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 "3.37.2"
150#define SQLITE_VERSION_NUMBER 3037002
151#define SQLITE_SOURCE_ID "2022-01-06 13:25:41 872ba256cbf61d9290b571c0e6d82a20c224ca3ad82971edc46b29818d5d17a0"
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_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
532#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
533#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
534#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
535#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
536#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
537#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
538#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
539#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
540#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
541#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
542#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
543#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
544#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
545#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
546#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
547#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
548#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
549#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
550#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
551#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
552#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
553#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
554#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
555#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
556#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
557#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
558#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
559#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
560#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
561#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
562#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
563#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
564#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
565#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
566#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
567#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
568#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
569#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8))
570
571/*
572** CAPI3REF: Flags For File Open Operations
573**
574** These bit values are intended for use in the
575** 3rd parameter to the [sqlite3_open_v2()] interface and
576** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
577**
578** Only those flags marked as "Ok for sqlite3_open_v2()" may be
579** used as the third argument to the [sqlite3_open_v2()] interface.
580** The other flags have historically been ignored by sqlite3_open_v2(),
581** though future versions of SQLite might change so that an error is
582** raised if any of the disallowed bits are passed into sqlite3_open_v2().
583** Applications should not depend on the historical behavior.
584**
585** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
586** [sqlite3_open_v2()] does *not* cause the underlying database file
587** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
588** [sqlite3_open_v2()] has historically be a no-op and might become an
589** error in future versions of SQLite.
590*/
591#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
592#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
593#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
594#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
595#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
596#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
597#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
598#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
599#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
600#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
601#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
602#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
603#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
604#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
605#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
606#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
607#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
608#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
609#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
610#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
611#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
612#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
613
614/* Reserved: 0x00F00000 */
615/* Legacy compatibility: */
616#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
617
618
619/*
620** CAPI3REF: Device Characteristics
621**
622** The xDeviceCharacteristics method of the [sqlite3_io_methods]
623** object returns an integer which is a vector of these
624** bit values expressing I/O characteristics of the mass storage
625** device that holds the file that the [sqlite3_io_methods]
626** refers to.
627**
628** The SQLITE_IOCAP_ATOMIC property means that all writes of
629** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
630** mean that writes of blocks that are nnn bytes in size and
631** are aligned to an address which is an integer multiple of
632** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
633** that when data is appended to a file, the data is appended
634** first then the size of the file is extended, never the other
635** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
636** information is written to disk in the same order as calls
637** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
638** after reboot following a crash or power loss, the only bytes in a
639** file that were written at the application level might have changed
640** and that adjacent bytes, even bytes within the same sector are
641** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
642** flag indicates that a file cannot be deleted when open. The
643** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
644** read-only media and cannot be changed even by processes with
645** elevated privileges.
646**
647** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
648** filesystem supports doing multiple write operations atomically when those
649** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
650** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
651*/
652#define SQLITE_IOCAP_ATOMIC 0x00000001
653#define SQLITE_IOCAP_ATOMIC512 0x00000002
654#define SQLITE_IOCAP_ATOMIC1K 0x00000004
655#define SQLITE_IOCAP_ATOMIC2K 0x00000008
656#define SQLITE_IOCAP_ATOMIC4K 0x00000010
657#define SQLITE_IOCAP_ATOMIC8K 0x00000020
658#define SQLITE_IOCAP_ATOMIC16K 0x00000040
659#define SQLITE_IOCAP_ATOMIC32K 0x00000080
660#define SQLITE_IOCAP_ATOMIC64K 0x00000100
661#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
662#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
663#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
664#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
665#define SQLITE_IOCAP_IMMUTABLE 0x00002000
666#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
667
668/*
669** CAPI3REF: File Locking Levels
670**
671** SQLite uses one of these integer values as the second
672** argument to calls it makes to the xLock() and xUnlock() methods
673** of an [sqlite3_io_methods] object.
674*/
675#define SQLITE_LOCK_NONE 0
676#define SQLITE_LOCK_SHARED 1
677#define SQLITE_LOCK_RESERVED 2
678#define SQLITE_LOCK_PENDING 3
679#define SQLITE_LOCK_EXCLUSIVE 4
680
681/*
682** CAPI3REF: Synchronization Type Flags
683**
684** When SQLite invokes the xSync() method of an
685** [sqlite3_io_methods] object it uses a combination of
686** these integer values as the second argument.
687**
688** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
689** sync operation only needs to flush data to mass storage. Inode
690** information need not be flushed. If the lower four bits of the flag
691** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
692** If the lower four bits equal SQLITE_SYNC_FULL, that means
693** to use Mac OS X style fullsync instead of fsync().
694**
695** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
696** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
697** settings. The [synchronous pragma] determines when calls to the
698** xSync VFS method occur and applies uniformly across all platforms.
699** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
700** energetic or rigorous or forceful the sync operations are and
701** only make a difference on Mac OSX for the default SQLite code.
702** (Third-party VFS implementations might also make the distinction
703** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
704** operating systems natively supported by SQLite, only Mac OSX
705** cares about the difference.)
706*/
707#define SQLITE_SYNC_NORMAL 0x00002
708#define SQLITE_SYNC_FULL 0x00003
709#define SQLITE_SYNC_DATAONLY 0x00010
710
711/*
712** CAPI3REF: OS Interface Open File Handle
713**
714** An [sqlite3_file] object represents an open file in the
715** [sqlite3_vfs | OS interface layer]. Individual OS interface
716** implementations will
717** want to subclass this object by appending additional fields
718** for their own use. The pMethods entry is a pointer to an
719** [sqlite3_io_methods] object that defines methods for performing
720** I/O operations on the open file.
721*/
722typedef struct sqlite3_file sqlite3_file;
723struct sqlite3_file {
724 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
725};
726
727/*
728** CAPI3REF: OS Interface File Virtual Methods Object
729**
730** Every file opened by the [sqlite3_vfs.xOpen] method populates an
731** [sqlite3_file] object (or, more commonly, a subclass of the
732** [sqlite3_file] object) with a pointer to an instance of this object.
733** This object defines the methods used to perform various operations
734** against the open file represented by the [sqlite3_file] object.
735**
736** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
737** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
738** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
739** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
740** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
741** to NULL.
742**
743** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
744** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
745** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
746** flag may be ORed in to indicate that only the data of the file
747** and not its inode needs to be synced.
748**
749** The integer values to xLock() and xUnlock() are one of
750** <ul>
751** <li> [SQLITE_LOCK_NONE],
752** <li> [SQLITE_LOCK_SHARED],
753** <li> [SQLITE_LOCK_RESERVED],
754** <li> [SQLITE_LOCK_PENDING], or
755** <li> [SQLITE_LOCK_EXCLUSIVE].
756** </ul>
757** xLock() increases the lock. xUnlock() decreases the lock.
758** The xCheckReservedLock() method checks whether any database connection,
759** either in this process or in some other process, is holding a RESERVED,
760** PENDING, or EXCLUSIVE lock on the file. It returns true
761** if such a lock exists and false otherwise.
762**
763** The xFileControl() method is a generic interface that allows custom
764** VFS implementations to directly control an open file using the
765** [sqlite3_file_control()] interface. The second "op" argument is an
766** integer opcode. The third argument is a generic pointer intended to
767** point to a structure that may contain arguments or space in which to
768** write return values. Potential uses for xFileControl() might be
769** functions to enable blocking locks with timeouts, to change the
770** locking strategy (for example to use dot-file locks), to inquire
771** about the status of a lock, or to break stale locks. The SQLite
772** core reserves all opcodes less than 100 for its own use.
773** A [file control opcodes | list of opcodes] less than 100 is available.
774** Applications that define a custom xFileControl method should use opcodes
775** greater than 100 to avoid conflicts. VFS implementations should
776** return [SQLITE_NOTFOUND] for file control opcodes that they do not
777** recognize.
778**
779** The xSectorSize() method returns the sector size of the
780** device that underlies the file. The sector size is the
781** minimum write that can be performed without disturbing
782** other bytes in the file. The xDeviceCharacteristics()
783** method returns a bit vector describing behaviors of the
784** underlying device:
785**
786** <ul>
787** <li> [SQLITE_IOCAP_ATOMIC]
788** <li> [SQLITE_IOCAP_ATOMIC512]
789** <li> [SQLITE_IOCAP_ATOMIC1K]
790** <li> [SQLITE_IOCAP_ATOMIC2K]
791** <li> [SQLITE_IOCAP_ATOMIC4K]
792** <li> [SQLITE_IOCAP_ATOMIC8K]
793** <li> [SQLITE_IOCAP_ATOMIC16K]
794** <li> [SQLITE_IOCAP_ATOMIC32K]
795** <li> [SQLITE_IOCAP_ATOMIC64K]
796** <li> [SQLITE_IOCAP_SAFE_APPEND]
797** <li> [SQLITE_IOCAP_SEQUENTIAL]
798** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
799** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
800** <li> [SQLITE_IOCAP_IMMUTABLE]
801** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
802** </ul>
803**
804** The SQLITE_IOCAP_ATOMIC property means that all writes of
805** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
806** mean that writes of blocks that are nnn bytes in size and
807** are aligned to an address which is an integer multiple of
808** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
809** that when data is appended to a file, the data is appended
810** first then the size of the file is extended, never the other
811** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
812** information is written to disk in the same order as calls
813** to xWrite().
814**
815** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
816** in the unread portions of the buffer with zeros. A VFS that
817** fails to zero-fill short reads might seem to work. However,
818** failure to zero-fill short reads will eventually lead to
819** database corruption.
820*/
821typedef struct sqlite3_io_methods sqlite3_io_methods;
822struct sqlite3_io_methods {
823 int iVersion;
824 int (*xClose)(sqlite3_file*);
825 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
826 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
827 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
828 int (*xSync)(sqlite3_file*, int flags);
829 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
830 int (*xLock)(sqlite3_file*, int);
831 int (*xUnlock)(sqlite3_file*, int);
832 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
833 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
834 int (*xSectorSize)(sqlite3_file*);
835 int (*xDeviceCharacteristics)(sqlite3_file*);
836 /* Methods above are valid for version 1 */
837 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
838 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
839 void (*xShmBarrier)(sqlite3_file*);
840 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
841 /* Methods above are valid for version 2 */
842 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
843 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
844 /* Methods above are valid for version 3 */
845 /* Additional methods may be added in future releases */
846};
847
848/*
849** CAPI3REF: Standard File Control Opcodes
850** KEYWORDS: {file control opcodes} {file control opcode}
851**
852** These integer constants are opcodes for the xFileControl method
853** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
854** interface.
855**
856** <ul>
857** <li>[[SQLITE_FCNTL_LOCKSTATE]]
858** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
859** opcode causes the xFileControl method to write the current state of
860** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
861** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
862** into an integer that the pArg argument points to. This capability
863** is used during testing and is only available when the SQLITE_TEST
864** compile-time option is used.
865**
866** <li>[[SQLITE_FCNTL_SIZE_HINT]]
867** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
868** layer a hint of how large the database file will grow to be during the
869** current transaction. This hint is not guaranteed to be accurate but it
870** is often close. The underlying VFS might choose to preallocate database
871** file space based on this hint in order to help writes to the database
872** file run faster.
873**
874** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
875** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
876** implements [sqlite3_deserialize()] to set an upper bound on the size
877** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
878** If the integer pointed to is negative, then it is filled in with the
879** current limit. Otherwise the limit is set to the larger of the value
880** of the integer pointed to and the current database size. The integer
881** pointed to is set to the new limit.
882**
883** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
884** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
885** extends and truncates the database file in chunks of a size specified
886** by the user. The fourth argument to [sqlite3_file_control()] should
887** point to an integer (type int) containing the new chunk-size to use
888** for the nominated database. Allocating database file space in large
889** chunks (say 1MB at a time), may reduce file-system fragmentation and
890** improve performance on some systems.
891**
892** <li>[[SQLITE_FCNTL_FILE_POINTER]]
893** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
894** to the [sqlite3_file] object associated with a particular database
895** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
896**
897** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
898** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
899** to the [sqlite3_file] object associated with the journal file (either
900** the [rollback journal] or the [write-ahead log]) for a particular database
901** connection. See also [SQLITE_FCNTL_FILE_POINTER].
902**
903** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
904** No longer in use.
905**
906** <li>[[SQLITE_FCNTL_SYNC]]
907** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
908** sent to the VFS immediately before the xSync method is invoked on a
909** database file descriptor. Or, if the xSync method is not invoked
910** because the user has configured SQLite with
911** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
912** of the xSync method. In most cases, the pointer argument passed with
913** this file-control is NULL. However, if the database file is being synced
914** as part of a multi-database commit, the argument points to a nul-terminated
915** string containing the transactions super-journal file name. VFSes that
916** do not need this signal should silently ignore this opcode. Applications
917** should not call [sqlite3_file_control()] with this opcode as doing so may
918** disrupt the operation of the specialized VFSes that do require it.
919**
920** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
921** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
922** and sent to the VFS after a transaction has been committed immediately
923** but before the database is unlocked. VFSes that do not need this signal
924** should silently ignore this opcode. Applications should not call
925** [sqlite3_file_control()] with this opcode as doing so may disrupt the
926** operation of the specialized VFSes that do require it.
927**
928** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
929** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
930** retry counts and intervals for certain disk I/O operations for the
931** windows [VFS] in order to provide robustness in the presence of
932** anti-virus programs. By default, the windows VFS will retry file read,
933** file write, and file delete operations up to 10 times, with a delay
934** of 25 milliseconds before the first retry and with the delay increasing
935** by an additional 25 milliseconds with each subsequent retry. This
936** opcode allows these two values (10 retries and 25 milliseconds of delay)
937** to be adjusted. The values are changed for all database connections
938** within the same process. The argument is a pointer to an array of two
939** integers where the first integer is the new retry count and the second
940** integer is the delay. If either integer is negative, then the setting
941** is not changed but instead the prior value of that setting is written
942** into the array entry, allowing the current retry settings to be
943** interrogated. The zDbName parameter is ignored.
944**
945** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
946** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
947** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
948** write ahead log ([WAL file]) and shared memory
949** files used for transaction control
950** are automatically deleted when the latest connection to the database
951** closes. Setting persistent WAL mode causes those files to persist after
952** close. Persisting the files is useful when other processes that do not
953** have write permission on the directory containing the database file want
954** to read the database file, as the WAL and shared memory files must exist
955** in order for the database to be readable. The fourth parameter to
956** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
957** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
958** WAL mode. If the integer is -1, then it is overwritten with the current
959** WAL persistence setting.
960**
961** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
962** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
963** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
964** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
965** xDeviceCharacteristics methods. The fourth parameter to
966** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
967** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
968** mode. If the integer is -1, then it is overwritten with the current
969** zero-damage mode setting.
970**
971** <li>[[SQLITE_FCNTL_OVERWRITE]]
972** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
973** a write transaction to indicate that, unless it is rolled back for some
974** reason, the entire database file will be overwritten by the current
975** transaction. This is used by VACUUM operations.
976**
977** <li>[[SQLITE_FCNTL_VFSNAME]]
978** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
979** all [VFSes] in the VFS stack. The names are of all VFS shims and the
980** final bottom-level VFS are written into memory obtained from
981** [sqlite3_malloc()] and the result is stored in the char* variable
982** that the fourth parameter of [sqlite3_file_control()] points to.
983** The caller is responsible for freeing the memory when done. As with
984** all file-control actions, there is no guarantee that this will actually
985** do anything. Callers should initialize the char* variable to a NULL
986** pointer in case this file-control is not implemented. This file-control
987** is intended for diagnostic use only.
988**
989** <li>[[SQLITE_FCNTL_VFS_POINTER]]
990** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
991** [VFSes] currently in use. ^(The argument X in
992** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
993** of type "[sqlite3_vfs] **". This opcodes will set *X
994** to a pointer to the top-level VFS.)^
995** ^When there are multiple VFS shims in the stack, this opcode finds the
996** upper-most shim only.
997**
998** <li>[[SQLITE_FCNTL_PRAGMA]]
999** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1000** file control is sent to the open [sqlite3_file] object corresponding
1001** to the database file to which the pragma statement refers. ^The argument
1002** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1003** pointers to strings (char**) in which the second element of the array
1004** is the name of the pragma and the third element is the argument to the
1005** pragma or NULL if the pragma has no argument. ^The handler for an
1006** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1007** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1008** or the equivalent and that string will become the result of the pragma or
1009** the error message if the pragma fails. ^If the
1010** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1011** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1012** file control returns [SQLITE_OK], then the parser assumes that the
1013** VFS has handled the PRAGMA itself and the parser generates a no-op
1014** prepared statement if result string is NULL, or that returns a copy
1015** of the result string if the string is non-NULL.
1016** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1017** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1018** that the VFS encountered an error while handling the [PRAGMA] and the
1019** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1020** file control occurs at the beginning of pragma statement analysis and so
1021** it is able to override built-in [PRAGMA] statements.
1022**
1023** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1024** ^The [SQLITE_FCNTL_BUSYHANDLER]
1025** file-control may be invoked by SQLite on the database file handle
1026** shortly after it is opened in order to provide a custom VFS with access
1027** to the connection's busy-handler callback. The argument is of type (void**)
1028** - an array of two (void *) values. The first (void *) actually points
1029** to a function of type (int (*)(void *)). In order to invoke the connection's
1030** busy-handler, this function should be invoked with the second (void *) in
1031** the array as the only argument. If it returns non-zero, then the operation
1032** should be retried. If it returns zero, the custom VFS should abandon the
1033** current operation.
1034**
1035** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1036** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1037** to have SQLite generate a
1038** temporary filename using the same algorithm that is followed to generate
1039** temporary filenames for TEMP tables and other internal uses. The
1040** argument should be a char** which will be filled with the filename
1041** written into memory obtained from [sqlite3_malloc()]. The caller should
1042** invoke [sqlite3_free()] on the result to avoid a memory leak.
1043**
1044** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1045** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1046** maximum number of bytes that will be used for memory-mapped I/O.
1047** The argument is a pointer to a value of type sqlite3_int64 that
1048** is an advisory maximum number of bytes in the file to memory map. The
1049** pointer is overwritten with the old value. The limit is not changed if
1050** the value originally pointed to is negative, and so the current limit
1051** can be queried by passing in a pointer to a negative number. This
1052** file-control is used internally to implement [PRAGMA mmap_size].
1053**
1054** <li>[[SQLITE_FCNTL_TRACE]]
1055** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1056** to the VFS about what the higher layers of the SQLite stack are doing.
1057** This file control is used by some VFS activity tracing [shims].
1058** The argument is a zero-terminated string. Higher layers in the
1059** SQLite stack may generate instances of this file control if
1060** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1061**
1062** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1063** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1064** pointer to an integer and it writes a boolean into that integer depending
1065** on whether or not the file has been renamed, moved, or deleted since it
1066** was first opened.
1067**
1068** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1069** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1070** underlying native file handle associated with a file handle. This file
1071** control interprets its argument as a pointer to a native file handle and
1072** writes the resulting value there.
1073**
1074** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1075** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1076** opcode causes the xFileControl method to swap the file handle with the one
1077** pointed to by the pArg argument. This capability is used during testing
1078** and only needs to be supported when SQLITE_TEST is defined.
1079**
1080** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1081** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1082** be advantageous to block on the next WAL lock if the lock is not immediately
1083** available. The WAL subsystem issues this signal during rare
1084** circumstances in order to fix a problem with priority inversion.
1085** Applications should <em>not</em> use this file-control.
1086**
1087** <li>[[SQLITE_FCNTL_ZIPVFS]]
1088** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1089** VFS should return SQLITE_NOTFOUND for this opcode.
1090**
1091** <li>[[SQLITE_FCNTL_RBU]]
1092** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1093** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1094** this opcode.
1095**
1096** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1097** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1098** the file descriptor is placed in "batch write mode", which
1099** means all subsequent write operations will be deferred and done
1100** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1101** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1102** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1103** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1104** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1105** no VFS interface calls on the same [sqlite3_file] file descriptor
1106** except for calls to the xWrite method and the xFileControl method
1107** with [SQLITE_FCNTL_SIZE_HINT].
1108**
1109** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1110** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1111** operations since the previous successful call to
1112** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1113** This file control returns [SQLITE_OK] if and only if the writes were
1114** all performed successfully and have been committed to persistent storage.
1115** ^Regardless of whether or not it is successful, this file control takes
1116** the file descriptor out of batch write mode so that all subsequent
1117** write operations are independent.
1118** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1119** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1120**
1121** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1122** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1123** operations since the previous successful call to
1124** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1125** ^This file control takes the file descriptor out of batch write mode
1126** so that all subsequent write operations are independent.
1127** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1128** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1129**
1130** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1131** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1132** to block for up to M milliseconds before failing when attempting to
1133** obtain a file lock using the xLock or xShmLock methods of the VFS.
1134** The parameter is a pointer to a 32-bit signed integer that contains
1135** the value that M is to be set to. Before returning, the 32-bit signed
1136** integer is overwritten with the previous value of M.
1137**
1138** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1139** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1140** a database file. The argument is a pointer to a 32-bit unsigned integer.
1141** The "data version" for the pager is written into the pointer. The
1142** "data version" changes whenever any change occurs to the corresponding
1143** database file, either through SQL statements on the same database
1144** connection or through transactions committed by separate database
1145** connections possibly in other processes. The [sqlite3_total_changes()]
1146** interface can be used to find if any database on the connection has changed,
1147** but that interface responds to changes on TEMP as well as MAIN and does
1148** not provide a mechanism to detect changes to MAIN only. Also, the
1149** [sqlite3_total_changes()] interface responds to internal changes only and
1150** omits changes made by other database connections. The
1151** [PRAGMA data_version] command provides a mechanism to detect changes to
1152** a single attached database that occur due to other database connections,
1153** but omits changes implemented by the database connection on which it is
1154** called. This file control is the only mechanism to detect changes that
1155** happen either internally or externally and that are associated with
1156** a particular attached database.
1157**
1158** <li>[[SQLITE_FCNTL_CKPT_START]]
1159** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1160** in wal mode before the client starts to copy pages from the wal
1161** file to the database file.
1162**
1163** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1164** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1165** in wal mode after the client has finished copying pages from the wal
1166** file to the database file, but before the *-shm file is updated to
1167** record the fact that the pages have been checkpointed.
1168** </ul>
1169**
1170** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1171** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1172** whether or not there is a database client in another process with a wal-mode
1173** transaction open on the database or not. It is only available on unix.The
1174** (void*) argument passed with this file-control should be a pointer to a
1175** value of type (int). The integer value is set to 1 if the database is a wal
1176** mode database and there exists at least one client in another process that
1177** currently has an SQL transaction open on the database. It is set to 0 if
1178** the database is not a wal-mode db, or if there is no such connection in any
1179** other process. This opcode cannot be used to detect transactions opened
1180** by clients within the current process, only within other processes.
1181** </ul>
1182**
1183** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1184** Used by the cksmvfs VFS module only.
1185** </ul>
1186*/
1187#define SQLITE_FCNTL_LOCKSTATE 1
1188#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1189#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1190#define SQLITE_FCNTL_LAST_ERRNO 4
1191#define SQLITE_FCNTL_SIZE_HINT 5
1192#define SQLITE_FCNTL_CHUNK_SIZE 6
1193#define SQLITE_FCNTL_FILE_POINTER 7
1194#define SQLITE_FCNTL_SYNC_OMITTED 8
1195#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1196#define SQLITE_FCNTL_PERSIST_WAL 10
1197#define SQLITE_FCNTL_OVERWRITE 11
1198#define SQLITE_FCNTL_VFSNAME 12
1199#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1200#define SQLITE_FCNTL_PRAGMA 14
1201#define SQLITE_FCNTL_BUSYHANDLER 15
1202#define SQLITE_FCNTL_TEMPFILENAME 16
1203#define SQLITE_FCNTL_MMAP_SIZE 18
1204#define SQLITE_FCNTL_TRACE 19
1205#define SQLITE_FCNTL_HAS_MOVED 20
1206#define SQLITE_FCNTL_SYNC 21
1207#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1208#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1209#define SQLITE_FCNTL_WAL_BLOCK 24
1210#define SQLITE_FCNTL_ZIPVFS 25
1211#define SQLITE_FCNTL_RBU 26
1212#define SQLITE_FCNTL_VFS_POINTER 27
1213#define SQLITE_FCNTL_JOURNAL_POINTER 28
1214#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1215#define SQLITE_FCNTL_PDB 30
1216#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1217#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1218#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1219#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1220#define SQLITE_FCNTL_DATA_VERSION 35
1221#define SQLITE_FCNTL_SIZE_LIMIT 36
1222#define SQLITE_FCNTL_CKPT_DONE 37
1223#define SQLITE_FCNTL_RESERVE_BYTES 38
1224#define SQLITE_FCNTL_CKPT_START 39
1225#define SQLITE_FCNTL_EXTERNAL_READER 40
1226#define SQLITE_FCNTL_CKSM_FILE 41
1227
1228/* deprecated names */
1229#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1230#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1231#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1232
1233
1234/*
1235** CAPI3REF: Mutex Handle
1236**
1237** The mutex module within SQLite defines [sqlite3_mutex] to be an
1238** abstract type for a mutex object. The SQLite core never looks
1239** at the internal representation of an [sqlite3_mutex]. It only
1240** deals with pointers to the [sqlite3_mutex] object.
1241**
1242** Mutexes are created using [sqlite3_mutex_alloc()].
1243*/
1244typedef struct sqlite3_mutex sqlite3_mutex;
1245
1246/*
1247** CAPI3REF: Loadable Extension Thunk
1248**
1249** A pointer to the opaque sqlite3_api_routines structure is passed as
1250** the third parameter to entry points of [loadable extensions]. This
1251** structure must be typedefed in order to work around compiler warnings
1252** on some platforms.
1253*/
1254typedef struct sqlite3_api_routines sqlite3_api_routines;
1255
1256/*
1257** CAPI3REF: OS Interface Object
1258**
1259** An instance of the sqlite3_vfs object defines the interface between
1260** the SQLite core and the underlying operating system. The "vfs"
1261** in the name of the object stands for "virtual file system". See
1262** the [VFS | VFS documentation] for further information.
1263**
1264** The VFS interface is sometimes extended by adding new methods onto
1265** the end. Each time such an extension occurs, the iVersion field
1266** is incremented. The iVersion value started out as 1 in
1267** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1268** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1269** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1270** may be appended to the sqlite3_vfs object and the iVersion value
1271** may increase again in future versions of SQLite.
1272** Note that due to an oversight, the structure
1273** of the sqlite3_vfs object changed in the transition from
1274** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1275** and yet the iVersion field was not increased.
1276**
1277** The szOsFile field is the size of the subclassed [sqlite3_file]
1278** structure used by this VFS. mxPathname is the maximum length of
1279** a pathname in this VFS.
1280**
1281** Registered sqlite3_vfs objects are kept on a linked list formed by
1282** the pNext pointer. The [sqlite3_vfs_register()]
1283** and [sqlite3_vfs_unregister()] interfaces manage this list
1284** in a thread-safe way. The [sqlite3_vfs_find()] interface
1285** searches the list. Neither the application code nor the VFS
1286** implementation should use the pNext pointer.
1287**
1288** The pNext field is the only field in the sqlite3_vfs
1289** structure that SQLite will ever modify. SQLite will only access
1290** or modify this field while holding a particular static mutex.
1291** The application should never modify anything within the sqlite3_vfs
1292** object once the object has been registered.
1293**
1294** The zName field holds the name of the VFS module. The name must
1295** be unique across all VFS modules.
1296**
1297** [[sqlite3_vfs.xOpen]]
1298** ^SQLite guarantees that the zFilename parameter to xOpen
1299** is either a NULL pointer or string obtained
1300** from xFullPathname() with an optional suffix added.
1301** ^If a suffix is added to the zFilename parameter, it will
1302** consist of a single "-" character followed by no more than
1303** 11 alphanumeric and/or "-" characters.
1304** ^SQLite further guarantees that
1305** the string will be valid and unchanged until xClose() is
1306** called. Because of the previous sentence,
1307** the [sqlite3_file] can safely store a pointer to the
1308** filename if it needs to remember the filename for some reason.
1309** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1310** must invent its own temporary name for the file. ^Whenever the
1311** xFilename parameter is NULL it will also be the case that the
1312** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1313**
1314** The flags argument to xOpen() includes all bits set in
1315** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1316** or [sqlite3_open16()] is used, then flags includes at least
1317** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1318** If xOpen() opens a file read-only then it sets *pOutFlags to
1319** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1320**
1321** ^(SQLite will also add one of the following flags to the xOpen()
1322** call, depending on the object being opened:
1323**
1324** <ul>
1325** <li> [SQLITE_OPEN_MAIN_DB]
1326** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1327** <li> [SQLITE_OPEN_TEMP_DB]
1328** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1329** <li> [SQLITE_OPEN_TRANSIENT_DB]
1330** <li> [SQLITE_OPEN_SUBJOURNAL]
1331** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1332** <li> [SQLITE_OPEN_WAL]
1333** </ul>)^
1334**
1335** The file I/O implementation can use the object type flags to
1336** change the way it deals with files. For example, an application
1337** that does not care about crash recovery or rollback might make
1338** the open of a journal file a no-op. Writes to this journal would
1339** also be no-ops, and any attempt to read the journal would return
1340** SQLITE_IOERR. Or the implementation might recognize that a database
1341** file will be doing page-aligned sector reads and writes in a random
1342** order and set up its I/O subsystem accordingly.
1343**
1344** SQLite might also add one of the following flags to the xOpen method:
1345**
1346** <ul>
1347** <li> [SQLITE_OPEN_DELETEONCLOSE]
1348** <li> [SQLITE_OPEN_EXCLUSIVE]
1349** </ul>
1350**
1351** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1352** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1353** will be set for TEMP databases and their journals, transient
1354** databases, and subjournals.
1355**
1356** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1357** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1358** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1359** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1360** SQLITE_OPEN_CREATE, is used to indicate that file should always
1361** be created, and that it is an error if it already exists.
1362** It is <i>not</i> used to indicate the file should be opened
1363** for exclusive access.
1364**
1365** ^At least szOsFile bytes of memory are allocated by SQLite
1366** to hold the [sqlite3_file] structure passed as the third
1367** argument to xOpen. The xOpen method does not have to
1368** allocate the structure; it should just fill it in. Note that
1369** the xOpen method must set the sqlite3_file.pMethods to either
1370** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1371** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1372** element will be valid after xOpen returns regardless of the success
1373** or failure of the xOpen call.
1374**
1375** [[sqlite3_vfs.xAccess]]
1376** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1377** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1378** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1379** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1380** flag is never actually used and is not implemented in the built-in
1381** VFSes of SQLite. The file is named by the second argument and can be a
1382** directory. The xAccess method returns [SQLITE_OK] on success or some
1383** non-zero error code if there is an I/O error or if the name of
1384** the file given in the second argument is illegal. If SQLITE_OK
1385** is returned, then non-zero or zero is written into *pResOut to indicate
1386** whether or not the file is accessible.
1387**
1388** ^SQLite will always allocate at least mxPathname+1 bytes for the
1389** output buffer xFullPathname. The exact size of the output buffer
1390** is also passed as a parameter to both methods. If the output buffer
1391** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1392** handled as a fatal error by SQLite, vfs implementations should endeavor
1393** to prevent this by setting mxPathname to a sufficiently large value.
1394**
1395** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1396** interfaces are not strictly a part of the filesystem, but they are
1397** included in the VFS structure for completeness.
1398** The xRandomness() function attempts to return nBytes bytes
1399** of good-quality randomness into zOut. The return value is
1400** the actual number of bytes of randomness obtained.
1401** The xSleep() method causes the calling thread to sleep for at
1402** least the number of microseconds given. ^The xCurrentTime()
1403** method returns a Julian Day Number for the current date and time as
1404** a floating point value.
1405** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1406** Day Number multiplied by 86400000 (the number of milliseconds in
1407** a 24-hour day).
1408** ^SQLite will use the xCurrentTimeInt64() method to get the current
1409** date and time if that method is available (if iVersion is 2 or
1410** greater and the function pointer is not NULL) and will fall back
1411** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1412**
1413** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1414** are not used by the SQLite core. These optional interfaces are provided
1415** by some VFSes to facilitate testing of the VFS code. By overriding
1416** system calls with functions under its control, a test program can
1417** simulate faults and error conditions that would otherwise be difficult
1418** or impossible to induce. The set of system calls that can be overridden
1419** varies from one VFS to another, and from one version of the same VFS to the
1420** next. Applications that use these interfaces must be prepared for any
1421** or all of these interfaces to be NULL or for their behavior to change
1422** from one release to the next. Applications must not attempt to access
1423** any of these methods if the iVersion of the VFS is less than 3.
1424*/
1425typedef struct sqlite3_vfs sqlite3_vfs;
1426typedef void (*sqlite3_syscall_ptr)(void);
1427struct sqlite3_vfs {
1428 int iVersion; /* Structure version number (currently 3) */
1429 int szOsFile; /* Size of subclassed sqlite3_file */
1430 int mxPathname; /* Maximum file pathname length */
1431 sqlite3_vfs *pNext; /* Next registered VFS */
1432 const char *zName; /* Name of this virtual file system */
1433 void *pAppData; /* Pointer to application-specific data */
1434 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1435 int flags, int *pOutFlags);
1436 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1437 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1438 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1439 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1440 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1441 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1442 void (*xDlClose)(sqlite3_vfs*, void*);
1443 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1444 int (*xSleep)(sqlite3_vfs*, int microseconds);
1445 int (*xCurrentTime)(sqlite3_vfs*, double*);
1446 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1447 /*
1448 ** The methods above are in version 1 of the sqlite_vfs object
1449 ** definition. Those that follow are added in version 2 or later
1450 */
1451 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1452 /*
1453 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1454 ** Those below are for version 3 and greater.
1455 */
1456 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1457 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1458 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1459 /*
1460 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1461 ** New fields may be appended in future versions. The iVersion
1462 ** value will increment whenever this happens.
1463 */
1464};
1465
1466/*
1467** CAPI3REF: Flags for the xAccess VFS method
1468**
1469** These integer constants can be used as the third parameter to
1470** the xAccess method of an [sqlite3_vfs] object. They determine
1471** what kind of permissions the xAccess method is looking for.
1472** With SQLITE_ACCESS_EXISTS, the xAccess method
1473** simply checks whether the file exists.
1474** With SQLITE_ACCESS_READWRITE, the xAccess method
1475** checks whether the named directory is both readable and writable
1476** (in other words, if files can be added, removed, and renamed within
1477** the directory).
1478** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1479** [temp_store_directory pragma], though this could change in a future
1480** release of SQLite.
1481** With SQLITE_ACCESS_READ, the xAccess method
1482** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1483** currently unused, though it might be used in a future release of
1484** SQLite.
1485*/
1486#define SQLITE_ACCESS_EXISTS 0
1487#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1488#define SQLITE_ACCESS_READ 2 /* Unused */
1489
1490/*
1491** CAPI3REF: Flags for the xShmLock VFS method
1492**
1493** These integer constants define the various locking operations
1494** allowed by the xShmLock method of [sqlite3_io_methods]. The
1495** following are the only legal combinations of flags to the
1496** xShmLock method:
1497**
1498** <ul>
1499** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1500** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1501** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1502** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1503** </ul>
1504**
1505** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1506** was given on the corresponding lock.
1507**
1508** The xShmLock method can transition between unlocked and SHARED or
1509** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1510** and EXCLUSIVE.
1511*/
1512#define SQLITE_SHM_UNLOCK 1
1513#define SQLITE_SHM_LOCK 2
1514#define SQLITE_SHM_SHARED 4
1515#define SQLITE_SHM_EXCLUSIVE 8
1516
1517/*
1518** CAPI3REF: Maximum xShmLock index
1519**
1520** The xShmLock method on [sqlite3_io_methods] may use values
1521** between 0 and this upper bound as its "offset" argument.
