlite3_update_hook()]
10298*/
10299#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10300SQLITE_API void *sqlite3_preupdate_hook(
10301 sqlite3 *db,
10302 void(*xPreUpdate)(
10303 void *pCtx, /* Copy of third arg to preupdate_hook() */
10304 sqlite3 *db, /* Database handle */
10305 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10306 char const *zDb, /* Database name */
10307 char const *zName, /* Table name */
10308 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10309 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10310 ),
10311 void*
10312);
10313SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10314SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10315SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10316SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10317SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10318#endif
10319
10320/*
10321** CAPI3REF: Low-level system error code
10322** METHOD: sqlite3
10323**
10324** ^Attempt to return the underlying operating system error code or error
10325** number that caused the most recent I/O error or failure to open a file.
10326** The return value is OS-dependent. For example, on unix systems, after
10327** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10328** called to get back the underlying "errno" that caused the problem, such
10329** as ENOSPC, EAUTH, EISDIR, and so forth.
10330*/
10331SQLITE_API int sqlite3_system_errno(sqlite3*);
10332
10333/*
10334** CAPI3REF: Database Snapshot
10335** KEYWORDS: {snapshot} {sqlite3_snapshot}
10336**
10337** An instance of the snapshot object records the state of a [WAL mode]
10338** database for some specific point in history.
10339**
10340** In [WAL mode], multiple [database connections] that are open on the
10341** same database file can each be reading a different historical version
10342** of the database file. When a [database connection] begins a read
10343** transaction, that connection sees an unchanging copy of the database
10344** as it existed for the point in time when the transaction first started.
10345** Subsequent changes to the database from other connections are not seen
10346** by the reader until a new read transaction is started.
10347**
10348** The sqlite3_snapshot object records state information about an historical
10349** version of the database file so that it is possible to later open a new read
10350** transaction that sees that historical version of the database rather than
10351** the most recent version.
10352*/
10353typedef struct sqlite3_snapshot {
10354 unsigned char hidden[48];
10355} sqlite3_snapshot;
10356
10357/*
10358** CAPI3REF: Record A Database Snapshot
10359** CONSTRUCTOR: sqlite3_snapshot
10360**
10361** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10362** new [sqlite3_snapshot] object that records the current state of
10363** schema S in database connection D. ^On success, the
10364** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10365** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10366** If there is not already a read-transaction open on schema S when
10367** this function is called, one is opened automatically.
10368**
10369** The following must be true for this function to succeed. If any of
10370** the following statements are false when sqlite3_snapshot_get() is
10371** called, SQLITE_ERROR is returned. The final value of *P is undefined
10372** in this case.
10373**
10374** <ul>
10375** <li> The database handle must not be in [autocommit mode].
10376**
10377** <li> Schema S of [database connection] D must be a [WAL mode] database.
10378**
10379** <li> There must not be a write transaction open on schema S of database
10380** connection D.
10381**
10382** <li> One or more transactions must have been written to the current wal
10383** file since it was created on disk (by any connection). This means
10384** that a snapshot cannot be taken on a wal mode database with no wal
10385** file immediately after it is first opened. At least one transaction
10386** must be written to it first.
10387** </ul>
10388**
10389** This function may also return SQLITE_NOMEM. If it is called with the
10390** database handle in autocommit mode but fails for some other reason,
10391** whether or not a read transaction is opened on schema S is undefined.
10392**
10393** The [sqlite3_snapshot] object returned from a successful call to
10394** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10395** to avoid a memory leak.
10396**
10397** The [sqlite3_snapshot_get()] interface is only available when the
10398** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10399*/
10400SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10401 sqlite3 *db,
10402 const char *zSchema,
10403 sqlite3_snapshot **ppSnapshot
10404);
10405
10406/*
10407** CAPI3REF: Start a read transaction on an historical snapshot
10408** METHOD: sqlite3_snapshot
10409**
10410** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10411** transaction or upgrades an existing one for schema S of
10412** [database connection] D such that the read transaction refers to
10413** historical [snapshot] P, rather than the most recent change to the
10414** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10415** on success or an appropriate [error code] if it fails.
10416**
10417** ^In order to succeed, the database connection must not be in
10418** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10419** is already a read transaction open on schema S, then the database handle
10420** must have no active statements (SELECT statements that have been passed
10421** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10422** SQLITE_ERROR is returned if either of these conditions is violated, or
10423** if schema S does not exist, or if the snapshot object is invalid.
10424**
10425** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10426** snapshot has been overwritten by a [checkpoint]. In this case
10427** SQLITE_ERROR_SNAPSHOT is returned.
10428**
10429** If there is already a read transaction open when this function is
10430** invoked, then the same read transaction remains open (on the same
10431** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10432** is returned. If another error code - for example SQLITE_PROTOCOL or an
10433** SQLITE_IOERR error code - is returned, then the final state of the
10434** read transaction is undefined. If SQLITE_OK is returned, then the
10435** read transaction is now open on database snapshot P.
10436**
10437** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10438** database connection D does not know that the database file for
10439** schema S is in [WAL mode]. A database connection might not know
10440** that the database file is in [WAL mode] if there has been no prior
10441** I/O on that database connection, or if the database entered [WAL mode]
10442** after the most recent I/O on the database connection.)^
10443** (Hint: Run "[PRAGMA application_id]" against a newly opened
10444** database connection in order to make it ready to use snapshots.)
10445**
10446** The [sqlite3_snapshot_open()] interface is only available when the
10447** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10448*/
10449SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10450 sqlite3 *db,
10451 const char *zSchema,
10452 sqlite3_snapshot *pSnapshot
10453);
10454
10455/*
10456** CAPI3REF: Destroy a snapshot
10457** DESTRUCTOR: sqlite3_snapshot
10458**
10459** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10460** The application must eventually free every [sqlite3_snapshot] object
10461** using this routine to avoid a memory leak.
10462**
10463** The [sqlite3_snapshot_free()] interface is only available when the
10464** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10465*/
10466SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10467
10468/*
10469** CAPI3REF: Compare the ages of two snapshot handles.
10470** METHOD: sqlite3_snapshot
10471**
10472** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10473** of two valid snapshot handles.
10474**
10475** If the two snapshot handles are not associated with the same database
10476** file, the result of the comparison is undefined.
10477**
10478** Additionally, the result of the comparison is only valid if both of the
10479** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10480** last time the wal file was deleted. The wal file is deleted when the
10481** database is changed back to rollback mode or when the number of database
10482** clients drops to zero. If either snapshot handle was obtained before the
10483** wal file was last deleted, the value returned by this function
10484** is undefined.
10485**
10486** Otherwise, this API returns a negative value if P1 refers to an older
10487** snapshot than P2, zero if the two handles refer to the same database
10488** snapshot, and a positive value if P1 is a newer snapshot than P2.
10489**
10490** This interface is only available if SQLite is compiled with the
10491** [SQLITE_ENABLE_SNAPSHOT] option.
10492*/
10493SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10494 sqlite3_snapshot *p1,
10495 sqlite3_snapshot *p2
10496);
10497
10498/*
10499** CAPI3REF: Recover snapshots from a wal file
10500** METHOD: sqlite3_snapshot
10501**
10502** If a [WAL file] remains on disk after all database connections close
10503** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10504** or because the last process to have the database opened exited without
10505** calling [sqlite3_close()]) and a new connection is subsequently opened
10506** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10507** will only be able to open the last transaction added to the WAL file
10508** even though the WAL file contains other valid transactions.
10509**
10510** This function attempts to scan the WAL file associated with database zDb
10511** of database handle db and make all valid snapshots available to
10512** sqlite3_snapshot_open(). It is an error if there is already a read
10513** transaction open on the database, or if the database is not a WAL mode
10514** database.
10515**
10516** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10517**
10518** This interface is only available if SQLite is compiled with the
10519** [SQLITE_ENABLE_SNAPSHOT] option.
10520*/
10521SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10522
10523/*
10524** CAPI3REF: Serialize a database
10525**
10526** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
10527** that is a serialization of the S database on [database connection] D.
10528** If P is not a NULL pointer, then the size of the database in bytes
10529** is written into *P.
10530**
10531** For an ordinary on-disk database file, the serialization is just a
10532** copy of the disk file. For an in-memory database or a "TEMP" database,
10533** the serialization is the same sequence of bytes which would be written
10534** to disk if that database where backed up to disk.
10535**
10536** The usual case is that sqlite3_serialize() copies the serialization of
10537** the database into memory obtained from [sqlite3_malloc64()] and returns
10538** a pointer to that memory. The caller is responsible for freeing the
10539** returned value to avoid a memory leak. However, if the F argument
10540** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10541** are made, and the sqlite3_serialize() function will return a pointer
10542** to the contiguous memory representation of the database that SQLite
10543** is currently using for that database, or NULL if the no such contiguous
10544** memory representation of the database exists. A contiguous memory
10545** representation of the database will usually only exist if there has
10546** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10547** values of D and S.
10548** The size of the database is written into *P even if the
10549** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10550** of the database exists.
10551**
10552** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10553** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10554** allocation error occurs.
10555**
10556** This interface is omitted if SQLite is compiled with the
10557** [SQLITE_OMIT_DESERIALIZE] option.
10558*/
10559SQLITE_API unsigned char *sqlite3_serialize(
10560 sqlite3 *db, /* The database connection */
10561 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10562 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10563 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10564);
10565
10566/*
10567** CAPI3REF: Flags for sqlite3_serialize
10568**
10569** Zero or more of the following constants can be OR-ed together for
10570** the F argument to [sqlite3_serialize(D,S,P,F)].
10571**
10572** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10573** a pointer to contiguous in-memory database that it is currently using,
10574** without making a copy of the database. If SQLite is not currently using
10575** a contiguous in-memory database, then this option causes
10576** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10577** using a contiguous in-memory database if it has been initialized by a
10578** prior call to [sqlite3_deserialize()].
10579*/
10580#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10581
10582/*
10583** CAPI3REF: Deserialize a database
10584**
10585** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10586** [database connection] D to disconnect from database S and then
10587** reopen S as an in-memory database based on the serialization contained
10588** in P. The serialized database P is N bytes in size. M is the size of
10589** the buffer P, which might be larger than N. If M is larger than N, and
10590** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10591** permitted to add content to the in-memory database as long as the total
10592** size does not exceed M bytes.
10593**
10594** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10595** invoke sqlite3_free() on the serialization buffer when the database
10596** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10597** SQLite will try to increase the buffer size using sqlite3_realloc64()
10598** if writes on the database cause it to grow larger than M bytes.
10599**
10600** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10601** database is currently in a read transaction or is involved in a backup
10602** operation.
10603**
10604** It is not possible to deserialized into the TEMP database. If the
10605** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10606** function returns SQLITE_ERROR.
10607**
10608** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10609** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10610** [sqlite3_free()] is invoked on argument P prior to returning.
10611**
10612** This interface is omitted if SQLite is compiled with the
10613** [SQLITE_OMIT_DESERIALIZE] option.
10614*/
10615SQLITE_API int sqlite3_deserialize(
10616 sqlite3 *db, /* The database connection */
10617 const char *zSchema, /* Which DB to reopen with the deserialization */
10618 unsigned char *pData, /* The serialized database content */
10619 sqlite3_int64 szDb, /* Number bytes in the deserialization */
10620 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10621 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10622);
10623
10624/*
10625** CAPI3REF: Flags for sqlite3_deserialize()
10626**
10627** The following are allowed values for 6th argument (the F argument) to
10628** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10629**
10630** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10631** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10632** and that SQLite should take ownership of this memory and automatically
10633** free it when it has finished using it. Without this flag, the caller
10634** is responsible for freeing any dynamically allocated memory.
10635**
10636** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10637** grow the size of the database using calls to [sqlite3_realloc64()]. This
10638** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10639** Without this flag, the deserialized database cannot increase in size beyond
10640** the number of bytes specified by the M parameter.
10641**
10642** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10643** should be treated as read-only.
10644*/
10645#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10646#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10647#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10648
10649/*
10650** Undo the hack that converts floating point types to integer for
10651** builds on processors without floating point support.
10652*/
10653#ifdef SQLITE_OMIT_FLOATING_POINT
10654# undef double
10655#endif
10656
10657#if defined(__wasi__)
10658# undef SQLITE_WASI
10659# define SQLITE_WASI 1
10660# undef SQLITE_OMIT_WAL
10661# define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */
10662# ifndef SQLITE_OMIT_LOAD_EXTENSION
10663# define SQLITE_OMIT_LOAD_EXTENSION
10664# endif
10665# ifndef SQLITE_THREADSAFE
10666# define SQLITE_THREADSAFE 0
10667# endif
10668#endif
10669
10670#ifdef __cplusplus
10671} /* End of the 'extern "C"' block */
10672#endif
10673#endif /* SQLITE3_H */
10674
10675/******** Begin file sqlite3rtree.h *********/
10676/*
10677** 2010 August 30
10678**
10679** The author disclaims copyright to this source code. In place of
10680** a legal notice, here is a blessing:
10681**
10682** May you do good and not evil.