1522** The SQLite core will never attempt to acquire or release a
1523** lock outside of this range
1524*/
1525#define SQLITE_SHM_NLOCK 8
1526
1527
1528/*
1529** CAPI3REF: Initialize The SQLite Library
1530**
1531** ^The sqlite3_initialize() routine initializes the
1532** SQLite library. ^The sqlite3_shutdown() routine
1533** deallocates any resources that were allocated by sqlite3_initialize().
1534** These routines are designed to aid in process initialization and
1535** shutdown on embedded systems. Workstation applications using
1536** SQLite normally do not need to invoke either of these routines.
1537**
1538** A call to sqlite3_initialize() is an "effective" call if it is
1539** the first time sqlite3_initialize() is invoked during the lifetime of
1540** the process, or if it is the first time sqlite3_initialize() is invoked
1541** following a call to sqlite3_shutdown(). ^(Only an effective call
1542** of sqlite3_initialize() does any initialization. All other calls
1543** are harmless no-ops.)^
1544**
1545** A call to sqlite3_shutdown() is an "effective" call if it is the first
1546** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1547** an effective call to sqlite3_shutdown() does any deinitialization.
1548** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1549**
1550** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1551** is not. The sqlite3_shutdown() interface must only be called from a
1552** single thread. All open [database connections] must be closed and all
1553** other SQLite resources must be deallocated prior to invoking
1554** sqlite3_shutdown().
1555**
1556** Among other things, ^sqlite3_initialize() will invoke
1557** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1558** will invoke sqlite3_os_end().
1559**
1560** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1561** ^If for some reason, sqlite3_initialize() is unable to initialize
1562** the library (perhaps it is unable to allocate a needed resource such
1563** as a mutex) it returns an [error code] other than [SQLITE_OK].
1564**
1565** ^The sqlite3_initialize() routine is called internally by many other
1566** SQLite interfaces so that an application usually does not need to
1567** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1568** calls sqlite3_initialize() so the SQLite library will be automatically
1569** initialized when [sqlite3_open()] is called if it has not be initialized
1570** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1571** compile-time option, then the automatic calls to sqlite3_initialize()
1572** are omitted and the application must call sqlite3_initialize() directly
1573** prior to using any other SQLite interface. For maximum portability,
1574** it is recommended that applications always invoke sqlite3_initialize()
1575** directly prior to using any other SQLite interface. Future releases
1576** of SQLite may require this. In other words, the behavior exhibited
1577** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1578** default behavior in some future release of SQLite.
1579**
1580** The sqlite3_os_init() routine does operating-system specific
1581** initialization of the SQLite library. The sqlite3_os_end()
1582** routine undoes the effect of sqlite3_os_init(). Typical tasks
1583** performed by these routines include allocation or deallocation
1584** of static resources, initialization of global variables,
1585** setting up a default [sqlite3_vfs] module, or setting up
1586** a default configuration using [sqlite3_config()].
1587**
1588** The application should never invoke either sqlite3_os_init()
1589** or sqlite3_os_end() directly. The application should only invoke
1590** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1591** interface is called automatically by sqlite3_initialize() and
1592** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1593** implementations for sqlite3_os_init() and sqlite3_os_end()
1594** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1595** When [custom builds | built for other platforms]
1596** (using the [SQLITE_OS_OTHER=1] compile-time
1597** option) the application must supply a suitable implementation for
1598** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1599** implementation of sqlite3_os_init() or sqlite3_os_end()
1600** must return [SQLITE_OK] on success and some other [error code] upon
1601** failure.
1602*/
1603SQLITE_API int sqlite3_initialize(void);
1604SQLITE_API int sqlite3_shutdown(void);
1605SQLITE_API int sqlite3_os_init(void);
1606SQLITE_API int sqlite3_os_end(void);
1607
1608/*
1609** CAPI3REF: Configuring The SQLite Library
1610**
1611** The sqlite3_config() interface is used to make global configuration
1612** changes to SQLite in order to tune SQLite to the specific needs of
1613** the application. The default configuration is recommended for most
1614** applications and so this routine is usually not necessary. It is
1615** provided to support rare applications with unusual needs.
1616**
1617** <b>The sqlite3_config() interface is not threadsafe. The application
1618** must ensure that no other SQLite interfaces are invoked by other
1619** threads while sqlite3_config() is running.</b>
1620**
1621** The sqlite3_config() interface
1622** may only be invoked prior to library initialization using
1623** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1624** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1625** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1626** Note, however, that ^sqlite3_config() can be called as part of the
1627** implementation of an application-defined [sqlite3_os_init()].
1628**
1629** The first argument to sqlite3_config() is an integer
1630** [configuration option] that determines
1631** what property of SQLite is to be configured. Subsequent arguments
1632** vary depending on the [configuration option]
1633** in the first argument.
1634**
1635** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1636** ^If the option is unknown or SQLite is unable to set the option
1637** then this routine returns a non-zero [error code].
1638*/
1639SQLITE_API int sqlite3_config(int, ...);
1640
1641/*
1642** CAPI3REF: Configure database connections
1643** METHOD: sqlite3
1644**
1645** The sqlite3_db_config() interface is used to make configuration
1646** changes to a [database connection]. The interface is similar to
1647** [sqlite3_config()] except that the changes apply to a single
1648** [database connection] (specified in the first argument).
1649**
1650** The second argument to sqlite3_db_config(D,V,...) is the
1651** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1652** that indicates what aspect of the [database connection] is being configured.
1653** Subsequent arguments vary depending on the configuration verb.
1654**
1655** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1656** the call is considered successful.
1657*/
1658SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1659
1660/*
1661** CAPI3REF: Memory Allocation Routines
1662**
1663** An instance of this object defines the interface between SQLite
1664** and low-level memory allocation routines.
1665**
1666** This object is used in only one place in the SQLite interface.
1667** A pointer to an instance of this object is the argument to
1668** [sqlite3_config()] when the configuration option is
1669** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1670** By creating an instance of this object
1671** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1672** during configuration, an application can specify an alternative
1673** memory allocation subsystem for SQLite to use for all of its
1674** dynamic memory needs.
1675**
1676** Note that SQLite comes with several [built-in memory allocators]
1677** that are perfectly adequate for the overwhelming majority of applications
1678** and that this object is only useful to a tiny minority of applications
1679** with specialized memory allocation requirements. This object is
1680** also used during testing of SQLite in order to specify an alternative
1681** memory allocator that simulates memory out-of-memory conditions in
1682** order to verify that SQLite recovers gracefully from such
1683** conditions.
1684**
1685** The xMalloc, xRealloc, and xFree methods must work like the
1686** malloc(), realloc() and free() functions from the standard C library.
1687** ^SQLite guarantees that the second argument to
1688** xRealloc is always a value returned by a prior call to xRoundup.
1689**
1690** xSize should return the allocated size of a memory allocation
1691** previously obtained from xMalloc or xRealloc. The allocated size
1692** is always at least as big as the requested size but may be larger.
1693**
1694** The xRoundup method returns what would be the allocated size of
1695** a memory allocation given a particular requested size. Most memory
1696** allocators round up memory allocations at least to the next multiple
1697** of 8. Some allocators round up to a larger multiple or to a power of 2.
1698** Every memory allocation request coming in through [sqlite3_malloc()]
1699** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1700** that causes the corresponding memory allocation to fail.
1701**
1702** The xInit method initializes the memory allocator. For example,
1703** it might allocate any required mutexes or initialize internal data
1704** structures. The xShutdown method is invoked (indirectly) by
1705** [sqlite3_shutdown()] and should deallocate any resources acquired
1706** by xInit. The pAppData pointer is used as the only parameter to
1707** xInit and xShutdown.
1708**
1709** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1710** the xInit method, so the xInit method need not be threadsafe. The
1711** xShutdown method is only called from [sqlite3_shutdown()] so it does
1712** not need to be threadsafe either. For all other methods, SQLite
1713** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1714** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1715** it is by default) and so the methods are automatically serialized.
1716** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1717** methods must be threadsafe or else make their own arrangements for
1718** serialization.
1719**
1720** SQLite will never invoke xInit() more than once without an intervening
1721** call to xShutdown().
1722*/
1723typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1724struct sqlite3_mem_methods {
1725 void *(*xMalloc)(int); /* Memory allocation function */
1726 void (*xFree)(void*); /* Free a prior allocation */
1727 void *(*xRealloc)(void*,int); /* Resize an allocation */
1728 int (*xSize)(void*); /* Return the size of an allocation */
1729 int (*xRoundup)(int); /* Round up request size to allocation size */
1730 int (*xInit)(void*); /* Initialize the memory allocator */
1731 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1732 void *pAppData; /* Argument to xInit() and xShutdown() */
1733};
1734
1735/*
1736** CAPI3REF: Configuration Options
1737** KEYWORDS: {configuration option}
1738**
1739** These constants are the available integer configuration options that
1740** can be passed as the first argument to the [sqlite3_config()] interface.
1741**
1742** New configuration options may be added in future releases of SQLite.
1743** Existing configuration options might be discontinued. Applications
1744** should check the return code from [sqlite3_config()] to make sure that
1745** the call worked. The [sqlite3_config()] interface will return a
1746** non-zero [error code] if a discontinued or unsupported configuration option
1747** is invoked.
1748**
1749** <dl>
1750** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1751** <dd>There are no arguments to this option. ^This option sets the
1752** [threading mode] to Single-thread. In other words, it disables
1753** all mutexing and puts SQLite into a mode where it can only be used
1754** by a single thread. ^If SQLite is compiled with
1755** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1756** it is not possible to change the [threading mode] from its default
1757** value of Single-thread and so [sqlite3_config()] will return
1758** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1759** configuration option.</dd>
1760**
1761** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1762** <dd>There are no arguments to this option. ^This option sets the
1763** [threading mode] to Multi-thread. In other words, it disables
1764** mutexing on [database connection] and [prepared statement] objects.
1765** The application is responsible for serializing access to
1766** [database connections] and [prepared statements]. But other mutexes
1767** are enabled so that SQLite will be safe to use in a multi-threaded
1768** environment as long as no two threads attempt to use the same
1769** [database connection] at the same time. ^If SQLite is compiled with
1770** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1771** it is not possible to set the Multi-thread [threading mode] and
1772** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1773** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1774**
1775** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1776** <dd>There are no arguments to this option. ^This option sets the
1777** [threading mode] to Serialized. In other words, this option enables
1778** all mutexes including the recursive
1779** mutexes on [database connection] and [prepared statement] objects.
1780** In this mode (which is the default when SQLite is compiled with
1781** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1782** to [database connections] and [prepared statements] so that the
1783** application is free to use the same [database connection] or the
1784** same [prepared statement] in different threads at the same time.
1785** ^If SQLite is compiled with
1786** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1787** it is not possible to set the Serialized [threading mode] and
1788** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1789** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1790**
1791** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1792** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1793** a pointer to an instance of the [sqlite3_mem_methods] structure.
1794** The argument specifies
1795** alternative low-level memory allocation routines to be used in place of
1796** the memory allocation routines built into SQLite.)^ ^SQLite makes
1797** its own private copy of the content of the [sqlite3_mem_methods] structure
1798** before the [sqlite3_config()] call returns.</dd>
1799**
1800** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1801** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1802** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1803** The [sqlite3_mem_methods]
1804** structure is filled with the currently defined memory allocation routines.)^
1805** This option can be used to overload the default memory allocation
1806** routines with a wrapper that simulations memory allocation failure or
1807** tracks memory usage, for example. </dd>
1808**
1809** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1810** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1811** type int, interpreted as a boolean, which if true provides a hint to
1812** SQLite that it should avoid large memory allocations if possible.
1813** SQLite will run faster if it is free to make large memory allocations,
1814** but some application might prefer to run slower in exchange for
1815** guarantees about memory fragmentation that are possible if large
1816** allocations are avoided. This hint is normally off.
1817** </dd>
1818**
1819** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1820** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1821** interpreted as a boolean, which enables or disables the collection of
1822** memory allocation statistics. ^(When memory allocation statistics are
1823** disabled, the following SQLite interfaces become non-operational:
1824** <ul>
1825** <li> [sqlite3_hard_heap_limit64()]
1826** <li> [sqlite3_memory_used()]
1827** <li> [sqlite3_memory_highwater()]
1828** <li> [sqlite3_soft_heap_limit64()]
1829** <li> [sqlite3_status64()]
1830** </ul>)^
1831** ^Memory allocation statistics are enabled by default unless SQLite is
1832** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1833** allocation statistics are disabled by default.
1834** </dd>
1835**
1836** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1837** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1838** </dd>
1839**
1840** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1841** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1842** that SQLite can use for the database page cache with the default page
1843** cache implementation.
1844** This configuration option is a no-op if an application-defined page
1845** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1846** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1847** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1848** and the number of cache lines (N).
1849** The sz argument should be the size of the largest database page
1850** (a power of two between 512 and 65536) plus some extra bytes for each
1851** page header. ^The number of extra bytes needed by the page header
1852** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1853** ^It is harmless, apart from the wasted memory,
1854** for the sz parameter to be larger than necessary. The pMem
1855** argument must be either a NULL pointer or a pointer to an 8-byte
1856** aligned block of memory of at least sz*N bytes, otherwise
1857** subsequent behavior is undefined.
1858** ^When pMem is not NULL, SQLite will strive to use the memory provided
1859** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1860** a page cache line is larger than sz bytes or if all of the pMem buffer
1861** is exhausted.
1862** ^If pMem is NULL and N is non-zero, then each database connection
1863** does an initial bulk allocation for page cache memory
1864** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1865** of -1024*N bytes if N is negative, . ^If additional
1866** page cache memory is needed beyond what is provided by the initial
1867** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1868** additional cache line. </dd>
1869**
1870** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1871** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1872** that SQLite will use for all of its dynamic memory allocation needs
1873** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1874** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1875** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1876** [SQLITE_ERROR] if invoked otherwise.
1877** ^There are three arguments to SQLITE_CONFIG_HEAP:
1878** An 8-byte aligned pointer to the memory,
1879** the number of bytes in the memory buffer, and the minimum allocation size.
1880** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1881** to using its default memory allocator (the system malloc() implementation),
1882** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1883** memory pointer is not NULL then the alternative memory
1884** allocator is engaged to handle all of SQLites memory allocation needs.
1885** The first pointer (the memory pointer) must be aligned to an 8-byte
1886** boundary or subsequent behavior of SQLite will be undefined.
1887** The minimum allocation size is capped at 2**12. Reasonable values
1888** for the minimum allocation size are 2**5 through 2**8.</dd>
1889**
1890** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1891** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1892** pointer to an instance of the [sqlite3_mutex_methods] structure.
1893** The argument specifies alternative low-level mutex routines to be used
1894** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1895** the content of the [sqlite3_mutex_methods] structure before the call to
1896** [sqlite3_config()] returns. ^If SQLite is compiled with
1897** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1898** the entire mutexing subsystem is omitted from the build and hence calls to
1899** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1900** return [SQLITE_ERROR].</dd>
1901**
1902** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1903** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1904** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1905** [sqlite3_mutex_methods]
1906** structure is filled with the currently defined mutex routines.)^
1907** This option can be used to overload the default mutex allocation
1908** routines with a wrapper used to track mutex usage for performance
1909** profiling or testing, for example. ^If SQLite is compiled with
1910** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1911** the entire mutexing subsystem is omitted from the build and hence calls to
1912** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1913** return [SQLITE_ERROR].</dd>
1914**
1915** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1916** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1917** the default size of lookaside memory on each [database connection].
1918** The first argument is the
1919** size of each lookaside buffer slot and the second is the number of
1920** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1921** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1922** option to [sqlite3_db_config()] can be used to change the lookaside
1923** configuration on individual connections.)^ </dd>
1924**
1925** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1926** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1927** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1928** the interface to a custom page cache implementation.)^
1929** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1930**
1931** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1932** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1933** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1934** the current page cache implementation into that object.)^ </dd>
1935**
1936** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1937** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1938** global [error log].
1939** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1940** function with a call signature of void(*)(void*,int,const char*),
1941** and a pointer to void. ^If the function pointer is not NULL, it is
1942** invoked by [sqlite3_log()] to process each logging event. ^If the
1943** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1944** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1945** passed through as the first parameter to the application-defined logger
1946** function whenever that function is invoked. ^The second parameter to
1947** the logger function is a copy of the first parameter to the corresponding
1948** [sqlite3_log()] call and is intended to be a [result code] or an
1949** [extended result code]. ^The third parameter passed to the logger is
1950** log message after formatting via [sqlite3_snprintf()].
1951** The SQLite logging interface is not reentrant; the logger function
1952** supplied by the application must not invoke any SQLite interface.
1953** In a multi-threaded application, the application-defined logger
1954** function must be threadsafe. </dd>
1955**
1956** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1957** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1958** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1959** then URI handling is globally disabled.)^ ^If URI handling is globally
1960** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1961** [sqlite3_open16()] or
1962** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1963** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1964** connection is opened. ^If it is globally disabled, filenames are
1965** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1966** database connection is opened. ^(By default, URI handling is globally
1967** disabled. The default value may be changed by compiling with the
1968** [SQLITE_USE_URI] symbol defined.)^
1969**
1970** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1971** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1972** argument which is interpreted as a boolean in order to enable or disable
1973** the use of covering indices for full table scans in the query optimizer.
1974** ^The default setting is determined
1975** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1976** if that compile-time option is omitted.
1977** The ability to disable the use of covering indices for full table scans
1978** is because some incorrectly coded legacy applications might malfunction
1979** when the optimization is enabled. Providing the ability to
1980** disable the optimization allows the older, buggy application code to work
1981** without change even with newer versions of SQLite.
1982**
1983** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1984** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1985** <dd> These options are obsolete and should not be used by new code.
1986** They are retained for backwards compatibility but are now no-ops.
1987** </dd>
1988**
1989** [[SQLITE_CONFIG_SQLLOG]]
1990** <dt>SQLITE_CONFIG_SQLLOG
1991** <dd>This option is only available if sqlite is compiled with the
1992** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1993** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1994** The second should be of type (void*). The callback is invoked by the library
1995** in three separate circumstances, identified by the value passed as the
1996** fourth parameter. If the fourth parameter is 0, then the database connection
1997** passed as the second argument has just been opened. The third argument
1998** points to a buffer containing the name of the main database file. If the
1999** fourth parameter is 1, then the SQL statement that the third parameter
2000** points to has just been executed. Or, if the fourth parameter is 2, then
2001** the connection being passed as the second parameter is being closed. The
2002** third parameter is passed NULL In this case. An example of using this
2003** configuration option can be seen in the "test_sqllog.c" source file in
2004** the canonical SQLite source tree.</dd>
2005**
2006** [[SQLITE_CONFIG_MMAP_SIZE]]
2007** <dt>SQLITE_CONFIG_MMAP_SIZE
2008** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2009** that are the default mmap size limit (the default setting for
2010** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2011** ^The default setting can be overridden by each database connection using
2012** either the [PRAGMA mmap_size] command, or by using the
2013** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2014** will be silently truncated if necessary so that it does not exceed the
2015** compile-time maximum mmap size set by the
2016** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2017** ^If either argument to this option is negative, then that argument is
2018** changed to its compile-time default.
2019**
2020** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2021** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2022** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2023** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2024** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2025** that specifies the maximum size of the created heap.
2026**
2027** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2028** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2029** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2030** is a pointer to an integer and writes into that integer the number of extra
2031** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2032** The amount of extra space required can change depending on the compiler,
2033** target platform, and SQLite version.
2034**
2035** [[SQLITE_CONFIG_PMASZ]]
2036** <dt>SQLITE_CONFIG_PMASZ
2037** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2038** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2039** sorter to that integer. The default minimum PMA Size is set by the
2040** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2041** to help with sort operations when multithreaded sorting
2042** is enabled (using the [PRAGMA threads] command) and the amount of content
2043** to be sorted exceeds the page size times the minimum of the
2044** [PRAGMA cache_size] setting and this value.
2045**
2046** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2047** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2048** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2049** becomes the [statement journal] spill-to-disk threshold.
2050** [Statement journals] are held in memory until their size (in bytes)
2051** exceeds this threshold, at which point they are written to disk.
2052** Or if the threshold is -1, statement journals are always held
2053** exclusively in memory.
2054** Since many statement journals never become large, setting the spill
2055** threshold to a value such as 64KiB can greatly reduce the amount of
2056** I/O required to support statement rollback.
2057** The default value for this setting is controlled by the
2058** [SQLITE_STMTJRNL_SPILL] compile-time option.
2059**
2060** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2061** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2062** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2063** of type (int) - the new value of the sorter-reference size threshold.
2064** Usually, when SQLite uses an external sort to order records according
2065** to an ORDER BY clause, all fields required by the caller are present in the
2066** sorted records. However, if SQLite determines based on the declared type
2067** of a table column that its values are likely to be very large - larger
2068** than the configured sorter-reference size threshold - then a reference
2069** is stored in each sorted record and the required column values loaded
2070** from the database as records are returned in sorted order. The default
2071** value for this option is to never use this optimization. Specifying a
2072** negative value for this option restores the default behaviour.
2073** This option is only available if SQLite is compiled with the
2074** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2075**
2076** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2077** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2078** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2079** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2080** database created using [sqlite3_deserialize()]. This default maximum
2081** size can be adjusted up or down for individual databases using the
2082** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2083** configuration setting is never used, then the default maximum is determined
2084** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2085** compile-time option is not set, then the default maximum is 1073741824.
2086** </dl>
2087*/
2088#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2089#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2090#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2091#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2092#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2093#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2094#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2095#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2096#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2097#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2098#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2099/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2100#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2101#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2102#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2103#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2104#define SQLITE_CONFIG_URI 17 /* int */
2105#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2106#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2107#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2108#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2109#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2110#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2111#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2112#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2113#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2114#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2115#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2116#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2117
2118/*
2119** CAPI3REF: Database Connection Configuration Options
2120**
2121** These constants are the available integer configuration options that
2122** can be passed as the second argument to the [sqlite3_db_config()] interface.
2123**
2124** New configuration options may be added in future releases of SQLite.
2125** Existing configuration options might be discontinued. Applications
2126** should check the return code from [sqlite3_db_config()] to make sure that
2127** the call worked. ^The [sqlite3_db_config()] interface will return a
2128** non-zero [error code] if a discontinued or unsupported configuration option
2129** is invoked.
2130**
2131** <dl>
2132** [[SQLITE_DBCONFIG_LOOKASIDE]]
2133** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2134** <dd> ^This option takes three additional arguments that determine the
2135** [lookaside memory allocator] configuration for the [database connection].
2136** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2137** pointer to a memory buffer to use for lookaside memory.
2138** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2139** may be NULL in which case SQLite will allocate the
2140** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2141** size of each lookaside buffer slot. ^The third argument is the number of
2142** slots. The size of the buffer in the first argument must be greater than
2143** or equal to the product of the second and third arguments. The buffer
2144** must be aligned to an 8-byte boundary. ^If the second argument to
2145** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2146** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2147** configuration for a database connection can only be changed when that
2148** connection is not currently using lookaside memory, or in other words
2149** when the "current value" returned by
2150** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2151** Any attempt to change the lookaside memory configuration when lookaside
2152** memory is in use leaves the configuration unchanged and returns
2153** [SQLITE_BUSY].)^</dd>
2154**
2155** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2156** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2157** <dd> ^This option is used to enable or disable the enforcement of
2158** [foreign key constraints]. There should be two additional arguments.
2159** The first argument is an integer which is 0 to disable FK enforcement,
2160** positive to enable FK enforcement or negative to leave FK enforcement
2161** unchanged. The second parameter is a pointer to an integer into which
2162** is written 0 or 1 to indicate whether FK enforcement is off or on
2163** following this call. The second parameter may be a NULL pointer, in
2164** which case the FK enforcement setting is not reported back. </dd>
2165**
2166** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2167** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2168** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2169** There should be two additional arguments.
2170** The first argument is an integer which is 0 to disable triggers,
2171** positive to enable triggers or negative to leave the setting unchanged.
2172** The second parameter is a pointer to an integer into which
2173** is written 0 or 1 to indicate whether triggers are disabled or enabled
2174** following this call. The second parameter may be a NULL pointer, in
2175** which case the trigger setting is not reported back.
2176**
2177** <p>Originally this option disabled all triggers. ^(However, since
2178** SQLite version 3.35.0, TEMP triggers are still allowed even if
2179** this option is off. So, in other words, this option now only disables
2180** triggers in the main database schema or in the schemas of ATTACH-ed
2181** databases.)^ </dd>
2182**
2183** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2184** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2185** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2186** There should be two additional arguments.
2187** The first argument is an integer which is 0 to disable views,
2188** positive to enable views or negative to leave the setting unchanged.
2189** The second parameter is a pointer to an integer into which
2190** is written 0 or 1 to indicate whether views are disabled or enabled
2191** following this call. The second parameter may be a NULL pointer, in
2192** which case the view setting is not reported back.
2193**
2194** <p>Originally this option disabled all views. ^(However, since
2195** SQLite version 3.35.0, TEMP views are still allowed even if
2196** this option is off. So, in other words, this option now only disables
2197** views in the main database schema or in the schemas of ATTACH-ed
2198** databases.)^ </dd>
2199**
2200** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2201** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2202** <dd> ^This option is used to enable or disable the
2203** [fts3_tokenizer()] function which is part of the
2204** [FTS3] full-text search engine extension.
2205** There should be two additional arguments.
2206** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2207** positive to enable fts3_tokenizer() or negative to leave the setting
2208** unchanged.
2209** The second parameter is a pointer to an integer into which
2210** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2211** following this call. The second parameter may be a NULL pointer, in
2212** which case the new setting is not reported back. </dd>
2213**
2214** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2215** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2216** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2217** interface independently of the [load_extension()] SQL function.
2218** The [sqlite3_enable_load_extension()] API enables or disables both the
2219** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2220** There should be two additional arguments.
2221** When the first argument to this interface is 1, then only the C-API is
2222** enabled and the SQL function remains disabled. If the first argument to
2223** this interface is 0, then both the C-API and the SQL function are disabled.
2224** If the first argument is -1, then no changes are made to state of either the
2225** C-API or the SQL function.
2226** The second parameter is a pointer to an integer into which
2227** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2228** is disabled or enabled following this call. The second parameter may
2229** be a NULL pointer, in which case the new setting is not reported back.
2230** </dd>
2231**
2232** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2233** <dd> ^This option is used to change the name of the "main" database
2234** schema. ^The sole argument is a pointer to a constant UTF8 string
2235** which will become the new schema name in place of "main". ^SQLite
2236** does not make a copy of the new main schema name string, so the application
2237** must ensure that the argument passed into this DBCONFIG option is unchanged
2238** until after the database connection closes.
2239** </dd>
2240**
2241** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2242** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2243** <dd> Usually, when a database in wal mode is closed or detached from a
2244** database handle, SQLite checks if this will mean that there are now no
2245** connections at all to the database. If so, it performs a checkpoint
2246** operation before closing the connection. This option may be used to
2247** override this behaviour. The first parameter passed to this operation
2248** is an integer - positive to disable checkpoints-on-close, or zero (the
2249** default) to enable them, and negative to leave the setting unchanged.
2250** The second parameter is a pointer to an integer
2251** into which is written 0 or 1 to indicate whether checkpoints-on-close
2252** have been disabled - 0 if they are not disabled, 1 if they are.
2253** </dd>
2254**
2255** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2256** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2257** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2258** a single SQL query statement will always use the same algorithm regardless
2259** of values of [bound parameters].)^ The QPSG disables some query optimizations
2260** that look at the values of bound parameters, which can make some queries
2261** slower. But the QPSG has the advantage of more predictable behavior. With
2262** the QPSG active, SQLite will always use the same query plan in the field as
2263** was used during testing in the lab.
2264** The first argument to this setting is an integer which is 0 to disable
2265** the QPSG, positive to enable QPSG, or negative to leave the setting
2266** unchanged. The second parameter is a pointer to an integer into which
2267** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2268** following this call.
2269** </dd>
2270**
2271** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2272** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2273** include output for any operations performed by trigger programs. This
2274** option is used to set or clear (the default) a flag that governs this
2275** behavior. The first parameter passed to this operation is an integer -
2276** positive to enable output for trigger programs, or zero to disable it,
2277** or negative to leave the setting unchanged.
2278** The second parameter is a pointer to an integer into which is written
2279** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2280** it is not disabled, 1 if it is.
2281** </dd>
2282**
2283** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2284** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2285** [VACUUM] in order to reset a database back to an empty database
2286** with no schema and no content. The following process works even for
2287** a badly corrupted database file:
2288** <ol>
2289** <li> If the database connection is newly opened, make sure it has read the
2290** database schema by preparing then discarding some query against the
2291** database, or calling sqlite3_table_column_metadata(), ignoring any
2292** errors. This step is only necessary if the application desires to keep
2293** the database in WAL mode after the reset if it was in WAL mode before
2294** the reset.
2295** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2296** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2297** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2298** </ol>
2299** Because resetting a database is destructive and irreversible, the
2300** process requires the use of this obscure API and multiple steps to help
2301** ensure that it does not happen by accident.
2302**
2303** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2304** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2305** "defensive" flag for a database connection. When the defensive
2306** flag is enabled, language features that allow ordinary SQL to
2307** deliberately corrupt the database file are disabled. The disabled
2308** features include but are not limited to the following:
2309** <ul>
2310** <li> The [PRAGMA writable_schema=ON] statement.
2311** <li> The [PRAGMA journal_mode=OFF] statement.
2312** <li> Writes to the [sqlite_dbpage] virtual table.
2313** <li> Direct writes to [shadow tables].
2314** </ul>
2315** </dd>
2316**
2317** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2318** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2319** "writable_schema" flag. This has the same effect and is logically equivalent
2320** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2321** The first argument to this setting is an integer which is 0 to disable
2322** the writable_schema, positive to enable writable_schema, or negative to
2323** leave the setting unchanged. The second parameter is a pointer to an
2324** integer into which is written 0 or 1 to indicate whether the writable_schema
2325** is enabled or disabled following this call.
2326** </dd>
2327**
2328** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2329** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2330** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2331** the legacy behavior of the [ALTER TABLE RENAME] command such it
2332** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2333** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2334** additional information. This feature can also be turned on and off
2335** using the [PRAGMA legacy_alter_table] statement.
2336** </dd>
2337**
2338** [[SQLITE_DBCONFIG_DQS_DML]]
2339** <dt>SQLITE_DBCONFIG_DQS_DML</td>
2340** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2341** the legacy [double-quoted string literal] misfeature for DML statements
2342** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2343** default value of this setting is determined by the [-DSQLITE_DQS]
2344** compile-time option.
2345** </dd>
2346**
2347** [[SQLITE_DBCONFIG_DQS_DDL]]
2348** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
2349** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2350** the legacy [double-quoted string literal] misfeature for DDL statements,
2351** such as CREATE TABLE and CREATE INDEX. The
2352** default value of this setting is determined by the [-DSQLITE_DQS]
2353** compile-time option.
2354** </dd>
2355**
2356** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2357** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
2358** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2359** assume that database schemas are untainted by malicious content.
2360** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2361** takes additional defensive steps to protect the application from harm
2362** including:
2363** <ul>
2364** <li> Prohibit the use of SQL functions inside triggers, views,
2365** CHECK constraints, DEFAULT clauses, expression indexes,
2366** partial indexes, or generated columns
2367** unless those functions are tagged with [SQLITE_INNOCUOUS].
2368** <li> Prohibit the use of virtual tables inside of triggers or views
2369** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2370** </ul>
2371** This setting defaults to "on" for legacy compatibility, however
2372** all applications are advised to turn it off if possible. This setting
2373** can also be controlled using the [PRAGMA trusted_schema] statement.
2374** </dd>
2375**
2376** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2377** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td>
2378** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2379** the legacy file format flag. When activated, this flag causes all newly
2380** created database file to have a schema format version number (the 4-byte
2381** integer found at offset 44 into the database header) of 1. This in turn
2382** means that the resulting database file will be readable and writable by
2383** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2384** newly created databases are generally not understandable by SQLite versions
2385** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2386** is now scarcely any need to generated database files that are compatible
2387** all the way back to version 3.0.0, and so this setting is of little
2388** practical use, but is provided so that SQLite can continue to claim the
2389** ability to generate new database files that are compatible with version
2390** 3.0.0.
2391** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2392** the [VACUUM] command will fail with an obscure error when attempting to
2393** process a table with generated columns and a descending index. This is
2394** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2395** either generated columns or decending indexes.
2396** </dd>
2397** </dl>
2398*/
2399#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2400#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2401#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2402#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2403#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2404#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2405#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2406#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2407#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2408#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2409#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2410#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2411#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2412#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2413#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2414#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2415#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2416#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2417#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */
2418
2419/*
2420** CAPI3REF: Enable Or Disable Extended Result Codes
2421** METHOD: sqlite3
2422**
2423** ^The sqlite3_extended_result_codes() routine enables or disables the
2424** [extended result codes] feature of SQLite. ^The extended result
2425** codes are disabled by default for historical compatibility.
2426*/
2427SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2428
2429/*
2430** CAPI3REF: Last Insert Rowid
2431** METHOD: sqlite3
2432**
2433** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2434** has a unique 64-bit signed
2435** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2436** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2437** names are not also used by explicitly declared columns. ^If
2438** the table has a column of type [INTEGER PRIMARY KEY] then that column
2439** is another alias for the rowid.
2440**
2441** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2442** the most recent successful [INSERT] into a rowid table or [virtual table]
2443** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2444** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2445** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2446** zero.
2447**
2448** As well as being set automatically as rows are inserted into database
2449** tables, the value returned by this function may be set explicitly by
2450** [sqlite3_set_last_insert_rowid()]
2451**
2452** Some virtual table implementations may INSERT rows into rowid tables as
2453** part of committing a transaction (e.g. to flush data accumulated in memory
2454** to disk). In this case subsequent calls to this function return the rowid
2455** associated with these internal INSERT operations, which leads to
2456** unintuitive results. Virtual table implementations that do write to rowid
2457** tables in this way can avoid this problem by restoring the original
2458** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2459** control to the user.
2460**
2461** ^(If an [INSERT] occurs within a trigger then this routine will
2462** return the [rowid] of the inserted row as long as the trigger is
2463** running. Once the trigger program ends, the value returned
2464** by this routine reverts to what it was before the trigger was fired.)^
2465**
2466** ^An [INSERT] that fails due to a constraint violation is not a
2467** successful [INSERT] and does not change the value returned by this
2468** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2469** and INSERT OR ABORT make no changes to the return value of this
2470** routine when their insertion fails. ^(When INSERT OR REPLACE
2471** encounters a constraint violation, it does not fail. The
2472** INSERT continues to completion after deleting rows that caused
2473** the constraint problem so INSERT OR REPLACE will always change
2474** the return value of this interface.)^
2475**
2476** ^For the purposes of this routine, an [INSERT] is considered to
2477** be successful even if it is subsequently rolled back.
2478**
2479** This function is accessible to SQL statements via the
2480** [last_insert_rowid() SQL function].
2481**
2482** If a separate thread performs a new [INSERT] on the same
2483** database connection while the [sqlite3_last_insert_rowid()]
2484** function is running and thus changes the last insert [rowid],
2485** then the value returned by [sqlite3_last_insert_rowid()] is
2486** unpredictable and might not equal either the old or the new
2487** last insert [rowid].
2488*/
2489SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2490
2491/*
2492** CAPI3REF: Set the Last Insert Rowid value.
2493** METHOD: sqlite3
2494**
2495** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2496** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2497** without inserting a row into the database.
2498*/
2499SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2500
2501/*
2502** CAPI3REF: Count The Number Of Rows Modified
2503** METHOD: sqlite3
2504**
2505** ^These functions return the number of rows modified, inserted or
2506** deleted by the most recently completed INSERT, UPDATE or DELETE
2507** statement on the database connection specified by the only parameter.
2508** The two functions are identical except for the type of the return value
2509** and that if the number of rows modified by the most recent INSERT, UPDATE
2510** or DELETE is greater than the maximum value supported by type "int", then
2511** the return value of sqlite3_changes() is undefined. ^Executing any other
2512** type of SQL statement does not modify the value returned by these functions.
2513**
2514** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2515** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2516** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2517**
2518** Changes to a view that are intercepted by
2519** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2520** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2521** DELETE statement run on a view is always zero. Only changes made to real
2522** tables are counted.
2523**
2524** Things are more complicated if the sqlite3_changes() function is
2525** executed while a trigger program is running. This may happen if the
2526** program uses the [changes() SQL function], or if some other callback
2527** function invokes sqlite3_changes() directly. Essentially:
2528**
2529** <ul>
2530** <li> ^(Before entering a trigger program the value returned by
2531** sqlite3_changes() function is saved. After the trigger program
2532** has finished, the original value is restored.)^
2533**
2534** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2535** statement sets the value returned by sqlite3_changes()
2536** upon completion as normal. Of course, this value will not include
2537** any changes performed by sub-triggers, as the sqlite3_changes()
2538** value will be saved and restored after each sub-trigger has run.)^
2539** </ul>
2540**
2541** ^This means that if the changes() SQL function (or similar) is used
2542** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2543** returns the value as set when the calling statement began executing.
2544** ^If it is used by the second or subsequent such statement within a trigger
2545** program, the value returned reflects the number of rows modified by the
2546** previous INSERT, UPDATE or DELETE statement within the same trigger.
2547**
2548** If a separate thread makes changes on the same database connection
2549** while [sqlite3_changes()] is running then the value returned
2550** is unpredictable and not meaningful.
2551**
2552** See also:
2553** <ul>
2554** <li> the [sqlite3_total_changes()] interface
2555** <li> the [count_changes pragma]
2556** <li> the [changes() SQL function]
2557** <li> the [data_version pragma]
2558** </ul>
2559*/
2560SQLITE_API int sqlite3_changes(sqlite3*);
2561SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2562
2563/*
2564** CAPI3REF: Total Number Of Rows Modified
2565** METHOD: sqlite3
2566**
2567** ^These functions return the total number of rows inserted, modified or
2568** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2569** since the database connection was opened, including those executed as
2570** part of trigger programs. The two functions are identical except for the
2571** type of the return value and that if the number of rows modified by the
2572** connection exceeds the maximum value supported by type "int", then
2573** the return value of sqlite3_total_changes() is undefined. ^Executing
2574** any other type of SQL statement does not affect the value returned by
2575** sqlite3_total_changes().
2576**
2577** ^Changes made as part of [foreign key actions] are included in the
2578** count, but those made as part of REPLACE constraint resolution are
2579** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2580** are not counted.
2581**
2582** The [sqlite3_total_changes(D)] interface only reports the number
2583** of rows that changed due to SQL statement run against database
2584** connection D. Any changes by other database connections are ignored.
2585** To detect changes against a database file from other database
2586** connections use the [PRAGMA data_version] command or the
2587** [SQLITE_FCNTL_DATA_VERSION] [file control].
2588**
2589** If a separate thread makes changes on the same database connection
2590** while [sqlite3_total_changes()] is running then the value
2591** returned is unpredictable and not meaningful.
2592**
2593** See also:
2594** <ul>
2595** <li> the [sqlite3_changes()] interface
2596** <li> the [count_changes pragma]
2597** <li> the [changes() SQL function]
2598** <li> the [data_version pragma]
2599** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2600** </ul>
2601*/
2602SQLITE_API int sqlite3_total_changes(sqlite3*);
2603SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2604
2605/*
2606** CAPI3REF: Interrupt A Long-Running Query
2607** METHOD: sqlite3
2608**
2609** ^This function causes any pending database operation to abort and
2610** return at its earliest opportunity. This routine is typically
2611** called in response to a user action such as pressing "Cancel"
2612** or Ctrl-C where the user wants a long query operation to halt
2613** immediately.
2614**
2615** ^It is safe to call this routine from a thread different from the
2616** thread that is currently running the database operation. But it
2617** is not safe to call this routine with a [database connection] that
2618** is closed or might close before sqlite3_interrupt() returns.
2619**
2620** ^If an SQL operation is very nearly finished at the time when
2621** sqlite3_interrupt() is called, then it might not have an opportunity
2622** to be interrupted and might continue to completion.
2623**
2624** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2625** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2626** that is inside an explicit transaction, then the entire transaction
2627** will be rolled back automatically.
2628**
2629** ^The sqlite3_interrupt(D) call is in effect until all currently running
2630** SQL statements on [database connection] D complete. ^Any new SQL statements
2631** that are started after the sqlite3_interrupt() call and before the
2632** running statement count reaches zero are interrupted as if they had been
2633** running prior to the sqlite3_interrupt() call. ^New SQL statements
2634** that are started after the running statement count reaches zero are
2635** not effected by the sqlite3_interrupt().
2636** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2637** SQL statements is a no-op and has no effect on SQL statements
2638** that are started after the sqlite3_interrupt() call returns.
2639*/
2640SQLITE_API void sqlite3_interrupt(sqlite3*);
2641
2642/*
2643** CAPI3REF: Determine If An SQL Statement Is Complete
2644**
2645** These routines are useful during command-line input to determine if the
2646** currently entered text seems to form a complete SQL statement or
2647** if additional input is needed before sending the text into
2648** SQLite for parsing. ^These routines return 1 if the input string
2649** appears to be a complete SQL statement. ^A statement is judged to be
2650** complete if it ends with a semicolon token and is not a prefix of a
2651** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2652** string literals or quoted identifier names or comments are not
2653** independent tokens (they are part of the token in which they are
2654** embedded) and thus do not count as a statement terminator. ^Whitespace
2655** and comments that follow the final semicolon are ignored.
2656**
2657** ^These routines return 0 if the statement is incomplete. ^If a
2658** memory allocation fails, then SQLITE_NOMEM is returned.
2659**
2660** ^These routines do not parse the SQL statements thus
2661** will not detect syntactically incorrect SQL.
2662**
2663** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2664** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2665** automatically by sqlite3_complete16(). If that initialization fails,
2666** then the return value from sqlite3_complete16() will be non-zero
2667** regardless of whether or not the input SQL is complete.)^
2668**
2669** The input to [sqlite3_complete()] must be a zero-terminated
2670** UTF-8 string.
2671**
2672** The input to [sqlite3_complete16()] must be a zero-terminated
2673** UTF-16 string in native byte order.
2674*/
2675SQLITE_API int sqlite3_complete(const char *sql);
2676SQLITE_API int sqlite3_complete16(const void *sql);
2677
2678/*
2679** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2680** KEYWORDS: {busy-handler callback} {busy handler}
2681** METHOD: sqlite3
2682**
2683** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2684** that might be invoked with argument P whenever
2685** an attempt is made to access a database table associated with
2686** [database connection] D when another thread
2687** or process has the table locked.
2688** The sqlite3_busy_handler() interface is used to implement
2689** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2690**
2691** ^If the busy callback is NULL, then [SQLITE_BUSY]
2692** is returned immediately upon encountering the lock. ^If the busy callback
2693** is not NULL, then the callback might be invoked with two arguments.
2694**
2695** ^The first argument to the busy handler is a copy of the void* pointer which
2696** is the third argument to sqlite3_busy_handler(). ^The second argument to
2697** the busy handler callback is the number of times that the busy handler has
2698** been invoked previously for the same locking event. ^If the
2699** busy callback returns 0, then no additional attempts are made to
2700** access the database and [SQLITE_BUSY] is returned
2701** to the application.
2702** ^If the callback returns non-zero, then another attempt
2703** is made to access the database and the cycle repeats.
2704**
2705** The presence of a busy handler does not guarantee that it will be invoked
2706** when there is lock contention. ^If SQLite determines that invoking the busy
2707** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2708** to the application instead of invoking the
2709** busy handler.
2710** Consider a scenario where one process is holding a read lock that
2711** it is trying to promote to a reserved lock and
2712** a second process is holding a reserved lock that it is trying
2713** to promote to an exclusive lock. The first process cannot proceed
2714** because it is blocked by the second and the second process cannot
2715** proceed because it is blocked by the first. If both processes
2716** invoke the busy handlers, neither will make any progress. Therefore,
2717** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2718** will induce the first process to release its read lock and allow
2719** the second process to proceed.
2720**
2721** ^The default busy callback is NULL.
2722**
2723** ^(There can only be a single busy handler defined for each
2724** [database connection]. Setting a new busy handler clears any
2725** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2726** or evaluating [PRAGMA busy_timeout=N] will change the
2727** busy handler and thus clear any previously set busy handler.
2728**
2729** The busy callback should not take any actions which modify the
2730** database connection that invoked the busy handler. In other words,
2731** the busy handler is not reentrant. Any such actions
2732** result in undefined behavior.
2733**
2734** A busy handler must not close the database connection
2735** or [prepared statement] that invoked the busy handler.
2736*/
2737SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2738
2739/*
2740** CAPI3REF: Set A Busy Timeout
2741** METHOD: sqlite3
2742**
2743** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2744** for a specified amount of time when a table is locked. ^The handler
2745** will sleep multiple times until at least "ms" milliseconds of sleeping
2746** have accumulated. ^After at least "ms" milliseconds of sleeping,
2747** the handler returns 0 which causes [sqlite3_step()] to return
2748** [SQLITE_BUSY].
2749**
2750** ^Calling this routine with an argument less than or equal to zero
2751** turns off all busy handlers.
2752**
2753** ^(There can only be a single busy handler for a particular
2754** [database connection] at any given moment. If another busy handler
2755** was defined (using [sqlite3_busy_handler()]) prior to calling
2756** this routine, that other busy handler is cleared.)^
2757**
2758** See also: [PRAGMA busy_timeout]
2759*/
2760SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2761
2762/*
2763** CAPI3REF: Convenience Routines For Running Queries
2764** METHOD: sqlite3
2765**
2766** This is a legacy interface that is preserved for backwards compatibility.
2767** Use of this interface is not recommended.
2768**
2769** Definition: A <b>result table</b> is memory data structure created by the
2770** [sqlite3_get_table()] interface. A result table records the
2771** complete query results from one or more queries.
2772**
2773** The table conceptually has a number of rows and columns. But
2774** these numbers are not part of the result table itself. These
2775** numbers are obtained separately. Let N be the number of rows
2776** and M be the number of columns.
2777**
2778** A result table is an array of pointers to zero-terminated UTF-8 strings.
2779** There are (N+1)*M elements in the array. The first M pointers point
2780** to zero-terminated strings that contain the names of the columns.
2781** The remaining entries all point to query results. NULL values result
2782** in NULL pointers. All other values are in their UTF-8 zero-terminated
2783** string representation as returned by [sqlite3_column_text()].
2784**
2785** A result table might consist of one or more memory allocations.
2786** It is not safe to pass a result table directly to [sqlite3_free()].
2787** A result table should be deallocated using [sqlite3_free_table()].
2788**
2789** ^(As an example of the result table format, suppose a query result
2790** is as follows:
2791**
2792** <blockquote><pre>
2793** Name | Age
2794** -----------------------
2795** Alice | 43
2796** Bob | 28
2797** Cindy | 21
2798** </pre></blockquote>
2799**
2800** There are two columns (M==2) and three rows (N==3). Thus the
2801** result table has 8 entries. Suppose the result table is stored
2802** in an array named azResult. Then azResult holds this content:
2803**
2804** <blockquote><pre>
2805** azResult&#91;0] = "Name";
2806** azResult&#91;1] = "Age";
2807** azResult&#91;2] = "Alice";
2808** azResult&#91;3] = "43";
2809** azResult&#91;4] = "Bob";
2810** azResult&#91;5] = "28";
2811** azResult&#91;6] = "Cindy";
2812** azResult&#91;7] = "21";
2813** </pre></blockquote>)^
2814**
2815** ^The sqlite3_get_table() function evaluates one or more
2816** semicolon-separated SQL statements in the zero-terminated UTF-8
2817** string of its 2nd parameter and returns a result table to the
2818** pointer given in its 3rd parameter.
2819**
2820** After the application has finished with the result from sqlite3_get_table(),
2821** it must pass the result table pointer to sqlite3_free_table() in order to
2822** release the memory that was malloced. Because of the way the
2823** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2824** function must not try to call [sqlite3_free()] directly. Only
2825** [sqlite3_free_table()] is able to release the memory properly and safely.
2826**
2827** The sqlite3_get_table() interface is implemented as a wrapper around
2828** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2829** to any internal data structures of SQLite. It uses only the public
2830** interface defined here. As a consequence, errors that occur in the
2831** wrapper layer outside of the internal [sqlite3_exec()] call are not
2832** reflected in subsequent calls to [sqlite3_errcode()] or
2833** [sqlite3_errmsg()].
2834*/
2835SQLITE_API int sqlite3_get_table(
2836 sqlite3 *db, /* An open database */
2837 const char *zSql, /* SQL to be evaluated */
2838 char ***pazResult, /* Results of the query */
2839 int *pnRow, /* Number of result rows written here */
2840 int *pnColumn, /* Number of result columns written here */
2841 char **pzErrmsg /* Error msg written here */
2842);
2843SQLITE_API void sqlite3_free_table(char **result);
2844
2845/*
2846** CAPI3REF: Formatted String Printing Functions
2847**
2848** These routines are work-alikes of the "printf()" family of functions
2849** from the standard C library.
2850** These routines understand most of the common formatting options from
2851** the standard library printf()
2852** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2853** See the [built-in printf()] documentation for details.
2854**
2855** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2856** results into memory obtained from [sqlite3_malloc64()].
2857** The strings returned by these two routines should be
2858** released by [sqlite3_free()]. ^Both routines return a
2859** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2860** memory to hold the resulting string.
2861**
2862** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2863** the standard C library. The result is written into the
2864** buffer supplied as the second parameter whose size is given by
2865** the first parameter. Note that the order of the
2866** first two parameters is reversed from snprintf().)^ This is an
2867** historical accident that cannot be fixed without breaking
2868** backwards compatibility. ^(Note also that sqlite3_snprintf()
2869** returns a pointer to its buffer instead of the number of
2870** characters actually written into the buffer.)^ We admit that
2871** the number of characters written would be a more useful return
2872** value but we cannot change the implementation of sqlite3_snprintf()
2873** now without breaking compatibility.
2874**
2875** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2876** guarantees that the buffer is always zero-terminated. ^The first
2877** parameter "n" is the total size of the buffer, including space for
2878** the zero terminator. So the longest string that can be completely
2879** written will be n-1 characters.
2880**
2881** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2882**
2883** See also: [built-in printf()], [printf() SQL function]
2884*/
2885SQLITE_API char *sqlite3_mprintf(const char*,...);
2886SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2887SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2888SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2889
2890/*
2891** CAPI3REF: Memory Allocation Subsystem
2892**
2893** The SQLite core uses these three routines for all of its own
2894** internal memory allocation needs. "Core" in the previous sentence
2895** does not include operating-system specific [VFS] implementation. The
2896** Windows VFS uses native malloc() and free() for some operations.
2897**
2898** ^The sqlite3_malloc() routine returns a pointer to a block
2899** of memory at least N bytes in length, where N is the parameter.
2900** ^If sqlite3_malloc() is unable to obtain sufficient free
2901** memory, it returns a NULL pointer. ^If the parameter N to
2902** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2903** a NULL pointer.
2904**
2905** ^The sqlite3_malloc64(N) routine works just like
2906** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2907** of a signed 32-bit integer.
2908**
2909** ^Calling sqlite3_free() with a pointer previously returned
2910** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2911** that it might be reused. ^The sqlite3_free() routine is
2912** a no-op if is called with a NULL pointer. Passing a NULL pointer
2913** to sqlite3_free() is harmless. After being freed, memory
2914** should neither be read nor written. Even reading previously freed
2915** memory might result in a segmentation fault or other severe error.
2916** Memory corruption, a segmentation fault, or other severe error
2917** might result if sqlite3_free() is called with a non-NULL pointer that
2918** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2919**
2920** ^The sqlite3_realloc(X,N) interface attempts to resize a
2921** prior memory allocation X to be at least N bytes.
2922** ^If the X parameter to sqlite3_realloc(X,N)
2923** is a NULL pointer then its behavior is identical to calling
2924** sqlite3_malloc(N).
2925** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2926** negative then the behavior is exactly the same as calling
2927** sqlite3_free(X).
2928** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2929** of at least N bytes in size or NULL if insufficient memory is available.
2930** ^If M is the size of the prior allocation, then min(N,M) bytes
2931** of the prior allocation are copied into the beginning of buffer returned
2932** by sqlite3_realloc(X,N) and the prior allocation is freed.
2933** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2934** prior allocation is not freed.
2935**
2936** ^The sqlite3_realloc64(X,N) interfaces works the same as
2937** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2938** of a 32-bit signed integer.
2939**
2940** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2941** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2942** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2943** ^The value returned by sqlite3_msize(X) might be larger than the number
2944** of bytes requested when X was allocated. ^If X is a NULL pointer then
2945** sqlite3_msize(X) returns zero. If X points to something that is not
2946** the beginning of memory allocation, or if it points to a formerly
2947** valid memory allocation that has now been freed, then the behavior
2948** of sqlite3_msize(X) is undefined and possibly harmful.
2949**
2950** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2951** sqlite3_malloc64(), and sqlite3_realloc64()
2952** is always aligned to at least an 8 byte boundary, or to a
2953** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2954** option is used.
2955**
2956** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2957** must be either NULL or else pointers obtained from a prior
2958** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2959** not yet been released.
2960**
2961** The application must not read or write any part of
2962** a block of memory after it has been released using
2963** [sqlite3_free()] or [sqlite3_realloc()].
2964*/
2965SQLITE_API void *sqlite3_malloc(int);
2966SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2967SQLITE_API void *sqlite3_realloc(void*, int);
2968SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2969SQLITE_API void sqlite3_free(void*);
2970SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2971
2972/*
2973** CAPI3REF: Memory Allocator Statistics
2974**
2975** SQLite provides these two interfaces for reporting on the status
2976** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2977** routines, which form the built-in memory allocation subsystem.
2978**
2979** ^The [sqlite3_memory_used()] routine returns the number of bytes
2980** of memory currently outstanding (malloced but not freed).
2981** ^The [sqlite3_memory_highwater()] routine returns the maximum
2982** value of [sqlite3_memory_used()] since the high-water mark
2983** was last reset. ^The values returned by [sqlite3_memory_used()] and
2984** [sqlite3_memory_highwater()] include any overhead
2985** added by SQLite in its implementation of [sqlite3_malloc()],
2986** but not overhead added by the any underlying system library
2987** routines that [sqlite3_malloc()] may call.
2988**
2989** ^The memory high-water mark is reset to the current value of
2990** [sqlite3_memory_used()] if and only if the parameter to
2991** [sqlite3_memory_highwater()] is true. ^The value returned
2992** by [sqlite3_memory_highwater(1)] is the high-water mark
2993** prior to the reset.
2994*/
2995SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2996SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2997
2998/*
2999** CAPI3REF: Pseudo-Random Number Generator
3000**
3001** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3002** select random [ROWID | ROWIDs] when inserting new records into a table that
3003** already uses the largest possible [ROWID]. The PRNG is also used for
3004** the built-in random() and randomblob() SQL functions. This interface allows
3005** applications to access the same PRNG for other purposes.
3006**
3007** ^A call to this routine stores N bytes of randomness into buffer P.
3008** ^The P parameter can be a NULL pointer.
3009**
3010** ^If this routine has not been previously called or if the previous
3011** call had N less than one or a NULL pointer for P, then the PRNG is
3012** seeded using randomness obtained from the xRandomness method of
3013** the default [sqlite3_vfs] object.
3014** ^If the previous call to this routine had an N of 1 or more and a
3015** non-NULL P then the pseudo-randomness is generated
3016** internally and without recourse to the [sqlite3_vfs] xRandomness
3017** method.
3018*/
3019SQLITE_API void sqlite3_randomness(int N, void *P);
3020
3021/*
3022** CAPI3REF: Compile-Time Authorization Callbacks
3023** METHOD: sqlite3
3024** KEYWORDS: {authorizer callback}
3025**
3026** ^This routine registers an authorizer callback with a particular
3027** [database connection], supplied in the first argument.
3028** ^The authorizer callback is invoked as SQL statements are being compiled
3029** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3030** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3031** and [sqlite3_prepare16_v3()]. ^At various
3032** points during the compilation process, as logic is being created
3033** to perform various actions, the authorizer callback is invoked to
3034** see if those actions are allowed. ^The authorizer callback should
3035** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3036** specific action but allow the SQL statement to continue to be
3037** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3038** rejected with an error. ^If the authorizer callback returns
3039** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3040** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3041** the authorizer will fail with an error message.
3042**
3043** When the callback returns [SQLITE_OK], that means the operation
3044** requested is ok. ^When the callback returns [SQLITE_DENY], the
3045** [sqlite3_prepare_v2()] or equivalent call that triggered the
3046** authorizer will fail with an error message explaining that
3047** access is denied.
3048**
3049** ^The first parameter to the authorizer callback is a copy of the third
3050** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3051** to the callback is an integer [SQLITE_COPY | action code] that specifies
3052** the particular action to be authorized. ^The third through sixth parameters
3053** to the callback are either NULL pointers or zero-terminated strings
3054** that contain additional details about the action to be authorized.
3055** Applications must always be prepared to encounter a NULL pointer in any
3056** of the third through the sixth parameters of the authorization callback.
3057**
3058** ^If the action code is [SQLITE_READ]
3059** and the callback returns [SQLITE_IGNORE] then the
3060** [prepared statement] statement is constructed to substitute
3061** a NULL value in place of the table column that would have
3062** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3063** return can be used to deny an untrusted user access to individual
3064** columns of a table.
3065** ^When a table is referenced by a [SELECT] but no column values are
3066** extracted from that table (for example in a query like
3067** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3068** is invoked once for that table with a column name that is an empty string.
3069** ^If the action code is [SQLITE_DELETE] and the callback returns
3070** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3071** [truncate optimization] is disabled and all rows are deleted individually.
3072**
3073** An authorizer is used when [sqlite3_prepare | preparing]
3074** SQL statements from an untrusted source, to ensure that the SQL statements
3075** do not try to access data they are not allowed to see, or that they do not
3076** try to execute malicious statements that damage the database. For
3077** example, an application may allow a user to enter arbitrary
3078** SQL queries for evaluation by a database. But the application does
3079** not want the user to be able to make arbitrary changes to the
3080** database. An authorizer could then be put in place while the
3081** user-entered SQL is being [sqlite3_prepare | prepared] that
3082** disallows everything except [SELECT] statements.
3083**
3084** Applications that need to process SQL from untrusted sources
3085** might also consider lowering resource limits using [sqlite3_limit()]
3086** and limiting database size using the [max_page_count] [PRAGMA]
3087** in addition to using an authorizer.
3088**
3089** ^(Only a single authorizer can be in place on a database connection
3090** at a time. Each call to sqlite3_set_authorizer overrides the
3091** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3092** The authorizer is disabled by default.
3093**
3094** The authorizer callback must not do anything that will modify
3095** the database connection that invoked the authorizer callback.
3096** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3097** database connections for the meaning of "modify" in this paragraph.
3098**
3099** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3100** statement might be re-prepared during [sqlite3_step()] due to a
3101** schema change. Hence, the application should ensure that the
3102** correct authorizer callback remains in place during the [sqlite3_step()].
3103**
3104** ^Note that the authorizer callback is invoked only during
3105** [sqlite3_prepare()] or its variants. Authorization is not
3106** performed during statement evaluation in [sqlite3_step()], unless
3107** as stated in the previous paragraph, sqlite3_step() invokes
3108** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3109*/
3110SQLITE_API int sqlite3_set_authorizer(
3111 sqlite3*,
3112 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3113 void *pUserData
3114);
3115
3116/*
3117** CAPI3REF: Authorizer Return Codes
3118**
3119** The [sqlite3_set_authorizer | authorizer callback function] must
3120** return either [SQLITE_OK] or one of these two constants in order
3121** to signal SQLite whether or not the action is permitted. See the
3122** [sqlite3_set_authorizer | authorizer documentation] for additional
3123** information.
3124**
3125** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3126** returned from the [sqlite3_vtab_on_conflict()] interface.
3127*/
3128#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3129#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3130
3131/*
3132** CAPI3REF: Authorizer Action Codes
3133**
3134** The [sqlite3_set_authorizer()] interface registers a callback function
3135** that is invoked to authorize certain SQL statement actions. The
3136** second parameter to the callback is an integer code that specifies
3137** what action is being authorized. These are the integer action codes that
3138** the authorizer callback may be passed.
3139**
3140** These action code values signify what kind of operation is to be
3141** authorized. The 3rd and 4th parameters to the authorization
3142** callback function will be parameters or NULL depending on which of these
3143** codes is used as the second parameter. ^(The 5th parameter to the
3144** authorizer callback is the name of the database ("main", "temp",
3145** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3146** is the name of the inner-most trigger or view that is responsible for
3147** the access attempt or NULL if this access attempt is directly from
3148** top-level SQL code.
3149*/
3150/******************************************* 3rd ************ 4th ***********/
3151#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3152#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3153#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3154#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3155#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3156#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3157#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3158#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3159#define SQLITE_DELETE 9 /* Table Name NULL */
3160#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3161#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3162#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3163#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3164#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3165#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3166#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3167#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3168#define SQLITE_INSERT 18 /* Table Name NULL */
3169#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3170#define SQLITE_READ 20 /* Table Name Column Name */
3171#define SQLITE_SELECT 21 /* NULL NULL */
3172#define SQLITE_TRANSACTION 22 /* Operation NULL */
3173#define SQLITE_UPDATE 23 /* Table Name Column Name */
3174#define SQLITE_ATTACH 24 /* Filename NULL */
3175#define SQLITE_DETACH 25 /* Database Name NULL */
3176#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3177#define SQLITE_REINDEX 27 /* Index Name NULL */
3178#define SQLITE_ANALYZE 28 /* Table Name NULL */
3179#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3180#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3181#define SQLITE_FUNCTION 31 /* NULL Function Name */
3182#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3183#define SQLITE_COPY 0 /* No longer used */
3184#define SQLITE_RECURSIVE 33 /* NULL NULL */
3185
3186/*
3187** CAPI3REF: Tracing And Profiling Functions
3188** METHOD: sqlite3
3189**
3190** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3191** instead of the routines described here.
3192**
3193** These routines register callback functions that can be used for
3194** tracing and profiling the execution of SQL statements.
3195**
3196** ^The callback function registered by sqlite3_trace() is invoked at
3197** various times when an SQL statement is being run by [sqlite3_step()].
3198** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3199** SQL statement text as the statement first begins executing.
3200** ^(Additional sqlite3_trace() callbacks might occur
3201** as each triggered subprogram is entered. The callbacks for triggers
3202** contain a UTF-8 SQL comment that identifies the trigger.)^
3203**
3204** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3205** the length of [bound parameter] expansion in the output of sqlite3_trace().
3206**
3207** ^The callback function registered by sqlite3_profile() is invoked
3208** as each SQL statement finishes. ^The profile callback contains
3209** the original statement text and an estimate of wall-clock time
3210** of how long that statement took to run. ^The profile callback
3211** time is in units of nanoseconds, however the current implementation
3212** is only capable of millisecond resolution so the six least significant
3213** digits in the time are meaningless. Future versions of SQLite
3214** might provide greater resolution on the profiler callback. Invoking
3215** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3216** profile callback.
3217*/
3218SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3219 void(*xTrace)(void*,const char*), void*);
3220SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3221 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3222
3223/*
3224** CAPI3REF: SQL Trace Event Codes
3225** KEYWORDS: SQLITE_TRACE
3226**
3227** These constants identify classes of events that can be monitored
3228** using the [sqlite3_trace_v2()] tracing logic. The M argument
3229** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3230** the following constants. ^The first argument to the trace callback
3231** is one of the following constants.
3232**
3233** New tracing constants may be added in future releases.
3234**
3235** ^A trace callback has four arguments: xCallback(T,C,P,X).
3236** ^The T argument is one of the integer type codes above.
3237** ^The C argument is a copy of the context pointer passed in as the
3238** fourth argument to [sqlite3_trace_v2()].
3239** The P and X arguments are pointers whose meanings depend on T.
3240**
3241** <dl>
3242** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3243** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3244** first begins running and possibly at other times during the
3245** execution of the prepared statement, such as at the start of each
3246** trigger subprogram. ^The P argument is a pointer to the
3247** [prepared statement]. ^The X argument is a pointer to a string which
3248** is the unexpanded SQL text of the prepared statement or an SQL comment
3249** that indicates the invocation of a trigger. ^The callback can compute
3250** the same text that would have been returned by the legacy [sqlite3_trace()]
3251** interface by using the X argument when X begins with "--" and invoking
3252** [sqlite3_expanded_sql(P)] otherwise.
3253**
3254** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3255** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3256** information as is provided by the [sqlite3_profile()] callback.
3257** ^The P argument is a pointer to the [prepared statement] and the
3258** X argument points to a 64-bit integer which is the estimated of
3259** the number of nanosecond that the prepared statement took to run.
3260** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3261**
3262** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3263** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3264** statement generates a single row of result.
3265** ^The P argument is a pointer to the [prepared statement] and the
3266** X argument is unused.
3267**
3268** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3269** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3270** connection closes.
3271** ^The P argument is a pointer to the [database connection] object
3272** and the X argument is unused.
3273** </dl>
3274*/
3275#define SQLITE_TRACE_STMT 0x01
3276#define SQLITE_TRACE_PROFILE 0x02
3277#define SQLITE_TRACE_ROW 0x04
3278#define SQLITE_TRACE_CLOSE 0x08
3279
3280/*
3281** CAPI3REF: SQL Trace Hook
3282** METHOD: sqlite3
3283**
3284** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3285** function X against [database connection] D, using property mask M
3286** and context pointer P. ^If the X callback is
3287** NULL or if the M mask is zero, then tracing is disabled. The
3288** M argument should be the bitwise OR-ed combination of
3289** zero or more [SQLITE_TRACE] constants.
3290**
3291** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3292** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3293**
3294** ^The X callback is invoked whenever any of the events identified by
3295** mask M occur. ^The integer return value from the callback is currently
3296** ignored, though this may change in future releases. Callback
3297** implementations should return zero to ensure future compatibility.
3298**
3299** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3300** ^The T argument is one of the [SQLITE_TRACE]
3301** constants to indicate why the callback was invoked.
3302** ^The C argument is a copy of the context pointer.
3303** The P and X arguments are pointers whose meanings depend on T.
3304**
3305** The sqlite3_trace_v2() interface is intended to replace the legacy
3306** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3307** are deprecated.
3308*/
3309SQLITE_API int sqlite3_trace_v2(
3310 sqlite3*,
3311 unsigned uMask,
3312 int(*xCallback)(unsigned,void*,void*,void*),
3313 void *pCtx
3314);
3315
3316/*
3317** CAPI3REF: Query Progress Callbacks
3318** METHOD: sqlite3
3319**
3320** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3321** function X to be invoked periodically during long running calls to
3322** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3323** database connection D. An example use for this
3324** interface is to keep a GUI updated during a large query.
3325**
3326** ^The parameter P is passed through as the only parameter to the
3327** callback function X. ^The parameter N is the approximate number of
3328** [virtual machine instructions] that are evaluated between successive
3329** invocations of the callback X. ^If N is less than one then the progress
3330** handler is disabled.
3331**
3332** ^Only a single progress handler may be defined at one time per
3333** [database connection]; setting a new progress handler cancels the
3334** old one. ^Setting parameter X to NULL disables the progress handler.
3335** ^The progress handler is also disabled by setting N to a value less
3336** than 1.
3337**
3338** ^If the progress callback returns non-zero, the operation is
3339** interrupted. This feature can be used to implement a
3340** "Cancel" button on a GUI progress dialog box.
3341**
3342** The progress handler callback must not do anything that will modify
3343** the database connection that invoked the progress handler.
3344** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3345** database connections for the meaning of "modify" in this paragraph.
3346**
3347*/
3348SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3349
3350/*
3351** CAPI3REF: Opening A New Database Connection
3352** CONSTRUCTOR: sqlite3
3353**
3354** ^These routines open an SQLite database file as specified by the
3355** filename argument. ^The filename argument is interpreted as UTF-8 for
3356** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3357** order for sqlite3_open16(). ^(A [database connection] handle is usually
3358** returned in *ppDb, even if an error occurs. The only exception is that
3359** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3360** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3361** object.)^ ^(If the database is opened (and/or created) successfully, then
3362** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3363** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3364** an English language description of the error following a failure of any
3365** of the sqlite3_open() routines.
3366**
3367** ^The default encoding will be UTF-8 for databases created using
3368** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3369** created using sqlite3_open16() will be UTF-16 in the native byte order.
3370**
3371** Whether or not an error occurs when it is opened, resources
3372** associated with the [database connection] handle should be released by
3373** passing it to [sqlite3_close()] when it is no longer required.
3374**
3375** The sqlite3_open_v2() interface works like sqlite3_open()
3376** except that it accepts two additional parameters for additional control
3377** over the new database connection. ^(The flags parameter to
3378** sqlite3_open_v2() must include, at a minimum, one of the following
3379** three flag combinations:)^
3380**
3381** <dl>
3382** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3383** <dd>The database is opened in read-only mode. If the database does not
3384** already exist, an error is returned.</dd>)^
3385**
3386** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3387** <dd>The database is opened for reading and writing if possible, or reading
3388** only if the file is write protected by the operating system. In either
3389** case the database must already exist, otherwise an error is returned.</dd>)^
3390**
3391** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3392** <dd>The database is opened for reading and writing, and is created if
3393** it does not already exist. This is the behavior that is always used for
3394** sqlite3_open() and sqlite3_open16().</dd>)^
3395** </dl>
3396**
3397** In addition to the required flags, the following optional flags are
3398** also supported:
3399**
3400** <dl>
3401** ^(<dt>[SQLITE_OPEN_URI]</dt>
3402** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3403**
3404** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3405** <dd>The database will be opened as an in-memory database. The database
3406** is named by the "filename" argument for the purposes of cache-sharing,
3407** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3408** </dd>)^
3409**
3410** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3411** <dd>The new database connection will use the "multi-thread"
3412** [threading mode].)^ This means that separate threads are allowed
3413** to use SQLite at the same time, as long as each thread is using
3414** a different [database connection].
3415**
3416** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3417** <dd>The new database connection will use the "serialized"
3418** [threading mode].)^ This means the multiple threads can safely
3419** attempt to use the same database connection at the same time.
3420** (Mutexes will block any actual concurrency, but in this mode
3421** there is no harm in trying.)
3422**
3423** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3424** <dd>The database is opened [shared cache] enabled, overriding
3425** the default shared cache setting provided by
3426** [sqlite3_enable_shared_cache()].)^
3427**
3428** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3429** <dd>The database is opened [shared cache] disabled, overriding
3430** the default shared cache setting provided by
3431** [sqlite3_enable_shared_cache()].)^
3432**
3433** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3434** <dd>The database connection comes up in "extended result code mode".
3435** In other words, the database behaves has if
3436** [sqlite3_extended_result_codes(db,1)] where called on the database
3437** connection as soon as the connection is created. In addition to setting
3438** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3439** to return an extended result code.</dd>
3440**
3441** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3442** <dd>The database filename is not allowed to be a symbolic link</dd>
3443** </dl>)^
3444**
3445** If the 3rd parameter to sqlite3_open_v2() is not one of the
3446** required combinations shown above optionally combined with other
3447** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3448** then the behavior is undefined. Historic versions of SQLite
3449** have silently ignored surplus bits in the flags parameter to
3450** sqlite3_open_v2(), however that behavior might not be carried through
3451** into future versions of SQLite and so applications should not rely
3452** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3453** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3454** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3455** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3456** by sqlite3_open_v2().
3457**
3458** ^The fourth parameter to sqlite3_open_v2() is the name of the
3459** [sqlite3_vfs] object that defines the operating system interface that
3460** the new database connection should use. ^If the fourth parameter is
3461** a NULL pointer then the default [sqlite3_vfs] object is used.
3462**
3463** ^If the filename is ":memory:", then a private, temporary in-memory database
3464** is created for the connection. ^This in-memory database will vanish when
3465** the database connection is closed. Future versions of SQLite might
3466** make use of additional special filenames that begin with the ":" character.
3467** It is recommended that when a database filename actually does begin with
3468** a ":" character you should prefix the filename with a pathname such as
3469** "./" to avoid ambiguity.