10683** May you find forgiveness for yourself and forgive others.
10684** May you share freely, never taking more than you give.
10685**
10686*************************************************************************
10687*/
10688
10689#ifndef _SQLITE3RTREE_H_
10690#define _SQLITE3RTREE_H_
10691
10692
10693#ifdef __cplusplus
10694extern "C" {
10695#endif
10696
10697typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10698typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10699
10700/* The double-precision datatype used by RTree depends on the
10701** SQLITE_RTREE_INT_ONLY compile-time option.
10702*/
10703#ifdef SQLITE_RTREE_INT_ONLY
10704 typedef sqlite3_int64 sqlite3_rtree_dbl;
10705#else
10706 typedef double sqlite3_rtree_dbl;
10707#endif
10708
10709/*
10710** Register a geometry callback named zGeom that can be used as part of an
10711** R-Tree geometry query as follows:
10712**
10713** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10714*/
10715SQLITE_API int sqlite3_rtree_geometry_callback(
10716 sqlite3 *db,
10717 const char *zGeom,
10718 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10719 void *pContext
10720);
10721
10722
10723/*
10724** A pointer to a structure of the following type is passed as the first
10725** argument to callbacks registered using rtree_geometry_callback().
10726*/
10727struct sqlite3_rtree_geometry {
10728 void *pContext; /* Copy of pContext passed to s_r_g_c() */
10729 int nParam; /* Size of array aParam[] */
10730 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10731 void *pUser; /* Callback implementation user data */
10732 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10733};
10734
10735/*
10736** Register a 2nd-generation geometry callback named zScore that can be
10737** used as part of an R-Tree geometry query as follows:
10738**
10739** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10740*/
10741SQLITE_API int sqlite3_rtree_query_callback(
10742 sqlite3 *db,
10743 const char *zQueryFunc,
10744 int (*xQueryFunc)(sqlite3_rtree_query_info*),
10745 void *pContext,
10746 void (*xDestructor)(void*)
10747);
10748
10749
10750/*
10751** A pointer to a structure of the following type is passed as the
10752** argument to scored geometry callback registered using
10753** sqlite3_rtree_query_callback().
10754**
10755** Note that the first 5 fields of this structure are identical to
10756** sqlite3_rtree_geometry. This structure is a subclass of
10757** sqlite3_rtree_geometry.
10758*/
10759struct sqlite3_rtree_query_info {
10760 void *pContext; /* pContext from when function registered */
10761 int nParam; /* Number of function parameters */
10762 sqlite3_rtree_dbl *aParam; /* value of function parameters */
10763 void *pUser; /* callback can use this, if desired */
10764 void (*xDelUser)(void*); /* function to free pUser */
10765 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10766 unsigned int *anQueue; /* Number of pending entries in the queue */
10767 int nCoord; /* Number of coordinates */
10768 int iLevel; /* Level of current node or entry */
10769 int mxLevel; /* The largest iLevel value in the tree */
10770 sqlite3_int64 iRowid; /* Rowid for current entry */
10771 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10772 int eParentWithin; /* Visibility of parent node */
10773 int eWithin; /* OUT: Visibility */
10774 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10775 /* The following fields are only available in 3.8.11 and later */
10776 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10777};
10778
10779/*
10780** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10781*/
10782#define NOT_WITHIN 0 /* Object completely outside of query region */
10783#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10784#define FULLY_WITHIN 2 /* Object fully contained within query region */
10785
10786
10787#ifdef __cplusplus
10788} /* end of the 'extern "C"' block */
10789#endif
10790
10791#endif /* ifndef _SQLITE3RTREE_H_ */
10792
10793/******** End of sqlite3rtree.h *********/
10794/******** Begin file sqlite3session.h *********/
10795
10796#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10797#define __SQLITESESSION_H_ 1
10798
10799/*
10800** Make sure we can call this stuff from C++.
10801*/
10802#ifdef __cplusplus
10803extern "C" {
10804#endif
10805
10806
10807/*
10808** CAPI3REF: Session Object Handle
10809**
10810** An instance of this object is a [session] that can be used to
10811** record changes to a database.
10812*/
10813typedef struct sqlite3_session sqlite3_session;
10814
10815/*
10816** CAPI3REF: Changeset Iterator Handle
10817**
10818** An instance of this object acts as a cursor for iterating
10819** over the elements of a [changeset] or [patchset].
10820*/
10821typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10822
10823/*
10824** CAPI3REF: Create A New Session Object
10825** CONSTRUCTOR: sqlite3_session
10826**
10827** Create a new session object attached to database handle db. If successful,
10828** a pointer to the new object is written to *ppSession and SQLITE_OK is
10829** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10830** error code (e.g. SQLITE_NOMEM) is returned.
10831**
10832** It is possible to create multiple session objects attached to a single
10833** database handle.
10834**
10835** Session objects created using this function should be deleted using the
10836** [sqlite3session_delete()] function before the database handle that they
10837** are attached to is itself closed. If the database handle is closed before
10838** the session object is deleted, then the results of calling any session
10839** module function, including [sqlite3session_delete()] on the session object
10840** are undefined.
10841**
10842** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10843** is not possible for an application to register a pre-update hook on a
10844** database handle that has one or more session objects attached. Nor is
10845** it possible to create a session object attached to a database handle for
10846** which a pre-update hook is already defined. The results of attempting
10847** either of these things are undefined.
10848**
10849** The session object will be used to create changesets for tables in
10850** database zDb, where zDb is either "main", or "temp", or the name of an
10851** attached database. It is not an error if database zDb is not attached
10852** to the database when the session object is created.
10853*/
10854SQLITE_API int sqlite3session_create(
10855 sqlite3 *db, /* Database handle */
10856 const char *zDb, /* Name of db (e.g. "main") */
10857 sqlite3_session **ppSession /* OUT: New session object */
10858);
10859
10860/*
10861** CAPI3REF: Delete A Session Object
10862** DESTRUCTOR: sqlite3_session
10863**
10864** Delete a session object previously allocated using
10865** [sqlite3session_create()]. Once a session object has been deleted, the
10866** results of attempting to use pSession with any other session module
10867** function are undefined.
10868**
10869** Session objects must be deleted before the database handle to which they
10870** are attached is closed. Refer to the documentation for
10871** [sqlite3session_create()] for details.
10872*/
10873SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
10874
10875/*
10876** CAPI3REF: Configure a Session Object
10877** METHOD: sqlite3_session
10878**
10879** This method is used to configure a session object after it has been
10880** created. At present the only valid values for the second parameter are
10881** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
10882**
10883*/
10884SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
10885
10886/*
10887** CAPI3REF: Options for sqlite3session_object_config
10888**
10889** The following values may passed as the the 2nd parameter to
10890** sqlite3session_object_config().
10891**
10892** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
10893** This option is used to set, clear or query the flag that enables
10894** the [sqlite3session_changeset_size()] API. Because it imposes some
10895** computational overhead, this API is disabled by default. Argument
10896** pArg must point to a value of type (int). If the value is initially
10897** 0, then the sqlite3session_changeset_size() API is disabled. If it
10898** is greater than 0, then the same API is enabled. Or, if the initial
10899** value is less than zero, no change is made. In all cases the (int)
10900** variable is set to 1 if the sqlite3session_changeset_size() API is
10901** enabled following the current call, or 0 otherwise.
10902**
10903** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
10904** the first table has been attached to the session object.
10905**
10906** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
10907** This option is used to set, clear or query the flag that enables
10908** collection of data for tables with no explicit PRIMARY KEY.
10909**
10910** Normally, tables with no explicit PRIMARY KEY are simply ignored
10911** by the sessions module. However, if this flag is set, it behaves
10912** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
10913** as their leftmost columns.
10914**
10915** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
10916** the first table has been attached to the session object.
10917*/
10918#define SQLITE_SESSION_OBJCONFIG_SIZE 1
10919#define SQLITE_SESSION_OBJCONFIG_ROWID 2
10920
10921/*
10922** CAPI3REF: Enable Or Disable A Session Object
10923** METHOD: sqlite3_session
10924**
10925** Enable or disable the recording of changes by a session object. When
10926** enabled, a session object records changes made to the database. When
10927** disabled - it does not. A newly created session object is enabled.
10928** Refer to the documentation for [sqlite3session_changeset()] for further
10929** details regarding how enabling and disabling a session object affects
10930** the eventual changesets.
10931**
10932** Passing zero to this function disables the session. Passing a value
10933** greater than zero enables it. Passing a value less than zero is a
10934** no-op, and may be used to query the current state of the session.
10935**
10936** The return value indicates the final state of the session object: 0 if
10937** the session is disabled, or 1 if it is enabled.
10938*/
10939SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
10940
10941/*
10942** CAPI3REF: Set Or Clear the Indirect Change Flag
10943** METHOD: sqlite3_session
10944**
10945** Each change recorded by a session object is marked as either direct or
10946** indirect. A change is marked as indirect if either:
10947**
10948** <ul>
10949** <li> The session object "indirect" flag is set when the change is
10950** made, or
10951** <li> The change is made by an SQL trigger or foreign key action
10952** instead of directly as a result of a users SQL statement.
10953** </ul>
10954**
10955** If a single row is affected by more than one operation within a session,
10956** then the change is considered indirect if all operations meet the criteria
10957** for an indirect change above, or direct otherwise.
10958**
10959** This function is used to set, clear or query the session object indirect
10960** flag. If the second argument passed to this function is zero, then the
10961** indirect flag is cleared. If it is greater than zero, the indirect flag
10962** is set. Passing a value less than zero does not modify the current value
10963** of the indirect flag, and may be used to query the current state of the
10964** indirect flag for the specified session object.
10965**
10966** The return value indicates the final state of the indirect flag: 0 if
10967** it is clear, or 1 if it is set.
10968*/
10969SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
10970
10971/*
10972** CAPI3REF: Attach A Table To A Session Object
10973** METHOD: sqlite3_session
10974**
10975** If argument zTab is not NULL, then it is the name of a table to attach
10976** to the session object passed as the first argument. All subsequent changes
10977** made to the table while the session object is enabled will be recorded. See
10978** documentation for [sqlite3session_changeset()] for further details.
10979**
10980** Or, if argument zTab is NULL, then changes are recorded for all tables
10981** in the database. If additional tables are added to the database (by
10982** executing "CREATE TABLE" statements) after this call is made, changes for
10983** the new tables are also recorded.
10984**
10985** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
10986** defined as part of their CREATE TABLE statement. It does not matter if the
10987** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10988** KEY may consist of a single column, or may be a composite key.
10989**
10990** It is not an error if the named table does not exist in the database. Nor
10991** is it an error if the named table does not have a PRIMARY KEY. However,
10992** no changes will be recorded in either of these scenarios.
10993**
10994** Changes are not recorded for individual rows that have NULL values stored
10995** in one or more of their PRIMARY KEY columns.
10996**
10997** SQLITE_OK is returned if the call completes without error. Or, if an error
10998** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
10999**
11000** <h3>Special sqlite_stat1 Handling</h3>
11001**
11002** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11003** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11004** <pre>
11005** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
11006** </pre>
11007**
11008** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11009** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11010** are recorded for rows for which (idx IS NULL) is true. However, for such
11011** rows a zero-length blob (SQL value X'') is stored in the changeset or
11012** patchset instead of a NULL value. This allows such changesets to be
11013** manipulated by legacy implementations of sqlite3changeset_invert(),
11014** concat() and similar.
11015**
11016** The sqlite3changeset_apply() function automatically converts the
11017** zero-length blob back to a NULL value when updating the sqlite_stat1
11018** table. However, if the application calls sqlite3changeset_new(),
11019** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11020** iterator directly (including on a changeset iterator passed to a
11021** conflict-handler callback) then the X'' value is returned. The application
11022** must translate X'' to NULL itself if required.
11023**
11024** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11025** changes made to the sqlite_stat1 table. Legacy versions of the
11026** sqlite3changeset_apply() function silently ignore any modifications to the
11027** sqlite_stat1 table that are part of a changeset or patchset.
11028*/
11029SQLITE_API int sqlite3session_attach(
11030 sqlite3_session *pSession, /* Session object */
11031 const char *zTab /* Table name */
11032);
11033
11034/*
11035** CAPI3REF: Set a table filter on a Session Object.
11036** METHOD: sqlite3_session
11037**
11038** The second argument (xFilter) is the "filter callback". For changes to rows
11039** in tables that are not attached to the Session object, the filter is called
11040** to determine whether changes to the table's rows should be tracked or not.
11041** If xFilter returns 0, changes are not tracked. Note that once a table is
11042** attached, xFilter will not be called again.