3470**
3471** ^If the filename is an empty string, then a private, temporary
3472** on-disk database will be created. ^This private database will be
3473** automatically deleted as soon as the database connection is closed.
3474**
3475** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3476**
3477** ^If [URI filename] interpretation is enabled, and the filename argument
3478** begins with "file:", then the filename is interpreted as a URI. ^URI
3479** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3480** set in the third argument to sqlite3_open_v2(), or if it has
3481** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3482** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3483** URI filename interpretation is turned off
3484** by default, but future releases of SQLite might enable URI filename
3485** interpretation by default. See "[URI filenames]" for additional
3486** information.
3487**
3488** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3489** authority, then it must be either an empty string or the string
3490** "localhost". ^If the authority is not an empty string or "localhost", an
3491** error is returned to the caller. ^The fragment component of a URI, if
3492** present, is ignored.
3493**
3494** ^SQLite uses the path component of the URI as the name of the disk file
3495** which contains the database. ^If the path begins with a '/' character,
3496** then it is interpreted as an absolute path. ^If the path does not begin
3497** with a '/' (meaning that the authority section is omitted from the URI)
3498** then the path is interpreted as a relative path.
3499** ^(On windows, the first component of an absolute path
3500** is a drive specification (e.g. "C:").)^
3501**
3502** [[core URI query parameters]]
3503** The query component of a URI may contain parameters that are interpreted
3504** either by SQLite itself, or by a [VFS | custom VFS implementation].
3505** SQLite and its built-in [VFSes] interpret the
3506** following query parameters:
3507**
3508** <ul>
3509** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3510** a VFS object that provides the operating system interface that should
3511** be used to access the database file on disk. ^If this option is set to
3512** an empty string the default VFS object is used. ^Specifying an unknown
3513** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3514** present, then the VFS specified by the option takes precedence over
3515** the value passed as the fourth parameter to sqlite3_open_v2().
3516**
3517** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3518** "rwc", or "memory". Attempting to set it to any other value is
3519** an error)^.
3520** ^If "ro" is specified, then the database is opened for read-only
3521** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3522** third argument to sqlite3_open_v2(). ^If the mode option is set to
3523** "rw", then the database is opened for read-write (but not create)
3524** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3525** been set. ^Value "rwc" is equivalent to setting both
3526** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3527** set to "memory" then a pure [in-memory database] that never reads
3528** or writes from disk is used. ^It is an error to specify a value for
3529** the mode parameter that is less restrictive than that specified by
3530** the flags passed in the third parameter to sqlite3_open_v2().
3531**
3532** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3533** "private". ^Setting it to "shared" is equivalent to setting the
3534** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3535** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3536** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3537** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3538** a URI filename, its value overrides any behavior requested by setting
3539** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3540**
3541** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3542** [powersafe overwrite] property does or does not apply to the
3543** storage media on which the database file resides.
3544**
3545** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3546** which if set disables file locking in rollback journal modes. This
3547** is useful for accessing a database on a filesystem that does not
3548** support locking. Caution: Database corruption might result if two
3549** or more processes write to the same database and any one of those
3550** processes uses nolock=1.
3551**
3552** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3553** parameter that indicates that the database file is stored on
3554** read-only media. ^When immutable is set, SQLite assumes that the
3555** database file cannot be changed, even by a process with higher
3556** privilege, and so the database is opened read-only and all locking
3557** and change detection is disabled. Caution: Setting the immutable
3558** property on a database file that does in fact change can result
3559** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3560** See also: [SQLITE_IOCAP_IMMUTABLE].
3561**
3562** </ul>
3563**
3564** ^Specifying an unknown parameter in the query component of a URI is not an
3565** error. Future versions of SQLite might understand additional query
3566** parameters. See "[query parameters with special meaning to SQLite]" for
3567** additional information.
3568**
3569** [[URI filename examples]] <h3>URI filename examples</h3>
3570**
3571** <table border="1" align=center cellpadding=5>
3572** <tr><th> URI filenames <th> Results
3573** <tr><td> file:data.db <td>
3574** Open the file "data.db" in the current directory.
3575** <tr><td> file:/home/fred/data.db<br>
3576** file:///home/fred/data.db <br>
3577** file://localhost/home/fred/data.db <br> <td>
3578** Open the database file "/home/fred/data.db".
3579** <tr><td> file://darkstar/home/fred/data.db <td>
3580** An error. "darkstar" is not a recognized authority.
3581** <tr><td style="white-space:nowrap">
3582** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3583** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3584** C:. Note that the %20 escaping in this example is not strictly
3585** necessary - space characters can be used literally
3586** in URI filenames.
3587** <tr><td> file:data.db?mode=ro&cache=private <td>
3588** Open file "data.db" in the current directory for read-only access.
3589** Regardless of whether or not shared-cache mode is enabled by
3590** default, use a private cache.
3591** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3592** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3593** that uses dot-files in place of posix advisory locking.
3594** <tr><td> file:data.db?mode=readonly <td>
3595** An error. "readonly" is not a valid option for the "mode" parameter.
3596** Use "ro" instead: "file:data.db?mode=ro".
3597** </table>
3598**
3599** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3600** query components of a URI. A hexadecimal escape sequence consists of a
3601** percent sign - "%" - followed by exactly two hexadecimal digits
3602** specifying an octet value. ^Before the path or query components of a
3603** URI filename are interpreted, they are encoded using UTF-8 and all
3604** hexadecimal escape sequences replaced by a single byte containing the
3605** corresponding octet. If this process generates an invalid UTF-8 encoding,
3606** the results are undefined.
3607**
3608** <b>Note to Windows users:</b> The encoding used for the filename argument
3609** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3610** codepage is currently defined. Filenames containing international
3611** characters must be converted to UTF-8 prior to passing them into
3612** sqlite3_open() or sqlite3_open_v2().
3613**
3614** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3615** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3616** features that require the use of temporary files may fail.
3617**
3618** See also: [sqlite3_temp_directory]
3619*/
3620SQLITE_API int sqlite3_open(
3621 const char *filename, /* Database filename (UTF-8) */
3622 sqlite3 **ppDb /* OUT: SQLite db handle */
3623);
3624SQLITE_API int sqlite3_open16(
3625 const void *filename, /* Database filename (UTF-16) */
3626 sqlite3 **ppDb /* OUT: SQLite db handle */
3627);
3628SQLITE_API int sqlite3_open_v2(
3629 const char *filename, /* Database filename (UTF-8) */
3630 sqlite3 **ppDb, /* OUT: SQLite db handle */
3631 int flags, /* Flags */
3632 const char *zVfs /* Name of VFS module to use */
3633);
3634
3635/*
3636** CAPI3REF: Obtain Values For URI Parameters
3637**
3638** These are utility routines, useful to [VFS|custom VFS implementations],
3639** that check if a database file was a URI that contained a specific query
3640** parameter, and if so obtains the value of that query parameter.
3641**
3642** The first parameter to these interfaces (hereafter referred to
3643** as F) must be one of:
3644** <ul>
3645** <li> A database filename pointer created by the SQLite core and
3646** passed into the xOpen() method of a VFS implemention, or
3647** <li> A filename obtained from [sqlite3_db_filename()], or
3648** <li> A new filename constructed using [sqlite3_create_filename()].
3649** </ul>
3650** If the F parameter is not one of the above, then the behavior is
3651** undefined and probably undesirable. Older versions of SQLite were
3652** more tolerant of invalid F parameters than newer versions.
3653**
3654** If F is a suitable filename (as described in the previous paragraph)
3655** and if P is the name of the query parameter, then
3656** sqlite3_uri_parameter(F,P) returns the value of the P
3657** parameter if it exists or a NULL pointer if P does not appear as a
3658** query parameter on F. If P is a query parameter of F and it
3659** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3660** a pointer to an empty string.
3661**
3662** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3663** parameter and returns true (1) or false (0) according to the value
3664** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3665** value of query parameter P is one of "yes", "true", or "on" in any
3666** case or if the value begins with a non-zero number. The
3667** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3668** query parameter P is one of "no", "false", or "off" in any case or
3669** if the value begins with a numeric zero. If P is not a query
3670** parameter on F or if the value of P does not match any of the
3671** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3672**
3673** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3674** 64-bit signed integer and returns that integer, or D if P does not
3675** exist. If the value of P is something other than an integer, then
3676** zero is returned.
3677**
3678** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3679** the value) of the N-th query parameter for filename F, or a NULL
3680** pointer if N is less than zero or greater than the number of query
3681** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3682** the name of the first query parameter, 1 for the second parameter, and
3683** so forth.
3684**
3685** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3686** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3687** is not a database file pathname pointer that the SQLite core passed
3688** into the xOpen VFS method, then the behavior of this routine is undefined
3689** and probably undesirable.
3690**
3691** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3692** parameter can also be the name of a rollback journal file or WAL file
3693** in addition to the main database file. Prior to version 3.31.0, these
3694** routines would only work if F was the name of the main database file.
3695** When the F parameter is the name of the rollback journal or WAL file,
3696** it has access to all the same query parameters as were found on the
3697** main database file.
3698**
3699** See the [URI filename] documentation for additional information.
3700*/
3701SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3702SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3703SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3704SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N);
3705
3706/*
3707** CAPI3REF: Translate filenames
3708**
3709** These routines are available to [VFS|custom VFS implementations] for
3710** translating filenames between the main database file, the journal file,
3711** and the WAL file.
3712**
3713** If F is the name of an sqlite database file, journal file, or WAL file
3714** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3715** returns the name of the corresponding database file.
3716**
3717** If F is the name of an sqlite database file, journal file, or WAL file
3718** passed by the SQLite core into the VFS, or if F is a database filename
3719** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3720** returns the name of the corresponding rollback journal file.
3721**
3722** If F is the name of an sqlite database file, journal file, or WAL file
3723** that was passed by the SQLite core into the VFS, or if F is a database
3724** filename obtained from [sqlite3_db_filename()], then
3725** sqlite3_filename_wal(F) returns the name of the corresponding
3726** WAL file.
3727**
3728** In all of the above, if F is not the name of a database, journal or WAL
3729** filename passed into the VFS from the SQLite core and F is not the
3730** return value from [sqlite3_db_filename()], then the result is
3731** undefined and is likely a memory access violation.
3732*/
3733SQLITE_API const char *sqlite3_filename_database(const char*);
3734SQLITE_API const char *sqlite3_filename_journal(const char*);
3735SQLITE_API const char *sqlite3_filename_wal(const char*);
3736
3737/*
3738** CAPI3REF: Database File Corresponding To A Journal
3739**
3740** ^If X is the name of a rollback or WAL-mode journal file that is
3741** passed into the xOpen method of [sqlite3_vfs], then
3742** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3743** object that represents the main database file.
3744**
3745** This routine is intended for use in custom [VFS] implementations
3746** only. It is not a general-purpose interface.
3747** The argument sqlite3_file_object(X) must be a filename pointer that
3748** has been passed into [sqlite3_vfs].xOpen method where the
3749** flags parameter to xOpen contains one of the bits
3750** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3751** of this routine results in undefined and probably undesirable
3752** behavior.
3753*/
3754SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3755
3756/*
3757** CAPI3REF: Create and Destroy VFS Filenames
3758**
3759** These interfces are provided for use by [VFS shim] implementations and
3760** are not useful outside of that context.
3761**
3762** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3763** database filename D with corresponding journal file J and WAL file W and
3764** with N URI parameters key/values pairs in the array P. The result from
3765** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3766** is safe to pass to routines like:
3767** <ul>
3768** <li> [sqlite3_uri_parameter()],
3769** <li> [sqlite3_uri_boolean()],
3770** <li> [sqlite3_uri_int64()],
3771** <li> [sqlite3_uri_key()],
3772** <li> [sqlite3_filename_database()],
3773** <li> [sqlite3_filename_journal()], or
3774** <li> [sqlite3_filename_wal()].
3775** </ul>
3776** If a memory allocation error occurs, sqlite3_create_filename() might
3777** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3778** must be released by a corresponding call to sqlite3_free_filename(Y).
3779**
3780** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3781** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3782** to a key and value for a query parameter. The P parameter may be a NULL
3783** pointer if N is zero. None of the 2*N pointers in the P array may be
3784** NULL pointers and key pointers should not be empty strings.
3785** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3786** be NULL pointers, though they can be empty strings.
3787**
3788** The sqlite3_free_filename(Y) routine releases a memory allocation
3789** previously obtained from sqlite3_create_filename(). Invoking
3790** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3791**
3792** If the Y parameter to sqlite3_free_filename(Y) is anything other
3793** than a NULL pointer or a pointer previously acquired from
3794** sqlite3_create_filename(), then bad things such as heap
3795** corruption or segfaults may occur. The value Y should not be
3796** used again after sqlite3_free_filename(Y) has been called. This means
3797** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3798** then the corresponding [sqlite3_module.xClose() method should also be
3799** invoked prior to calling sqlite3_free_filename(Y).
3800*/
3801SQLITE_API char *sqlite3_create_filename(
3802 const char *zDatabase,
3803 const char *zJournal,
3804 const char *zWal,
3805 int nParam,
3806 const char **azParam
3807);
3808SQLITE_API void sqlite3_free_filename(char*);
3809
3810/*
3811** CAPI3REF: Error Codes And Messages
3812** METHOD: sqlite3
3813**
3814** ^If the most recent sqlite3_* API call associated with
3815** [database connection] D failed, then the sqlite3_errcode(D) interface
3816** returns the numeric [result code] or [extended result code] for that
3817** API call.
3818** ^The sqlite3_extended_errcode()
3819** interface is the same except that it always returns the
3820** [extended result code] even when extended result codes are
3821** disabled.
3822**
3823** The values returned by sqlite3_errcode() and/or
3824** sqlite3_extended_errcode() might change with each API call.
3825** Except, there are some interfaces that are guaranteed to never
3826** change the value of the error code. The error-code preserving
3827** interfaces are:
3828**
3829** <ul>
3830** <li> sqlite3_errcode()
3831** <li> sqlite3_extended_errcode()
3832** <li> sqlite3_errmsg()
3833** <li> sqlite3_errmsg16()
3834** </ul>
3835**
3836** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3837** text that describes the error, as either UTF-8 or UTF-16 respectively.
3838** ^(Memory to hold the error message string is managed internally.
3839** The application does not need to worry about freeing the result.
3840** However, the error string might be overwritten or deallocated by
3841** subsequent calls to other SQLite interface functions.)^
3842**
3843** ^The sqlite3_errstr() interface returns the English-language text
3844** that describes the [result code], as UTF-8.
3845** ^(Memory to hold the error message string is managed internally
3846** and must not be freed by the application)^.
3847**
3848** When the serialized [threading mode] is in use, it might be the
3849** case that a second error occurs on a separate thread in between
3850** the time of the first error and the call to these interfaces.
3851** When that happens, the second error will be reported since these
3852** interfaces always report the most recent result. To avoid
3853** this, each thread can obtain exclusive use of the [database connection] D
3854** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3855** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3856** all calls to the interfaces listed here are completed.
3857**
3858** If an interface fails with SQLITE_MISUSE, that means the interface
3859** was invoked incorrectly by the application. In that case, the
3860** error code and message may or may not be set.
3861*/
3862SQLITE_API int sqlite3_errcode(sqlite3 *db);
3863SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3864SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3865SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3866SQLITE_API const char *sqlite3_errstr(int);
3867
3868/*
3869** CAPI3REF: Prepared Statement Object
3870** KEYWORDS: {prepared statement} {prepared statements}
3871**
3872** An instance of this object represents a single SQL statement that
3873** has been compiled into binary form and is ready to be evaluated.
3874**
3875** Think of each SQL statement as a separate computer program. The
3876** original SQL text is source code. A prepared statement object
3877** is the compiled object code. All SQL must be converted into a
3878** prepared statement before it can be run.
3879**
3880** The life-cycle of a prepared statement object usually goes like this:
3881**
3882** <ol>
3883** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3884** <li> Bind values to [parameters] using the sqlite3_bind_*()
3885** interfaces.
3886** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3887** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3888** to step 2. Do this zero or more times.
3889** <li> Destroy the object using [sqlite3_finalize()].
3890** </ol>
3891*/
3892typedef struct sqlite3_stmt sqlite3_stmt;
3893
3894/*
3895** CAPI3REF: Run-time Limits
3896** METHOD: sqlite3
3897**
3898** ^(This interface allows the size of various constructs to be limited
3899** on a connection by connection basis. The first parameter is the
3900** [database connection] whose limit is to be set or queried. The
3901** second parameter is one of the [limit categories] that define a
3902** class of constructs to be size limited. The third parameter is the
3903** new limit for that construct.)^
3904**
3905** ^If the new limit is a negative number, the limit is unchanged.
3906** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3907** [limits | hard upper bound]
3908** set at compile-time by a C preprocessor macro called
3909** [limits | SQLITE_MAX_<i>NAME</i>].
3910** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3911** ^Attempts to increase a limit above its hard upper bound are
3912** silently truncated to the hard upper bound.
3913**
3914** ^Regardless of whether or not the limit was changed, the
3915** [sqlite3_limit()] interface returns the prior value of the limit.
3916** ^Hence, to find the current value of a limit without changing it,
3917** simply invoke this interface with the third parameter set to -1.
3918**
3919** Run-time limits are intended for use in applications that manage
3920** both their own internal database and also databases that are controlled
3921** by untrusted external sources. An example application might be a
3922** web browser that has its own databases for storing history and
3923** separate databases controlled by JavaScript applications downloaded
3924** off the Internet. The internal databases can be given the
3925** large, default limits. Databases managed by external sources can
3926** be given much smaller limits designed to prevent a denial of service
3927** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3928** interface to further control untrusted SQL. The size of the database
3929** created by an untrusted script can be contained using the
3930** [max_page_count] [PRAGMA].
3931**
3932** New run-time limit categories may be added in future releases.
3933*/
3934SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3935
3936/*
3937** CAPI3REF: Run-Time Limit Categories
3938** KEYWORDS: {limit category} {*limit categories}
3939**
3940** These constants define various performance limits
3941** that can be lowered at run-time using [sqlite3_limit()].
3942** The synopsis of the meanings of the various limits is shown below.
3943** Additional information is available at [limits | Limits in SQLite].
3944**
3945** <dl>
3946** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3947** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3948**
3949** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3950** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3951**
3952** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3953** <dd>The maximum number of columns in a table definition or in the
3954** result set of a [SELECT] or the maximum number of columns in an index
3955** or in an ORDER BY or GROUP BY clause.</dd>)^
3956**
3957** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3958** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3959**
3960** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3961** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3962**
3963** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3964** <dd>The maximum number of instructions in a virtual machine program
3965** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3966** the equivalent tries to allocate space for more than this many opcodes
3967** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3968**
3969** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3970** <dd>The maximum number of arguments on a function.</dd>)^
3971**
3972** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3973** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3974**
3975** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3976** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3977** <dd>The maximum length of the pattern argument to the [LIKE] or
3978** [GLOB] operators.</dd>)^
3979**
3980** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3981** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3982** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3983**
3984** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3985** <dd>The maximum depth of recursion for triggers.</dd>)^
3986**
3987** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3988** <dd>The maximum number of auxiliary worker threads that a single
3989** [prepared statement] may start.</dd>)^
3990** </dl>
3991*/
3992#define SQLITE_LIMIT_LENGTH 0
3993#define SQLITE_LIMIT_SQL_LENGTH 1
3994#define SQLITE_LIMIT_COLUMN 2
3995#define SQLITE_LIMIT_EXPR_DEPTH 3
3996#define SQLITE_LIMIT_COMPOUND_SELECT 4
3997#define SQLITE_LIMIT_VDBE_OP 5
3998#define SQLITE_LIMIT_FUNCTION_ARG 6
3999#define SQLITE_LIMIT_ATTACHED 7
4000#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4001#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4002#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4003#define SQLITE_LIMIT_WORKER_THREADS 11
4004
4005/*
4006** CAPI3REF: Prepare Flags
4007**
4008** These constants define various flags that can be passed into
4009** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4010** [sqlite3_prepare16_v3()] interfaces.
4011**
4012** New flags may be added in future releases of SQLite.
4013**
4014** <dl>
4015** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4016** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4017** that the prepared statement will be retained for a long time and
4018** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4019** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4020** be used just once or at most a few times and then destroyed using
4021** [sqlite3_finalize()] relatively soon. The current implementation acts
4022** on this hint by avoiding the use of [lookaside memory] so as not to
4023** deplete the limited store of lookaside memory. Future versions of
4024** SQLite may act on this hint differently.
4025**
4026** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4027** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4028** to be required for any prepared statement that wanted to use the
4029** [sqlite3_normalized_sql()] interface. However, the
4030** [sqlite3_normalized_sql()] interface is now available to all
4031** prepared statements, regardless of whether or not they use this
4032** flag.
4033**
4034** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4035** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4036** to return an error (error code SQLITE_ERROR) if the statement uses
4037** any virtual tables.
4038** </dl>
4039*/
4040#define SQLITE_PREPARE_PERSISTENT 0x01
4041#define SQLITE_PREPARE_NORMALIZE 0x02
4042#define SQLITE_PREPARE_NO_VTAB 0x04
4043
4044/*
4045** CAPI3REF: Compiling An SQL Statement
4046** KEYWORDS: {SQL statement compiler}
4047** METHOD: sqlite3
4048** CONSTRUCTOR: sqlite3_stmt
4049**
4050** To execute an SQL statement, it must first be compiled into a byte-code
4051** program using one of these routines. Or, in other words, these routines
4052** are constructors for the [prepared statement] object.
4053**
4054** The preferred routine to use is [sqlite3_prepare_v2()]. The
4055** [sqlite3_prepare()] interface is legacy and should be avoided.
4056** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4057** for special purposes.
4058**
4059** The use of the UTF-8 interfaces is preferred, as SQLite currently
4060** does all parsing using UTF-8. The UTF-16 interfaces are provided
4061** as a convenience. The UTF-16 interfaces work by converting the
4062** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4063**
4064** The first argument, "db", is a [database connection] obtained from a
4065** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4066** [sqlite3_open16()]. The database connection must not have been closed.
4067**
4068** The second argument, "zSql", is the statement to be compiled, encoded
4069** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4070** and sqlite3_prepare_v3()
4071** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4072** and sqlite3_prepare16_v3() use UTF-16.
4073**
4074** ^If the nByte argument is negative, then zSql is read up to the
4075** first zero terminator. ^If nByte is positive, then it is the
4076** number of bytes read from zSql. ^If nByte is zero, then no prepared
4077** statement is generated.
4078** If the caller knows that the supplied string is nul-terminated, then
4079** there is a small performance advantage to passing an nByte parameter that
4080** is the number of bytes in the input string <i>including</i>
4081** the nul-terminator.
4082**
4083** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4084** past the end of the first SQL statement in zSql. These routines only
4085** compile the first statement in zSql, so *pzTail is left pointing to
4086** what remains uncompiled.
4087**
4088** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4089** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4090** to NULL. ^If the input text contains no SQL (if the input is an empty
4091** string or a comment) then *ppStmt is set to NULL.
4092** The calling procedure is responsible for deleting the compiled
4093** SQL statement using [sqlite3_finalize()] after it has finished with it.
4094** ppStmt may not be NULL.
4095**
4096** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4097** otherwise an [error code] is returned.
4098**
4099** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4100** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4101** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4102** are retained for backwards compatibility, but their use is discouraged.
4103** ^In the "vX" interfaces, the prepared statement
4104** that is returned (the [sqlite3_stmt] object) contains a copy of the
4105** original SQL text. This causes the [sqlite3_step()] interface to
4106** behave differently in three ways:
4107**
4108** <ol>
4109** <li>
4110** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4111** always used to do, [sqlite3_step()] will automatically recompile the SQL
4112** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4113** retries will occur before sqlite3_step() gives up and returns an error.
4114** </li>
4115**
4116** <li>
4117** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4118** [error codes] or [extended error codes]. ^The legacy behavior was that
4119** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4120** and the application would have to make a second call to [sqlite3_reset()]
4121** in order to find the underlying cause of the problem. With the "v2" prepare
4122** interfaces, the underlying reason for the error is returned immediately.
4123** </li>
4124**
4125** <li>
4126** ^If the specific value bound to a [parameter | host parameter] in the
4127** WHERE clause might influence the choice of query plan for a statement,
4128** then the statement will be automatically recompiled, as if there had been
4129** a schema change, on the first [sqlite3_step()] call following any change
4130** to the [sqlite3_bind_text | bindings] of that [parameter].
4131** ^The specific value of a WHERE-clause [parameter] might influence the
4132** choice of query plan if the parameter is the left-hand side of a [LIKE]
4133** or [GLOB] operator or if the parameter is compared to an indexed column
4134** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4135** </li>
4136** </ol>
4137**
4138** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4139** the extra prepFlags parameter, which is a bit array consisting of zero or
4140** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4141** sqlite3_prepare_v2() interface works exactly the same as
4142** sqlite3_prepare_v3() with a zero prepFlags parameter.
4143*/
4144SQLITE_API int sqlite3_prepare(
4145 sqlite3 *db, /* Database handle */
4146 const char *zSql, /* SQL statement, UTF-8 encoded */
4147 int nByte, /* Maximum length of zSql in bytes. */
4148 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4149 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4150);
4151SQLITE_API int sqlite3_prepare_v2(
4152 sqlite3 *db, /* Database handle */
4153 const char *zSql, /* SQL statement, UTF-8 encoded */
4154 int nByte, /* Maximum length of zSql in bytes. */
4155 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4156 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4157);
4158SQLITE_API int sqlite3_prepare_v3(
4159 sqlite3 *db, /* Database handle */
4160 const char *zSql, /* SQL statement, UTF-8 encoded */
4161 int nByte, /* Maximum length of zSql in bytes. */
4162 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4163 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4164 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4165);
4166SQLITE_API int sqlite3_prepare16(
4167 sqlite3 *db, /* Database handle */
4168 const void *zSql, /* SQL statement, UTF-16 encoded */
4169 int nByte, /* Maximum length of zSql in bytes. */
4170 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4171 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4172);
4173SQLITE_API int sqlite3_prepare16_v2(
4174 sqlite3 *db, /* Database handle */
4175 const void *zSql, /* SQL statement, UTF-16 encoded */
4176 int nByte, /* Maximum length of zSql in bytes. */
4177 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4178 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4179);
4180SQLITE_API int sqlite3_prepare16_v3(
4181 sqlite3 *db, /* Database handle */
4182 const void *zSql, /* SQL statement, UTF-16 encoded */
4183 int nByte, /* Maximum length of zSql in bytes. */
4184 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4185 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4186 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4187);
4188
4189/*
4190** CAPI3REF: Retrieving Statement SQL
4191** METHOD: sqlite3_stmt
4192**
4193** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4194** SQL text used to create [prepared statement] P if P was
4195** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4196** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4197** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4198** string containing the SQL text of prepared statement P with
4199** [bound parameters] expanded.
4200** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4201** string containing the normalized SQL text of prepared statement P. The
4202** semantics used to normalize a SQL statement are unspecified and subject
4203** to change. At a minimum, literal values will be replaced with suitable
4204** placeholders.
4205**
4206** ^(For example, if a prepared statement is created using the SQL
4207** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4208** and parameter :xyz is unbound, then sqlite3_sql() will return
4209** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4210** will return "SELECT 2345,NULL".)^
4211**
4212** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4213** is available to hold the result, or if the result would exceed the
4214** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4215**
4216** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4217** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4218** option causes sqlite3_expanded_sql() to always return NULL.
4219**
4220** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4221** are managed by SQLite and are automatically freed when the prepared
4222** statement is finalized.
4223** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4224** is obtained from [sqlite3_malloc()] and must be freed by the application
4225** by passing it to [sqlite3_free()].
4226**
4227** ^The sqlite3_normalized_sql() interface is only available if
4228** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4229*/
4230SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4231SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4232#ifdef SQLITE_ENABLE_NORMALIZE
4233SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4234#endif
4235
4236/*
4237** CAPI3REF: Determine If An SQL Statement Writes The Database
4238** METHOD: sqlite3_stmt
4239**
4240** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4241** and only if the [prepared statement] X makes no direct changes to
4242** the content of the database file.
4243**
4244** Note that [application-defined SQL functions] or
4245** [virtual tables] might change the database indirectly as a side effect.
4246** ^(For example, if an application defines a function "eval()" that
4247** calls [sqlite3_exec()], then the following SQL statement would
4248** change the database file through side-effects:
4249**
4250** <blockquote><pre>
4251** SELECT eval('DELETE FROM t1') FROM t2;
4252** </pre></blockquote>
4253**
4254** But because the [SELECT] statement does not change the database file
4255** directly, sqlite3_stmt_readonly() would still return true.)^
4256**
4257** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4258** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4259** since the statements themselves do not actually modify the database but
4260** rather they control the timing of when other statements modify the
4261** database. ^The [ATTACH] and [DETACH] statements also cause
4262** sqlite3_stmt_readonly() to return true since, while those statements
4263** change the configuration of a database connection, they do not make
4264** changes to the content of the database files on disk.
4265** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4266** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4267** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4268** sqlite3_stmt_readonly() returns false for those commands.
4269**
4270** ^This routine returns false if there is any possibility that the
4271** statement might change the database file. ^A false return does
4272** not guarantee that the statement will change the database file.
4273** ^For example, an UPDATE statement might have a WHERE clause that
4274** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4275** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4276** read-only no-op if the table already exists, but
4277** sqlite3_stmt_readonly() still returns false for such a statement.
4278*/
4279SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4280
4281/*
4282** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4283** METHOD: sqlite3_stmt
4284**
4285** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4286** prepared statement S is an EXPLAIN statement, or 2 if the
4287** statement S is an EXPLAIN QUERY PLAN.
4288** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4289** an ordinary statement or a NULL pointer.
4290*/
4291SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4292
4293/*
4294** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4295** METHOD: sqlite3_stmt
4296**
4297** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4298** [prepared statement] S has been stepped at least once using
4299** [sqlite3_step(S)] but has neither run to completion (returned
4300** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4301** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4302** interface returns false if S is a NULL pointer. If S is not a
4303** NULL pointer and is not a pointer to a valid [prepared statement]
4304** object, then the behavior is undefined and probably undesirable.
4305**
4306** This interface can be used in combination [sqlite3_next_stmt()]
4307** to locate all prepared statements associated with a database
4308** connection that are in need of being reset. This can be used,
4309** for example, in diagnostic routines to search for prepared
4310** statements that are holding a transaction open.
4311*/
4312SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4313
4314/*
4315** CAPI3REF: Dynamically Typed Value Object
4316** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4317**
4318** SQLite uses the sqlite3_value object to represent all values
4319** that can be stored in a database table. SQLite uses dynamic typing
4320** for the values it stores. ^Values stored in sqlite3_value objects
4321** can be integers, floating point values, strings, BLOBs, or NULL.
4322**
4323** An sqlite3_value object may be either "protected" or "unprotected".
4324** Some interfaces require a protected sqlite3_value. Other interfaces
4325** will accept either a protected or an unprotected sqlite3_value.
4326** Every interface that accepts sqlite3_value arguments specifies
4327** whether or not it requires a protected sqlite3_value. The
4328** [sqlite3_value_dup()] interface can be used to construct a new
4329** protected sqlite3_value from an unprotected sqlite3_value.
4330**
4331** The terms "protected" and "unprotected" refer to whether or not
4332** a mutex is held. An internal mutex is held for a protected
4333** sqlite3_value object but no mutex is held for an unprotected
4334** sqlite3_value object. If SQLite is compiled to be single-threaded
4335** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4336** or if SQLite is run in one of reduced mutex modes
4337** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4338** then there is no distinction between protected and unprotected
4339** sqlite3_value objects and they can be used interchangeably. However,
4340** for maximum code portability it is recommended that applications
4341** still make the distinction between protected and unprotected
4342** sqlite3_value objects even when not strictly required.
4343**
4344** ^The sqlite3_value objects that are passed as parameters into the
4345** implementation of [application-defined SQL functions] are protected.
4346** ^The sqlite3_value object returned by
4347** [sqlite3_column_value()] is unprotected.
4348** Unprotected sqlite3_value objects may only be used as arguments
4349** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4350** [sqlite3_value_dup()].
4351** The [sqlite3_value_blob | sqlite3_value_type()] family of
4352** interfaces require protected sqlite3_value objects.
4353*/
4354typedef struct sqlite3_value sqlite3_value;
4355
4356/*
4357** CAPI3REF: SQL Function Context Object
4358**
4359** The context in which an SQL function executes is stored in an
4360** sqlite3_context object. ^A pointer to an sqlite3_context object
4361** is always first parameter to [application-defined SQL functions].
4362** The application-defined SQL function implementation will pass this
4363** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4364** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4365** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4366** and/or [sqlite3_set_auxdata()].
4367*/
4368typedef struct sqlite3_context sqlite3_context;
4369
4370/*
4371** CAPI3REF: Binding Values To Prepared Statements
4372** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4373** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4374** METHOD: sqlite3_stmt
4375**
4376** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4377** literals may be replaced by a [parameter] that matches one of following
4378** templates:
4379**
4380** <ul>
4381** <li> ?
4382** <li> ?NNN
4383** <li> :VVV
4384** <li> @VVV
4385** <li> $VVV
4386** </ul>
4387**
4388** In the templates above, NNN represents an integer literal,
4389** and VVV represents an alphanumeric identifier.)^ ^The values of these
4390** parameters (also called "host parameter names" or "SQL parameters")
4391** can be set using the sqlite3_bind_*() routines defined here.
4392**
4393** ^The first argument to the sqlite3_bind_*() routines is always
4394** a pointer to the [sqlite3_stmt] object returned from
4395** [sqlite3_prepare_v2()] or its variants.
4396**
4397** ^The second argument is the index of the SQL parameter to be set.
4398** ^The leftmost SQL parameter has an index of 1. ^When the same named
4399** SQL parameter is used more than once, second and subsequent
4400** occurrences have the same index as the first occurrence.
4401** ^The index for named parameters can be looked up using the
4402** [sqlite3_bind_parameter_index()] API if desired. ^The index
4403** for "?NNN" parameters is the value of NNN.
4404** ^The NNN value must be between 1 and the [sqlite3_limit()]
4405** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4406**
4407** ^The third argument is the value to bind to the parameter.
4408** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4409** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4410** is ignored and the end result is the same as sqlite3_bind_null().
4411** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4412** it should be a pointer to well-formed UTF8 text.
4413** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4414** it should be a pointer to well-formed UTF16 text.
4415** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4416** it should be a pointer to a well-formed unicode string that is
4417** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4418** otherwise.
4419**
4420** [[byte-order determination rules]] ^The byte-order of
4421** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4422** found in first character, which is removed, or in the absence of a BOM
4423** the byte order is the native byte order of the host
4424** machine for sqlite3_bind_text16() or the byte order specified in
4425** the 6th parameter for sqlite3_bind_text64().)^
4426** ^If UTF16 input text contains invalid unicode
4427** characters, then SQLite might change those invalid characters
4428** into the unicode replacement character: U+FFFD.
4429**
4430** ^(In those routines that have a fourth argument, its value is the
4431** number of bytes in the parameter. To be clear: the value is the
4432** number of <u>bytes</u> in the value, not the number of characters.)^
4433** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4434** is negative, then the length of the string is
4435** the number of bytes up to the first zero terminator.
4436** If the fourth parameter to sqlite3_bind_blob() is negative, then
4437** the behavior is undefined.
4438** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4439** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4440** that parameter must be the byte offset
4441** where the NUL terminator would occur assuming the string were NUL
4442** terminated. If any NUL characters occurs at byte offsets less than
4443** the value of the fourth parameter then the resulting string value will
4444** contain embedded NULs. The result of expressions involving strings
4445** with embedded NULs is undefined.
4446**
4447** ^The fifth argument to the BLOB and string binding interfaces controls
4448** or indicates the lifetime of the object referenced by the third parameter.
4449** These three options exist:
4450** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4451** with it may be passed. ^It is called to dispose of the BLOB or string even
4452** if the call to the bind API fails, except the destructor is not called if
4453** the third parameter is a NULL pointer or the fourth parameter is negative.
4454** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that
4455** the application remains responsible for disposing of the object. ^In this
4456** case, the object and the provided pointer to it must remain valid until
4457** either the prepared statement is finalized or the same SQL parameter is
4458** bound to something else, whichever occurs sooner.
4459** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4460** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4461** object and pointer to it must remain valid until then. ^SQLite will then
4462** manage the lifetime of its private copy.
4463**
4464** ^The sixth argument to sqlite3_bind_text64() must be one of
4465** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4466** to specify the encoding of the text in the third parameter. If
4467** the sixth argument to sqlite3_bind_text64() is not one of the
4468** allowed values shown above, or if the text encoding is different
4469** from the encoding specified by the sixth parameter, then the behavior
4470** is undefined.
4471**
4472** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4473** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4474** (just an integer to hold its size) while it is being processed.
4475** Zeroblobs are intended to serve as placeholders for BLOBs whose
4476** content is later written using
4477** [sqlite3_blob_open | incremental BLOB I/O] routines.
4478** ^A negative value for the zeroblob results in a zero-length BLOB.
4479**
4480** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4481** [prepared statement] S to have an SQL value of NULL, but to also be
4482** associated with the pointer P of type T. ^D is either a NULL pointer or
4483** a pointer to a destructor function for P. ^SQLite will invoke the
4484** destructor D with a single argument of P when it is finished using
4485** P. The T parameter should be a static string, preferably a string
4486** literal. The sqlite3_bind_pointer() routine is part of the
4487** [pointer passing interface] added for SQLite 3.20.0.
4488**
4489** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4490** for the [prepared statement] or with a prepared statement for which
4491** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4492** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4493** routine is passed a [prepared statement] that has been finalized, the
4494** result is undefined and probably harmful.
4495**
4496** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4497** ^Unbound parameters are interpreted as NULL.
4498**
4499** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4500** [error code] if anything goes wrong.
4501** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4502** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4503** [SQLITE_MAX_LENGTH].
4504** ^[SQLITE_RANGE] is returned if the parameter
4505** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4506**
4507** See also: [sqlite3_bind_parameter_count()],
4508** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4509*/
4510SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4511SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4512 void(*)(void*));
4513SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4514SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4515SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4516SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4517SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4518SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4519SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4520 void(*)(void*), unsigned char encoding);
4521SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4522SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4523SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4524SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4525
4526/*
4527** CAPI3REF: Number Of SQL Parameters
4528** METHOD: sqlite3_stmt
4529**
4530** ^This routine can be used to find the number of [SQL parameters]
4531** in a [prepared statement]. SQL parameters are tokens of the
4532** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4533** placeholders for values that are [sqlite3_bind_blob | bound]
4534** to the parameters at a later time.
4535**
4536** ^(This routine actually returns the index of the largest (rightmost)
4537** parameter. For all forms except ?NNN, this will correspond to the
4538** number of unique parameters. If parameters of the ?NNN form are used,
4539** there may be gaps in the list.)^
4540**
4541** See also: [sqlite3_bind_blob|sqlite3_bind()],
4542** [sqlite3_bind_parameter_name()], and
4543** [sqlite3_bind_parameter_index()].
4544*/
4545SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4546
4547/*
4548** CAPI3REF: Name Of A Host Parameter
4549** METHOD: sqlite3_stmt
4550**
4551** ^The sqlite3_bind_parameter_name(P,N) interface returns
4552** the name of the N-th [SQL parameter] in the [prepared statement] P.
4553** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4554** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4555** respectively.
4556** In other words, the initial ":" or "$" or "@" or "?"
4557** is included as part of the name.)^
4558** ^Parameters of the form "?" without a following integer have no name
4559** and are referred to as "nameless" or "anonymous parameters".
4560**
4561** ^The first host parameter has an index of 1, not 0.
4562**
4563** ^If the value N is out of range or if the N-th parameter is
4564** nameless, then NULL is returned. ^The returned string is
4565** always in UTF-8 encoding even if the named parameter was
4566** originally specified as UTF-16 in [sqlite3_prepare16()],
4567** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4568**
4569** See also: [sqlite3_bind_blob|sqlite3_bind()],
4570** [sqlite3_bind_parameter_count()], and
4571** [sqlite3_bind_parameter_index()].
4572*/
4573SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4574
4575/*
4576** CAPI3REF: Index Of A Parameter With A Given Name
4577** METHOD: sqlite3_stmt
4578**
4579** ^Return the index of an SQL parameter given its name. ^The
4580** index value returned is suitable for use as the second
4581** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4582** is returned if no matching parameter is found. ^The parameter
4583** name must be given in UTF-8 even if the original statement
4584** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4585** [sqlite3_prepare16_v3()].
4586**
4587** See also: [sqlite3_bind_blob|sqlite3_bind()],
4588** [sqlite3_bind_parameter_count()], and
4589** [sqlite3_bind_parameter_name()].
4590*/
4591SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4592
4593/*
4594** CAPI3REF: Reset All Bindings On A Prepared Statement
4595** METHOD: sqlite3_stmt
4596**
4597** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4598** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4599** ^Use this routine to reset all host parameters to NULL.
4600*/
4601SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4602
4603/*
4604** CAPI3REF: Number Of Columns In A Result Set
4605** METHOD: sqlite3_stmt
4606**
4607** ^Return the number of columns in the result set returned by the
4608** [prepared statement]. ^If this routine returns 0, that means the
4609** [prepared statement] returns no data (for example an [UPDATE]).
4610** ^However, just because this routine returns a positive number does not
4611** mean that one or more rows of data will be returned. ^A SELECT statement
4612** will always have a positive sqlite3_column_count() but depending on the
4613** WHERE clause constraints and the table content, it might return no rows.
4614**
4615** See also: [sqlite3_data_count()]
4616*/
4617SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4618
4619/*
4620** CAPI3REF: Column Names In A Result Set
4621** METHOD: sqlite3_stmt
4622**
4623** ^These routines return the name assigned to a particular column
4624** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4625** interface returns a pointer to a zero-terminated UTF-8 string
4626** and sqlite3_column_name16() returns a pointer to a zero-terminated
4627** UTF-16 string. ^The first parameter is the [prepared statement]
4628** that implements the [SELECT] statement. ^The second parameter is the
4629** column number. ^The leftmost column is number 0.
4630**
4631** ^The returned string pointer is valid until either the [prepared statement]
4632** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4633** reprepared by the first call to [sqlite3_step()] for a particular run
4634** or until the next call to
4635** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4636**
4637** ^If sqlite3_malloc() fails during the processing of either routine
4638** (for example during a conversion from UTF-8 to UTF-16) then a
4639** NULL pointer is returned.
4640**
4641** ^The name of a result column is the value of the "AS" clause for
4642** that column, if there is an AS clause. If there is no AS clause
4643** then the name of the column is unspecified and may change from
4644** one release of SQLite to the next.
4645*/
4646SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4647SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4648
4649/*
4650** CAPI3REF: Source Of Data In A Query Result
4651** METHOD: sqlite3_stmt
4652**
4653** ^These routines provide a means to determine the database, table, and
4654** table column that is the origin of a particular result column in
4655** [SELECT] statement.
4656** ^The name of the database or table or column can be returned as
4657** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4658** the database name, the _table_ routines return the table name, and
4659** the origin_ routines return the column name.
4660** ^The returned string is valid until the [prepared statement] is destroyed
4661** using [sqlite3_finalize()] or until the statement is automatically
4662** reprepared by the first call to [sqlite3_step()] for a particular run
4663** or until the same information is requested
4664** again in a different encoding.
4665**
4666** ^The names returned are the original un-aliased names of the
4667** database, table, and column.
4668**
4669** ^The first argument to these interfaces is a [prepared statement].
4670** ^These functions return information about the Nth result column returned by
4671** the statement, where N is the second function argument.
4672** ^The left-most column is column 0 for these routines.
4673**
4674** ^If the Nth column returned by the statement is an expression or
4675** subquery and is not a column value, then all of these functions return
4676** NULL. ^These routines might also return NULL if a memory allocation error
4677** occurs. ^Otherwise, they return the name of the attached database, table,
4678** or column that query result column was extracted from.
4679**
4680** ^As with all other SQLite APIs, those whose names end with "16" return
4681** UTF-16 encoded strings and the other functions return UTF-8.
4682**
4683** ^These APIs are only available if the library was compiled with the
4684** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4685**
4686** If two or more threads call one or more
4687** [sqlite3_column_database_name | column metadata interfaces]
4688** for the same [prepared statement] and result column
4689** at the same time then the results are undefined.
4690*/
4691SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4692SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4693SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4694SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4695SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4696SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4697
4698/*
4699** CAPI3REF: Declared Datatype Of A Query Result
4700** METHOD: sqlite3_stmt
4701**
4702** ^(The first parameter is a [prepared statement].
4703** If this statement is a [SELECT] statement and the Nth column of the
4704** returned result set of that [SELECT] is a table column (not an
4705** expression or subquery) then the declared type of the table
4706** column is returned.)^ ^If the Nth column of the result set is an
4707** expression or subquery, then a NULL pointer is returned.
4708** ^The returned string is always UTF-8 encoded.
4709**
4710** ^(For example, given the database schema:
4711**
4712** CREATE TABLE t1(c1 VARIANT);
4713**
4714** and the following statement to be compiled:
4715**
4716** SELECT c1 + 1, c1 FROM t1;
4717**
4718** this routine would return the string "VARIANT" for the second result
4719** column (i==1), and a NULL pointer for the first result column (i==0).)^
4720**
4721** ^SQLite uses dynamic run-time typing. ^So just because a column
4722** is declared to contain a particular type does not mean that the
4723** data stored in that column is of the declared type. SQLite is
4724** strongly typed, but the typing is dynamic not static. ^Type
4725** is associated with individual values, not with the containers
4726** used to hold those values.
4727*/
4728SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4729SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4730
4731/*
4732** CAPI3REF: Evaluate An SQL Statement
4733** METHOD: sqlite3_stmt
4734**
4735** After a [prepared statement] has been prepared using any of
4736** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4737** or [sqlite3_prepare16_v3()] or one of the legacy
4738** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4739** must be called one or more times to evaluate the statement.
4740**
4741** The details of the behavior of the sqlite3_step() interface depend
4742** on whether the statement was prepared using the newer "vX" interfaces
4743** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4744** [sqlite3_prepare16_v2()] or the older legacy
4745** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4746** new "vX" interface is recommended for new applications but the legacy
4747** interface will continue to be supported.
4748**
4749** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4750** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4751** ^With the "v2" interface, any of the other [result codes] or
4752** [extended result codes] might be returned as well.
4753**
4754** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4755** database locks it needs to do its job. ^If the statement is a [COMMIT]
4756** or occurs outside of an explicit transaction, then you can retry the
4757** statement. If the statement is not a [COMMIT] and occurs within an
4758** explicit transaction then you should rollback the transaction before
4759** continuing.
4760**
4761** ^[SQLITE_DONE] means that the statement has finished executing
4762** successfully. sqlite3_step() should not be called again on this virtual
4763** machine without first calling [sqlite3_reset()] to reset the virtual
4764** machine back to its initial state.
4765**
4766** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4767** is returned each time a new row of data is ready for processing by the
4768** caller. The values may be accessed using the [column access functions].
4769** sqlite3_step() is called again to retrieve the next row of data.
4770**
4771** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4772** violation) has occurred. sqlite3_step() should not be called again on
4773** the VM. More information may be found by calling [sqlite3_errmsg()].
4774** ^With the legacy interface, a more specific error code (for example,
4775** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4776** can be obtained by calling [sqlite3_reset()] on the
4777** [prepared statement]. ^In the "v2" interface,
4778** the more specific error code is returned directly by sqlite3_step().
4779**
4780** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4781** Perhaps it was called on a [prepared statement] that has
4782** already been [sqlite3_finalize | finalized] or on one that had
4783** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4784** be the case that the same database connection is being used by two or
4785** more threads at the same moment in time.
4786**
4787** For all versions of SQLite up to and including 3.6.23.1, a call to
4788** [sqlite3_reset()] was required after sqlite3_step() returned anything
4789** other than [SQLITE_ROW] before any subsequent invocation of
4790** sqlite3_step(). Failure to reset the prepared statement using
4791** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4792** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4793** sqlite3_step() began
4794** calling [sqlite3_reset()] automatically in this circumstance rather
4795** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4796** break because any application that ever receives an SQLITE_MISUSE error
4797** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4798** can be used to restore the legacy behavior.
4799**
4800** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4801** API always returns a generic error code, [SQLITE_ERROR], following any
4802** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4803** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4804** specific [error codes] that better describes the error.
4805** We admit that this is a goofy design. The problem has been fixed
4806** with the "v2" interface. If you prepare all of your SQL statements
4807** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4808** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4809** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4810** then the more specific [error codes] are returned directly
4811** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4812*/
4813SQLITE_API int sqlite3_step(sqlite3_stmt*);
4814
4815/*
4816** CAPI3REF: Number of columns in a result set
4817** METHOD: sqlite3_stmt
4818**
4819** ^The sqlite3_data_count(P) interface returns the number of columns in the
4820** current row of the result set of [prepared statement] P.
4821** ^If prepared statement P does not have results ready to return
4822** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4823** interfaces) then sqlite3_data_count(P) returns 0.
4824** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4825** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4826** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4827** will return non-zero if previous call to [sqlite3_step](P) returned
4828** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4829** where it always returns zero since each step of that multi-step
4830** pragma returns 0 columns of data.
4831**
4832** See also: [sqlite3_column_count()]
4833*/
4834SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4835
4836/*
4837** CAPI3REF: Fundamental Datatypes
4838** KEYWORDS: SQLITE_TEXT
4839**
4840** ^(Every value in SQLite has one of five fundamental datatypes:
4841**
4842** <ul>
4843** <li> 64-bit signed integer
4844** <li> 64-bit IEEE floating point number
4845** <li> string
4846** <li> BLOB
4847** <li> NULL
4848** </ul>)^
4849**
4850** These constants are codes for each of those types.
4851**
4852** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4853** for a completely different meaning. Software that links against both
4854** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4855** SQLITE_TEXT.
4856*/
4857#define SQLITE_INTEGER 1
4858#define SQLITE_FLOAT 2
4859#define SQLITE_BLOB 4
4860#define SQLITE_NULL 5
4861#ifdef SQLITE_TEXT
4862# undef SQLITE_TEXT
4863#else
4864# define SQLITE_TEXT 3
4865#endif
4866#define SQLITE3_TEXT 3
4867
4868/*
4869** CAPI3REF: Result Values From A Query
4870** KEYWORDS: {column access functions}
4871** METHOD: sqlite3_stmt
4872**
4873** <b>Summary:</b>
4874** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4875** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4876** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4877** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4878** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4879** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4880** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4881** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4882** [sqlite3_value|unprotected sqlite3_value] object.
4883** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4884** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4885** or a UTF-8 TEXT result in bytes
4886** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4887** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4888** TEXT in bytes
4889** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4890** datatype of the result
4891** </table></blockquote>
4892**
4893** <b>Details:</b>
4894**
4895** ^These routines return information about a single column of the current
4896** result row of a query. ^In every case the first argument is a pointer
4897** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4898** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4899** and the second argument is the index of the column for which information
4900** should be returned. ^The leftmost column of the result set has the index 0.
4901** ^The number of columns in the result can be determined using
4902** [sqlite3_column_count()].
4903**
4904** If the SQL statement does not currently point to a valid row, or if the
4905** column index is out of range, the result is undefined.
4906** These routines may only be called when the most recent call to
4907** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4908** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4909** If any of these routines are called after [sqlite3_reset()] or
4910** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4911** something other than [SQLITE_ROW], the results are undefined.
4912** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4913** are called from a different thread while any of these routines
4914** are pending, then the results are undefined.
4915**
4916** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4917** each return the value of a result column in a specific data format. If
4918** the result column is not initially in the requested format (for example,
4919** if the query returns an integer but the sqlite3_column_text() interface
4920** is used to extract the value) then an automatic type conversion is performed.
4921**
4922** ^The sqlite3_column_type() routine returns the
4923** [SQLITE_INTEGER | datatype code] for the initial data type
4924** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4925** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4926** The return value of sqlite3_column_type() can be used to decide which
4927** of the first six interface should be used to extract the column value.
4928** The value returned by sqlite3_column_type() is only meaningful if no
4929** automatic type conversions have occurred for the value in question.
4930** After a type conversion, the result of calling sqlite3_column_type()
4931** is undefined, though harmless. Future
4932** versions of SQLite may change the behavior of sqlite3_column_type()
4933** following a type conversion.
4934**
4935** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4936** or sqlite3_column_bytes16() interfaces can be used to determine the size
4937** of that BLOB or string.
4938**
4939** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4940** routine returns the number of bytes in that BLOB or string.
4941** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4942** the string to UTF-8 and then returns the number of bytes.
4943** ^If the result is a numeric value then sqlite3_column_bytes() uses
4944** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4945** the number of bytes in that string.
4946** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4947**
4948** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4949** routine returns the number of bytes in that BLOB or string.
4950** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4951** the string to UTF-16 and then returns the number of bytes.
4952** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4953** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4954** the number of bytes in that string.
4955** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4956**
4957** ^The values returned by [sqlite3_column_bytes()] and
4958** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4959** of the string. ^For clarity: the values returned by
4960** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4961** bytes in the string, not the number of characters.
4962**
4963** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4964** even empty strings, are always zero-terminated. ^The return
4965** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4966**
4967** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4968** [unprotected sqlite3_value] object. In a multithreaded environment,
4969** an unprotected sqlite3_value object may only be used safely with
4970** [sqlite3_bind_value()] and [sqlite3_result_value()].
4971** If the [unprotected sqlite3_value] object returned by
4972** [sqlite3_column_value()] is used in any other way, including calls
4973** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4974** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4975** Hence, the sqlite3_column_value() interface
4976** is normally only useful within the implementation of
4977** [application-defined SQL functions] or [virtual tables], not within
4978** top-level application code.
4979**
4980** The these routines may attempt to convert the datatype of the result.
4981** ^For example, if the internal representation is FLOAT and a text result
4982** is requested, [sqlite3_snprintf()] is used internally to perform the
4983** conversion automatically. ^(The following table details the conversions
4984** that are applied:
4985**
4986** <blockquote>
4987** <table border="1">
4988** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4989**
4990** <tr><td> NULL <td> INTEGER <td> Result is 0
4991** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4992** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4993** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4994** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4995** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4996** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4997** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4998** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4999** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5000** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5001** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5002** <tr><td> TEXT <td> BLOB <td> No change
5003** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5004** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5005** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
5006** </table>
5007** </blockquote>)^
5008**
5009** Note that when type conversions occur, pointers returned by prior
5010** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5011** sqlite3_column_text16() may be invalidated.
5012** Type conversions and pointer invalidations might occur
5013** in the following cases:
5014**
5015** <ul>
5016** <li> The initial content is a BLOB and sqlite3_column_text() or
5017** sqlite3_column_text16() is called. A zero-terminator might
5018** need to be added to the string.</li>
5019** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5020** sqlite3_column_text16() is called. The content must be converted
5021** to UTF-16.</li>
5022** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5023** sqlite3_column_text() is called. The content must be converted
5024** to UTF-8.</li>
5025** </ul>
5026**
5027** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5028** not invalidate a prior pointer, though of course the content of the buffer
5029** that the prior pointer references will have been modified. Other kinds
5030** of conversion are done in place when it is possible, but sometimes they
5031** are not possible and in those cases prior pointers are invalidated.
5032**
5033** The safest policy is to invoke these routines
5034** in one of the following ways:
5035**
5036** <ul>
5037** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5038** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5039** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5040** </ul>
5041**
5042** In other words, you should call sqlite3_column_text(),
5043** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5044** into the desired format, then invoke sqlite3_column_bytes() or
5045** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5046** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5047** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5048** with calls to sqlite3_column_bytes().
5049**
5050** ^The pointers returned are valid until a type conversion occurs as
5051** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5052** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5053** and BLOBs is freed automatically. Do not pass the pointers returned
5054** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5055** [sqlite3_free()].
5056**
5057** As long as the input parameters are correct, these routines will only
5058** fail if an out-of-memory error occurs during a format conversion.
5059** Only the following subset of interfaces are subject to out-of-memory
5060** errors:
5061**
5062** <ul>
5063** <li> sqlite3_column_blob()
5064** <li> sqlite3_column_text()
5065** <li> sqlite3_column_text16()
5066** <li> sqlite3_column_bytes()
5067** <li> sqlite3_column_bytes16()
5068** </ul>
5069**
5070** If an out-of-memory error occurs, then the return value from these
5071** routines is the same as if the column had contained an SQL NULL value.
5072** Valid SQL NULL returns can be distinguished from out-of-memory errors
5073** by invoking the [sqlite3_errcode()] immediately after the suspect
5074** return value is obtained and before any
5075** other SQLite interface is called on the same [database connection].
5076*/
5077SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5078SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5079SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5080SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5081SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5082SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5083SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5084SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5085SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5086SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5087
5088/*
5089** CAPI3REF: Destroy A Prepared Statement Object
5090** DESTRUCTOR: sqlite3_stmt
5091**
5092** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5093** ^If the most recent evaluation of the statement encountered no errors
5094** or if the statement is never been evaluated, then sqlite3_finalize() returns
5095** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5096** sqlite3_finalize(S) returns the appropriate [error code] or
5097** [extended error code].
5098**
5099** ^The sqlite3_finalize(S) routine can be called at any point during
5100** the life cycle of [prepared statement] S:
5101** before statement S is ever evaluated, after
5102** one or more calls to [sqlite3_reset()], or after any call
5103** to [sqlite3_step()] regardless of whether or not the statement has
5104** completed execution.
5105**
5106** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5107**
5108** The application must finalize every [prepared statement] in order to avoid
5109** resource leaks. It is a grievous error for the application to try to use
5110** a prepared statement after it has been finalized. Any use of a prepared
5111** statement after it has been finalized can result in undefined and
5112** undesirable behavior such as segfaults and heap corruption.
5113*/
5114SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5115
5116/*
5117** CAPI3REF: Reset A Prepared Statement Object
5118** METHOD: sqlite3_stmt
5119**
5120** The sqlite3_reset() function is called to reset a [prepared statement]
5121** object back to its initial state, ready to be re-executed.
5122** ^Any SQL statement variables that had values bound to them using
5123** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5124** Use [sqlite3_clear_bindings()] to reset the bindings.
5125**
5126** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5127** back to the beginning of its program.
5128**
5129** ^If the most recent call to [sqlite3_step(S)] for the
5130** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
5131** or if [sqlite3_step(S)] has never before been called on S,
5132** then [sqlite3_reset(S)] returns [SQLITE_OK].
5133**
5134** ^If the most recent call to [sqlite3_step(S)] for the
5135** [prepared statement] S indicated an error, then
5136** [sqlite3_reset(S)] returns an appropriate [error code].
5137**
5138** ^The [sqlite3_reset(S)] interface does not change the values
5139** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5140*/
5141SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5142
5143/*
5144** CAPI3REF: Create Or Redefine SQL Functions
5145** KEYWORDS: {function creation routines}
5146** METHOD: sqlite3
5147**
5148** ^These functions (collectively known as "function creation routines")
5149** are used to add SQL functions or aggregates or to redefine the behavior
5150** of existing SQL functions or aggregates. The only differences between
5151** the three "sqlite3_create_function*" routines are the text encoding
5152** expected for the second parameter (the name of the function being
5153** created) and the presence or absence of a destructor callback for
5154** the application data pointer. Function sqlite3_create_window_function()
5155** is similar, but allows the user to supply the extra callback functions
5156** needed by [aggregate window functions].
5157**
5158** ^The first parameter is the [database connection] to which the SQL
5159** function is to be added. ^If an application uses more than one database
5160** connection then application-defined SQL functions must be added
5161** to each database connection separately.
5162**
5163** ^The second parameter is the name of the SQL function to be created or
5164** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5165** representation, exclusive of the zero-terminator. ^Note that the name
5166** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5167** ^Any attempt to create a function with a longer name
5168** will result in [SQLITE_MISUSE] being returned.
5169**
5170** ^The third parameter (nArg)
5171** is the number of arguments that the SQL function or
5172** aggregate takes. ^If this parameter is -1, then the SQL function or
5173** aggregate may take any number of arguments between 0 and the limit
5174** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5175** parameter is less than -1 or greater than 127 then the behavior is
5176** undefined.
5177**
5178** ^The fourth parameter, eTextRep, specifies what
5179** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5180** its parameters. The application should set this parameter to
5181** [SQLITE_UTF16LE] if the function implementation invokes
5182** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5183** implementation invokes [sqlite3_value_text16be()] on an input, or
5184** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5185** otherwise. ^The same SQL function may be registered multiple times using
5186** different preferred text encodings, with different implementations for
5187** each encoding.
5188** ^When multiple implementations of the same function are available, SQLite
5189** will pick the one that involves the least amount of data conversion.
5190**
5191** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5192** to signal that the function will always return the same result given
5193** the same inputs within a single SQL statement. Most SQL functions are
5194** deterministic. The built-in [random()] SQL function is an example of a
5195** function that is not deterministic. The SQLite query planner is able to
5196** perform additional optimizations on deterministic functions, so use
5197** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5198**
5199** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5200** flag, which if present prevents the function from being invoked from
5201** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5202** index expressions, or the WHERE clause of partial indexes.
5203**
5204** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5205** all application-defined SQL functions that do not need to be
5206** used inside of triggers, view, CHECK constraints, or other elements of
5207** the database schema. This flags is especially recommended for SQL
5208** functions that have side effects or reveal internal application state.
5209** Without this flag, an attacker might be able to modify the schema of
5210** a database file to include invocations of the function with parameters
5211** chosen by the attacker, which the application will then execute when
5212** the database file is opened and read.
5213**
5214** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5215** function can gain access to this pointer using [sqlite3_user_data()].)^
5216**
5217** ^The sixth, seventh and eighth parameters passed to the three
5218** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5219** pointers to C-language functions that implement the SQL function or
5220** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5221** callback only; NULL pointers must be passed as the xStep and xFinal
5222** parameters. ^An aggregate SQL function requires an implementation of xStep
5223** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5224** SQL function or aggregate, pass NULL pointers for all three function
5225** callbacks.
5226**
5227** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5228** and xInverse) passed to sqlite3_create_window_function are pointers to
5229** C-language callbacks that implement the new function. xStep and xFinal
5230** must both be non-NULL. xValue and xInverse may either both be NULL, in
5231** which case a regular aggregate function is created, or must both be
5232** non-NULL, in which case the new function may be used as either an aggregate
5233** or aggregate window function. More details regarding the implementation
5234** of aggregate window functions are
5235** [user-defined window functions|available here].
5236**
5237** ^(If the final parameter to sqlite3_create_function_v2() or
5238** sqlite3_create_window_function() is not NULL, then it is destructor for
5239** the application data pointer. The destructor is invoked when the function
5240** is deleted, either by being overloaded or when the database connection
5241** closes.)^ ^The destructor is also invoked if the call to
5242** sqlite3_create_function_v2() fails. ^When the destructor callback is
5243** invoked, it is passed a single argument which is a copy of the application
5244** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5245**
5246** ^It is permitted to register multiple implementations of the same
5247** functions with the same name but with either differing numbers of
5248** arguments or differing preferred text encodings. ^SQLite will use
5249** the implementation that most closely matches the way in which the
5250** SQL function is used. ^A function implementation with a non-negative
5251** nArg parameter is a better match than a function implementation with
5252** a negative nArg. ^A function where the preferred text encoding
5253** matches the database encoding is a better
5254** match than a function where the encoding is different.
5255** ^A function where the encoding difference is between UTF16le and UTF16be
5256** is a closer match than a function where the encoding difference is
5257** between UTF8 and UTF16.
5258**
5259** ^Built-in functions may be overloaded by new application-defined functions.
5260**
5261** ^An application-defined function is permitted to call other
5262** SQLite interfaces. However, such calls must not
5263** close the database connection nor finalize or reset the prepared
5264** statement in which the function is running.
5265*/
5266SQLITE_API int sqlite3_create_function(
5267 sqlite3 *db,
5268 const char *zFunctionName,
5269 int nArg,
5270 int eTextRep,
5271 void *pApp,
5272 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5273 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5274 void (*xFinal)(sqlite3_context*)
5275);
5276SQLITE_API int sqlite3_create_function16(
5277 sqlite3 *db,
5278 const void *zFunctionName,
5279 int nArg,
5280 int eTextRep,
5281 void *pApp,
5282 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5283 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5284 void (*xFinal)(sqlite3_context*)
5285);
5286SQLITE_API int sqlite3_create_function_v2(
5287 sqlite3 *db,
5288 const char *zFunctionName,
5289 int nArg,
5290 int eTextRep,
5291 void *pApp,
5292 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5293 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5294 void (*xFinal)(sqlite3_context*),
5295 void(*xDestroy)(void*)
5296);
5297SQLITE_API int sqlite3_create_window_function(
5298 sqlite3 *db,
5299 const char *zFunctionName,
5300 int nArg,
5301 int eTextRep,
5302 void *pApp,
5303 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5304 void (*xFinal)(sqlite3_context*),
5305 void (*xValue)(sqlite3_context*),
5306 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5307 void(*xDestroy)(void*)
5308);
5309
5310/*
5311** CAPI3REF: Text Encodings
5312**
5313** These constant define integer codes that represent the various
5314** text encodings supported by SQLite.
5315*/
5316#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5317#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5318#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5319#define SQLITE_UTF16 4 /* Use native byte order */
5320#define SQLITE_ANY 5 /* Deprecated */
5321#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5322
5323/*
5324** CAPI3REF: Function Flags
5325**
5326** These constants may be ORed together with the
5327** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5328** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5329** [sqlite3_create_function_v2()].
5330**
5331** <dl>
5332** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5333** The SQLITE_DETERMINISTIC flag means that the new function always gives
5334** the same output when the input parameters are the same.
5335** The [abs|abs() function] is deterministic, for example, but
5336** [randomblob|randomblob()] is not. Functions must
5337** be deterministic in order to be used in certain contexts such as
5338** with the WHERE clause of [partial indexes] or in [generated columns].
5339** SQLite might also optimize deterministic functions by factoring them
5340** out of inner loops.
5341** </dd>
5342**
5343** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5344** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5345** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5346** schema structures such as [CHECK constraints], [DEFAULT clauses],
5347** [expression indexes], [partial indexes], or [generated columns].
5348** The SQLITE_DIRECTONLY flags is a security feature which is recommended
5349** for all [application-defined SQL functions], and especially for functions
5350** that have side-effects or that could potentially leak sensitive
5351** information.
5352** </dd>
5353**
5354** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5355** The SQLITE_INNOCUOUS flag means that the function is unlikely
5356** to cause problems even if misused. An innocuous function should have
5357** no side effects and should not depend on any values other than its
5358** input parameters. The [abs|abs() function] is an example of an
5359** innocuous function.
5360** The [load_extension() SQL function] is not innocuous because of its
5361** side effects.
5362** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5363** exactly the same. The [random|random() function] is an example of a
5364** function that is innocuous but not deterministic.
5365** <p>Some heightened security settings
5366** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5367** disable the use of SQL functions inside views and triggers and in
5368** schema structures such as [CHECK constraints], [DEFAULT clauses],
5369** [expression indexes], [partial indexes], and [generated columns] unless
5370** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5371** are innocuous. Developers are advised to avoid using the
5372** SQLITE_INNOCUOUS flag for application-defined functions unless the
5373** function has been carefully audited and found to be free of potentially
5374** security-adverse side-effects and information-leaks.
5375** </dd>
5376**
5377** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5378** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5379** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5380** Specifying this flag makes no difference for scalar or aggregate user
5381** functions. However, if it is not specified for a user-defined window
5382** function, then any sub-types belonging to arguments passed to the window
5383** function may be discarded before the window function is called (i.e.
5384** sqlite3_value_subtype() will always return 0).
5385** </dd>
5386** </dl>
5387*/
5388#define SQLITE_DETERMINISTIC 0x000000800
5389#define SQLITE_DIRECTONLY 0x000080000
5390#define SQLITE_SUBTYPE 0x000100000
5391#define SQLITE_INNOCUOUS 0x000200000
5392
5393/*
5394** CAPI3REF: Deprecated Functions
5395** DEPRECATED
5396**
5397** These functions are [deprecated]. In order to maintain
5398** backwards compatibility with older code, these functions continue
5399** to be supported. However, new applications should avoid
5400** the use of these functions. To encourage programmers to avoid
5401** these functions, we will not explain what they do.
5402*/
5403#ifndef SQLITE_OMIT_DEPRECATED
5404SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5405SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5406SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5407SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5408SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5409SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5410 void*,sqlite3_int64);
5411#endif
5412
5413/*
5414** CAPI3REF: Obtaining SQL Values
5415** METHOD: sqlite3_value
5416**
5417** <b>Summary:</b>
5418** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5419** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5420** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5421** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5422** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5423** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5424** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5425** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5426** the native byteorder
5427** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5428** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5429** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5430** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5431** or a UTF-8 TEXT in bytes
5432** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5433** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5434** TEXT in bytes
5435** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5436** datatype of the value
5437** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5438** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5439** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5440** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5441** against a virtual table.
5442** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5443** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5444** </table></blockquote>
5445**
5446** <b>Details:</b>
5447**
5448** These routines extract type, size, and content information from
5449** [protected sqlite3_value] objects. Protected sqlite3_value objects
5450** are used to pass parameter information into the functions that
5451** implement [application-defined SQL functions] and [virtual tables].
5452**
5453** These routines work only with [protected sqlite3_value] objects.
5454** Any attempt to use these routines on an [unprotected sqlite3_value]
5455** is not threadsafe.
5456**
5457** ^These routines work just like the corresponding [column access functions]
5458** except that these routines take a single [protected sqlite3_value] object
5459** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5460**
5461** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5462** in the native byte-order of the host machine. ^The
5463** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5464** extract UTF-16 strings as big-endian and little-endian respectively.
5465**
5466** ^If [sqlite3_value] object V was initialized
5467** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5468** and if X and Y are strings that compare equal according to strcmp(X,Y),
5469** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5470** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5471** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5472**
5473** ^(The sqlite3_value_type(V) interface returns the
5474** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5475** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5476** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5477** Other interfaces might change the datatype for an sqlite3_value object.
5478** For example, if the datatype is initially SQLITE_INTEGER and
5479** sqlite3_value_text(V) is called to extract a text value for that
5480** integer, then subsequent calls to sqlite3_value_type(V) might return
5481** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5482** occurs is undefined and may change from one release of SQLite to the next.
5483**
5484** ^(The sqlite3_value_numeric_type() interface attempts to apply
5485** numeric affinity to the value. This means that an attempt is
5486** made to convert the value to an integer or floating point. If
5487** such a conversion is possible without loss of information (in other
5488** words, if the value is a string that looks like a number)
5489** then the conversion is performed. Otherwise no conversion occurs.
5490** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5491**
5492** ^Within the [xUpdate] method of a [virtual table], the
5493** sqlite3_value_nochange(X) interface returns true if and only if
5494** the column corresponding to X is unchanged by the UPDATE operation
5495** that the xUpdate method call was invoked to implement and if
5496** and the prior [xColumn] method call that was invoked to extracted
5497** the value for that column returned without setting a result (probably
5498** because it queried [sqlite3_vtab_nochange()] and found that the column
5499** was unchanging). ^Within an [xUpdate] method, any value for which
5500** sqlite3_value_nochange(X) is true will in all other respects appear
5501** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5502** than within an [xUpdate] method call for an UPDATE statement, then
5503** the return value is arbitrary and meaningless.
5504**
5505** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5506** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5507** interfaces. ^If X comes from an SQL literal value, or a table column,
5508** or an expression, then sqlite3_value_frombind(X) returns zero.
5509**
5510** Please pay particular attention to the fact that the pointer returned
5511** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5512** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5513** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5514** or [sqlite3_value_text16()].
5515**
5516** These routines must be called from the same thread as
5517** the SQL function that supplied the [sqlite3_value*] parameters.