11043*/
11044SQLITE_API void sqlite3session_table_filter(
11045 sqlite3_session *pSession, /* Session object */
11046 int(*xFilter)(
11047 void *pCtx, /* Copy of third arg to _filter_table() */
11048 const char *zTab /* Table name */
11049 ),
11050 void *pCtx /* First argument passed to xFilter */
11051);
11052
11053/*
11054** CAPI3REF: Generate A Changeset From A Session Object
11055** METHOD: sqlite3_session
11056**
11057** Obtain a changeset containing changes to the tables attached to the
11058** session object passed as the first argument. If successful,
11059** set *ppChangeset to point to a buffer containing the changeset
11060** and *pnChangeset to the size of the changeset in bytes before returning
11061** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11062** zero and return an SQLite error code.
11063**
11064** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11065** each representing a change to a single row of an attached table. An INSERT
11066** change contains the values of each field of a new database row. A DELETE
11067** contains the original values of each field of a deleted database row. An
11068** UPDATE change contains the original values of each field of an updated
11069** database row along with the updated values for each updated non-primary-key
11070** column. It is not possible for an UPDATE change to represent a change that
11071** modifies the values of primary key columns. If such a change is made, it
11072** is represented in a changeset as a DELETE followed by an INSERT.
11073**
11074** Changes are not recorded for rows that have NULL values stored in one or
11075** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11076** no corresponding change is present in the changesets returned by this
11077** function. If an existing row with one or more NULL values stored in
11078** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11079** only an INSERT is appears in the changeset. Similarly, if an existing row
11080** with non-NULL PRIMARY KEY values is updated so that one or more of its
11081** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11082** DELETE change only.
11083**
11084** The contents of a changeset may be traversed using an iterator created
11085** using the [sqlite3changeset_start()] API. A changeset may be applied to
11086** a database with a compatible schema using the [sqlite3changeset_apply()]
11087** API.
11088**
11089** Within a changeset generated by this function, all changes related to a
11090** single table are grouped together. In other words, when iterating through
11091** a changeset or when applying a changeset to a database, all changes related
11092** to a single table are processed before moving on to the next table. Tables
11093** are sorted in the same order in which they were attached (or auto-attached)
11094** to the sqlite3_session object. The order in which the changes related to
11095** a single table are stored is undefined.
11096**
11097** Following a successful call to this function, it is the responsibility of
11098** the caller to eventually free the buffer that *ppChangeset points to using
11099** [sqlite3_free()].
11100**
11101** <h3>Changeset Generation</h3>
11102**
11103** Once a table has been attached to a session object, the session object
11104** records the primary key values of all new rows inserted into the table.
11105** It also records the original primary key and other column values of any
11106** deleted or updated rows. For each unique primary key value, data is only
11107** recorded once - the first time a row with said primary key is inserted,
11108** updated or deleted in the lifetime of the session.
11109**
11110** There is one exception to the previous paragraph: when a row is inserted,
11111** updated or deleted, if one or more of its primary key columns contain a
11112** NULL value, no record of the change is made.
11113**
11114** The session object therefore accumulates two types of records - those
11115** that consist of primary key values only (created when the user inserts
11116** a new record) and those that consist of the primary key values and the
11117** original values of other table columns (created when the users deletes
11118** or updates a record).
11119**
11120** When this function is called, the requested changeset is created using
11121** both the accumulated records and the current contents of the database
11122** file. Specifically:
11123**
11124** <ul>
11125** <li> For each record generated by an insert, the database is queried
11126** for a row with a matching primary key. If one is found, an INSERT
11127** change is added to the changeset. If no such row is found, no change
11128** is added to the changeset.
11129**
11130** <li> For each record generated by an update or delete, the database is
11131** queried for a row with a matching primary key. If such a row is
11132** found and one or more of the non-primary key fields have been
11133** modified from their original values, an UPDATE change is added to
11134** the changeset. Or, if no such row is found in the table, a DELETE
11135** change is added to the changeset. If there is a row with a matching
11136** primary key in the database, but all fields contain their original
11137** values, no change is added to the changeset.
11138** </ul>
11139**
11140** This means, amongst other things, that if a row is inserted and then later
11141** deleted while a session object is active, neither the insert nor the delete
11142** will be present in the changeset. Or if a row is deleted and then later a
11143** row with the same primary key values inserted while a session object is
11144** active, the resulting changeset will contain an UPDATE change instead of
11145** a DELETE and an INSERT.
11146**
11147** When a session object is disabled (see the [sqlite3session_enable()] API),
11148** it does not accumulate records when rows are inserted, updated or deleted.
11149** This may appear to have some counter-intuitive effects if a single row
11150** is written to more than once during a session. For example, if a row
11151** is inserted while a session object is enabled, then later deleted while
11152** the same session object is disabled, no INSERT record will appear in the
11153** changeset, even though the delete took place while the session was disabled.
11154** Or, if one field of a row is updated while a session is disabled, and
11155** another field of the same row is updated while the session is enabled, the
11156** resulting changeset will contain an UPDATE change that updates both fields.
11157*/
11158SQLITE_API int sqlite3session_changeset(
11159 sqlite3_session *pSession, /* Session object */
11160 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11161 void **ppChangeset /* OUT: Buffer containing changeset */
11162);
11163
11164/*
11165** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11166** METHOD: sqlite3_session
11167**
11168** By default, this function always returns 0. For it to return
11169** a useful result, the sqlite3_session object must have been configured
11170** to enable this API using sqlite3session_object_config() with the
11171** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11172**
11173** When enabled, this function returns an upper limit, in bytes, for the size
11174** of the changeset that might be produced if sqlite3session_changeset() were
11175** called. The final changeset size might be equal to or smaller than the
11176** size in bytes returned by this function.
11177*/
11178SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11179
11180/*
11181** CAPI3REF: Load The Difference Between Tables Into A Session
11182** METHOD: sqlite3_session
11183**
11184** If it is not already attached to the session object passed as the first
11185** argument, this function attaches table zTbl in the same manner as the
11186** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11187** does not have a primary key, this function is a no-op (but does not return
11188** an error).
11189**
11190** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11191** attached to the same database handle as the session object that contains
11192** a table compatible with the table attached to the session by this function.
11193** A table is considered compatible if it:
11194**
11195** <ul>
11196** <li> Has the same name,
11197** <li> Has the same set of columns declared in the same order, and
11198** <li> Has the same PRIMARY KEY definition.
11199** </ul>
11200**
11201** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11202** are compatible but do not have any PRIMARY KEY columns, it is not an error
11203** but no changes are added to the session object. As with other session
11204** APIs, tables without PRIMARY KEYs are simply ignored.
11205**
11206** This function adds a set of changes to the session object that could be
11207** used to update the table in database zFrom (call this the "from-table")
11208** so that its content is the same as the table attached to the session
11209** object (call this the "to-table"). Specifically:
11210**
11211** <ul>
11212** <li> For each row (primary key) that exists in the to-table but not in
11213** the from-table, an INSERT record is added to the session object.
11214**
11215** <li> For each row (primary key) that exists in the to-table but not in
11216** the from-table, a DELETE record is added to the session object.
11217**
11218** <li> For each row (primary key) that exists in both tables, but features
11219** different non-PK values in each, an UPDATE record is added to the
11220** session.
11221** </ul>
11222**
11223** To clarify, if this function is called and then a changeset constructed
11224** using [sqlite3session_changeset()], then after applying that changeset to
11225** database zFrom the contents of the two compatible tables would be
11226** identical.
11227**
11228** It an error if database zFrom does not exist or does not contain the
11229** required compatible table.
11230**
11231** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11232** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11233** may be set to point to a buffer containing an English language error
11234** message. It is the responsibility of the caller to free this buffer using
11235** sqlite3_free().
11236*/
11237SQLITE_API int sqlite3session_diff(
11238 sqlite3_session *pSession,
11239 const char *zFromDb,
11240 const char *zTbl,
11241 char **pzErrMsg
11242);
11243
11244
11245/*
11246** CAPI3REF: Generate A Patchset From A Session Object
11247** METHOD: sqlite3_session
11248**
11249** The differences between a patchset and a changeset are that:
11250**
11251** <ul>
11252** <li> DELETE records consist of the primary key fields only. The
11253** original values of other fields are omitted.
11254** <li> The original values of any modified fields are omitted from
11255** UPDATE records.
11256** </ul>
11257**
11258** A patchset blob may be used with up to date versions of all
11259** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11260** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11261** attempting to use a patchset blob with old versions of the
11262** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11263**
11264** Because the non-primary key "old.*" fields are omitted, no
11265** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11266** is passed to the sqlite3changeset_apply() API. Other conflict types work
11267** in the same way as for changesets.
11268**
11269** Changes within a patchset are ordered in the same way as for changesets
11270** generated by the sqlite3session_changeset() function (i.e. all changes for
11271** a single table are grouped together, tables appear in the order in which
11272** they were attached to the session object).
11273*/
11274SQLITE_API int sqlite3session_patchset(
11275 sqlite3_session *pSession, /* Session object */
11276 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11277 void **ppPatchset /* OUT: Buffer containing patchset */
11278);
11279
11280/*
11281** CAPI3REF: Test if a changeset has recorded any changes.
11282**
11283** Return non-zero if no changes to attached tables have been recorded by
11284** the session object passed as the first argument. Otherwise, if one or
11285** more changes have been recorded, return zero.
11286**
11287** Even if this function returns zero, it is possible that calling
11288** [sqlite3session_changeset()] on the session handle may still return a
11289** changeset that contains no changes. This can happen when a row in
11290** an attached table is modified and then later on the original values
11291** are restored. However, if this function returns non-zero, then it is
11292** guaranteed that a call to sqlite3session_changeset() will return a
11293** changeset containing zero changes.
11294*/
11295SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11296
11297/*
11298** CAPI3REF: Query for the amount of heap memory used by a session object.
11299**
11300** This API returns the total amount of heap memory in bytes currently
11301** used by the session object passed as the only argument.
11302*/
11303SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11304
11305/*
11306** CAPI3REF: Create An Iterator To Traverse A Changeset
11307** CONSTRUCTOR: sqlite3_changeset_iter
11308**
11309** Create an iterator used to iterate through the contents of a changeset.
11310** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11311** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11312** SQLite error code is returned.
11313**
11314** The following functions can be used to advance and query a changeset
11315** iterator created by this function:
11316**
11317** <ul>
11318** <li> [sqlite3changeset_next()]
11319** <li> [sqlite3changeset_op()]
11320** <li> [sqlite3changeset_new()]
11321** <li> [sqlite3changeset_old()]
11322** </ul>
11323**
11324** It is the responsibility of the caller to eventually destroy the iterator
11325** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11326** changeset (pChangeset) must remain valid until after the iterator is
11327** destroyed.
11328**
11329** Assuming the changeset blob was created by one of the
11330** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11331** [sqlite3changeset_invert()] functions, all changes within the changeset
11332** that apply to a single table are grouped together. This means that when
11333** an application iterates through a changeset using an iterator created by
11334** this function, all changes that relate to a single table are visited
11335** consecutively. There is no chance that the iterator will visit a change
11336** the applies to table X, then one for table Y, and then later on visit
11337** another change for table X.
11338**
11339** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11340** may be modified by passing a combination of
11341** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11342**
11343** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11344** and therefore subject to change.
11345*/
11346SQLITE_API int sqlite3changeset_start(
11347 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11348 int nChangeset, /* Size of changeset blob in bytes */
11349 void *pChangeset /* Pointer to blob containing changeset */
11350);
11351SQLITE_API int sqlite3changeset_start_v2(
11352 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11353 int nChangeset, /* Size of changeset blob in bytes */
11354 void *pChangeset, /* Pointer to blob containing changeset */
11355 int flags /* SESSION_CHANGESETSTART_* flags */
11356);
11357
11358/*
11359** CAPI3REF: Flags for sqlite3changeset_start_v2
11360**
11361** The following flags may passed via the 4th parameter to
11362** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11363**
11364** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11365** Invert the changeset while iterating through it. This is equivalent to
11366** inverting a changeset using sqlite3changeset_invert() before applying it.
11367** It is an error to specify this flag with a patchset.
11368*/
11369#define SQLITE_CHANGESETSTART_INVERT 0x0002
11370
11371
11372/*
11373** CAPI3REF: Advance A Changeset Iterator
11374** METHOD: sqlite3_changeset_iter
11375**
11376** This function may only be used with iterators created by the function
11377** [sqlite3changeset_start()]. If it is called on an iterator passed to
11378** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11379** is returned and the call has no effect.
11380**
11381** Immediately after an iterator is created by sqlite3changeset_start(), it
11382** does not point to any change in the changeset. Assuming the changeset
11383** is not empty, the first call to this function advances the iterator to
11384** point to the first change in the changeset. Each subsequent call advances
11385** the iterator to point to the next change in the changeset (if any). If
11386** no error occurs and the iterator points to a valid change after a call
11387** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11388** Otherwise, if all changes in the changeset have already been visited,
11389** SQLITE_DONE is returned.
11390**
11391** If an error occurs, an SQLite error code is returned. Possible error
11392** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11393** SQLITE_NOMEM.
11394*/
11395SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11396
11397/*
11398** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11399** METHOD: sqlite3_changeset_iter
11400**
11401** The pIter argument passed to this function may either be an iterator
11402** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11403** created by [sqlite3changeset_start()]. In the latter case, the most recent
11404** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11405** is not the case, this function returns [SQLITE_MISUSE].
11406**
11407** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11408** outputs are set through these pointers:
11409**
11410** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11411** depending on the type of change that the iterator currently points to;
11412**
11413** *pnCol is set to the number of columns in the table affected by the change; and
11414**
11415** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11416** the name of the table affected by the current change. The buffer remains
11417** valid until either sqlite3changeset_next() is called on the iterator
11418** or until the conflict-handler function returns.
11419**
11420** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11421** is an indirect change, or false (0) otherwise. See the documentation for
11422** [sqlite3session_indirect()] for a description of direct and indirect
11423** changes.
11424**
11425** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11426** SQLite error code is returned. The values of the output variables may not
11427** be trusted in this case.
11428*/
11429SQLITE_API int sqlite3changeset_op(
11430 sqlite3_changeset_iter *pIter, /* Iterator object */
11431 const char **pzTab, /* OUT: Pointer to table name */
11432 int *pnCol, /* OUT: Number of columns in table */
11433 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11434 int *pbIndirect /* OUT: True for an 'indirect' change */
11435);
11436
11437/*
11438** CAPI3REF: Obtain The Primary Key Definition Of A Table
11439** METHOD: sqlite3_changeset_iter
11440**
11441** For each modified table, a changeset includes the following:
11442**
11443** <ul>
11444** <li> The number of columns in the table, and
11445** <li> Which of those columns make up the tables PRIMARY KEY.
11446** </ul>
11447**
11448** This function is used to find which columns comprise the PRIMARY KEY of
11449** the table modified by the change that iterator pIter currently points to.
11450** If successful, *pabPK is set to point to an array of nCol entries, where
11451** nCol is the number of columns in the table. Elements of *pabPK are set to
11452** 0x01 if the corresponding column is part of the tables primary key, or
11453** 0x00 if it is not.
11454**
11455** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11456** in the table.
11457**
11458** If this function is called when the iterator does not point to a valid
11459** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11460** SQLITE_OK is returned and the output variables populated as described
11461** above.
11462*/
11463SQLITE_API int sqlite3changeset_pk(
11464 sqlite3_changeset_iter *pIter, /* Iterator object */
11465 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11466 int *pnCol /* OUT: Number of entries in output array */
11467);
11468
11469/*
11470** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11471** METHOD: sqlite3_changeset_iter
11472**
11473** The pIter argument passed to this function may either be an iterator
11474** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11475** created by [sqlite3changeset_start()]. In the latter case, the most recent
11476** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11477** Furthermore, it may only be called if the type of change that the iterator
11478** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11479** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11480**
11481** Argument iVal must be greater than or equal to 0, and less than the number
11482** of columns in the table affected by the current change. Otherwise,
11483** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11484**
11485** If successful, this function sets *ppValue to point to a protected
11486** sqlite3_value object containing the iVal'th value from the vector of
11487** original row values stored as part of the UPDATE or DELETE change and
11488** returns SQLITE_OK. The name of the function comes from the fact that this
11489** is similar to the "old.*" columns available to update or delete triggers.
11490**
11491** If some other error occurs (e.g. an OOM condition), an SQLite error code
11492** is returned and *ppValue is set to NULL.
11493*/
11494SQLITE_API int sqlite3changeset_old(
11495 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11496 int iVal, /* Column number */
11497 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11498);
11499
11500/*
11501** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11502** METHOD: sqlite3_changeset_iter
11503**
11504** The pIter argument passed to this function may either be an iterator
11505** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11506** created by [sqlite3changeset_start()]. In the latter case, the most recent
11507** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11508** Furthermore, it may only be called if the type of change that the iterator
11509** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11510** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11511**
11512** Argument iVal must be greater than or equal to 0, and less than the number
11513** of columns in the table affected by the current change. Otherwise,
11514** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11515**
11516** If successful, this function sets *ppValue to point to a protected
11517** sqlite3_value object containing the iVal'th value from the vector of
11518** new row values stored as part of the UPDATE or INSERT change and
11519** returns SQLITE_OK. If the change is an UPDATE and does not include
11520** a new value for the requested column, *ppValue is set to NULL and
11521** SQLITE_OK returned. The name of the function comes from the fact that
11522** this is similar to the "new.*" columns available to update or delete
11523** triggers.
11524**
11525** If some other error occurs (e.g. an OOM condition), an SQLite error code
11526** is returned and *ppValue is set to NULL.
11527*/
11528SQLITE_API int sqlite3changeset_new(
11529 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11530 int iVal, /* Column number */
11531 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11532);
11533
11534/*
11535** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11536** METHOD: sqlite3_changeset_iter
11537**
11538** This function should only be used with iterator objects passed to a
11539** conflict-handler callback by [sqlite3changeset_apply()] with either
11540** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11541** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11542** is set to NULL.
11543**
11544** Argument iVal must be greater than or equal to 0, and less than the number
11545** of columns in the table affected by the current change. Otherwise,
11546** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11547**
11548** If successful, this function sets *ppValue to point to a protected
11549** sqlite3_value object containing the iVal'th value from the
11550** "conflicting row" associated with the current conflict-handler callback
11551** and returns SQLITE_OK.
11552**
11553** If some other error occurs (e.g. an OOM condition), an SQLite error code
11554** is returned and *ppValue is set to NULL.
11555*/
11556SQLITE_API int sqlite3changeset_conflict(
11557 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11558 int iVal, /* Column number */
11559 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11560);
11561
11562/*
11563** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11564** METHOD: sqlite3_changeset_iter
11565**
11566** This function may only be called with an iterator passed to an
11567** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11568** it sets the output variable to the total number of known foreign key
11569** violations in the destination database and returns SQLITE_OK.
11570**
11571** In all other cases this function returns SQLITE_MISUSE.
11572*/
11573SQLITE_API int sqlite3changeset_fk_conflicts(
11574 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11575 int *pnOut /* OUT: Number of FK violations */
11576);
11577
11578
11579/*
11580** CAPI3REF: Finalize A Changeset Iterator
11581** METHOD: sqlite3_changeset_iter
11582**
11583** This function is used to finalize an iterator allocated with
11584** [sqlite3changeset_start()].
11585**
11586** This function should only be called on iterators created using the
11587** [sqlite3changeset_start()] function. If an application calls this
11588** function with an iterator passed to a conflict-handler by
11589** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11590** call has no effect.
11591**
11592** If an error was encountered within a call to an sqlite3changeset_xxx()
11593** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
11594** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
11595** to that error is returned by this function. Otherwise, SQLITE_OK is
11596** returned. This is to allow the following pattern (pseudo-code):
11597**
11598** <pre>
11599** sqlite3changeset_start();
11600** while( SQLITE_ROW==sqlite3changeset_next() ){
11601** // Do something with change.
11602** }
11603** rc = sqlite3changeset_finalize();
11604** if( rc!=SQLITE_OK ){
11605** // An error has occurred
11606** }
11607** </pre>
11608*/
11609SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
11610
11611/*
11612** CAPI3REF: Invert A Changeset
11613**
11614** This function is used to "invert" a changeset object. Applying an inverted
11615** changeset to a database reverses the effects of applying the uninverted
11616** changeset. Specifically:
11617**
11618** <ul>
11619** <li> Each DELETE change is changed to an INSERT, and
11620** <li> Each INSERT change is changed to a DELETE, and
11621** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11622** </ul>
11623**
11624** This function does not change the order in which changes appear within
11625** the changeset. It merely reverses the sense of each individual change.
11626**
11627** If successful, a pointer to a buffer containing the inverted changeset
11628** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11629** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11630** zeroed and an SQLite error code returned.
11631**
11632** It is the responsibility of the caller to eventually call sqlite3_free()
11633** on the *ppOut pointer to free the buffer allocation following a successful
11634** call to this function.
11635**
11636** WARNING/TODO: This function currently assumes that the input is a valid
11637** changeset. If it is not, the results are undefined.
11638*/
11639SQLITE_API int sqlite3changeset_invert(
11640 int nIn, const void *pIn, /* Input changeset */
11641 int *pnOut, void **ppOut /* OUT: Inverse of input */
11642);
11643
11644/*
11645** CAPI3REF: Concatenate Two Changeset Objects
11646**
11647** This function is used to concatenate two changesets, A and B, into a
11648** single changeset. The result is a changeset equivalent to applying
11649** changeset A followed by changeset B.
11650**
11651** This function combines the two input changesets using an
11652** sqlite3_changegroup object. Calling it produces similar results as the
11653** following code fragment:
11654**
11655** <pre>
11656** sqlite3_changegroup *pGrp;
11657** rc = sqlite3_changegroup_new(&pGrp);
11658** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11659** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11660** if( rc==SQLITE_OK ){
11661** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11662** }else{
11663** *ppOut = 0;
11664** *pnOut = 0;
11665** }
11666** </pre>
11667**
11668** Refer to the sqlite3_changegroup documentation below for details.
11669*/
11670SQLITE_API int sqlite3changeset_concat(
11671 int nA, /* Number of bytes in buffer pA */
11672 void *pA, /* Pointer to buffer containing changeset A */
11673 int nB, /* Number of bytes in buffer pB */
11674 void *pB, /* Pointer to buffer containing changeset B */
11675 int *pnOut, /* OUT: Number of bytes in output changeset */
11676 void **ppOut /* OUT: Buffer containing output changeset */
11677);
11678
11679
11680/*
11681** CAPI3REF: Changegroup Handle
11682**
11683** A changegroup is an object used to combine two or more
11684** [changesets] or [patchsets]
11685*/
11686typedef struct sqlite3_changegroup sqlite3_changegroup;
11687
11688/*
11689** CAPI3REF: Create A New Changegroup Object
11690** CONSTRUCTOR: sqlite3_changegroup
11691**
11692** An sqlite3_changegroup object is used to combine two or more changesets
11693** (or patchsets) into a single changeset (or patchset). A single changegroup
11694** object may combine changesets or patchsets, but not both. The output is
11695** always in the same format as the input.
11696**
11697** If successful, this function returns SQLITE_OK and populates (*pp) with
11698** a pointer to a new sqlite3_changegroup object before returning. The caller
11699** should eventually free the returned object using a call to
11700** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11701** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11702**
11703** The usual usage pattern for an sqlite3_changegroup object is as follows:
11704**
11705** <ul>
11706** <li> It is created using a call to sqlite3changegroup_new().
11707**
11708** <li> Zero or more changesets (or patchsets) are added to the object
11709** by calling sqlite3changegroup_add().
11710**
11711** <li> The result of combining all input changesets together is obtained
11712** by the application via a call to sqlite3changegroup_output().
11713**
11714** <li> The object is deleted using a call to sqlite3changegroup_delete().
11715** </ul>
11716**
11717** Any number of calls to add() and output() may be made between the calls to
11718** new() and delete(), and in any order.
11719**
11720** As well as the regular sqlite3changegroup_add() and
11721** sqlite3changegroup_output() functions, also available are the streaming
11722** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11723*/
11724SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11725
11726/*
11727** CAPI3REF: Add A Changeset To A Changegroup
11728** METHOD: sqlite3_changegroup
11729**
11730** Add all changes within the changeset (or patchset) in buffer pData (size
11731** nData bytes) to the changegroup.
11732**
11733** If the buffer contains a patchset, then all prior calls to this function
11734** on the same changegroup object must also have specified patchsets. Or, if
11735** the buffer contains a changeset, so must have the earlier calls to this
11736** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11737** to the changegroup.
11738**
11739** Rows within the changeset and changegroup are identified by the values in
11740** their PRIMARY KEY columns. A change in the changeset is considered to
11741** apply to the same row as a change already present in the changegroup if
11742** the two rows have the same primary key.
11743**
11744** Changes to rows that do not already appear in the changegroup are
11745** simply copied into it. Or, if both the new changeset and the changegroup
11746** contain changes that apply to a single row, the final contents of the
11747** changegroup depends on the type of each change, as follows:
11748**
11749** <table border=1 style="margin-left:8ex;margin-right:8ex">
11750** <tr><th style="white-space:pre">Existing Change </th>
11751** <th style="white-space:pre">New Change </th>
11752** <th>Output Change
11753** <tr><td>INSERT <td>INSERT <td>
11754** The new change is ignored. This case does not occur if the new
11755** changeset was recorded immediately after the changesets already
11756** added to the changegroup.
11757** <tr><td>INSERT <td>UPDATE <td>
11758** The INSERT change remains in the changegroup. The values in the
11759** INSERT change are modified as if the row was inserted by the
11760** existing change and then updated according to the new change.
11761** <tr><td>INSERT <td>DELETE <td>
11762** The existing INSERT is removed from the changegroup. The DELETE is
11763** not added.