5518**
5519** As long as the input parameter is correct, these routines can only
5520** fail if an out-of-memory error occurs during a format conversion.
5521** Only the following subset of interfaces are subject to out-of-memory
5522** errors:
5523**
5524** <ul>
5525** <li> sqlite3_value_blob()
5526** <li> sqlite3_value_text()
5527** <li> sqlite3_value_text16()
5528** <li> sqlite3_value_text16le()
5529** <li> sqlite3_value_text16be()
5530** <li> sqlite3_value_bytes()
5531** <li> sqlite3_value_bytes16()
5532** </ul>
5533**
5534** If an out-of-memory error occurs, then the return value from these
5535** routines is the same as if the column had contained an SQL NULL value.
5536** Valid SQL NULL returns can be distinguished from out-of-memory errors
5537** by invoking the [sqlite3_errcode()] immediately after the suspect
5538** return value is obtained and before any
5539** other SQLite interface is called on the same [database connection].
5540*/
5541SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5542SQLITE_API double sqlite3_value_double(sqlite3_value*);
5543SQLITE_API int sqlite3_value_int(sqlite3_value*);
5544SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5545SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5546SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5547SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5548SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5549SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5550SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5551SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5552SQLITE_API int sqlite3_value_type(sqlite3_value*);
5553SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5554SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5555SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5556
5557/*
5558** CAPI3REF: Finding The Subtype Of SQL Values
5559** METHOD: sqlite3_value
5560**
5561** The sqlite3_value_subtype(V) function returns the subtype for
5562** an [application-defined SQL function] argument V. The subtype
5563** information can be used to pass a limited amount of context from
5564** one SQL function to another. Use the [sqlite3_result_subtype()]
5565** routine to set the subtype for the return value of an SQL function.
5566*/
5567SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5568
5569/*
5570** CAPI3REF: Copy And Free SQL Values
5571** METHOD: sqlite3_value
5572**
5573** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5574** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5575** is a [protected sqlite3_value] object even if the input is not.
5576** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5577** memory allocation fails.
5578**
5579** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5580** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5581** then sqlite3_value_free(V) is a harmless no-op.
5582*/
5583SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5584SQLITE_API void sqlite3_value_free(sqlite3_value*);
5585
5586/*
5587** CAPI3REF: Obtain Aggregate Function Context
5588** METHOD: sqlite3_context
5589**
5590** Implementations of aggregate SQL functions use this
5591** routine to allocate memory for storing their state.
5592**
5593** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5594** for a particular aggregate function, SQLite allocates
5595** N bytes of memory, zeroes out that memory, and returns a pointer
5596** to the new memory. ^On second and subsequent calls to
5597** sqlite3_aggregate_context() for the same aggregate function instance,
5598** the same buffer is returned. Sqlite3_aggregate_context() is normally
5599** called once for each invocation of the xStep callback and then one
5600** last time when the xFinal callback is invoked. ^(When no rows match
5601** an aggregate query, the xStep() callback of the aggregate function
5602** implementation is never called and xFinal() is called exactly once.
5603** In those cases, sqlite3_aggregate_context() might be called for the
5604** first time from within xFinal().)^
5605**
5606** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5607** when first called if N is less than or equal to zero or if a memory
5608** allocate error occurs.
5609**
5610** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5611** determined by the N parameter on first successful call. Changing the
5612** value of N in any subsequent call to sqlite3_aggregate_context() within
5613** the same aggregate function instance will not resize the memory
5614** allocation.)^ Within the xFinal callback, it is customary to set
5615** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5616** pointless memory allocations occur.
5617**
5618** ^SQLite automatically frees the memory allocated by
5619** sqlite3_aggregate_context() when the aggregate query concludes.
5620**
5621** The first parameter must be a copy of the
5622** [sqlite3_context | SQL function context] that is the first parameter
5623** to the xStep or xFinal callback routine that implements the aggregate
5624** function.
5625**
5626** This routine must be called from the same thread in which
5627** the aggregate SQL function is running.
5628*/
5629SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5630
5631/*
5632** CAPI3REF: User Data For Functions
5633** METHOD: sqlite3_context
5634**
5635** ^The sqlite3_user_data() interface returns a copy of
5636** the pointer that was the pUserData parameter (the 5th parameter)
5637** of the [sqlite3_create_function()]
5638** and [sqlite3_create_function16()] routines that originally
5639** registered the application defined function.
5640**
5641** This routine must be called from the same thread in which
5642** the application-defined function is running.
5643*/
5644SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5645
5646/*
5647** CAPI3REF: Database Connection For Functions
5648** METHOD: sqlite3_context
5649**
5650** ^The sqlite3_context_db_handle() interface returns a copy of
5651** the pointer to the [database connection] (the 1st parameter)
5652** of the [sqlite3_create_function()]
5653** and [sqlite3_create_function16()] routines that originally
5654** registered the application defined function.
5655*/
5656SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5657
5658/*
5659** CAPI3REF: Function Auxiliary Data
5660** METHOD: sqlite3_context
5661**
5662** These functions may be used by (non-aggregate) SQL functions to
5663** associate metadata with argument values. If the same value is passed to
5664** multiple invocations of the same SQL function during query execution, under
5665** some circumstances the associated metadata may be preserved. An example
5666** of where this might be useful is in a regular-expression matching
5667** function. The compiled version of the regular expression can be stored as
5668** metadata associated with the pattern string.
5669** Then as long as the pattern string remains the same,
5670** the compiled regular expression can be reused on multiple
5671** invocations of the same function.
5672**
5673** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5674** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5675** value to the application-defined function. ^N is zero for the left-most
5676** function argument. ^If there is no metadata
5677** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5678** returns a NULL pointer.
5679**
5680** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5681** argument of the application-defined function. ^Subsequent
5682** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5683** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5684** NULL if the metadata has been discarded.
5685** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5686** SQLite will invoke the destructor function X with parameter P exactly
5687** once, when the metadata is discarded.
5688** SQLite is free to discard the metadata at any time, including: <ul>
5689** <li> ^(when the corresponding function parameter changes)^, or
5690** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5691** SQL statement)^, or
5692** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5693** parameter)^, or
5694** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5695** allocation error occurs.)^ </ul>
5696**
5697** Note the last bullet in particular. The destructor X in
5698** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5699** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5700** should be called near the end of the function implementation and the
5701** function implementation should not make any use of P after
5702** sqlite3_set_auxdata() has been called.
5703**
5704** ^(In practice, metadata is preserved between function calls for
5705** function parameters that are compile-time constants, including literal
5706** values and [parameters] and expressions composed from the same.)^
5707**
5708** The value of the N parameter to these interfaces should be non-negative.
5709** Future enhancements may make use of negative N values to define new
5710** kinds of function caching behavior.
5711**
5712** These routines must be called from the same thread in which
5713** the SQL function is running.
5714*/
5715SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5716SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5717
5718
5719/*
5720** CAPI3REF: Constants Defining Special Destructor Behavior
5721**
5722** These are special values for the destructor that is passed in as the
5723** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5724** argument is SQLITE_STATIC, it means that the content pointer is constant
5725** and will never change. It does not need to be destroyed. ^The
5726** SQLITE_TRANSIENT value means that the content will likely change in
5727** the near future and that SQLite should make its own private copy of
5728** the content before returning.
5729**
5730** The typedef is necessary to work around problems in certain
5731** C++ compilers.
5732*/
5733typedef void (*sqlite3_destructor_type)(void*);
5734#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5735#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5736
5737/*
5738** CAPI3REF: Setting The Result Of An SQL Function
5739** METHOD: sqlite3_context
5740**
5741** These routines are used by the xFunc or xFinal callbacks that
5742** implement SQL functions and aggregates. See
5743** [sqlite3_create_function()] and [sqlite3_create_function16()]
5744** for additional information.
5745**
5746** These functions work very much like the [parameter binding] family of
5747** functions used to bind values to host parameters in prepared statements.
5748** Refer to the [SQL parameter] documentation for additional information.
5749**
5750** ^The sqlite3_result_blob() interface sets the result from
5751** an application-defined function to be the BLOB whose content is pointed
5752** to by the second parameter and which is N bytes long where N is the
5753** third parameter.
5754**
5755** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5756** interfaces set the result of the application-defined function to be
5757** a BLOB containing all zero bytes and N bytes in size.
5758**
5759** ^The sqlite3_result_double() interface sets the result from
5760** an application-defined function to be a floating point value specified
5761** by its 2nd argument.
5762**
5763** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5764** cause the implemented SQL function to throw an exception.
5765** ^SQLite uses the string pointed to by the
5766** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5767** as the text of an error message. ^SQLite interprets the error
5768** message string from sqlite3_result_error() as UTF-8. ^SQLite
5769** interprets the string from sqlite3_result_error16() as UTF-16 using
5770** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5771** ^If the third parameter to sqlite3_result_error()
5772** or sqlite3_result_error16() is negative then SQLite takes as the error
5773** message all text up through the first zero character.
5774** ^If the third parameter to sqlite3_result_error() or
5775** sqlite3_result_error16() is non-negative then SQLite takes that many
5776** bytes (not characters) from the 2nd parameter as the error message.
5777** ^The sqlite3_result_error() and sqlite3_result_error16()
5778** routines make a private copy of the error message text before
5779** they return. Hence, the calling function can deallocate or
5780** modify the text after they return without harm.
5781** ^The sqlite3_result_error_code() function changes the error code
5782** returned by SQLite as a result of an error in a function. ^By default,
5783** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5784** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5785**
5786** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5787** error indicating that a string or BLOB is too long to represent.
5788**
5789** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5790** error indicating that a memory allocation failed.
5791**
5792** ^The sqlite3_result_int() interface sets the return value
5793** of the application-defined function to be the 32-bit signed integer
5794** value given in the 2nd argument.
5795** ^The sqlite3_result_int64() interface sets the return value
5796** of the application-defined function to be the 64-bit signed integer
5797** value given in the 2nd argument.
5798**
5799** ^The sqlite3_result_null() interface sets the return value
5800** of the application-defined function to be NULL.
5801**
5802** ^The sqlite3_result_text(), sqlite3_result_text16(),
5803** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5804** set the return value of the application-defined function to be
5805** a text string which is represented as UTF-8, UTF-16 native byte order,
5806** UTF-16 little endian, or UTF-16 big endian, respectively.
5807** ^The sqlite3_result_text64() interface sets the return value of an
5808** application-defined function to be a text string in an encoding
5809** specified by the fifth (and last) parameter, which must be one
5810** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5811** ^SQLite takes the text result from the application from
5812** the 2nd parameter of the sqlite3_result_text* interfaces.
5813** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5814** is negative, then SQLite takes result text from the 2nd parameter
5815** through the first zero character.
5816** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5817** is non-negative, then as many bytes (not characters) of the text
5818** pointed to by the 2nd parameter are taken as the application-defined
5819** function result. If the 3rd parameter is non-negative, then it
5820** must be the byte offset into the string where the NUL terminator would
5821** appear if the string where NUL terminated. If any NUL characters occur
5822** in the string at a byte offset that is less than the value of the 3rd
5823** parameter, then the resulting string will contain embedded NULs and the
5824** result of expressions operating on strings with embedded NULs is undefined.
5825** ^If the 4th parameter to the sqlite3_result_text* interfaces
5826** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5827** function as the destructor on the text or BLOB result when it has
5828** finished using that result.
5829** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5830** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5831** assumes that the text or BLOB result is in constant space and does not
5832** copy the content of the parameter nor call a destructor on the content
5833** when it has finished using that result.
5834** ^If the 4th parameter to the sqlite3_result_text* interfaces
5835** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5836** then SQLite makes a copy of the result into space obtained
5837** from [sqlite3_malloc()] before it returns.
5838**
5839** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
5840** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
5841** when the encoding is not UTF8, if the input UTF16 begins with a
5842** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
5843** string and the rest of the string is interpreted according to the
5844** byte-order specified by the BOM. ^The byte-order specified by
5845** the BOM at the beginning of the text overrides the byte-order
5846** specified by the interface procedure. ^So, for example, if
5847** sqlite3_result_text16le() is invoked with text that begins
5848** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
5849** first two bytes of input are skipped and the remaining input
5850** is interpreted as UTF16BE text.
5851**
5852** ^For UTF16 input text to the sqlite3_result_text16(),
5853** sqlite3_result_text16be(), sqlite3_result_text16le(), and
5854** sqlite3_result_text64() routines, if the text contains invalid
5855** UTF16 characters, the invalid characters might be converted
5856** into the unicode replacement character, U+FFFD.
5857**
5858** ^The sqlite3_result_value() interface sets the result of
5859** the application-defined function to be a copy of the
5860** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5861** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5862** so that the [sqlite3_value] specified in the parameter may change or
5863** be deallocated after sqlite3_result_value() returns without harm.
5864** ^A [protected sqlite3_value] object may always be used where an
5865** [unprotected sqlite3_value] object is required, so either
5866** kind of [sqlite3_value] object can be used with this interface.
5867**
5868** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5869** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5870** also associates the host-language pointer P or type T with that
5871** NULL value such that the pointer can be retrieved within an
5872** [application-defined SQL function] using [sqlite3_value_pointer()].
5873** ^If the D parameter is not NULL, then it is a pointer to a destructor
5874** for the P parameter. ^SQLite invokes D with P as its only argument
5875** when SQLite is finished with P. The T parameter should be a static
5876** string and preferably a string literal. The sqlite3_result_pointer()
5877** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5878**
5879** If these routines are called from within the different thread
5880** than the one containing the application-defined function that received
5881** the [sqlite3_context] pointer, the results are undefined.
5882*/
5883SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5884SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5885 sqlite3_uint64,void(*)(void*));
5886SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5887SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5888SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5889SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5890SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5891SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5892SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5893SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5894SQLITE_API void sqlite3_result_null(sqlite3_context*);
5895SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5896SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5897 void(*)(void*), unsigned char encoding);
5898SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5899SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5900SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5901SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5902SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5903SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5904SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5905
5906
5907/*
5908** CAPI3REF: Setting The Subtype Of An SQL Function
5909** METHOD: sqlite3_context
5910**
5911** The sqlite3_result_subtype(C,T) function causes the subtype of
5912** the result from the [application-defined SQL function] with
5913** [sqlite3_context] C to be the value T. Only the lower 8 bits
5914** of the subtype T are preserved in current versions of SQLite;
5915** higher order bits are discarded.
5916** The number of subtype bytes preserved by SQLite might increase
5917** in future releases of SQLite.
5918*/
5919SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5920
5921/*
5922** CAPI3REF: Define New Collating Sequences
5923** METHOD: sqlite3
5924**
5925** ^These functions add, remove, or modify a [collation] associated
5926** with the [database connection] specified as the first argument.
5927**
5928** ^The name of the collation is a UTF-8 string
5929** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5930** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5931** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5932** considered to be the same name.
5933**
5934** ^(The third argument (eTextRep) must be one of the constants:
5935** <ul>
5936** <li> [SQLITE_UTF8],
5937** <li> [SQLITE_UTF16LE],
5938** <li> [SQLITE_UTF16BE],
5939** <li> [SQLITE_UTF16], or
5940** <li> [SQLITE_UTF16_ALIGNED].
5941** </ul>)^
5942** ^The eTextRep argument determines the encoding of strings passed
5943** to the collating function callback, xCompare.
5944** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5945** force strings to be UTF16 with native byte order.
5946** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5947** on an even byte address.
5948**
5949** ^The fourth argument, pArg, is an application data pointer that is passed
5950** through as the first argument to the collating function callback.
5951**
5952** ^The fifth argument, xCompare, is a pointer to the collating function.
5953** ^Multiple collating functions can be registered using the same name but
5954** with different eTextRep parameters and SQLite will use whichever
5955** function requires the least amount of data transformation.
5956** ^If the xCompare argument is NULL then the collating function is
5957** deleted. ^When all collating functions having the same name are deleted,
5958** that collation is no longer usable.
5959**
5960** ^The collating function callback is invoked with a copy of the pArg
5961** application data pointer and with two strings in the encoding specified
5962** by the eTextRep argument. The two integer parameters to the collating
5963** function callback are the length of the two strings, in bytes. The collating
5964** function must return an integer that is negative, zero, or positive
5965** if the first string is less than, equal to, or greater than the second,
5966** respectively. A collating function must always return the same answer
5967** given the same inputs. If two or more collating functions are registered
5968** to the same collation name (using different eTextRep values) then all
5969** must give an equivalent answer when invoked with equivalent strings.
5970** The collating function must obey the following properties for all
5971** strings A, B, and C:
5972**
5973** <ol>
5974** <li> If A==B then B==A.
5975** <li> If A==B and B==C then A==C.
5976** <li> If A&lt;B THEN B&gt;A.
5977** <li> If A&lt;B and B&lt;C then A&lt;C.
5978** </ol>
5979**
5980** If a collating function fails any of the above constraints and that
5981** collating function is registered and used, then the behavior of SQLite
5982** is undefined.
5983**
5984** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5985** with the addition that the xDestroy callback is invoked on pArg when
5986** the collating function is deleted.
5987** ^Collating functions are deleted when they are overridden by later
5988** calls to the collation creation functions or when the
5989** [database connection] is closed using [sqlite3_close()].
5990**
5991** ^The xDestroy callback is <u>not</u> called if the
5992** sqlite3_create_collation_v2() function fails. Applications that invoke
5993** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5994** check the return code and dispose of the application data pointer
5995** themselves rather than expecting SQLite to deal with it for them.
5996** This is different from every other SQLite interface. The inconsistency
5997** is unfortunate but cannot be changed without breaking backwards
5998** compatibility.
5999**
6000** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6001*/
6002SQLITE_API int sqlite3_create_collation(
6003 sqlite3*,
6004 const char *zName,
6005 int eTextRep,
6006 void *pArg,
6007 int(*xCompare)(void*,int,const void*,int,const void*)
6008);
6009SQLITE_API int sqlite3_create_collation_v2(
6010 sqlite3*,
6011 const char *zName,
6012 int eTextRep,
6013 void *pArg,
6014 int(*xCompare)(void*,int,const void*,int,const void*),
6015 void(*xDestroy)(void*)
6016);
6017SQLITE_API int sqlite3_create_collation16(
6018 sqlite3*,
6019 const void *zName,
6020 int eTextRep,
6021 void *pArg,
6022 int(*xCompare)(void*,int,const void*,int,const void*)
6023);
6024
6025/*
6026** CAPI3REF: Collation Needed Callbacks
6027** METHOD: sqlite3
6028**
6029** ^To avoid having to register all collation sequences before a database
6030** can be used, a single callback function may be registered with the
6031** [database connection] to be invoked whenever an undefined collation
6032** sequence is required.
6033**
6034** ^If the function is registered using the sqlite3_collation_needed() API,
6035** then it is passed the names of undefined collation sequences as strings
6036** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6037** the names are passed as UTF-16 in machine native byte order.
6038** ^A call to either function replaces the existing collation-needed callback.
6039**
6040** ^(When the callback is invoked, the first argument passed is a copy
6041** of the second argument to sqlite3_collation_needed() or
6042** sqlite3_collation_needed16(). The second argument is the database
6043** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6044** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6045** sequence function required. The fourth parameter is the name of the
6046** required collation sequence.)^
6047**
6048** The callback function should register the desired collation using
6049** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6050** [sqlite3_create_collation_v2()].
6051*/
6052SQLITE_API int sqlite3_collation_needed(
6053 sqlite3*,
6054 void*,
6055 void(*)(void*,sqlite3*,int eTextRep,const char*)
6056);
6057SQLITE_API int sqlite3_collation_needed16(
6058 sqlite3*,
6059 void*,
6060 void(*)(void*,sqlite3*,int eTextRep,const void*)
6061);
6062
6063#ifdef SQLITE_ENABLE_CEROD
6064/*
6065** Specify the activation key for a CEROD database. Unless
6066** activated, none of the CEROD routines will work.
6067*/
6068SQLITE_API void sqlite3_activate_cerod(
6069 const char *zPassPhrase /* Activation phrase */
6070);
6071#endif
6072
6073/*
6074** CAPI3REF: Suspend Execution For A Short Time
6075**
6076** The sqlite3_sleep() function causes the current thread to suspend execution
6077** for at least a number of milliseconds specified in its parameter.
6078**
6079** If the operating system does not support sleep requests with
6080** millisecond time resolution, then the time will be rounded up to
6081** the nearest second. The number of milliseconds of sleep actually
6082** requested from the operating system is returned.
6083**
6084** ^SQLite implements this interface by calling the xSleep()
6085** method of the default [sqlite3_vfs] object. If the xSleep() method
6086** of the default VFS is not implemented correctly, or not implemented at
6087** all, then the behavior of sqlite3_sleep() may deviate from the description
6088** in the previous paragraphs.
6089*/
6090SQLITE_API int sqlite3_sleep(int);
6091
6092/*
6093** CAPI3REF: Name Of The Folder Holding Temporary Files
6094**
6095** ^(If this global variable is made to point to a string which is
6096** the name of a folder (a.k.a. directory), then all temporary files
6097** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6098** will be placed in that directory.)^ ^If this variable
6099** is a NULL pointer, then SQLite performs a search for an appropriate
6100** temporary file directory.
6101**
6102** Applications are strongly discouraged from using this global variable.
6103** It is required to set a temporary folder on Windows Runtime (WinRT).
6104** But for all other platforms, it is highly recommended that applications
6105** neither read nor write this variable. This global variable is a relic
6106** that exists for backwards compatibility of legacy applications and should
6107** be avoided in new projects.
6108**
6109** It is not safe to read or modify this variable in more than one
6110** thread at a time. It is not safe to read or modify this variable
6111** if a [database connection] is being used at the same time in a separate
6112** thread.
6113** It is intended that this variable be set once
6114** as part of process initialization and before any SQLite interface
6115** routines have been called and that this variable remain unchanged
6116** thereafter.
6117**
6118** ^The [temp_store_directory pragma] may modify this variable and cause
6119** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6120** the [temp_store_directory pragma] always assumes that any string
6121** that this variable points to is held in memory obtained from
6122** [sqlite3_malloc] and the pragma may attempt to free that memory
6123** using [sqlite3_free].
6124** Hence, if this variable is modified directly, either it should be
6125** made NULL or made to point to memory obtained from [sqlite3_malloc]
6126** or else the use of the [temp_store_directory pragma] should be avoided.
6127** Except when requested by the [temp_store_directory pragma], SQLite
6128** does not free the memory that sqlite3_temp_directory points to. If
6129** the application wants that memory to be freed, it must do
6130** so itself, taking care to only do so after all [database connection]
6131** objects have been destroyed.
6132**
6133** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6134** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6135** features that require the use of temporary files may fail. Here is an
6136** example of how to do this using C++ with the Windows Runtime:
6137**
6138** <blockquote><pre>
6139** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6140** &nbsp; TemporaryFolder->Path->Data();
6141** char zPathBuf&#91;MAX_PATH + 1&#93;;
6142** memset(zPathBuf, 0, sizeof(zPathBuf));
6143** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6144** &nbsp; NULL, NULL);
6145** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6146** </pre></blockquote>
6147*/
6148SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6149
6150/*
6151** CAPI3REF: Name Of The Folder Holding Database Files
6152**
6153** ^(If this global variable is made to point to a string which is
6154** the name of a folder (a.k.a. directory), then all database files
6155** specified with a relative pathname and created or accessed by
6156** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6157** to be relative to that directory.)^ ^If this variable is a NULL
6158** pointer, then SQLite assumes that all database files specified
6159** with a relative pathname are relative to the current directory
6160** for the process. Only the windows VFS makes use of this global
6161** variable; it is ignored by the unix VFS.
6162**
6163** Changing the value of this variable while a database connection is
6164** open can result in a corrupt database.
6165**
6166** It is not safe to read or modify this variable in more than one
6167** thread at a time. It is not safe to read or modify this variable
6168** if a [database connection] is being used at the same time in a separate
6169** thread.
6170** It is intended that this variable be set once
6171** as part of process initialization and before any SQLite interface
6172** routines have been called and that this variable remain unchanged
6173** thereafter.
6174**
6175** ^The [data_store_directory pragma] may modify this variable and cause
6176** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6177** the [data_store_directory pragma] always assumes that any string
6178** that this variable points to is held in memory obtained from
6179** [sqlite3_malloc] and the pragma may attempt to free that memory
6180** using [sqlite3_free].
6181** Hence, if this variable is modified directly, either it should be
6182** made NULL or made to point to memory obtained from [sqlite3_malloc]
6183** or else the use of the [data_store_directory pragma] should be avoided.
6184*/
6185SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6186
6187/*
6188** CAPI3REF: Win32 Specific Interface
6189**
6190** These interfaces are available only on Windows. The
6191** [sqlite3_win32_set_directory] interface is used to set the value associated
6192** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6193** zValue, depending on the value of the type parameter. The zValue parameter
6194** should be NULL to cause the previous value to be freed via [sqlite3_free];
6195** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6196** prior to being used. The [sqlite3_win32_set_directory] interface returns
6197** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6198** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6199** [sqlite3_data_directory] variable is intended to act as a replacement for
6200** the current directory on the sub-platforms of Win32 where that concept is
6201** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6202** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6203** sqlite3_win32_set_directory interface except the string parameter must be
6204** UTF-8 or UTF-16, respectively.
6205*/
6206SQLITE_API int sqlite3_win32_set_directory(
6207 unsigned long type, /* Identifier for directory being set or reset */
6208 void *zValue /* New value for directory being set or reset */
6209);
6210SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6211SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6212
6213/*
6214** CAPI3REF: Win32 Directory Types
6215**
6216** These macros are only available on Windows. They define the allowed values
6217** for the type argument to the [sqlite3_win32_set_directory] interface.
6218*/
6219#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6220#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6221
6222/*
6223** CAPI3REF: Test For Auto-Commit Mode
6224** KEYWORDS: {autocommit mode}
6225** METHOD: sqlite3
6226**
6227** ^The sqlite3_get_autocommit() interface returns non-zero or
6228** zero if the given database connection is or is not in autocommit mode,
6229** respectively. ^Autocommit mode is on by default.
6230** ^Autocommit mode is disabled by a [BEGIN] statement.
6231** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6232**
6233** If certain kinds of errors occur on a statement within a multi-statement
6234** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6235** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6236** transaction might be rolled back automatically. The only way to
6237** find out whether SQLite automatically rolled back the transaction after
6238** an error is to use this function.
6239**
6240** If another thread changes the autocommit status of the database
6241** connection while this routine is running, then the return value
6242** is undefined.
6243*/
6244SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6245
6246/*
6247** CAPI3REF: Find The Database Handle Of A Prepared Statement
6248** METHOD: sqlite3_stmt
6249**
6250** ^The sqlite3_db_handle interface returns the [database connection] handle
6251** to which a [prepared statement] belongs. ^The [database connection]
6252** returned by sqlite3_db_handle is the same [database connection]
6253** that was the first argument
6254** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6255** create the statement in the first place.
6256*/
6257SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6258
6259/*
6260** CAPI3REF: Return The Filename For A Database Connection
6261** METHOD: sqlite3
6262**
6263** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6264** associated with database N of connection D.
6265** ^If there is no attached database N on the database
6266** connection D, or if database N is a temporary or in-memory database, then
6267** this function will return either a NULL pointer or an empty string.
6268**
6269** ^The string value returned by this routine is owned and managed by
6270** the database connection. ^The value will be valid until the database N
6271** is [DETACH]-ed or until the database connection closes.
6272**
6273** ^The filename returned by this function is the output of the
6274** xFullPathname method of the [VFS]. ^In other words, the filename
6275** will be an absolute pathname, even if the filename used
6276** to open the database originally was a URI or relative pathname.
6277**
6278** If the filename pointer returned by this routine is not NULL, then it
6279** can be used as the filename input parameter to these routines:
6280** <ul>
6281** <li> [sqlite3_uri_parameter()]
6282** <li> [sqlite3_uri_boolean()]
6283** <li> [sqlite3_uri_int64()]
6284** <li> [sqlite3_filename_database()]
6285** <li> [sqlite3_filename_journal()]
6286** <li> [sqlite3_filename_wal()]
6287** </ul>
6288*/
6289SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6290
6291/*
6292** CAPI3REF: Determine if a database is read-only
6293** METHOD: sqlite3
6294**
6295** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6296** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6297** the name of a database on connection D.
6298*/
6299SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6300
6301/*
6302** CAPI3REF: Determine the transaction state of a database
6303** METHOD: sqlite3
6304**
6305** ^The sqlite3_txn_state(D,S) interface returns the current
6306** [transaction state] of schema S in database connection D. ^If S is NULL,
6307** then the highest transaction state of any schema on database connection D
6308** is returned. Transaction states are (in order of lowest to highest):
6309** <ol>
6310** <li value="0"> SQLITE_TXN_NONE
6311** <li value="1"> SQLITE_TXN_READ
6312** <li value="2"> SQLITE_TXN_WRITE
6313** </ol>
6314** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6315** a valid schema, then -1 is returned.
6316*/
6317SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6318
6319/*
6320** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
6321** KEYWORDS: {transaction state}
6322**
6323** These constants define the current transaction state of a database file.
6324** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6325** constants in order to describe the transaction state of schema S
6326** in [database connection] D.
6327**
6328** <dl>
6329** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6330** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6331** pending.</dd>
6332**
6333** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6334** <dd>The SQLITE_TXN_READ state means that the database is currently
6335** in a read transaction. Content has been read from the database file
6336** but nothing in the database file has changed. The transaction state
6337** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6338** no other conflicting concurrent write transactions. The transaction
6339** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6340** [COMMIT].</dd>
6341**
6342** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6343** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6344** in a write transaction. Content has been written to the database file
6345** but has not yet committed. The transaction state will change to
6346** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6347*/
6348#define SQLITE_TXN_NONE 0
6349#define SQLITE_TXN_READ 1
6350#define SQLITE_TXN_WRITE 2
6351
6352/*
6353** CAPI3REF: Find the next prepared statement
6354** METHOD: sqlite3
6355**
6356** ^This interface returns a pointer to the next [prepared statement] after
6357** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6358** then this interface returns a pointer to the first prepared statement
6359** associated with the database connection pDb. ^If no prepared statement
6360** satisfies the conditions of this routine, it returns NULL.
6361**
6362** The [database connection] pointer D in a call to
6363** [sqlite3_next_stmt(D,S)] must refer to an open database
6364** connection and in particular must not be a NULL pointer.
6365*/
6366SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6367
6368/*
6369** CAPI3REF: Commit And Rollback Notification Callbacks
6370** METHOD: sqlite3
6371**
6372** ^The sqlite3_commit_hook() interface registers a callback
6373** function to be invoked whenever a transaction is [COMMIT | committed].
6374** ^Any callback set by a previous call to sqlite3_commit_hook()
6375** for the same database connection is overridden.
6376** ^The sqlite3_rollback_hook() interface registers a callback
6377** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6378** ^Any callback set by a previous call to sqlite3_rollback_hook()
6379** for the same database connection is overridden.
6380** ^The pArg argument is passed through to the callback.
6381** ^If the callback on a commit hook function returns non-zero,
6382** then the commit is converted into a rollback.
6383**
6384** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6385** return the P argument from the previous call of the same function
6386** on the same [database connection] D, or NULL for
6387** the first call for each function on D.
6388**
6389** The commit and rollback hook callbacks are not reentrant.
6390** The callback implementation must not do anything that will modify
6391** the database connection that invoked the callback. Any actions
6392** to modify the database connection must be deferred until after the
6393** completion of the [sqlite3_step()] call that triggered the commit
6394** or rollback hook in the first place.
6395** Note that running any other SQL statements, including SELECT statements,
6396** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6397** the database connections for the meaning of "modify" in this paragraph.
6398**
6399** ^Registering a NULL function disables the callback.
6400**
6401** ^When the commit hook callback routine returns zero, the [COMMIT]
6402** operation is allowed to continue normally. ^If the commit hook
6403** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6404** ^The rollback hook is invoked on a rollback that results from a commit
6405** hook returning non-zero, just as it would be with any other rollback.
6406**
6407** ^For the purposes of this API, a transaction is said to have been
6408** rolled back if an explicit "ROLLBACK" statement is executed, or
6409** an error or constraint causes an implicit rollback to occur.
6410** ^The rollback callback is not invoked if a transaction is
6411** automatically rolled back because the database connection is closed.
6412**
6413** See also the [sqlite3_update_hook()] interface.
6414*/
6415SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6416SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6417
6418/*
6419** CAPI3REF: Autovacuum Compaction Amount Callback
6420** METHOD: sqlite3
6421**
6422** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6423** function C that is invoked prior to each autovacuum of the database
6424** file. ^The callback is passed a copy of the generic data pointer (P),
6425** the schema-name of the attached database that is being autovacuumed,
6426** the the size of the database file in pages, the number of free pages,
6427** and the number of bytes per page, respectively. The callback should
6428** return the number of free pages that should be removed by the
6429** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6430** ^If the value returned is greater than or equal to the number of
6431** free pages, then a complete autovacuum happens.
6432**
6433** <p>^If there are multiple ATTACH-ed database files that are being
6434** modified as part of a transaction commit, then the autovacuum pages
6435** callback is invoked separately for each file.
6436**
6437** <p><b>The callback is not reentrant.</b> The callback function should
6438** not attempt to invoke any other SQLite interface. If it does, bad
6439** things may happen, including segmentation faults and corrupt database
6440** files. The callback function should be a simple function that
6441** does some arithmetic on its input parameters and returns a result.
6442**
6443** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6444** destructor for the P parameter. ^If X is not NULL, then X(P) is
6445** invoked whenever the database connection closes or when the callback
6446** is overwritten by another invocation of sqlite3_autovacuum_pages().
6447**
6448** <p>^There is only one autovacuum pages callback per database connection.
6449** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6450** previous invocations for that database connection. ^If the callback
6451** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6452** then the autovacuum steps callback is cancelled. The return value
6453** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6454** be some other error code if something goes wrong. The current
6455** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6456** return codes might be added in future releases.
6457**
6458** <p>If no autovacuum pages callback is specified (the usual case) or
6459** a NULL pointer is provided for the callback,
6460** then the default behavior is to vacuum all free pages. So, in other
6461** words, the default behavior is the same as if the callback function
6462** were something like this:
6463**
6464** <blockquote><pre>
6465** &nbsp; unsigned int demonstration_autovac_pages_callback(
6466** &nbsp; void *pClientData,
6467** &nbsp; const char *zSchema,
6468** &nbsp; unsigned int nDbPage,
6469** &nbsp; unsigned int nFreePage,
6470** &nbsp; unsigned int nBytePerPage
6471** &nbsp; ){
6472** &nbsp; return nFreePage;
6473** &nbsp; }
6474** </pre></blockquote>
6475*/
6476SQLITE_API int sqlite3_autovacuum_pages(
6477 sqlite3 *db,
6478 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6479 void*,
6480 void(*)(void*)
6481);
6482
6483
6484/*
6485** CAPI3REF: Data Change Notification Callbacks
6486** METHOD: sqlite3
6487**
6488** ^The sqlite3_update_hook() interface registers a callback function
6489** with the [database connection] identified by the first argument
6490** to be invoked whenever a row is updated, inserted or deleted in
6491** a [rowid table].
6492** ^Any callback set by a previous call to this function
6493** for the same database connection is overridden.
6494**
6495** ^The second argument is a pointer to the function to invoke when a
6496** row is updated, inserted or deleted in a rowid table.
6497** ^The first argument to the callback is a copy of the third argument
6498** to sqlite3_update_hook().
6499** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6500** or [SQLITE_UPDATE], depending on the operation that caused the callback
6501** to be invoked.
6502** ^The third and fourth arguments to the callback contain pointers to the
6503** database and table name containing the affected row.
6504** ^The final callback parameter is the [rowid] of the row.
6505** ^In the case of an update, this is the [rowid] after the update takes place.
6506**
6507** ^(The update hook is not invoked when internal system tables are
6508** modified (i.e. sqlite_sequence).)^
6509** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6510**
6511** ^In the current implementation, the update hook
6512** is not invoked when conflicting rows are deleted because of an
6513** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6514** invoked when rows are deleted using the [truncate optimization].
6515** The exceptions defined in this paragraph might change in a future
6516** release of SQLite.
6517**
6518** The update hook implementation must not do anything that will modify
6519** the database connection that invoked the update hook. Any actions
6520** to modify the database connection must be deferred until after the
6521** completion of the [sqlite3_step()] call that triggered the update hook.
6522** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6523** database connections for the meaning of "modify" in this paragraph.
6524**
6525** ^The sqlite3_update_hook(D,C,P) function
6526** returns the P argument from the previous call
6527** on the same [database connection] D, or NULL for
6528** the first call on D.
6529**
6530** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6531** and [sqlite3_preupdate_hook()] interfaces.
6532*/
6533SQLITE_API void *sqlite3_update_hook(
6534 sqlite3*,
6535 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6536 void*
6537);
6538
6539/*
6540** CAPI3REF: Enable Or Disable Shared Pager Cache
6541**
6542** ^(This routine enables or disables the sharing of the database cache
6543** and schema data structures between [database connection | connections]
6544** to the same database. Sharing is enabled if the argument is true
6545** and disabled if the argument is false.)^
6546**
6547** ^Cache sharing is enabled and disabled for an entire process.
6548** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6549** In prior versions of SQLite,
6550** sharing was enabled or disabled for each thread separately.
6551**
6552** ^(The cache sharing mode set by this interface effects all subsequent
6553** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6554** Existing database connections continue to use the sharing mode
6555** that was in effect at the time they were opened.)^
6556**
6557** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6558** successfully. An [error code] is returned otherwise.)^
6559**
6560** ^Shared cache is disabled by default. It is recommended that it stay
6561** that way. In other words, do not use this routine. This interface
6562** continues to be provided for historical compatibility, but its use is
6563** discouraged. Any use of shared cache is discouraged. If shared cache
6564** must be used, it is recommended that shared cache only be enabled for
6565** individual database connections using the [sqlite3_open_v2()] interface
6566** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6567**
6568** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6569** and will always return SQLITE_MISUSE. On those systems,
6570** shared cache mode should be enabled per-database connection via
6571** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6572**
6573** This interface is threadsafe on processors where writing a
6574** 32-bit integer is atomic.
6575**
6576** See Also: [SQLite Shared-Cache Mode]
6577*/
6578SQLITE_API int sqlite3_enable_shared_cache(int);
6579
6580/*
6581** CAPI3REF: Attempt To Free Heap Memory
6582**
6583** ^The sqlite3_release_memory() interface attempts to free N bytes
6584** of heap memory by deallocating non-essential memory allocations
6585** held by the database library. Memory used to cache database
6586** pages to improve performance is an example of non-essential memory.
6587** ^sqlite3_release_memory() returns the number of bytes actually freed,
6588** which might be more or less than the amount requested.
6589** ^The sqlite3_release_memory() routine is a no-op returning zero
6590** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6591**
6592** See also: [sqlite3_db_release_memory()]
6593*/
6594SQLITE_API int sqlite3_release_memory(int);
6595
6596/*
6597** CAPI3REF: Free Memory Used By A Database Connection
6598** METHOD: sqlite3
6599**
6600** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6601** memory as possible from database connection D. Unlike the
6602** [sqlite3_release_memory()] interface, this interface is in effect even
6603** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6604** omitted.
6605**
6606** See also: [sqlite3_release_memory()]
6607*/
6608SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6609
6610/*
6611** CAPI3REF: Impose A Limit On Heap Size
6612**
6613** These interfaces impose limits on the amount of heap memory that will be
6614** by all database connections within a single process.
6615**
6616** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6617** soft limit on the amount of heap memory that may be allocated by SQLite.
6618** ^SQLite strives to keep heap memory utilization below the soft heap
6619** limit by reducing the number of pages held in the page cache
6620** as heap memory usages approaches the limit.
6621** ^The soft heap limit is "soft" because even though SQLite strives to stay
6622** below the limit, it will exceed the limit rather than generate
6623** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6624** is advisory only.
6625**
6626** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6627** N bytes on the amount of memory that will be allocated. ^The
6628** sqlite3_hard_heap_limit64(N) interface is similar to
6629** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6630** when the hard heap limit is reached.
6631**
6632** ^The return value from both sqlite3_soft_heap_limit64() and
6633** sqlite3_hard_heap_limit64() is the size of
6634** the heap limit prior to the call, or negative in the case of an
6635** error. ^If the argument N is negative
6636** then no change is made to the heap limit. Hence, the current
6637** size of heap limits can be determined by invoking
6638** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6639**
6640** ^Setting the heap limits to zero disables the heap limiter mechanism.
6641**
6642** ^The soft heap limit may not be greater than the hard heap limit.
6643** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6644** is invoked with a value of N that is greater than the hard heap limit,
6645** the the soft heap limit is set to the value of the hard heap limit.
6646** ^The soft heap limit is automatically enabled whenever the hard heap
6647** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6648** the soft heap limit is outside the range of 1..N, then the soft heap
6649** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6650** hard heap limit is enabled makes the soft heap limit equal to the
6651** hard heap limit.
6652**
6653** The memory allocation limits can also be adjusted using
6654** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
6655**
6656** ^(The heap limits are not enforced in the current implementation
6657** if one or more of following conditions are true:
6658**
6659** <ul>
6660** <li> The limit value is set to zero.
6661** <li> Memory accounting is disabled using a combination of the
6662** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6663** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6664** <li> An alternative page cache implementation is specified using
6665** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6666** <li> The page cache allocates from its own memory pool supplied
6667** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6668** from the heap.
6669** </ul>)^
6670**
6671** The circumstances under which SQLite will enforce the heap limits may
6672** changes in future releases of SQLite.
6673*/
6674SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6675SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
6676
6677/*
6678** CAPI3REF: Deprecated Soft Heap Limit Interface
6679** DEPRECATED
6680**
6681** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6682** interface. This routine is provided for historical compatibility
6683** only. All new applications should use the
6684** [sqlite3_soft_heap_limit64()] interface rather than this one.
6685*/
6686SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6687
6688
6689/*
6690** CAPI3REF: Extract Metadata About A Column Of A Table
6691** METHOD: sqlite3
6692**
6693** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6694** information about column C of table T in database D
6695** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6696** interface returns SQLITE_OK and fills in the non-NULL pointers in
6697** the final five arguments with appropriate values if the specified
6698** column exists. ^The sqlite3_table_column_metadata() interface returns
6699** SQLITE_ERROR if the specified column does not exist.
6700** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6701** NULL pointer, then this routine simply checks for the existence of the
6702** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6703** does not. If the table name parameter T in a call to
6704** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6705** undefined behavior.
6706**
6707** ^The column is identified by the second, third and fourth parameters to
6708** this function. ^(The second parameter is either the name of the database
6709** (i.e. "main", "temp", or an attached database) containing the specified
6710** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6711** for the table using the same algorithm used by the database engine to
6712** resolve unqualified table references.
6713**
6714** ^The third and fourth parameters to this function are the table and column
6715** name of the desired column, respectively.
6716**
6717** ^Metadata is returned by writing to the memory locations passed as the 5th
6718** and subsequent parameters to this function. ^Any of these arguments may be
6719** NULL, in which case the corresponding element of metadata is omitted.
6720**
6721** ^(<blockquote>
6722** <table border="1">
6723** <tr><th> Parameter <th> Output<br>Type <th> Description
6724**
6725** <tr><td> 5th <td> const char* <td> Data type
6726** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6727** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6728** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6729** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6730** </table>
6731** </blockquote>)^
6732**
6733** ^The memory pointed to by the character pointers returned for the
6734** declaration type and collation sequence is valid until the next
6735** call to any SQLite API function.
6736**
6737** ^If the specified table is actually a view, an [error code] is returned.
6738**
6739** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6740** is not a [WITHOUT ROWID] table and an
6741** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6742** parameters are set for the explicitly declared column. ^(If there is no
6743** [INTEGER PRIMARY KEY] column, then the outputs
6744** for the [rowid] are set as follows:
6745**
6746** <pre>
6747** data type: "INTEGER"
6748** collation sequence: "BINARY"
6749** not null: 0
6750** primary key: 1
6751** auto increment: 0
6752** </pre>)^
6753**
6754** ^This function causes all database schemas to be read from disk and
6755** parsed, if that has not already been done, and returns an error if
6756** any errors are encountered while loading the schema.
6757*/
6758SQLITE_API int sqlite3_table_column_metadata(
6759 sqlite3 *db, /* Connection handle */
6760 const char *zDbName, /* Database name or NULL */
6761 const char *zTableName, /* Table name */
6762 const char *zColumnName, /* Column name */
6763 char const **pzDataType, /* OUTPUT: Declared data type */
6764 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6765 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6766 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6767 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6768);
6769
6770/*
6771** CAPI3REF: Load An Extension
6772** METHOD: sqlite3
6773**
6774** ^This interface loads an SQLite extension library from the named file.
6775**
6776** ^The sqlite3_load_extension() interface attempts to load an
6777** [SQLite extension] library contained in the file zFile. If
6778** the file cannot be loaded directly, attempts are made to load
6779** with various operating-system specific extensions added.
6780** So for example, if "samplelib" cannot be loaded, then names like
6781** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6782** be tried also.
6783**
6784** ^The entry point is zProc.
6785** ^(zProc may be 0, in which case SQLite will try to come up with an
6786** entry point name on its own. It first tries "sqlite3_extension_init".
6787** If that does not work, it constructs a name "sqlite3_X_init" where the
6788** X is consists of the lower-case equivalent of all ASCII alphabetic
6789** characters in the filename from the last "/" to the first following
6790** "." and omitting any initial "lib".)^
6791** ^The sqlite3_load_extension() interface returns
6792** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6793** ^If an error occurs and pzErrMsg is not 0, then the
6794** [sqlite3_load_extension()] interface shall attempt to
6795** fill *pzErrMsg with error message text stored in memory
6796** obtained from [sqlite3_malloc()]. The calling function
6797** should free this memory by calling [sqlite3_free()].
6798**
6799** ^Extension loading must be enabled using
6800** [sqlite3_enable_load_extension()] or
6801** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6802** prior to calling this API,
6803** otherwise an error will be returned.
6804**
6805** <b>Security warning:</b> It is recommended that the
6806** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6807** interface. The use of the [sqlite3_enable_load_extension()] interface
6808** should be avoided. This will keep the SQL function [load_extension()]
6809** disabled and prevent SQL injections from giving attackers
6810** access to extension loading capabilities.
6811**
6812** See also the [load_extension() SQL function].
6813*/
6814SQLITE_API int sqlite3_load_extension(
6815 sqlite3 *db, /* Load the extension into this database connection */
6816 const char *zFile, /* Name of the shared library containing extension */
6817 const char *zProc, /* Entry point. Derived from zFile if 0 */
6818 char **pzErrMsg /* Put error message here if not 0 */
6819);
6820
6821/*
6822** CAPI3REF: Enable Or Disable Extension Loading
6823** METHOD: sqlite3
6824**
6825** ^So as not to open security holes in older applications that are
6826** unprepared to deal with [extension loading], and as a means of disabling
6827** [extension loading] while evaluating user-entered SQL, the following API
6828** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6829**
6830** ^Extension loading is off by default.
6831** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6832** to turn extension loading on and call it with onoff==0 to turn
6833** it back off again.
6834**
6835** ^This interface enables or disables both the C-API
6836** [sqlite3_load_extension()] and the SQL function [load_extension()].
6837** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6838** to enable or disable only the C-API.)^
6839**
6840** <b>Security warning:</b> It is recommended that extension loading
6841** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6842** rather than this interface, so the [load_extension()] SQL function
6843** remains disabled. This will prevent SQL injections from giving attackers
6844** access to extension loading capabilities.
6845*/
6846SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6847
6848/*
6849** CAPI3REF: Automatically Load Statically Linked Extensions
6850**
6851** ^This interface causes the xEntryPoint() function to be invoked for
6852** each new [database connection] that is created. The idea here is that
6853** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6854** that is to be automatically loaded into all new database connections.
6855**
6856** ^(Even though the function prototype shows that xEntryPoint() takes
6857** no arguments and returns void, SQLite invokes xEntryPoint() with three
6858** arguments and expects an integer result as if the signature of the
6859** entry point where as follows:
6860**
6861** <blockquote><pre>
6862** &nbsp; int xEntryPoint(
6863** &nbsp; sqlite3 *db,
6864** &nbsp; const char **pzErrMsg,
6865** &nbsp; const struct sqlite3_api_routines *pThunk
6866** &nbsp; );
6867** </pre></blockquote>)^
6868**
6869** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6870** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6871** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6872** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6873** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6874** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6875** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6876**
6877** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6878** on the list of automatic extensions is a harmless no-op. ^No entry point
6879** will be called more than once for each database connection that is opened.
6880**
6881** See also: [sqlite3_reset_auto_extension()]
6882** and [sqlite3_cancel_auto_extension()]
6883*/
6884SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6885
6886/*
6887** CAPI3REF: Cancel Automatic Extension Loading
6888**
6889** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6890** initialization routine X that was registered using a prior call to
6891** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6892** routine returns 1 if initialization routine X was successfully
6893** unregistered and it returns 0 if X was not on the list of initialization
6894** routines.
6895*/
6896SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6897
6898/*
6899** CAPI3REF: Reset Automatic Extension Loading
6900**
6901** ^This interface disables all automatic extensions previously
6902** registered using [sqlite3_auto_extension()].
6903*/
6904SQLITE_API void sqlite3_reset_auto_extension(void);
6905
6906/*
6907** The interface to the virtual-table mechanism is currently considered
6908** to be experimental. The interface might change in incompatible ways.
6909** If this is a problem for you, do not use the interface at this time.
6910**
6911** When the virtual-table mechanism stabilizes, we will declare the
6912** interface fixed, support it indefinitely, and remove this comment.
6913*/
6914
6915/*
6916** Structures used by the virtual table interface
6917*/
6918typedef struct sqlite3_vtab sqlite3_vtab;
6919typedef struct sqlite3_index_info sqlite3_index_info;
6920typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6921typedef struct sqlite3_module sqlite3_module;
6922
6923/*
6924** CAPI3REF: Virtual Table Object
6925** KEYWORDS: sqlite3_module {virtual table module}
6926**
6927** This structure, sometimes called a "virtual table module",
6928** defines the implementation of a [virtual table].
6929** This structure consists mostly of methods for the module.
6930**
6931** ^A virtual table module is created by filling in a persistent
6932** instance of this structure and passing a pointer to that instance
6933** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6934** ^The registration remains valid until it is replaced by a different
6935** module or until the [database connection] closes. The content
6936** of this structure must not change while it is registered with
6937** any database connection.
6938*/
6939struct sqlite3_module {
6940 int iVersion;
6941 int (*xCreate)(sqlite3*, void *pAux,
6942 int argc, const char *const*argv,
6943 sqlite3_vtab **ppVTab, char**);
6944 int (*xConnect)(sqlite3*, void *pAux,
6945 int argc, const char *const*argv,
6946 sqlite3_vtab **ppVTab, char**);
6947 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6948 int (*xDisconnect)(sqlite3_vtab *pVTab);
6949 int (*xDestroy)(sqlite3_vtab *pVTab);
6950 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6951 int (*xClose)(sqlite3_vtab_cursor*);
6952 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6953 int argc, sqlite3_value **argv);
6954 int (*xNext)(sqlite3_vtab_cursor*);
6955 int (*xEof)(sqlite3_vtab_cursor*);
6956 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6957 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6958 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6959 int (*xBegin)(sqlite3_vtab *pVTab);
6960 int (*xSync)(sqlite3_vtab *pVTab);
6961 int (*xCommit)(sqlite3_vtab *pVTab);
6962 int (*xRollback)(sqlite3_vtab *pVTab);
6963 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6964 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6965 void **ppArg);
6966 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6967 /* The methods above are in version 1 of the sqlite_module object. Those
6968 ** below are for version 2 and greater. */
6969 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6970 int (*xRelease)(sqlite3_vtab *pVTab, int);
6971 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6972 /* The methods above are in versions 1 and 2 of the sqlite_module object.
6973 ** Those below are for version 3 and greater. */
6974 int (*xShadowName)(const char*);
6975};
6976
6977/*
6978** CAPI3REF: Virtual Table Indexing Information
6979** KEYWORDS: sqlite3_index_info
6980**
6981** The sqlite3_index_info structure and its substructures is used as part
6982** of the [virtual table] interface to
6983** pass information into and receive the reply from the [xBestIndex]
6984** method of a [virtual table module]. The fields under **Inputs** are the
6985** inputs to xBestIndex and are read-only. xBestIndex inserts its
6986** results into the **Outputs** fields.
6987**
6988** ^(The aConstraint[] array records WHERE clause constraints of the form:
6989**
6990** <blockquote>column OP expr</blockquote>
6991**
6992** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
6993** stored in aConstraint[].op using one of the
6994** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6995** ^(The index of the column is stored in
6996** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6997** expr on the right-hand side can be evaluated (and thus the constraint
6998** is usable) and false if it cannot.)^
6999**
7000** ^The optimizer automatically inverts terms of the form "expr OP column"
7001** and makes other simplifications to the WHERE clause in an attempt to
7002** get as many WHERE clause terms into the form shown above as possible.
7003** ^The aConstraint[] array only reports WHERE clause terms that are
7004** relevant to the particular virtual table being queried.
7005**
7006** ^Information about the ORDER BY clause is stored in aOrderBy[].
7007** ^Each term of aOrderBy records a column of the ORDER BY clause.
7008**
7009** The colUsed field indicates which columns of the virtual table may be
7010** required by the current scan. Virtual table columns are numbered from
7011** zero in the order in which they appear within the CREATE TABLE statement
7012** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7013** the corresponding bit is set within the colUsed mask if the column may be
7014** required by SQLite. If the table has at least 64 columns and any column
7015** to the right of the first 63 is required, then bit 63 of colUsed is also
7016** set. In other words, column iCol may be required if the expression
7017** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7018** non-zero.
7019**
7020** The [xBestIndex] method must fill aConstraintUsage[] with information
7021** about what parameters to pass to xFilter. ^If argvIndex>0 then
7022** the right-hand side of the corresponding aConstraint[] is evaluated
7023** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7024** is true, then the constraint is assumed to be fully handled by the
7025** virtual table and might not be checked again by the byte code.)^ ^(The
7026** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7027** is left in its default setting of false, the constraint will always be
7028** checked separately in byte code. If the omit flag is change to true, then
7029** the constraint may or may not be checked in byte code. In other words,
7030** when the omit flag is true there is no guarantee that the constraint will
7031** not be checked again using byte code.)^
7032**
7033** ^The idxNum and idxPtr values are recorded and passed into the
7034** [xFilter] method.
7035** ^[sqlite3_free()] is used to free idxPtr if and only if
7036** needToFreeIdxPtr is true.
7037**
7038** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7039** the correct order to satisfy the ORDER BY clause so that no separate
7040** sorting step is required.
7041**
7042** ^The estimatedCost value is an estimate of the cost of a particular
7043** strategy. A cost of N indicates that the cost of the strategy is similar
7044** to a linear scan of an SQLite table with N rows. A cost of log(N)
7045** indicates that the expense of the operation is similar to that of a
7046** binary search on a unique indexed field of an SQLite table with N rows.
7047**
7048** ^The estimatedRows value is an estimate of the number of rows that
7049** will be returned by the strategy.
7050**
7051** The xBestIndex method may optionally populate the idxFlags field with a
7052** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7053** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7054** assumes that the strategy may visit at most one row.
7055**
7056** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7057** SQLite also assumes that if a call to the xUpdate() method is made as
7058** part of the same statement to delete or update a virtual table row and the
7059** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7060** any database changes. In other words, if the xUpdate() returns
7061** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7062** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7063** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7064** the xUpdate method are automatically rolled back by SQLite.
7065**
7066** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7067** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7068** If a virtual table extension is
7069** used with an SQLite version earlier than 3.8.2, the results of attempting
7070** to read or write the estimatedRows field are undefined (but are likely
7071** to include crashing the application). The estimatedRows field should
7072** therefore only be used if [sqlite3_libversion_number()] returns a
7073** value greater than or equal to 3008002. Similarly, the idxFlags field
7074** was added for [version 3.9.0] ([dateof:3.9.0]).
7075** It may therefore only be used if
7076** sqlite3_libversion_number() returns a value greater than or equal to
7077** 3009000.
7078*/
7079struct sqlite3_index_info {
7080 /* Inputs */
7081 int nConstraint; /* Number of entries in aConstraint */
7082 struct sqlite3_index_constraint {
7083 int iColumn; /* Column constrained. -1 for ROWID */
7084 unsigned char op; /* Constraint operator */
7085 unsigned char usable; /* True if this constraint is usable */
7086 int iTermOffset; /* Used internally - xBestIndex should ignore */
7087 } *aConstraint; /* Table of WHERE clause constraints */
7088 int nOrderBy; /* Number of terms in the ORDER BY clause */
7089 struct sqlite3_index_orderby {
7090 int iColumn; /* Column number */
7091 unsigned char desc; /* True for DESC. False for ASC. */
7092 } *aOrderBy; /* The ORDER BY clause */
7093 /* Outputs */
7094 struct sqlite3_index_constraint_usage {
7095 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7096 unsigned char omit; /* Do not code a test for this constraint */
7097 } *aConstraintUsage;
7098 int idxNum; /* Number used to identify the index */
7099 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7100 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7101 int orderByConsumed; /* True if output is already ordered */
7102 double estimatedCost; /* Estimated cost of using this index */
7103 /* Fields below are only available in SQLite 3.8.2 and later */
7104 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7105 /* Fields below are only available in SQLite 3.9.0 and later */
7106 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7107 /* Fields below are only available in SQLite 3.10.0 and later */
7108 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7109};
7110
7111/*
7112** CAPI3REF: Virtual Table Scan Flags
7113**
7114** Virtual table implementations are allowed to set the
7115** [sqlite3_index_info].idxFlags field to some combination of
7116** these bits.
7117*/
7118#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7119
7120/*
7121** CAPI3REF: Virtual Table Constraint Operator Codes
7122**
7123** These macros define the allowed values for the
7124** [sqlite3_index_info].aConstraint[].op field. Each value represents
7125** an operator that is part of a constraint term in the wHERE clause of
7126** a query that uses a [virtual table].
7127*/
7128#define SQLITE_INDEX_CONSTRAINT_EQ 2
7129#define SQLITE_INDEX_CONSTRAINT_GT 4
7130#define SQLITE_INDEX_CONSTRAINT_LE 8
7131#define SQLITE_INDEX_CONSTRAINT_LT 16
7132#define SQLITE_INDEX_CONSTRAINT_GE 32
7133#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7134#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7135#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7136#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7137#define SQLITE_INDEX_CONSTRAINT_NE 68
7138#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7139#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7140#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7141#define SQLITE_INDEX_CONSTRAINT_IS 72
7142#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7143
7144/*
7145** CAPI3REF: Register A Virtual Table Implementation
7146** METHOD: sqlite3
7147**
7148** ^These routines are used to register a new [virtual table module] name.
7149** ^Module names must be registered before
7150** creating a new [virtual table] using the module and before using a
7151** preexisting [virtual table] for the module.
7152**
7153** ^The module name is registered on the [database connection] specified
7154** by the first parameter. ^The name of the module is given by the
7155** second parameter. ^The third parameter is a pointer to
7156** the implementation of the [virtual table module]. ^The fourth
7157** parameter is an arbitrary client data pointer that is passed through
7158** into the [xCreate] and [xConnect] methods of the virtual table module
7159** when a new virtual table is be being created or reinitialized.
7160**
7161** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7162** is a pointer to a destructor for the pClientData. ^SQLite will
7163** invoke the destructor function (if it is not NULL) when SQLite
7164** no longer needs the pClientData pointer. ^The destructor will also
7165** be invoked if the call to sqlite3_create_module_v2() fails.
7166** ^The sqlite3_create_module()
7167** interface is equivalent to sqlite3_create_module_v2() with a NULL
7168** destructor.
7169**
7170** ^If the third parameter (the pointer to the sqlite3_module object) is
7171** NULL then no new module is create and any existing modules with the
7172** same name are dropped.
7173**
7174** See also: [sqlite3_drop_modules()]
7175*/
7176SQLITE_API int sqlite3_create_module(
7177 sqlite3 *db, /* SQLite connection to register module with */
7178 const char *zName, /* Name of the module */
7179 const sqlite3_module *p, /* Methods for the module */
7180 void *pClientData /* Client data for xCreate/xConnect */
7181);
7182SQLITE_API int sqlite3_create_module_v2(
7183 sqlite3 *db, /* SQLite connection to register module with */
7184 const char *zName, /* Name of the module */
7185 const sqlite3_module *p, /* Methods for the module */
7186 void *pClientData, /* Client data for xCreate/xConnect */
7187 void(*xDestroy)(void*) /* Module destructor function */
7188);
7189
7190/*
7191** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7192** METHOD: sqlite3
7193**
7194** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7195** table modules from database connection D except those named on list L.
7196** The L parameter must be either NULL or a pointer to an array of pointers
7197** to strings where the array is terminated by a single NULL pointer.
7198** ^If the L parameter is NULL, then all virtual table modules are removed.
7199**
7200** See also: [sqlite3_create_module()]
7201*/
7202SQLITE_API int sqlite3_drop_modules(
7203 sqlite3 *db, /* Remove modules from this connection */
7204 const char **azKeep /* Except, do not remove the ones named here */
7205);
7206
7207/*
7208** CAPI3REF: Virtual Table Instance Object
7209** KEYWORDS: sqlite3_vtab
7210**
7211** Every [virtual table module] implementation uses a subclass
7212** of this object to describe a particular instance
7213** of the [virtual table]. Each subclass will
7214** be tailored to the specific needs of the module implementation.
7215** The purpose of this superclass is to define certain fields that are
7216** common to all module implementations.
7217**
7218** ^Virtual tables methods can set an error message by assigning a
7219** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7220** take care that any prior string is freed by a call to [sqlite3_free()]
7221** prior to assigning a new string to zErrMsg. ^After the error message
7222** is delivered up to the client application, the string will be automatically
7223** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7224*/
7225struct sqlite3_vtab {
7226 const sqlite3_module *pModule; /* The module for this virtual table */
7227 int nRef; /* Number of open cursors */
7228 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7229 /* Virtual table implementations will typically add additional fields */
7230};
7231
7232/*
7233** CAPI3REF: Virtual Table Cursor Object
7234** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7235**
7236** Every [virtual table module] implementation uses a subclass of the
7237** following structure to describe cursors that point into the
7238** [virtual table] and are used
7239** to loop through the virtual table. Cursors are created using the
7240** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7241** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7242** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7243** of the module. Each module implementation will define
7244** the content of a cursor structure to suit its own needs.
7245**
7246** This superclass exists in order to define fields of the cursor that
7247** are common to all implementations.
7248*/
7249struct sqlite3_vtab_cursor {
7250 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7251 /* Virtual table implementations will typically add additional fields */
7252};
7253
7254/*
7255** CAPI3REF: Declare The Schema Of A Virtual Table
7256**
7257** ^The [xCreate] and [xConnect] methods of a
7258** [virtual table module] call this interface
7259** to declare the format (the names and datatypes of the columns) of
7260** the virtual tables they implement.
7261*/
7262SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7263
7264/*
7265** CAPI3REF: Overload A Function For A Virtual Table
7266** METHOD: sqlite3
7267**
7268** ^(Virtual tables can provide alternative implementations of functions
7269** using the [xFindFunction] method of the [virtual table module].
7270** But global versions of those functions
7271** must exist in order to be overloaded.)^
7272**
7273** ^(This API makes sure a global version of a function with a particular
7274** name and number of parameters exists. If no such function exists
7275** before this API is called, a new function is created.)^ ^The implementation
7276** of the new function always causes an exception to be thrown. So
7277** the new function is not good for anything by itself. Its only
7278** purpose is to be a placeholder function that can be overloaded
7279** by a [virtual table].
7280*/
7281SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7282
7283/*
7284** The interface to the virtual-table mechanism defined above (back up
7285** to a comment remarkably similar to this one) is currently considered
7286** to be experimental. The interface might change in incompatible ways.
7287** If this is a problem for you, do not use the interface at this time.
7288**
7289** When the virtual-table mechanism stabilizes, we will declare the
7290** interface fixed, support it indefinitely, and remove this comment.
7291*/
7292
7293/*
7294** CAPI3REF: A Handle To An Open BLOB
7295** KEYWORDS: {BLOB handle} {BLOB handles}
7296**
7297** An instance of this object represents an open BLOB on which
7298** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7299** ^Objects of this type are created by [sqlite3_blob_open()]
7300** and destroyed by [sqlite3_blob_close()].
7301** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7302** can be used to read or write small subsections of the BLOB.
7303** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7304*/
7305typedef struct sqlite3_blob sqlite3_blob;
7306
7307/*
7308** CAPI3REF: Open A BLOB For Incremental I/O
7309** METHOD: sqlite3
7310** CONSTRUCTOR: sqlite3_blob
7311**
7312** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7313** in row iRow, column zColumn, table zTable in database zDb;
7314** in other words, the same BLOB that would be selected by:
7315**
7316** <pre>
7317** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7318** </pre>)^
7319**
7320** ^(Parameter zDb is not the filename that contains the database, but
7321** rather the symbolic name of the database. For attached databases, this is
7322** the name that appears after the AS keyword in the [ATTACH] statement.
7323** For the main database file, the database name is "main". For TEMP
7324** tables, the database name is "temp".)^
7325**
7326** ^If the flags parameter is non-zero, then the BLOB is opened for read
7327** and write access. ^If the flags parameter is zero, the BLOB is opened for
7328** read-only access.
7329**
7330** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7331** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7332** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7333** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7334** on *ppBlob after this function it returns.
7335**
7336** This function fails with SQLITE_ERROR if any of the following are true:
7337** <ul>
7338** <li> ^(Database zDb does not exist)^,
7339** <li> ^(Table zTable does not exist within database zDb)^,
7340** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7341** <li> ^(Column zColumn does not exist)^,
7342** <li> ^(Row iRow is not present in the table)^,
7343** <li> ^(The specified column of row iRow contains a value that is not
7344** a TEXT or BLOB value)^,
7345** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7346** constraint and the blob is being opened for read/write access)^,
7347** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7348** column zColumn is part of a [child key] definition and the blob is
7349** being opened for read/write access)^.
7350** </ul>
7351**
7352** ^Unless it returns SQLITE_MISUSE, this function sets the
7353** [database connection] error code and message accessible via
7354** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7355**
7356** A BLOB referenced by sqlite3_blob_open() may be read using the
7357** [sqlite3_blob_read()] interface and modified by using
7358** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7359** different row of the same table using the [sqlite3_blob_reopen()]
7360** interface. However, the column, table, or database of a [BLOB handle]
7361** cannot be changed after the [BLOB handle] is opened.
7362**
7363** ^(If the row that a BLOB handle points to is modified by an
7364** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7365** then the BLOB handle is marked as "expired".
7366** This is true if any column of the row is changed, even a column
7367** other than the one the BLOB handle is open on.)^
7368** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7369** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7370** ^(Changes written into a BLOB prior to the BLOB expiring are not
7371** rolled back by the expiration of the BLOB. Such changes will eventually
7372** commit if the transaction continues to completion.)^
7373**
7374** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7375** the opened blob. ^The size of a blob may not be changed by this
7376** interface. Use the [UPDATE] SQL command to change the size of a
7377** blob.
7378**
7379** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7380** and the built-in [zeroblob] SQL function may be used to create a
7381** zero-filled blob to read or write using the incremental-blob interface.
7382**
7383** To avoid a resource leak, every open [BLOB handle] should eventually
7384** be released by a call to [sqlite3_blob_close()].
7385**
7386** See also: [sqlite3_blob_close()],
7387** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7388** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7389*/
7390SQLITE_API int sqlite3_blob_open(
7391 sqlite3*,
7392 const char *zDb,
7393 const char *zTable,
7394 const char *zColumn,
7395 sqlite3_int64 iRow,
7396 int flags,
7397 sqlite3_blob **ppBlob
7398);
7399
7400/*
7401** CAPI3REF: Move a BLOB Handle to a New Row
7402** METHOD: sqlite3_blob
7403**
7404** ^This function is used to move an existing [BLOB handle] so that it points
7405** to a different row of the same database table. ^The new row is identified
7406** by the rowid value passed as the second argument. Only the row can be
7407** changed. ^The database, table and column on which the blob handle is open
7408** remain the same. Moving an existing [BLOB handle] to a new row is
7409** faster than closing the existing handle and opening a new one.
7410**
7411** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7412** it must exist and there must be either a blob or text value stored in
7413** the nominated column.)^ ^If the new row is not present in the table, or if
7414** it does not contain a blob or text value, or if another error occurs, an
7415** SQLite error code is returned and the blob handle is considered aborted.
7416** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7417** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7418** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7419** always returns zero.
7420**
7421** ^This function sets the database handle error code and message.
7422*/
7423SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7424
7425/*
7426** CAPI3REF: Close A BLOB Handle
7427** DESTRUCTOR: sqlite3_blob
7428**
7429** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7430** unconditionally. Even if this routine returns an error code, the
7431** handle is still closed.)^
7432**
7433** ^If the blob handle being closed was opened for read-write access, and if
7434** the database is in auto-commit mode and there are no other open read-write
7435** blob handles or active write statements, the current transaction is
7436** committed. ^If an error occurs while committing the transaction, an error
7437** code is returned and the transaction rolled back.
7438**
7439** Calling this function with an argument that is not a NULL pointer or an
7440** open blob handle results in undefined behaviour. ^Calling this routine
7441** with a null pointer (such as would be returned by a failed call to
7442** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7443** is passed a valid open blob handle, the values returned by the
7444** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7445*/
7446SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7447
7448/*
7449** CAPI3REF: Return The Size Of An Open BLOB
7450** METHOD: sqlite3_blob
7451**
7452** ^Returns the size in bytes of the BLOB accessible via the
7453** successfully opened [BLOB handle] in its only argument. ^The
7454** incremental blob I/O routines can only read or overwriting existing
7455** blob content; they cannot change the size of a blob.
7456**
7457** This routine only works on a [BLOB handle] which has been created
7458** by a prior successful call to [sqlite3_blob_open()] and which has not
7459** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7460** to this routine results in undefined and probably undesirable behavior.
7461*/
7462SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7463
7464/*
7465** CAPI3REF: Read Data From A BLOB Incrementally
7466** METHOD: sqlite3_blob
7467**
7468** ^(This function is used to read data from an open [BLOB handle] into a
7469** caller-supplied buffer. N bytes of data are copied into buffer Z
7470** from the open BLOB, starting at offset iOffset.)^
7471**
7472** ^If offset iOffset is less than N bytes from the end of the BLOB,
7473** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7474** less than zero, [SQLITE_ERROR] is returned and no data is read.
7475** ^The size of the blob (and hence the maximum value of N+iOffset)
7476** can be determined using the [sqlite3_blob_bytes()] interface.
7477**
7478** ^An attempt to read from an expired [BLOB handle] fails with an
7479** error code of [SQLITE_ABORT].
7480**
7481** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7482** Otherwise, an [error code] or an [extended error code] is returned.)^
7483**
7484** This routine only works on a [BLOB handle] which has been created
7485** by a prior successful call to [sqlite3_blob_open()] and which has not
7486** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7487** to this routine results in undefined and probably undesirable behavior.
7488**
7489** See also: [sqlite3_blob_write()].
7490*/
7491SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7492
7493/*
7494** CAPI3REF: Write Data Into A BLOB Incrementally
7495** METHOD: sqlite3_blob
7496**
7497** ^(This function is used to write data into an open [BLOB handle] from a
7498** caller-supplied buffer. N bytes of data are copied from the buffer Z
7499** into the open BLOB, starting at offset iOffset.)^
7500**
7501** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7502** Otherwise, an [error code] or an [extended error code] is returned.)^
7503** ^Unless SQLITE_MISUSE is returned, this function sets the
7504** [database connection] error code and message accessible via
7505** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7506**
7507** ^If the [BLOB handle] passed as the first argument was not opened for
7508** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7509** this function returns [SQLITE_READONLY].