11764** <tr><td>UPDATE <td>INSERT <td>
11765** The new change is ignored. This case does not occur if the new
11766** changeset was recorded immediately after the changesets already
11767** added to the changegroup.
11768** <tr><td>UPDATE <td>UPDATE <td>
11769** The existing UPDATE remains within the changegroup. It is amended
11770** so that the accompanying values are as if the row was updated once
11771** by the existing change and then again by the new change.
11772** <tr><td>UPDATE <td>DELETE <td>
11773** The existing UPDATE is replaced by the new DELETE within the
11774** changegroup.
11775** <tr><td>DELETE <td>INSERT <td>
11776** If one or more of the column values in the row inserted by the
11777** new change differ from those in the row deleted by the existing
11778** change, the existing DELETE is replaced by an UPDATE within the
11779** changegroup. Otherwise, if the inserted row is exactly the same
11780** as the deleted row, the existing DELETE is simply discarded.
11781** <tr><td>DELETE <td>UPDATE <td>
11782** The new change is ignored. This case does not occur if the new
11783** changeset was recorded immediately after the changesets already
11784** added to the changegroup.
11785** <tr><td>DELETE <td>DELETE <td>
11786** The new change is ignored. This case does not occur if the new
11787** changeset was recorded immediately after the changesets already
11788** added to the changegroup.
11789** </table>
11790**
11791** If the new changeset contains changes to a table that is already present
11792** in the changegroup, then the number of columns and the position of the
11793** primary key columns for the table must be consistent. If this is not the
11794** case, this function fails with SQLITE_SCHEMA. If the input changeset
11795** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
11796** returned. Or, if an out-of-memory condition occurs during processing, this
11797** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
11798** of the final contents of the changegroup is undefined.
11799**
11800** If no error occurs, SQLITE_OK is returned.
11801*/
11802SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
11803
11804/*
11805** CAPI3REF: Obtain A Composite Changeset From A Changegroup
11806** METHOD: sqlite3_changegroup
11807**
11808** Obtain a buffer containing a changeset (or patchset) representing the
11809** current contents of the changegroup. If the inputs to the changegroup
11810** were themselves changesets, the output is a changeset. Or, if the
11811** inputs were patchsets, the output is also a patchset.
11812**
11813** As with the output of the sqlite3session_changeset() and
11814** sqlite3session_patchset() functions, all changes related to a single
11815** table are grouped together in the output of this function. Tables appear
11816** in the same order as for the very first changeset added to the changegroup.
11817** If the second or subsequent changesets added to the changegroup contain
11818** changes for tables that do not appear in the first changeset, they are
11819** appended onto the end of the output changeset, again in the order in
11820** which they are first encountered.
11821**
11822** If an error occurs, an SQLite error code is returned and the output
11823** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
11824** is returned and the output variables are set to the size of and a
11825** pointer to the output buffer, respectively. In this case it is the
11826** responsibility of the caller to eventually free the buffer using a
11827** call to sqlite3_free().
11828*/
11829SQLITE_API int sqlite3changegroup_output(
11830 sqlite3_changegroup*,
11831 int *pnData, /* OUT: Size of output buffer in bytes */
11832 void **ppData /* OUT: Pointer to output buffer */
11833);
11834
11835/*
11836** CAPI3REF: Delete A Changegroup Object
11837** DESTRUCTOR: sqlite3_changegroup
11838*/
11839SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
11840
11841/*
11842** CAPI3REF: Apply A Changeset To A Database
11843**
11844** Apply a changeset or patchset to a database. These functions attempt to
11845** update the "main" database attached to handle db with the changes found in
11846** the changeset passed via the second and third arguments.
11847**
11848** The fourth argument (xFilter) passed to these functions is the "filter
11849** callback". If it is not NULL, then for each table affected by at least one
11850** change in the changeset, the filter callback is invoked with
11851** the table name as the second argument, and a copy of the context pointer
11852** passed as the sixth argument as the first. If the "filter callback"
11853** returns zero, then no attempt is made to apply any changes to the table.
11854** Otherwise, if the return value is non-zero or the xFilter argument to
11855** is NULL, all changes related to the table are attempted.
11856**
11857** For each table that is not excluded by the filter callback, this function
11858** tests that the target database contains a compatible table. A table is
11859** considered compatible if all of the following are true:
11860**
11861** <ul>
11862** <li> The table has the same name as the name recorded in the
11863** changeset, and
11864** <li> The table has at least as many columns as recorded in the
11865** changeset, and
11866** <li> The table has primary key columns in the same position as
11867** recorded in the changeset.
11868** </ul>
11869**
11870** If there is no compatible table, it is not an error, but none of the
11871** changes associated with the table are applied. A warning message is issued
11872** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
11873** one such warning is issued for each table in the changeset.
11874**
11875** For each change for which there is a compatible table, an attempt is made
11876** to modify the table contents according to the UPDATE, INSERT or DELETE
11877** change. If a change cannot be applied cleanly, the conflict handler
11878** function passed as the fifth argument to sqlite3changeset_apply() may be
11879** invoked. A description of exactly when the conflict handler is invoked for
11880** each type of change is below.
11881**
11882** Unlike the xFilter argument, xConflict may not be passed NULL. The results
11883** of passing anything other than a valid function pointer as the xConflict
11884** argument are undefined.
11885**
11886** Each time the conflict handler function is invoked, it must return one
11887** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
11888** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
11889** if the second argument passed to the conflict handler is either
11890** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
11891** returns an illegal value, any changes already made are rolled back and
11892** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
11893** actions are taken by sqlite3changeset_apply() depending on the value
11894** returned by each invocation of the conflict-handler function. Refer to
11895** the documentation for the three
11896** [SQLITE_CHANGESET_OMIT|available return values] for details.
11897**
11898** <dl>
11899** <dt>DELETE Changes<dd>
11900** For each DELETE change, the function checks if the target database
11901** contains a row with the same primary key value (or values) as the
11902** original row values stored in the changeset. If it does, and the values
11903** stored in all non-primary key columns also match the values stored in
11904** the changeset the row is deleted from the target database.
11905**
11906** If a row with matching primary key values is found, but one or more of
11907** the non-primary key fields contains a value different from the original
11908** row value stored in the changeset, the conflict-handler function is
11909** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
11910** database table has more columns than are recorded in the changeset,
11911** only the values of those non-primary key fields are compared against
11912** the current database contents - any trailing database table columns
11913** are ignored.
11914**
11915** If no row with matching primary key values is found in the database,
11916** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11917** passed as the second argument.
11918**
11919** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
11920** (which can only happen if a foreign key constraint is violated), the
11921** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
11922** passed as the second argument. This includes the case where the DELETE
11923** operation is attempted because an earlier call to the conflict handler
11924** function returned [SQLITE_CHANGESET_REPLACE].
11925**
11926** <dt>INSERT Changes<dd>
11927** For each INSERT change, an attempt is made to insert the new row into
11928** the database. If the changeset row contains fewer fields than the
11929** database table, the trailing fields are populated with their default
11930** values.
11931**
11932** If the attempt to insert the row fails because the database already
11933** contains a row with the same primary key values, the conflict handler
11934** function is invoked with the second argument set to
11935** [SQLITE_CHANGESET_CONFLICT].
11936**
11937** If the attempt to insert the row fails because of some other constraint
11938** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
11939** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
11940** This includes the case where the INSERT operation is re-attempted because
11941** an earlier call to the conflict handler function returned
11942** [SQLITE_CHANGESET_REPLACE].
11943**
11944** <dt>UPDATE Changes<dd>
11945** For each UPDATE change, the function checks if the target database
11946** contains a row with the same primary key value (or values) as the
11947** original row values stored in the changeset. If it does, and the values
11948** stored in all modified non-primary key columns also match the values
11949** stored in the changeset the row is updated within the target database.
11950**
11951** If a row with matching primary key values is found, but one or more of
11952** the modified non-primary key fields contains a value different from an
11953** original row value stored in the changeset, the conflict-handler function
11954** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
11955** UPDATE changes only contain values for non-primary key fields that are
11956** to be modified, only those fields need to match the original values to
11957** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11958**
11959** If no row with matching primary key values is found in the database,
11960** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11961** passed as the second argument.
11962**
11963** If the UPDATE operation is attempted, but SQLite returns
11964** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
11965** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
11966** This includes the case where the UPDATE operation is attempted after
11967** an earlier call to the conflict handler function returned
11968** [SQLITE_CHANGESET_REPLACE].
11969** </dl>
11970**
11971** It is safe to execute SQL statements, including those that write to the
11972** table that the callback related to, from within the xConflict callback.
11973** This can be used to further customize the application's conflict
11974** resolution strategy.
11975**
11976** All changes made by these functions are enclosed in a savepoint transaction.
11977** If any other error (aside from a constraint failure when attempting to
11978** write to the target database) occurs, then the savepoint transaction is
11979** rolled back, restoring the target database to its original state, and an
11980** SQLite error code returned.
11981**
11982** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11983** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11984** may set (*ppRebase) to point to a "rebase" that may be used with the
11985** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11986** is set to the size of the buffer in bytes. It is the responsibility of the
11987** caller to eventually free any such buffer using sqlite3_free(). The buffer
11988** is only allocated and populated if one or more conflicts were encountered
11989** while applying the patchset. See comments surrounding the sqlite3_rebaser
11990** APIs for further details.
11991**
11992** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11993** may be modified by passing a combination of
11994** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11995**
11996** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11997** and therefore subject to change.
11998*/
11999SQLITE_API int sqlite3changeset_apply(
12000 sqlite3 *db, /* Apply change to "main" db of this handle */
12001 int nChangeset, /* Size of changeset in bytes */
12002 void *pChangeset, /* Changeset blob */
12003 int(*xFilter)(
12004 void *pCtx, /* Copy of sixth arg to _apply() */
12005 const char *zTab /* Table name */
12006 ),
12007 int(*xConflict)(
12008 void *pCtx, /* Copy of sixth arg to _apply() */
12009 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12010 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12011 ),
12012 void *pCtx /* First argument passed to xConflict */
12013);
12014SQLITE_API int sqlite3changeset_apply_v2(
12015 sqlite3 *db, /* Apply change to "main" db of this handle */
12016 int nChangeset, /* Size of changeset in bytes */
12017 void *pChangeset, /* Changeset blob */
12018 int(*xFilter)(
12019 void *pCtx, /* Copy of sixth arg to _apply() */
12020 const char *zTab /* Table name */
12021 ),
12022 int(*xConflict)(
12023 void *pCtx, /* Copy of sixth arg to _apply() */
12024 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12025 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12026 ),
12027 void *pCtx, /* First argument passed to xConflict */
12028 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12029 int flags /* SESSION_CHANGESETAPPLY_* flags */
12030);
12031
12032/*
12033** CAPI3REF: Flags for sqlite3changeset_apply_v2
12034**
12035** The following flags may passed via the 9th parameter to
12036** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12037**
12038** <dl>
12039** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12040** Usually, the sessions module encloses all operations performed by
12041** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12042** SAVEPOINT is committed if the changeset or patchset is successfully
12043** applied, or rolled back if an error occurs. Specifying this flag
12044** causes the sessions module to omit this savepoint. In this case, if the
12045** caller has an open transaction or savepoint when apply_v2() is called,
12046** it may revert the partially applied changeset by rolling it back.
12047**
12048** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12049** Invert the changeset before applying it. This is equivalent to inverting
12050** a changeset using sqlite3changeset_invert() before applying it. It is
12051** an error to specify this flag with a patchset.
12052**
12053** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12054** Do not invoke the conflict handler callback for any changes that
12055** would not actually modify the database even if they were applied.
12056** Specifically, this means that the conflict handler is not invoked
12057** for:
12058** <ul>
12059** <li>a delete change if the row being deleted cannot be found,
12060** <li>an update change if the modified fields are already set to
12061** their new values in the conflicting row, or
12062** <li>an insert change if all fields of the conflicting row match
12063** the row being inserted.
12064** </ul>
12065*/
12066#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12067#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12068#define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12069
12070/*
12071** CAPI3REF: Constants Passed To The Conflict Handler
12072**
12073** Values that may be passed as the second argument to a conflict-handler.
12074**
12075** <dl>
12076** <dt>SQLITE_CHANGESET_DATA<dd>
12077** The conflict handler is invoked with CHANGESET_DATA as the second argument
12078** when processing a DELETE or UPDATE change if a row with the required
12079** PRIMARY KEY fields is present in the database, but one or more other
12080** (non primary-key) fields modified by the update do not contain the
12081** expected "before" values.
12082**
12083** The conflicting row, in this case, is the database row with the matching
12084** primary key.
12085**
12086** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12087** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12088** argument when processing a DELETE or UPDATE change if a row with the
12089** required PRIMARY KEY fields is not present in the database.
12090**
12091** There is no conflicting row in this case. The results of invoking the
12092** sqlite3changeset_conflict() API are undefined.
12093**
12094** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12095** CHANGESET_CONFLICT is passed as the second argument to the conflict
12096** handler while processing an INSERT change if the operation would result
12097** in duplicate primary key values.
12098**
12099** The conflicting row in this case is the database row with the matching
12100** primary key.
12101**
12102** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12103** If foreign key handling is enabled, and applying a changeset leaves the
12104** database in a state containing foreign key violations, the conflict
12105** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12106** exactly once before the changeset is committed. If the conflict handler
12107** returns CHANGESET_OMIT, the changes, including those that caused the
12108** foreign key constraint violation, are committed. Or, if it returns
12109** CHANGESET_ABORT, the changeset is rolled back.
12110**
12111** No current or conflicting row information is provided. The only function
12112** it is possible to call on the supplied sqlite3_changeset_iter handle
12113** is sqlite3changeset_fk_conflicts().
12114**
12115** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12116** If any other constraint violation occurs while applying a change (i.e.
12117** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12118** invoked with CHANGESET_CONSTRAINT as the second argument.
12119**
12120** There is no conflicting row in this case. The results of invoking the
12121** sqlite3changeset_conflict() API are undefined.
12122**
12123** </dl>
12124*/
12125#define SQLITE_CHANGESET_DATA 1
12126#define SQLITE_CHANGESET_NOTFOUND 2
12127#define SQLITE_CHANGESET_CONFLICT 3
12128#define SQLITE_CHANGESET_CONSTRAINT 4
12129#define SQLITE_CHANGESET_FOREIGN_KEY 5
12130
12131/*
12132** CAPI3REF: Constants Returned By The Conflict Handler
12133**
12134** A conflict handler callback must return one of the following three values.
12135**
12136** <dl>
12137** <dt>SQLITE_CHANGESET_OMIT<dd>
12138** If a conflict handler returns this value no special action is taken. The
12139** change that caused the conflict is not applied. The session module
12140** continues to the next change in the changeset.
12141**
12142** <dt>SQLITE_CHANGESET_REPLACE<dd>
12143** This value may only be returned if the second argument to the conflict
12144** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12145** is not the case, any changes applied so far are rolled back and the
12146** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12147**
12148** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12149** handler, then the conflicting row is either updated or deleted, depending
12150** on the type of change.
12151**
12152** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12153** handler, then the conflicting row is removed from the database and a
12154** second attempt to apply the change is made. If this second attempt fails,
12155** the original row is restored to the database before continuing.
12156**
12157** <dt>SQLITE_CHANGESET_ABORT<dd>
12158** If this value is returned, any changes applied so far are rolled back
12159** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12160** </dl>
12161*/
12162#define SQLITE_CHANGESET_OMIT 0
12163#define SQLITE_CHANGESET_REPLACE 1
12164#define SQLITE_CHANGESET_ABORT 2
12165
12166/*
12167** CAPI3REF: Rebasing changesets
12168** EXPERIMENTAL
12169**
12170** Suppose there is a site hosting a database in state S0. And that
12171** modifications are made that move that database to state S1 and a
12172** changeset recorded (the "local" changeset). Then, a changeset based
12173** on S0 is received from another site (the "remote" changeset) and
12174** applied to the database. The database is then in state
12175** (S1+"remote"), where the exact state depends on any conflict
12176** resolution decisions (OMIT or REPLACE) made while applying "remote".
12177** Rebasing a changeset is to update it to take those conflict
12178** resolution decisions into account, so that the same conflicts
12179** do not have to be resolved elsewhere in the network.
12180**
12181** For example, if both the local and remote changesets contain an
12182** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12183**
12184** local: INSERT INTO t1 VALUES(1, 'v1');
12185** remote: INSERT INTO t1 VALUES(1, 'v2');
12186**
12187** and the conflict resolution is REPLACE, then the INSERT change is
12188** removed from the local changeset (it was overridden). Or, if the
12189** conflict resolution was "OMIT", then the local changeset is modified
12190** to instead contain:
12191**
12192** UPDATE t1 SET b = 'v2' WHERE a=1;
12193**
12194** Changes within the local changeset are rebased as follows:
12195**
12196** <dl>
12197** <dt>Local INSERT<dd>
12198** This may only conflict with a remote INSERT. If the conflict
12199** resolution was OMIT, then add an UPDATE change to the rebased
12200** changeset. Or, if the conflict resolution was REPLACE, add
12201** nothing to the rebased changeset.
12202**
12203** <dt>Local DELETE<dd>
12204** This may conflict with a remote UPDATE or DELETE. In both cases the
12205** only possible resolution is OMIT. If the remote operation was a
12206** DELETE, then add no change to the rebased changeset. If the remote
12207** operation was an UPDATE, then the old.* fields of change are updated
12208** to reflect the new.* values in the UPDATE.
12209**
12210** <dt>Local UPDATE<dd>
12211** This may conflict with a remote UPDATE or DELETE. If it conflicts
12212** with a DELETE, and the conflict resolution was OMIT, then the update
12213** is changed into an INSERT. Any undefined values in the new.* record
12214** from the update change are filled in using the old.* values from
12215** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12216** the UPDATE change is simply omitted from the rebased changeset.
12217**
12218** If conflict is with a remote UPDATE and the resolution is OMIT, then
12219** the old.* values are rebased using the new.* values in the remote
12220** change. Or, if the resolution is REPLACE, then the change is copied
12221** into the rebased changeset with updates to columns also updated by
12222** the conflicting remote UPDATE removed. If this means no columns would
12223** be updated, the change is omitted.
12224** </dl>
12225**
12226** A local change may be rebased against multiple remote changes
12227** simultaneously. If a single key is modified by multiple remote
12228** changesets, they are combined as follows before the local changeset
12229** is rebased:
12230**
12231** <ul>
12232** <li> If there has been one or more REPLACE resolutions on a
12233** key, it is rebased according to a REPLACE.
12234**
12235** <li> If there have been no REPLACE resolutions on a key, then
12236** the local changeset is rebased according to the most recent
12237** of the OMIT resolutions.
12238** </ul>
12239**
12240** Note that conflict resolutions from multiple remote changesets are
12241** combined on a per-field basis, not per-row. This means that in the
12242** case of multiple remote UPDATE operations, some fields of a single
12243** local change may be rebased for REPLACE while others are rebased for
12244** OMIT.
12245**
12246** In order to rebase a local changeset, the remote changeset must first
12247** be applied to the local database using sqlite3changeset_apply_v2() and
12248** the buffer of rebase information captured. Then:
12249**
12250** <ol>
12251** <li> An sqlite3_rebaser object is created by calling
12252** sqlite3rebaser_create().
12253** <li> The new object is configured with the rebase buffer obtained from
12254** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12255** If the local changeset is to be rebased against multiple remote
12256** changesets, then sqlite3rebaser_configure() should be called
12257** multiple times, in the same order that the multiple
12258** sqlite3changeset_apply_v2() calls were made.
12259** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12260** <li> The sqlite3_rebaser object is deleted by calling
12261** sqlite3rebaser_delete().
12262** </ol>
12263*/
12264typedef struct sqlite3_rebaser sqlite3_rebaser;
12265
12266/*
12267** CAPI3REF: Create a changeset rebaser object.
12268** EXPERIMENTAL
12269**
12270** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12271** point to the new object and return SQLITE_OK. Otherwise, if an error
12272** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12273** to NULL.
12274*/
12275SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12276
12277/*
12278** CAPI3REF: Configure a changeset rebaser object.
12279** EXPERIMENTAL
12280**
12281** Configure the changeset rebaser object to rebase changesets according
12282** to the conflict resolutions described by buffer pRebase (size nRebase
12283** bytes), which must have been obtained from a previous call to
12284** sqlite3changeset_apply_v2().
12285*/
12286SQLITE_API int sqlite3rebaser_configure(
12287 sqlite3_rebaser*,
12288 int nRebase, const void *pRebase
12289);
12290
12291/*
12292** CAPI3REF: Rebase a changeset
12293** EXPERIMENTAL
12294**
12295** Argument pIn must point to a buffer containing a changeset nIn bytes
12296** in size. This function allocates and populates a buffer with a copy
12297** of the changeset rebased according to the configuration of the
12298** rebaser object passed as the first argument. If successful, (*ppOut)
12299** is set to point to the new buffer containing the rebased changeset and
12300** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12301** responsibility of the caller to eventually free the new buffer using
12302** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12303** are set to zero and an SQLite error code returned.
12304*/
12305SQLITE_API int sqlite3rebaser_rebase(
12306 sqlite3_rebaser*,
12307 int nIn, const void *pIn,
12308 int *pnOut, void **ppOut
12309);
12310
12311/*
12312** CAPI3REF: Delete a changeset rebaser object.
12313** EXPERIMENTAL
12314**
12315** Delete the changeset rebaser object and all associated resources. There
12316** should be one call to this function for each successful invocation
12317** of sqlite3rebaser_create().
12318*/
12319SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12320
12321/*
12322** CAPI3REF: Streaming Versions of API functions.
12323**
12324** The six streaming API xxx_strm() functions serve similar purposes to the
12325** corresponding non-streaming API functions:
12326**
12327** <table border=1 style="margin-left:8ex;margin-right:8ex">
12328** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12329** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12330** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12331** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12332** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12333** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12334** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12335** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12336** </table>
12337**
12338** Non-streaming functions that accept changesets (or patchsets) as input
12339** require that the entire changeset be stored in a single buffer in memory.
12340** Similarly, those that return a changeset or patchset do so by returning
12341** a pointer to a single large buffer allocated using sqlite3_malloc().
12342** Normally this is convenient. However, if an application running in a
12343** low-memory environment is required to handle very large changesets, the
12344** large contiguous memory allocations required can become onerous.
12345**
12346** In order to avoid this problem, instead of a single large buffer, input
12347** is passed to a streaming API functions by way of a callback function that
12348** the sessions module invokes to incrementally request input data as it is
12349** required. In all cases, a pair of API function parameters such as
12350**
12351** <pre>
12352** &nbsp; int nChangeset,
12353** &nbsp; void *pChangeset,
12354** </pre>
12355**
12356** Is replaced by:
12357**
12358** <pre>
12359** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
12360** &nbsp; void *pIn,
12361** </pre>
12362**
12363** Each time the xInput callback is invoked by the sessions module, the first
12364** argument passed is a copy of the supplied pIn context pointer. The second
12365** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12366** error occurs the xInput method should copy up to (*pnData) bytes of data
12367** into the buffer and set (*pnData) to the actual number of bytes copied
12368** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12369** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12370** error code should be returned. In all cases, if an xInput callback returns
12371** an error, all processing is abandoned and the streaming API function
12372** returns a copy of the error code to the caller.
12373**
12374** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12375** invoked by the sessions module at any point during the lifetime of the
12376** iterator. If such an xInput callback returns an error, the iterator enters
12377** an error state, whereby all subsequent calls to iterator functions
12378** immediately fail with the same error code as returned by xInput.
12379**
12380** Similarly, streaming API functions that return changesets (or patchsets)
12381** return them in chunks by way of a callback function instead of via a
12382** pointer to a single large buffer. In this case, a pair of parameters such
12383** as:
12384**
12385** <pre>
12386** &nbsp; int *pnChangeset,
12387** &nbsp; void **ppChangeset,
12388** </pre>
12389**
12390** Is replaced by:
12391**
12392** <pre>
12393** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
12394** &nbsp; void *pOut
12395** </pre>
12396**
12397** The xOutput callback is invoked zero or more times to return data to
12398** the application. The first parameter passed to each call is a copy of the
12399** pOut pointer supplied by the application. The second parameter, pData,
12400** points to a buffer nData bytes in size containing the chunk of output
12401** data being returned. If the xOutput callback successfully processes the
12402** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12403** it should return some other SQLite error code. In this case processing
12404** is immediately abandoned and the streaming API function returns a copy
12405** of the xOutput error code to the application.
12406**
12407** The sessions module never invokes an xOutput callback with the third
12408** parameter set to a value less than or equal to zero. Other than this,
12409** no guarantees are made as to the size of the chunks of data returned.
12410*/
12411SQLITE_API int sqlite3changeset_apply_strm(
12412 sqlite3 *db, /* Apply change to "main" db of this handle */
12413 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12414 void *pIn, /* First arg for xInput */
12415 int(*xFilter)(
12416 void *pCtx, /* Copy of sixth arg to _apply() */
12417 const char *zTab /* Table name */
12418 ),
12419 int(*xConflict)(
12420 void *pCtx, /* Copy of sixth arg to _apply() */
12421 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12422 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12423 ),
12424 void *pCtx /* First argument passed to xConflict */
12425);
12426SQLITE_API int sqlite3changeset_apply_v2_strm(
12427 sqlite3 *db, /* Apply change to "main" db of this handle */
12428 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12429 void *pIn, /* First arg for xInput */
12430 int(*xFilter)(
12431 void *pCtx, /* Copy of sixth arg to _apply() */
12432 const char *zTab /* Table name */
12433 ),
12434 int(*xConflict)(
12435 void *pCtx, /* Copy of sixth arg to _apply() */
12436 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12437 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12438 ),
12439 void *pCtx, /* First argument passed to xConflict */
12440 void **ppRebase, int *pnRebase,
12441 int flags
12442);
12443SQLITE_API int sqlite3changeset_concat_strm(
12444 int (*xInputA)(void *pIn, void *pData, int *pnData),
12445 void *pInA,
12446 int (*xInputB)(void *pIn, void *pData, int *pnData),
12447 void *pInB,
12448 int (*xOutput)(void *pOut, const void *pData, int nData),
12449 void *pOut
12450);
12451SQLITE_API int sqlite3changeset_invert_strm(
12452 int (*xInput)(void *pIn, void *pData, int *pnData),
12453 void *pIn,
12454 int (*xOutput)(void *pOut, const void *pData, int nData),
12455 void *pOut
12456);
12457SQLITE_API int sqlite3changeset_start_strm(
12458 sqlite3_changeset_iter **pp,
12459 int (*xInput)(void *pIn, void *pData, int *pnData),
12460 void *pIn
12461);
12462SQLITE_API int sqlite3changeset_start_v2_strm(
12463 sqlite3_changeset_iter **pp,
12464 int (*xInput)(void *pIn, void *pData, int *pnData),
12465 void *pIn,
12466 int flags
12467);
12468SQLITE_API int sqlite3session_changeset_strm(
12469 sqlite3_session *pSession,
12470 int (*xOutput)(void *pOut, const void *pData, int nData),
12471 void *pOut
12472);
12473SQLITE_API int sqlite3session_patchset_strm(
12474 sqlite3_session *pSession,
12475 int (*xOutput)(void *pOut, const void *pData, int nData),
12476 void *pOut
12477);
12478SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12479 int (*xInput)(void *pIn, void *pData, int *pnData),
12480 void *pIn
12481);
12482SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12483 int (*xOutput)(void *pOut, const void *pData, int nData),
12484 void *pOut
12485);
12486SQLITE_API int sqlite3rebaser_rebase_strm(
12487 sqlite3_rebaser *pRebaser,
12488 int (*xInput)(void *pIn, void *pData, int *pnData),
12489 void *pIn,
12490 int (*xOutput)(void *pOut, const void *pData, int nData),
12491 void *pOut
12492);
12493
12494/*
12495** CAPI3REF: Configure global parameters
12496**
12497** The sqlite3session_config() interface is used to make global configuration
12498** changes to the sessions module in order to tune it to the specific needs
12499** of the application.
12500**
12501** The sqlite3session_config() interface is not threadsafe. If it is invoked
12502** while any other thread is inside any other sessions method then the
12503** results are undefined. Furthermore, if it is invoked after any sessions
12504** related objects have been created, the results are also undefined.
12505**
12506** The first argument to the sqlite3session_config() function must be one
12507** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12508** interpretation of the (void*) value passed as the second parameter and
12509** the effect of calling this function depends on the value of the first
12510** parameter.
12511**
12512** <dl>
12513** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12514** By default, the sessions module streaming interfaces attempt to input
12515** and output data in approximately 1 KiB chunks. This operand may be used
12516** to set and query the value of this configuration setting. The pointer
12517** passed as the second argument must point to a value of type (int).
12518** If this value is greater than 0, it is used as the new streaming data
12519** chunk size for both input and output. Before returning, the (int) value
12520** pointed to by pArg is set to the final value of the streaming interface
12521** chunk size.
12522** </dl>
12523**
12524** This function returns SQLITE_OK if successful, or an SQLite error code
12525** otherwise.
12526*/
12527SQLITE_API int sqlite3session_config(int op, void *pArg);
12528
12529/*
12530** CAPI3REF: Values for sqlite3session_config().
12531*/
12532#define SQLITE_SESSION_CONFIG_STRMSIZE 1
12533
12534/*
12535** Make sure we can call this stuff from C++.
12536*/
12537#ifdef __cplusplus
12538}
12539#endif
12540
12541#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
12542
12543/******** End of sqlite3session.h *********/
12544/******** Begin file fts5.h *********/
12545/*
12546** 2014 May 31
12547**
12548** The author disclaims copyright to this source code. In place of
12549** a legal notice, here is a blessing:
12550**
12551** May you do good and not evil.
12552** May you find forgiveness for yourself and forgive others.
12553** May you share freely, never taking more than you give.
12554**
12555******************************************************************************
12556**
12557** Interfaces to extend FTS5. Using the interfaces defined in this file,
12558** FTS5 may be extended with:
12559**
12560** * custom tokenizers, and
12561** * custom auxiliary functions.
12562*/
12563
12564
12565#ifndef _FTS5_H
12566#define _FTS5_H
12567
12568
12569#ifdef __cplusplus
12570extern "C" {
12571#endif
12572
12573/*************************************************************************
12574** CUSTOM AUXILIARY FUNCTIONS
12575**
12576** Virtual table implementations may overload SQL functions by implementing
12577** the sqlite3_module.xFindFunction() method.
12578*/
12579
12580typedef struct Fts5ExtensionApi Fts5ExtensionApi;
12581typedef struct Fts5Context Fts5Context;
12582typedef struct Fts5PhraseIter Fts5PhraseIter;
12583
12584typedef void (*fts5_extension_function)(
12585 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
12586 Fts5Context *pFts, /* First arg to pass to pApi functions */
12587 sqlite3_context *pCtx, /* Context for returning result/error */
12588 int nVal, /* Number of values in apVal[] array */
12589 sqlite3_value **apVal /* Array of trailing arguments */
12590);
12591
12592struct Fts5PhraseIter {
12593 const unsigned char *a;
12594 const unsigned char *b;
12595};
12596
12597/*
12598** EXTENSION API FUNCTIONS
12599**
12600** xUserData(pFts):
12601** Return a copy of the context pointer the extension function was
12602** registered with.
12603**
12604** xColumnTotalSize(pFts, iCol, pnToken):
12605** If parameter iCol is less than zero, set output variable *pnToken
12606** to the total number of tokens in the FTS5 table. Or, if iCol is
12607** non-negative but less than the number of columns in the table, return
12608** the total number of tokens in column iCol, considering all rows in
12609** the FTS5 table.
12610**
12611** If parameter iCol is greater than or equal to the number of columns
12612** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12613** an OOM condition or IO error), an appropriate SQLite error code is
12614** returned.
12615**
12616** xColumnCount(pFts):
12617** Return the number of columns in the table.
12618**
12619** xColumnSize(pFts, iCol, pnToken):
12620** If parameter iCol is less than zero, set output variable *pnToken
12621** to the total number of tokens in the current row. Or, if iCol is
12622** non-negative but less than the number of columns in the table, set
12623** *pnToken to the number of tokens in column iCol of the current row.
12624**
12625** If parameter iCol is greater than or equal to the number of columns
12626** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12627** an OOM condition or IO error), an appropriate SQLite error code is
12628** returned.
12629**
12630** This function may be quite inefficient if used with an FTS5 table
12631** created with the "columnsize=0" option.
12632**
12633** xColumnText:
12634** This function attempts to retrieve the text of column iCol of the
12635** current document. If successful, (*pz) is set to point to a buffer
12636** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12637** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12638** if an error occurs, an SQLite error code is returned and the final values
12639** of (*pz) and (*pn) are undefined.
12640**
12641** xPhraseCount:
12642** Returns the number of phrases in the current query expression.
12643**
12644** xPhraseSize:
12645** Returns the number of tokens in phrase iPhrase of the query. Phrases
12646** are numbered starting from zero.
12647**
12648** xInstCount:
12649** Set *pnInst to the total number of occurrences of all phrases within
12650** the query within the current row. Return SQLITE_OK if successful, or
12651** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12652**
12653** This API can be quite slow if used with an FTS5 table created with the
12654** "detail=none" or "detail=column" option. If the FTS5 table is created
12655** with either "detail=none" or "detail=column" and "content=" option
12656** (i.e. if it is a contentless table), then this API always returns 0.
12657**
12658** xInst:
12659** Query for the details of phrase match iIdx within the current row.
12660** Phrase matches are numbered starting from zero, so the iIdx argument
12661** should be greater than or equal to zero and smaller than the value
12662** output by xInstCount().
12663**
12664** Usually, output parameter *piPhrase is set to the phrase number, *piCol
12665** to the column in which it occurs and *piOff the token offset of the
12666** first token of the phrase. Returns SQLITE_OK if successful, or an error
12667** code (i.e. SQLITE_NOMEM) if an error occurs.
12668**
12669** This API can be quite slow if used with an FTS5 table created with the
12670** "detail=none" or "detail=column" option.
12671**
12672** xRowid:
12673** Returns the rowid of the current row.
12674**
12675** xTokenize:
12676** Tokenize text using the tokenizer belonging to the FTS5 table.
12677**
12678** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12679** This API function is used to query the FTS table for phrase iPhrase
12680** of the current query. Specifically, a query equivalent to:
12681**
12682** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12683**
12684** with $p set to a phrase equivalent to the phrase iPhrase of the
12685** current query is executed. Any column filter that applies to
12686** phrase iPhrase of the current query is included in $p. For each
12687** row visited, the callback function passed as the fourth argument
12688** is invoked. The context and API objects passed to the callback
12689** function may be used to access the properties of each matched row.
12690** Invoking Api.xUserData() returns a copy of the pointer passed as
12691** the third argument to pUserData.
12692**
12693** If the callback function returns any value other than SQLITE_OK, the
12694** query is abandoned and the xQueryPhrase function returns immediately.
12695** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12696** Otherwise, the error code is propagated upwards.
12697**
12698** If the query runs to completion without incident, SQLITE_OK is returned.
12699** Or, if some error occurs before the query completes or is aborted by
12700** the callback, an SQLite error code is returned.
12701**
12702**
12703** xSetAuxdata(pFts5, pAux, xDelete)
12704**
12705** Save the pointer passed as the second argument as the extension function's
12706** "auxiliary data". The pointer may then be retrieved by the current or any
12707** future invocation of the same fts5 extension function made as part of
12708** the same MATCH query using the xGetAuxdata() API.
12709**
12710** Each extension function is allocated a single auxiliary data slot for
12711** each FTS query (MATCH expression). If the extension function is invoked
12712** more than once for a single FTS query, then all invocations share a
12713** single auxiliary data context.
12714**
12715** If there is already an auxiliary data pointer when this function is
12716** invoked, then it is replaced by the new pointer. If an xDelete callback
12717** was specified along with the original pointer, it is invoked at this
12718** point.
12719**
12720** The xDelete callback, if one is specified, is also invoked on the
12721** auxiliary data pointer after the FTS5 query has finished.
12722**
12723** If an error (e.g. an OOM condition) occurs within this function,
12724** the auxiliary data is set to NULL and an error code returned. If the
12725** xDelete parameter was not NULL, it is invoked on the auxiliary data
12726** pointer before returning.
12727**
12728**
12729** xGetAuxdata(pFts5, bClear)
12730**
12731** Returns the current auxiliary data pointer for the fts5 extension
12732** function. See the xSetAuxdata() method for details.
12733**
12734** If the bClear argument is non-zero, then the auxiliary data is cleared
12735** (set to NULL) before this function returns. In this case the xDelete,
12736** if any, is not invoked.
12737**
12738**
12739** xRowCount(pFts5, pnRow)
12740**
12741** This function is used to retrieve the total number of rows in the table.
12742** In other words, the same value that would be returned by:
12743**
12744** SELECT count(*) FROM ftstable;
12745**
12746** xPhraseFirst()
12747** This function is used, along with type Fts5PhraseIter and the xPhraseNext
12748** method, to iterate through all instances of a single query phrase within
12749** the current row. This is the same information as is accessible via the
12750** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
12751** to use, this API may be faster under some circumstances. To iterate
12752** through instances of phrase iPhrase, use the following code:
12753**
12754** Fts5PhraseIter iter;
12755** int iCol, iOff;
12756** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
12757** iCol>=0;
12758** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
12759** ){
12760** // An instance of phrase iPhrase at offset iOff of column iCol
12761** }
12762**
12763** The Fts5PhraseIter structure is defined above. Applications should not
12764** modify this structure directly - it should only be used as shown above
12765** with the xPhraseFirst() and xPhraseNext() API methods (and by
12766** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
12767**
12768** This API can be quite slow if used with an FTS5 table created with the
12769** "detail=none" or "detail=column" option. If the FTS5 table is created
12770** with either "detail=none" or "detail=column" and "content=" option
12771** (i.e. if it is a contentless table), then this API always iterates
12772** through an empty set (all calls to xPhraseFirst() set iCol to -1).
12773**
12774** xPhraseNext()
12775** See xPhraseFirst above.
12776**
12777** xPhraseFirstColumn()
12778** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
12779** and xPhraseNext() APIs described above. The difference is that instead
12780** of iterating through all instances of a phrase in the current row, these
12781** APIs are used to iterate through the set of columns in the current row
12782** that contain one or more instances of a specified phrase. For example:
12783**
12784** Fts5PhraseIter iter;
12785** int iCol;
12786** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
12787** iCol>=0;
12788** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
12789** ){
12790** // Column iCol contains at least one instance of phrase iPhrase
12791** }
12792**
12793** This API can be quite slow if used with an FTS5 table created with the
12794** "detail=none" option. If the FTS5 table is created with either
12795** "detail=none" "content=" option (i.e. if it is a contentless table),
12796** then this API always iterates through an empty set (all calls to
12797** xPhraseFirstColumn() set iCol to -1).
12798**
12799** The information accessed using this API and its companion
12800** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
12801** (or xInst/xInstCount). The chief advantage of this API is that it is
12802** significantly more efficient than those alternatives when used with
12803** "detail=column" tables.
12804**
12805** xPhraseNextColumn()
12806** See xPhraseFirstColumn above.
12807*/
12808struct Fts5ExtensionApi {
12809 int iVersion; /* Currently always set to 2 */
12810
12811 void *(*xUserData)(Fts5Context*);
12812
12813 int (*xColumnCount)(Fts5Context*);
12814 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
12815 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
12816
12817 int (*xTokenize)(Fts5Context*,
12818 const char *pText, int nText, /* Text to tokenize */
12819 void *pCtx, /* Context passed to xToken() */
12820 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
12821 );
12822
12823 int (*xPhraseCount)(Fts5Context*);
12824 int (*xPhraseSize)(Fts5Context*, int iPhrase);
12825
12826 int (*xInstCount)(Fts5Context*, int *pnInst);
12827 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
12828
12829 sqlite3_int64 (*xRowid)(Fts5Context*);
12830 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
12831 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
12832
12833 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
12834 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
12835 );
12836 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
12837 void *(*xGetAuxdata)(Fts5Context*, int bClear);
12838
12839 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
12840 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
12841
12842 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
12843 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
12844};
12845
12846/*
12847** CUSTOM AUXILIARY FUNCTIONS
12848*************************************************************************/
12849
12850/*************************************************************************
12851** CUSTOM TOKENIZERS
12852**
12853** Applications may also register custom tokenizer types. A tokenizer
12854** is registered by providing fts5 with a populated instance of the
12855** following structure. All structure methods must be defined, setting
12856** any member of the fts5_tokenizer struct to NULL leads to undefined
12857** behaviour. The structure methods are expected to function as follows:
12858**
12859** xCreate:
12860** This function is used to allocate and initialize a tokenizer instance.
12861** A tokenizer instance is required to actually tokenize text.
12862**
12863** The first argument passed to this function is a copy of the (void*)
12864** pointer provided by the application when the fts5_tokenizer object
12865** was registered with FTS5 (the third argument to xCreateTokenizer()).
12866** The second and third arguments are an array of nul-terminated strings
12867** containing the tokenizer arguments, if any, specified following the
12868** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
12869** to create the FTS5 table.
12870**
12871** The final argument is an output variable. If successful, (*ppOut)
12872** should be set to point to the new tokenizer handle and SQLITE_OK
12873** returned. If an error occurs, some value other than SQLITE_OK should
12874** be returned. In this case, fts5 assumes that the final value of *ppOut
12875** is undefined.
12876**
12877** xDelete:
12878** This function is invoked to delete a tokenizer handle previously
12879** allocated using xCreate(). Fts5 guarantees that this function will
12880** be invoked exactly once for each successful call to xCreate().
12881**
12882** xTokenize:
12883** This function is expected to tokenize the nText byte string indicated
12884** by argument pText. pText may or may not be nul-terminated. The first
12885** argument passed to this function is a pointer to an Fts5Tokenizer object
12886** returned by an earlier call to xCreate().
12887**
12888** The second argument indicates the reason that FTS5 is requesting
12889** tokenization of the supplied text. This is always one of the following
12890** four values:
12891**
12892** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
12893** or removed from the FTS table. The tokenizer is being invoked to
12894** determine the set of tokens to add to (or delete from) the
12895** FTS index.
12896**
12897** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
12898** against the FTS index. The tokenizer is being called to tokenize
12899** a bareword or quoted string specified as part of the query.
12900**
12901** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
12902** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
12903** followed by a "*" character, indicating that the last token
12904** returned by the tokenizer will be treated as a token prefix.
12905**
12906** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
12907** satisfy an fts5_api.xTokenize() request made by an auxiliary
12908** function. Or an fts5_api.xColumnSize() request made by the same
12909** on a columnsize=0 database.
12910** </ul>
12911**
12912** For each token in the input string, the supplied callback xToken() must
12913** be invoked. The first argument to it should be a copy of the pointer
12914** passed as the second argument to xTokenize(). The third and fourth
12915** arguments are a pointer to a buffer containing the token text, and the
12916** size of the token in bytes. The 4th and 5th arguments are the byte offsets
12917** of the first byte of and first byte immediately following the text from
12918** which the token is derived within the input.
12919**
12920** The second argument passed to the xToken() callback ("tflags") should
12921** normally be set to 0. The exception is if the tokenizer supports
12922** synonyms. In this case see the discussion below for details.
12923**
12924** FTS5 assumes the xToken() callback is invoked for each token in the
12925** order that they occur within the input text.
12926**
12927** If an xToken() callback returns any value other than SQLITE_OK, then
12928** the tokenization should be abandoned and the xTokenize() method should
12929** immediately return a copy of the xToken() return value. Or, if the
12930** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
12931** if an error occurs with the xTokenize() implementation itself, it
12932** may abandon the tokenization and return any error code other than
12933** SQLITE_OK or SQLITE_DONE.
12934**
12935** SYNONYM SUPPORT
12936**
12937** Custom tokenizers may also support synonyms. Consider a case in which a
12938** user wishes to query for a phrase such as "first place". Using the
12939** built-in tokenizers, the FTS5 query 'first + place' will match instances
12940** of "first place" within the document set, but not alternative forms
12941** such as "1st place". In some applications, it would be better to match
12942** all instances of "first place" or "1st place" regardless of which form
12943** the user specified in the MATCH query text.
12944**
12945** There are several ways to approach this in FTS5:
12946**
12947** <ol><li> By mapping all synonyms to a single token. In this case, using
12948** the above example, this means that the tokenizer returns the
12949** same token for inputs "first" and "1st". Say that token is in
12950** fact "first", so that when the user inserts the document "I won
12951** 1st place" entries are added to the index for tokens "i", "won",
12952** "first" and "place". If the user then queries for '1st + place',
12953** the tokenizer substitutes "first" for "1st" and the query works
12954** as expected.
12955**
12956** <li> By querying the index for all synonyms of each query term
12957** separately. In this case, when tokenizing query text, the
12958** tokenizer may provide multiple synonyms for a single term
12959** within the document. FTS5 then queries the index for each
12960** synonym individually. For example, faced with the query:
12961**
12962** <codeblock>
12963** ... MATCH 'first place'</codeblock>
12964**
12965** the tokenizer offers both "1st" and "first" as synonyms for the
12966** first token in the MATCH query and FTS5 effectively runs a query
12967** similar to:
12968**
12969** <codeblock>
12970** ... MATCH '(first OR 1st) place'</codeblock>
12971**
12972** except that, for the purposes of auxiliary functions, the query
12973** still appears to contain just two phrases - "(first OR 1st)"
12974** being treated as a single phrase.
12975**
12976** <li> By adding multiple synonyms for a single term to the FTS index.
12977** Using this method, when tokenizing document text, the tokenizer
12978** provides multiple synonyms for each token. So that when a
12979** document such as "I won first place" is tokenized, entries are
12980** added to the FTS index for "i", "won", "first", "1st" and
12981** "place".
12982**
12983** This way, even if the tokenizer does not provide synonyms
12984** when tokenizing query text (it should not - to do so would be
12985** inefficient), it doesn't matter if the user queries for
12986** 'first + place' or '1st + place', as there are entries in the
12987** FTS index corresponding to both forms of the first token.
12988** </ol>
12989**
12990** Whether it is parsing document or query text, any call to xToken that
12991** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12992** is considered to supply a synonym for the previous token. For example,
12993** when parsing the document "I won first place", a tokenizer that supports
12994** synonyms would call xToken() 5 times, as follows:
12995**
12996** <codeblock>
12997** xToken(pCtx, 0, "i", 1, 0, 1);
12998** xToken(pCtx, 0, "won", 3, 2, 5);
12999** xToken(pCtx, 0, "first", 5, 6, 11);
13000** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13001** xToken(pCtx, 0, "place", 5, 12, 17);
13002**</codeblock>
13003**
13004** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13005** xToken() is called. Multiple synonyms may be specified for a single token
13006** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13007** There is no limit to the number of synonyms that may be provided for a
13008** single token.
13009**
13010** In many cases, method (1) above is the best approach. It does not add
13011** extra data to the FTS index or require FTS5 to query for multiple terms,
13012** so it is efficient in terms of disk space and query speed. However, it
13013** does not support prefix queries very well. If, as suggested above, the
13014** token "first" is substituted for "1st" by the tokenizer, then the query:
13015**
13016** <codeblock>
13017** ... MATCH '1s*'</codeblock>
13018**
13019** will not match documents that contain the token "1st" (as the tokenizer
13020** will probably not map "1s" to any prefix of "first").
13021**
13022** For full prefix support, method (3) may be preferred. In this case,
13023** because the index contains entries for both "first" and "1st", prefix
13024** queries such as 'fi*' or '1s*' will match correctly. However, because
13025** extra entries are added to the FTS index, this method uses more space
13026** within the database.
13027**
13028** Method (2) offers a midpoint between (1) and (3). Using this method,
13029** a query such as '1s*' will match documents that contain the literal
13030** token "1st", but not "first" (assuming the tokenizer is not able to
13031** provide synonyms for prefixes). However, a non-prefix query like '1st'
13032** will match against "1st" and "first". This method does not require
13033** extra disk space, as no extra entries are added to the FTS index.
13034** On the other hand, it may require more CPU cycles to run MATCH queries,
13035** as separate queries of the FTS index are required for each synonym.
13036**
13037** When using methods (2) or (3), it is important that the tokenizer only
13038** provide synonyms when tokenizing document text (method (3)) or query
13039** text (method (2)), not both. Doing so will not cause any errors, but is
13040** inefficient.
13041*/
13042typedef struct Fts5Tokenizer Fts5Tokenizer;
13043typedef struct fts5_tokenizer fts5_tokenizer;
13044struct fts5_tokenizer {
13045 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13046 void (*xDelete)(Fts5Tokenizer*);
13047 int (*xTokenize)(Fts5Tokenizer*,
13048 void *pCtx,
13049 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13050 const char *pText, int nText,
13051 int (*xToken)(
13052 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13053 int tflags, /* Mask of FTS5_TOKEN_* flags */
13054 const char *pToken, /* Pointer to buffer containing token */
13055 int nToken, /* Size of token in bytes */
13056 int iStart, /* Byte offset of token within input text */
13057 int iEnd /* Byte offset of end of token within input text */
13058 )
13059 );
13060};
13061
13062/* Flags that may be passed as the third argument to xTokenize() */
13063#define FTS5_TOKENIZE_QUERY 0x0001
13064#define FTS5_TOKENIZE_PREFIX 0x0002
13065#define FTS5_TOKENIZE_DOCUMENT 0x0004
13066#define FTS5_TOKENIZE_AUX 0x0008
13067
13068/* Flags that may be passed by the tokenizer implementation back to FTS5
13069** as the third argument to the supplied xToken callback. */
13070#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13071
13072/*
13073** END OF CUSTOM TOKENIZERS
13074*************************************************************************/
13075
13076/*************************************************************************
13077** FTS5 EXTENSION REGISTRATION API
13078*/
13079typedef struct fts5_api fts5_api;
13080struct fts5_api {
13081 int iVersion; /* Currently always set to 2 */
13082
13083 /* Create a new tokenizer */
13084 int (*xCreateTokenizer)(
13085 fts5_api *pApi,
13086 const char *zName,
13087 void *pUserData,
13088 fts5_tokenizer *pTokenizer,
13089 void (*xDestroy)(void*)
13090 );
13091
13092 /* Find an existing tokenizer */
13093 int (*xFindTokenizer)(
13094 fts5_api *pApi,
13095 const char *zName,
13096 void **ppUserData,
13097 fts5_tokenizer *pTokenizer
13098 );
13099
13100 /* Create a new auxiliary function */
13101 int (*xCreateFunction)(
13102 fts5_api *pApi,
13103 const char *zName,
13104 void *pUserData,
13105 fts5_extension_function xFunction,
13106 void (*xDestroy)(void*)
13107 );
13108};
13109
13110/*
13111** END OF REGISTRATION API
13112*************************************************************************/
13113
13114#ifdef __cplusplus
13115} /* end of the 'extern "C"' block */
13116#endif
13117
13118#endif /* _FTS5_H */
13119
13120/******** End of fts5.h *********/
13121

source code of qtbase/src/3rdparty/sqlite/sqlite3.h