7510**
7511** This function may only modify the contents of the BLOB; it is
7512** not possible to increase the size of a BLOB using this API.
7513** ^If offset iOffset is less than N bytes from the end of the BLOB,
7514** [SQLITE_ERROR] is returned and no data is written. The size of the
7515** BLOB (and hence the maximum value of N+iOffset) can be determined
7516** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7517** than zero [SQLITE_ERROR] is returned and no data is written.
7518**
7519** ^An attempt to write to an expired [BLOB handle] fails with an
7520** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7521** before the [BLOB handle] expired are not rolled back by the
7522** expiration of the handle, though of course those changes might
7523** have been overwritten by the statement that expired the BLOB handle
7524** or by other independent statements.
7525**
7526** This routine only works on a [BLOB handle] which has been created
7527** by a prior successful call to [sqlite3_blob_open()] and which has not
7528** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7529** to this routine results in undefined and probably undesirable behavior.
7530**
7531** See also: [sqlite3_blob_read()].
7532*/
7533SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7534
7535/*
7536** CAPI3REF: Virtual File System Objects
7537**
7538** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7539** that SQLite uses to interact
7540** with the underlying operating system. Most SQLite builds come with a
7541** single default VFS that is appropriate for the host computer.
7542** New VFSes can be registered and existing VFSes can be unregistered.
7543** The following interfaces are provided.
7544**
7545** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7546** ^Names are case sensitive.
7547** ^Names are zero-terminated UTF-8 strings.
7548** ^If there is no match, a NULL pointer is returned.
7549** ^If zVfsName is NULL then the default VFS is returned.
7550**
7551** ^New VFSes are registered with sqlite3_vfs_register().
7552** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7553** ^The same VFS can be registered multiple times without injury.
7554** ^To make an existing VFS into the default VFS, register it again
7555** with the makeDflt flag set. If two different VFSes with the
7556** same name are registered, the behavior is undefined. If a
7557** VFS is registered with a name that is NULL or an empty string,
7558** then the behavior is undefined.
7559**
7560** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7561** ^(If the default VFS is unregistered, another VFS is chosen as
7562** the default. The choice for the new VFS is arbitrary.)^
7563*/
7564SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7565SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7566SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7567
7568/*
7569** CAPI3REF: Mutexes
7570**
7571** The SQLite core uses these routines for thread
7572** synchronization. Though they are intended for internal
7573** use by SQLite, code that links against SQLite is
7574** permitted to use any of these routines.
7575**
7576** The SQLite source code contains multiple implementations
7577** of these mutex routines. An appropriate implementation
7578** is selected automatically at compile-time. The following
7579** implementations are available in the SQLite core:
7580**
7581** <ul>
7582** <li> SQLITE_MUTEX_PTHREADS
7583** <li> SQLITE_MUTEX_W32
7584** <li> SQLITE_MUTEX_NOOP
7585** </ul>
7586**
7587** The SQLITE_MUTEX_NOOP implementation is a set of routines
7588** that does no real locking and is appropriate for use in
7589** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7590** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7591** and Windows.
7592**
7593** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7594** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7595** implementation is included with the library. In this case the
7596** application must supply a custom mutex implementation using the
7597** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7598** before calling sqlite3_initialize() or any other public sqlite3_
7599** function that calls sqlite3_initialize().
7600**
7601** ^The sqlite3_mutex_alloc() routine allocates a new
7602** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7603** routine returns NULL if it is unable to allocate the requested
7604** mutex. The argument to sqlite3_mutex_alloc() must one of these
7605** integer constants:
7606**
7607** <ul>
7608** <li> SQLITE_MUTEX_FAST
7609** <li> SQLITE_MUTEX_RECURSIVE
7610** <li> SQLITE_MUTEX_STATIC_MAIN
7611** <li> SQLITE_MUTEX_STATIC_MEM
7612** <li> SQLITE_MUTEX_STATIC_OPEN
7613** <li> SQLITE_MUTEX_STATIC_PRNG
7614** <li> SQLITE_MUTEX_STATIC_LRU
7615** <li> SQLITE_MUTEX_STATIC_PMEM
7616** <li> SQLITE_MUTEX_STATIC_APP1
7617** <li> SQLITE_MUTEX_STATIC_APP2
7618** <li> SQLITE_MUTEX_STATIC_APP3
7619** <li> SQLITE_MUTEX_STATIC_VFS1
7620** <li> SQLITE_MUTEX_STATIC_VFS2
7621** <li> SQLITE_MUTEX_STATIC_VFS3
7622** </ul>
7623**
7624** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7625** cause sqlite3_mutex_alloc() to create
7626** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7627** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7628** The mutex implementation does not need to make a distinction
7629** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7630** not want to. SQLite will only request a recursive mutex in
7631** cases where it really needs one. If a faster non-recursive mutex
7632** implementation is available on the host platform, the mutex subsystem
7633** might return such a mutex in response to SQLITE_MUTEX_FAST.
7634**
7635** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7636** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7637** a pointer to a static preexisting mutex. ^Nine static mutexes are
7638** used by the current version of SQLite. Future versions of SQLite
7639** may add additional static mutexes. Static mutexes are for internal
7640** use by SQLite only. Applications that use SQLite mutexes should
7641** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7642** SQLITE_MUTEX_RECURSIVE.
7643**
7644** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7645** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7646** returns a different mutex on every call. ^For the static
7647** mutex types, the same mutex is returned on every call that has
7648** the same type number.
7649**
7650** ^The sqlite3_mutex_free() routine deallocates a previously
7651** allocated dynamic mutex. Attempting to deallocate a static
7652** mutex results in undefined behavior.
7653**
7654** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7655** to enter a mutex. ^If another thread is already within the mutex,
7656** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7657** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7658** upon successful entry. ^(Mutexes created using
7659** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7660** In such cases, the
7661** mutex must be exited an equal number of times before another thread
7662** can enter.)^ If the same thread tries to enter any mutex other
7663** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7664**
7665** ^(Some systems (for example, Windows 95) do not support the operation
7666** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7667** will always return SQLITE_BUSY. The SQLite core only ever uses
7668** sqlite3_mutex_try() as an optimization so this is acceptable
7669** behavior.)^
7670**
7671** ^The sqlite3_mutex_leave() routine exits a mutex that was
7672** previously entered by the same thread. The behavior
7673** is undefined if the mutex is not currently entered by the
7674** calling thread or is not currently allocated.
7675**
7676** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7677** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7678** behave as no-ops.
7679**
7680** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7681*/
7682SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7683SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7684SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7685SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7686SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7687
7688/*
7689** CAPI3REF: Mutex Methods Object
7690**
7691** An instance of this structure defines the low-level routines
7692** used to allocate and use mutexes.
7693**
7694** Usually, the default mutex implementations provided by SQLite are
7695** sufficient, however the application has the option of substituting a custom
7696** implementation for specialized deployments or systems for which SQLite
7697** does not provide a suitable implementation. In this case, the application
7698** creates and populates an instance of this structure to pass
7699** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7700** Additionally, an instance of this structure can be used as an
7701** output variable when querying the system for the current mutex
7702** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7703**
7704** ^The xMutexInit method defined by this structure is invoked as
7705** part of system initialization by the sqlite3_initialize() function.
7706** ^The xMutexInit routine is called by SQLite exactly once for each
7707** effective call to [sqlite3_initialize()].
7708**
7709** ^The xMutexEnd method defined by this structure is invoked as
7710** part of system shutdown by the sqlite3_shutdown() function. The
7711** implementation of this method is expected to release all outstanding
7712** resources obtained by the mutex methods implementation, especially
7713** those obtained by the xMutexInit method. ^The xMutexEnd()
7714** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7715**
7716** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7717** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7718** xMutexNotheld) implement the following interfaces (respectively):
7719**
7720** <ul>
7721** <li> [sqlite3_mutex_alloc()] </li>
7722** <li> [sqlite3_mutex_free()] </li>
7723** <li> [sqlite3_mutex_enter()] </li>
7724** <li> [sqlite3_mutex_try()] </li>
7725** <li> [sqlite3_mutex_leave()] </li>
7726** <li> [sqlite3_mutex_held()] </li>
7727** <li> [sqlite3_mutex_notheld()] </li>
7728** </ul>)^
7729**
7730** The only difference is that the public sqlite3_XXX functions enumerated
7731** above silently ignore any invocations that pass a NULL pointer instead
7732** of a valid mutex handle. The implementations of the methods defined
7733** by this structure are not required to handle this case. The results
7734** of passing a NULL pointer instead of a valid mutex handle are undefined
7735** (i.e. it is acceptable to provide an implementation that segfaults if
7736** it is passed a NULL pointer).
7737**
7738** The xMutexInit() method must be threadsafe. It must be harmless to
7739** invoke xMutexInit() multiple times within the same process and without
7740** intervening calls to xMutexEnd(). Second and subsequent calls to
7741** xMutexInit() must be no-ops.
7742**
7743** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7744** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7745** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7746** memory allocation for a fast or recursive mutex.
7747**
7748** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7749** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7750** If xMutexInit fails in any way, it is expected to clean up after itself
7751** prior to returning.
7752*/
7753typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7754struct sqlite3_mutex_methods {
7755 int (*xMutexInit)(void);
7756 int (*xMutexEnd)(void);
7757 sqlite3_mutex *(*xMutexAlloc)(int);
7758 void (*xMutexFree)(sqlite3_mutex *);
7759 void (*xMutexEnter)(sqlite3_mutex *);
7760 int (*xMutexTry)(sqlite3_mutex *);
7761 void (*xMutexLeave)(sqlite3_mutex *);
7762 int (*xMutexHeld)(sqlite3_mutex *);
7763 int (*xMutexNotheld)(sqlite3_mutex *);
7764};
7765
7766/*
7767** CAPI3REF: Mutex Verification Routines
7768**
7769** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7770** are intended for use inside assert() statements. The SQLite core
7771** never uses these routines except inside an assert() and applications
7772** are advised to follow the lead of the core. The SQLite core only
7773** provides implementations for these routines when it is compiled
7774** with the SQLITE_DEBUG flag. External mutex implementations
7775** are only required to provide these routines if SQLITE_DEBUG is
7776** defined and if NDEBUG is not defined.
7777**
7778** These routines should return true if the mutex in their argument
7779** is held or not held, respectively, by the calling thread.
7780**
7781** The implementation is not required to provide versions of these
7782** routines that actually work. If the implementation does not provide working
7783** versions of these routines, it should at least provide stubs that always
7784** return true so that one does not get spurious assertion failures.
7785**
7786** If the argument to sqlite3_mutex_held() is a NULL pointer then
7787** the routine should return 1. This seems counter-intuitive since
7788** clearly the mutex cannot be held if it does not exist. But
7789** the reason the mutex does not exist is because the build is not
7790** using mutexes. And we do not want the assert() containing the
7791** call to sqlite3_mutex_held() to fail, so a non-zero return is
7792** the appropriate thing to do. The sqlite3_mutex_notheld()
7793** interface should also return 1 when given a NULL pointer.
7794*/
7795#ifndef NDEBUG
7796SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7797SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7798#endif
7799
7800/*
7801** CAPI3REF: Mutex Types
7802**
7803** The [sqlite3_mutex_alloc()] interface takes a single argument
7804** which is one of these integer constants.
7805**
7806** The set of static mutexes may change from one SQLite release to the
7807** next. Applications that override the built-in mutex logic must be
7808** prepared to accommodate additional static mutexes.
7809*/
7810#define SQLITE_MUTEX_FAST 0
7811#define SQLITE_MUTEX_RECURSIVE 1
7812#define SQLITE_MUTEX_STATIC_MAIN 2
7813#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7814#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7815#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7816#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7817#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7818#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7819#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7820#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7821#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7822#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7823#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7824#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7825#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7826
7827/* Legacy compatibility: */
7828#define SQLITE_MUTEX_STATIC_MASTER 2
7829
7830
7831/*
7832** CAPI3REF: Retrieve the mutex for a database connection
7833** METHOD: sqlite3
7834**
7835** ^This interface returns a pointer the [sqlite3_mutex] object that
7836** serializes access to the [database connection] given in the argument
7837** when the [threading mode] is Serialized.
7838** ^If the [threading mode] is Single-thread or Multi-thread then this
7839** routine returns a NULL pointer.
7840*/
7841SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7842
7843/*
7844** CAPI3REF: Low-Level Control Of Database Files
7845** METHOD: sqlite3
7846** KEYWORDS: {file control}
7847**
7848** ^The [sqlite3_file_control()] interface makes a direct call to the
7849** xFileControl method for the [sqlite3_io_methods] object associated
7850** with a particular database identified by the second argument. ^The
7851** name of the database is "main" for the main database or "temp" for the
7852** TEMP database, or the name that appears after the AS keyword for
7853** databases that are added using the [ATTACH] SQL command.
7854** ^A NULL pointer can be used in place of "main" to refer to the
7855** main database file.
7856** ^The third and fourth parameters to this routine
7857** are passed directly through to the second and third parameters of
7858** the xFileControl method. ^The return value of the xFileControl
7859** method becomes the return value of this routine.
7860**
7861** A few opcodes for [sqlite3_file_control()] are handled directly
7862** by the SQLite core and never invoke the
7863** sqlite3_io_methods.xFileControl method.
7864** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7865** a pointer to the underlying [sqlite3_file] object to be written into
7866** the space pointed to by the 4th parameter. The
7867** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7868** the [sqlite3_file] object associated with the journal file instead of
7869** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7870** a pointer to the underlying [sqlite3_vfs] object for the file.
7871** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7872** from the pager.
7873**
7874** ^If the second parameter (zDbName) does not match the name of any
7875** open database file, then SQLITE_ERROR is returned. ^This error
7876** code is not remembered and will not be recalled by [sqlite3_errcode()]
7877** or [sqlite3_errmsg()]. The underlying xFileControl method might
7878** also return SQLITE_ERROR. There is no way to distinguish between
7879** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7880** xFileControl method.
7881**
7882** See also: [file control opcodes]
7883*/
7884SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7885
7886/*
7887** CAPI3REF: Testing Interface
7888**
7889** ^The sqlite3_test_control() interface is used to read out internal
7890** state of SQLite and to inject faults into SQLite for testing
7891** purposes. ^The first parameter is an operation code that determines
7892** the number, meaning, and operation of all subsequent parameters.
7893**
7894** This interface is not for use by applications. It exists solely
7895** for verifying the correct operation of the SQLite library. Depending
7896** on how the SQLite library is compiled, this interface might not exist.
7897**
7898** The details of the operation codes, their meanings, the parameters
7899** they take, and what they do are all subject to change without notice.
7900** Unlike most of the SQLite API, this function is not guaranteed to
7901** operate consistently from one release to the next.
7902*/
7903SQLITE_API int sqlite3_test_control(int op, ...);
7904
7905/*
7906** CAPI3REF: Testing Interface Operation Codes
7907**
7908** These constants are the valid operation code parameters used
7909** as the first argument to [sqlite3_test_control()].
7910**
7911** These parameters and their meanings are subject to change
7912** without notice. These values are for testing purposes only.
7913** Applications should not use any of these parameters or the
7914** [sqlite3_test_control()] interface.
7915*/
7916#define SQLITE_TESTCTRL_FIRST 5
7917#define SQLITE_TESTCTRL_PRNG_SAVE 5
7918#define SQLITE_TESTCTRL_PRNG_RESTORE 6
7919#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
7920#define SQLITE_TESTCTRL_BITVEC_TEST 8
7921#define SQLITE_TESTCTRL_FAULT_INSTALL 9
7922#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7923#define SQLITE_TESTCTRL_PENDING_BYTE 11
7924#define SQLITE_TESTCTRL_ASSERT 12
7925#define SQLITE_TESTCTRL_ALWAYS 13
7926#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
7927#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7928#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7929#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7930#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
7931#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7932#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7933#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7934#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7935#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7936#define SQLITE_TESTCTRL_BYTEORDER 22
7937#define SQLITE_TESTCTRL_ISINIT 23
7938#define SQLITE_TESTCTRL_SORTER_MMAP 24
7939#define SQLITE_TESTCTRL_IMPOSTER 25
7940#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7941#define SQLITE_TESTCTRL_RESULT_INTREAL 27
7942#define SQLITE_TESTCTRL_PRNG_SEED 28
7943#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
7944#define SQLITE_TESTCTRL_SEEK_COUNT 30
7945#define SQLITE_TESTCTRL_TRACEFLAGS 31
7946#define SQLITE_TESTCTRL_TUNE 32
7947#define SQLITE_TESTCTRL_LAST 32 /* Largest TESTCTRL */
7948
7949/*
7950** CAPI3REF: SQL Keyword Checking
7951**
7952** These routines provide access to the set of SQL language keywords
7953** recognized by SQLite. Applications can uses these routines to determine
7954** whether or not a specific identifier needs to be escaped (for example,
7955** by enclosing in double-quotes) so as not to confuse the parser.
7956**
7957** The sqlite3_keyword_count() interface returns the number of distinct
7958** keywords understood by SQLite.
7959**
7960** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7961** makes *Z point to that keyword expressed as UTF8 and writes the number
7962** of bytes in the keyword into *L. The string that *Z points to is not
7963** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7964** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7965** or L are NULL or invalid pointers then calls to
7966** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7967**
7968** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7969** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7970** if it is and zero if not.
7971**
7972** The parser used by SQLite is forgiving. It is often possible to use
7973** a keyword as an identifier as long as such use does not result in a
7974** parsing ambiguity. For example, the statement
7975** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7976** creates a new table named "BEGIN" with three columns named
7977** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7978** using keywords as identifiers. Common techniques used to avoid keyword
7979** name collisions include:
7980** <ul>
7981** <li> Put all identifier names inside double-quotes. This is the official
7982** SQL way to escape identifier names.
7983** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
7984** but it is what SQL Server does and so lots of programmers use this
7985** technique.
7986** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7987** with "Z".
7988** <li> Include a digit somewhere in every identifier name.
7989** </ul>
7990**
7991** Note that the number of keywords understood by SQLite can depend on
7992** compile-time options. For example, "VACUUM" is not a keyword if
7993** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7994** new keywords may be added to future releases of SQLite.
7995*/
7996SQLITE_API int sqlite3_keyword_count(void);
7997SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7998SQLITE_API int sqlite3_keyword_check(const char*,int);
7999
8000/*
8001** CAPI3REF: Dynamic String Object
8002** KEYWORDS: {dynamic string}
8003**
8004** An instance of the sqlite3_str object contains a dynamically-sized
8005** string under construction.
8006**
8007** The lifecycle of an sqlite3_str object is as follows:
8008** <ol>
8009** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8010** <li> ^Text is appended to the sqlite3_str object using various
8011** methods, such as [sqlite3_str_appendf()].
8012** <li> ^The sqlite3_str object is destroyed and the string it created
8013** is returned using the [sqlite3_str_finish()] interface.
8014** </ol>
8015*/
8016typedef struct sqlite3_str sqlite3_str;
8017
8018/*
8019** CAPI3REF: Create A New Dynamic String Object
8020** CONSTRUCTOR: sqlite3_str
8021**
8022** ^The [sqlite3_str_new(D)] interface allocates and initializes
8023** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8024** [sqlite3_str_new()] must be freed by a subsequent call to
8025** [sqlite3_str_finish(X)].
8026**
8027** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8028** valid [sqlite3_str] object, though in the event of an out-of-memory
8029** error the returned object might be a special singleton that will
8030** silently reject new text, always return SQLITE_NOMEM from
8031** [sqlite3_str_errcode()], always return 0 for
8032** [sqlite3_str_length()], and always return NULL from
8033** [sqlite3_str_finish(X)]. It is always safe to use the value
8034** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8035** to any of the other [sqlite3_str] methods.
8036**
8037** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8038** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8039** length of the string contained in the [sqlite3_str] object will be
8040** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8041** of [SQLITE_MAX_LENGTH].
8042*/
8043SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8044
8045/*
8046** CAPI3REF: Finalize A Dynamic String
8047** DESTRUCTOR: sqlite3_str
8048**
8049** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8050** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8051** that contains the constructed string. The calling application should
8052** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8053** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8054** errors were encountered during construction of the string. ^The
8055** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8056** string in [sqlite3_str] object X is zero bytes long.
8057*/
8058SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8059
8060/*
8061** CAPI3REF: Add Content To A Dynamic String
8062** METHOD: sqlite3_str
8063**
8064** These interfaces add content to an sqlite3_str object previously obtained
8065** from [sqlite3_str_new()].
8066**
8067** ^The [sqlite3_str_appendf(X,F,...)] and
8068** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8069** functionality of SQLite to append formatted text onto the end of
8070** [sqlite3_str] object X.
8071**
8072** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8073** onto the end of the [sqlite3_str] object X. N must be non-negative.
8074** S must contain at least N non-zero bytes of content. To append a
8075** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8076** method instead.
8077**
8078** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8079** zero-terminated string S onto the end of [sqlite3_str] object X.
8080**
8081** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8082** single-byte character C onto the end of [sqlite3_str] object X.
8083** ^This method can be used, for example, to add whitespace indentation.
8084**
8085** ^The [sqlite3_str_reset(X)] method resets the string under construction
8086** inside [sqlite3_str] object X back to zero bytes in length.
8087**
8088** These methods do not return a result code. ^If an error occurs, that fact
8089** is recorded in the [sqlite3_str] object and can be recovered by a
8090** subsequent call to [sqlite3_str_errcode(X)].
8091*/
8092SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8093SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8094SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8095SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8096SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8097SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8098
8099/*
8100** CAPI3REF: Status Of A Dynamic String
8101** METHOD: sqlite3_str
8102**
8103** These interfaces return the current status of an [sqlite3_str] object.
8104**
8105** ^If any prior errors have occurred while constructing the dynamic string
8106** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8107** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8108** [SQLITE_NOMEM] following any out-of-memory error, or
8109** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8110** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8111**
8112** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8113** of the dynamic string under construction in [sqlite3_str] object X.
8114** ^The length returned by [sqlite3_str_length(X)] does not include the
8115** zero-termination byte.
8116**
8117** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8118** content of the dynamic string under construction in X. The value
8119** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8120** and might be freed or altered by any subsequent method on the same
8121** [sqlite3_str] object. Applications must not used the pointer returned
8122** [sqlite3_str_value(X)] after any subsequent method call on the same
8123** object. ^Applications may change the content of the string returned
8124** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8125** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8126** write any byte after any subsequent sqlite3_str method call.
8127*/
8128SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8129SQLITE_API int sqlite3_str_length(sqlite3_str*);
8130SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8131
8132/*
8133** CAPI3REF: SQLite Runtime Status
8134**
8135** ^These interfaces are used to retrieve runtime status information
8136** about the performance of SQLite, and optionally to reset various
8137** highwater marks. ^The first argument is an integer code for
8138** the specific parameter to measure. ^(Recognized integer codes
8139** are of the form [status parameters | SQLITE_STATUS_...].)^
8140** ^The current value of the parameter is returned into *pCurrent.
8141** ^The highest recorded value is returned in *pHighwater. ^If the
8142** resetFlag is true, then the highest record value is reset after
8143** *pHighwater is written. ^(Some parameters do not record the highest
8144** value. For those parameters
8145** nothing is written into *pHighwater and the resetFlag is ignored.)^
8146** ^(Other parameters record only the highwater mark and not the current
8147** value. For these latter parameters nothing is written into *pCurrent.)^
8148**
8149** ^The sqlite3_status() and sqlite3_status64() routines return
8150** SQLITE_OK on success and a non-zero [error code] on failure.
8151**
8152** If either the current value or the highwater mark is too large to
8153** be represented by a 32-bit integer, then the values returned by
8154** sqlite3_status() are undefined.
8155**
8156** See also: [sqlite3_db_status()]
8157*/
8158SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8159SQLITE_API int sqlite3_status64(
8160 int op,
8161 sqlite3_int64 *pCurrent,
8162 sqlite3_int64 *pHighwater,
8163 int resetFlag
8164);
8165
8166
8167/*
8168** CAPI3REF: Status Parameters
8169** KEYWORDS: {status parameters}
8170**
8171** These integer constants designate various run-time status parameters
8172** that can be returned by [sqlite3_status()].
8173**
8174** <dl>
8175** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8176** <dd>This parameter is the current amount of memory checked out
8177** using [sqlite3_malloc()], either directly or indirectly. The
8178** figure includes calls made to [sqlite3_malloc()] by the application
8179** and internal memory usage by the SQLite library. Auxiliary page-cache
8180** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8181** this parameter. The amount returned is the sum of the allocation
8182** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8183**
8184** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8185** <dd>This parameter records the largest memory allocation request
8186** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8187** internal equivalents). Only the value returned in the
8188** *pHighwater parameter to [sqlite3_status()] is of interest.
8189** The value written into the *pCurrent parameter is undefined.</dd>)^
8190**
8191** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8192** <dd>This parameter records the number of separate memory allocations
8193** currently checked out.</dd>)^
8194**
8195** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8196** <dd>This parameter returns the number of pages used out of the
8197** [pagecache memory allocator] that was configured using
8198** [SQLITE_CONFIG_PAGECACHE]. The
8199** value returned is in pages, not in bytes.</dd>)^
8200**
8201** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8202** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8203** <dd>This parameter returns the number of bytes of page cache
8204** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8205** buffer and where forced to overflow to [sqlite3_malloc()]. The
8206** returned value includes allocations that overflowed because they
8207** where too large (they were larger than the "sz" parameter to
8208** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8209** no space was left in the page cache.</dd>)^
8210**
8211** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8212** <dd>This parameter records the largest memory allocation request
8213** handed to the [pagecache memory allocator]. Only the value returned in the
8214** *pHighwater parameter to [sqlite3_status()] is of interest.
8215** The value written into the *pCurrent parameter is undefined.</dd>)^
8216**
8217** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8218** <dd>No longer used.</dd>
8219**
8220** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8221** <dd>No longer used.</dd>
8222**
8223** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8224** <dd>No longer used.</dd>
8225**
8226** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8227** <dd>The *pHighwater parameter records the deepest parser stack.
8228** The *pCurrent value is undefined. The *pHighwater value is only
8229** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8230** </dl>
8231**
8232** New status parameters may be added from time to time.
8233*/
8234#define SQLITE_STATUS_MEMORY_USED 0
8235#define SQLITE_STATUS_PAGECACHE_USED 1
8236#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8237#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8238#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8239#define SQLITE_STATUS_MALLOC_SIZE 5
8240#define SQLITE_STATUS_PARSER_STACK 6
8241#define SQLITE_STATUS_PAGECACHE_SIZE 7
8242#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8243#define SQLITE_STATUS_MALLOC_COUNT 9
8244
8245/*
8246** CAPI3REF: Database Connection Status
8247** METHOD: sqlite3
8248**
8249** ^This interface is used to retrieve runtime status information
8250** about a single [database connection]. ^The first argument is the
8251** database connection object to be interrogated. ^The second argument
8252** is an integer constant, taken from the set of
8253** [SQLITE_DBSTATUS options], that
8254** determines the parameter to interrogate. The set of
8255** [SQLITE_DBSTATUS options] is likely
8256** to grow in future releases of SQLite.
8257**
8258** ^The current value of the requested parameter is written into *pCur
8259** and the highest instantaneous value is written into *pHiwtr. ^If
8260** the resetFlg is true, then the highest instantaneous value is
8261** reset back down to the current value.
8262**
8263** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8264** non-zero [error code] on failure.
8265**
8266** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8267*/
8268SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8269
8270/*
8271** CAPI3REF: Status Parameters for database connections
8272** KEYWORDS: {SQLITE_DBSTATUS options}
8273**
8274** These constants are the available integer "verbs" that can be passed as
8275** the second argument to the [sqlite3_db_status()] interface.
8276**
8277** New verbs may be added in future releases of SQLite. Existing verbs
8278** might be discontinued. Applications should check the return code from
8279** [sqlite3_db_status()] to make sure that the call worked.
8280** The [sqlite3_db_status()] interface will return a non-zero error code
8281** if a discontinued or unsupported verb is invoked.
8282**
8283** <dl>
8284** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8285** <dd>This parameter returns the number of lookaside memory slots currently
8286** checked out.</dd>)^
8287**
8288** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8289** <dd>This parameter returns the number of malloc attempts that were
8290** satisfied using lookaside memory. Only the high-water value is meaningful;
8291** the current value is always zero.)^
8292**
8293** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8294** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8295** <dd>This parameter returns the number malloc attempts that might have
8296** been satisfied using lookaside memory but failed due to the amount of
8297** memory requested being larger than the lookaside slot size.
8298** Only the high-water value is meaningful;
8299** the current value is always zero.)^
8300**
8301** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8302** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8303** <dd>This parameter returns the number malloc attempts that might have
8304** been satisfied using lookaside memory but failed due to all lookaside
8305** memory already being in use.
8306** Only the high-water value is meaningful;
8307** the current value is always zero.)^
8308**
8309** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8310** <dd>This parameter returns the approximate number of bytes of heap
8311** memory used by all pager caches associated with the database connection.)^
8312** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8313**
8314** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8315** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8316** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8317** pager cache is shared between two or more connections the bytes of heap
8318** memory used by that pager cache is divided evenly between the attached
8319** connections.)^ In other words, if none of the pager caches associated
8320** with the database connection are shared, this request returns the same
8321** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8322** shared, the value returned by this call will be smaller than that returned
8323** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8324** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8325**
8326** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8327** <dd>This parameter returns the approximate number of bytes of heap
8328** memory used to store the schema for all databases associated
8329** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8330** ^The full amount of memory used by the schemas is reported, even if the
8331** schema memory is shared with other database connections due to
8332** [shared cache mode] being enabled.
8333** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8334**
8335** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8336** <dd>This parameter returns the approximate number of bytes of heap
8337** and lookaside memory used by all prepared statements associated with
8338** the database connection.)^
8339** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8340** </dd>
8341**
8342** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8343** <dd>This parameter returns the number of pager cache hits that have
8344** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8345** is always 0.
8346** </dd>
8347**
8348** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8349** <dd>This parameter returns the number of pager cache misses that have
8350** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8351** is always 0.
8352** </dd>
8353**
8354** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8355** <dd>This parameter returns the number of dirty cache entries that have
8356** been written to disk. Specifically, the number of pages written to the
8357** wal file in wal mode databases, or the number of pages written to the
8358** database file in rollback mode databases. Any pages written as part of
8359** transaction rollback or database recovery operations are not included.
8360** If an IO or other error occurs while writing a page to disk, the effect
8361** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8362** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8363** </dd>
8364**
8365** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8366** <dd>This parameter returns the number of dirty cache entries that have
8367** been written to disk in the middle of a transaction due to the page
8368** cache overflowing. Transactions are more efficient if they are written
8369** to disk all at once. When pages spill mid-transaction, that introduces
8370** additional overhead. This parameter can be used help identify
8371** inefficiencies that can be resolved by increasing the cache size.
8372** </dd>
8373**
8374** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8375** <dd>This parameter returns zero for the current value if and only if
8376** all foreign key constraints (deferred or immediate) have been
8377** resolved.)^ ^The highwater mark is always 0.
8378** </dd>
8379** </dl>
8380*/
8381#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8382#define SQLITE_DBSTATUS_CACHE_USED 1
8383#define SQLITE_DBSTATUS_SCHEMA_USED 2
8384#define SQLITE_DBSTATUS_STMT_USED 3
8385#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8386#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8387#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8388#define SQLITE_DBSTATUS_CACHE_HIT 7
8389#define SQLITE_DBSTATUS_CACHE_MISS 8
8390#define SQLITE_DBSTATUS_CACHE_WRITE 9
8391#define SQLITE_DBSTATUS_DEFERRED_FKS 10
8392#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8393#define SQLITE_DBSTATUS_CACHE_SPILL 12
8394#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8395
8396
8397/*
8398** CAPI3REF: Prepared Statement Status
8399** METHOD: sqlite3_stmt
8400**
8401** ^(Each prepared statement maintains various
8402** [SQLITE_STMTSTATUS counters] that measure the number
8403** of times it has performed specific operations.)^ These counters can
8404** be used to monitor the performance characteristics of the prepared
8405** statements. For example, if the number of table steps greatly exceeds
8406** the number of table searches or result rows, that would tend to indicate
8407** that the prepared statement is using a full table scan rather than
8408** an index.
8409**
8410** ^(This interface is used to retrieve and reset counter values from
8411** a [prepared statement]. The first argument is the prepared statement
8412** object to be interrogated. The second argument
8413** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8414** to be interrogated.)^
8415** ^The current value of the requested counter is returned.
8416** ^If the resetFlg is true, then the counter is reset to zero after this
8417** interface call returns.
8418**
8419** See also: [sqlite3_status()] and [sqlite3_db_status()].
8420*/
8421SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8422
8423/*
8424** CAPI3REF: Status Parameters for prepared statements
8425** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8426**
8427** These preprocessor macros define integer codes that name counter
8428** values associated with the [sqlite3_stmt_status()] interface.
8429** The meanings of the various counters are as follows:
8430**
8431** <dl>
8432** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8433** <dd>^This is the number of times that SQLite has stepped forward in
8434** a table as part of a full table scan. Large numbers for this counter
8435** may indicate opportunities for performance improvement through
8436** careful use of indices.</dd>
8437**
8438** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8439** <dd>^This is the number of sort operations that have occurred.
8440** A non-zero value in this counter may indicate an opportunity to
8441** improvement performance through careful use of indices.</dd>
8442**
8443** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8444** <dd>^This is the number of rows inserted into transient indices that
8445** were created automatically in order to help joins run faster.
8446** A non-zero value in this counter may indicate an opportunity to
8447** improvement performance by adding permanent indices that do not
8448** need to be reinitialized each time the statement is run.</dd>
8449**
8450** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8451** <dd>^This is the number of virtual machine operations executed
8452** by the prepared statement if that number is less than or equal
8453** to 2147483647. The number of virtual machine operations can be
8454** used as a proxy for the total work done by the prepared statement.
8455** If the number of virtual machine operations exceeds 2147483647
8456** then the value returned by this statement status code is undefined.
8457**
8458** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8459** <dd>^This is the number of times that the prepare statement has been
8460** automatically regenerated due to schema changes or changes to
8461** [bound parameters] that might affect the query plan.
8462**
8463** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8464** <dd>^This is the number of times that the prepared statement has
8465** been run. A single "run" for the purposes of this counter is one
8466** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8467** The counter is incremented on the first [sqlite3_step()] call of each
8468** cycle.
8469**
8470** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8471** <dd>^This is the approximate number of bytes of heap memory
8472** used to store the prepared statement. ^This value is not actually
8473** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8474** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8475** </dd>
8476** </dl>
8477*/
8478#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8479#define SQLITE_STMTSTATUS_SORT 2
8480#define SQLITE_STMTSTATUS_AUTOINDEX 3
8481#define SQLITE_STMTSTATUS_VM_STEP 4
8482#define SQLITE_STMTSTATUS_REPREPARE 5
8483#define SQLITE_STMTSTATUS_RUN 6
8484#define SQLITE_STMTSTATUS_MEMUSED 99
8485
8486/*
8487** CAPI3REF: Custom Page Cache Object
8488**
8489** The sqlite3_pcache type is opaque. It is implemented by
8490** the pluggable module. The SQLite core has no knowledge of
8491** its size or internal structure and never deals with the
8492** sqlite3_pcache object except by holding and passing pointers
8493** to the object.
8494**
8495** See [sqlite3_pcache_methods2] for additional information.
8496*/
8497typedef struct sqlite3_pcache sqlite3_pcache;
8498
8499/*
8500** CAPI3REF: Custom Page Cache Object
8501**
8502** The sqlite3_pcache_page object represents a single page in the
8503** page cache. The page cache will allocate instances of this
8504** object. Various methods of the page cache use pointers to instances
8505** of this object as parameters or as their return value.
8506**
8507** See [sqlite3_pcache_methods2] for additional information.
8508*/
8509typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8510struct sqlite3_pcache_page {
8511 void *pBuf; /* The content of the page */
8512 void *pExtra; /* Extra information associated with the page */
8513};
8514
8515/*
8516** CAPI3REF: Application Defined Page Cache.
8517** KEYWORDS: {page cache}
8518**
8519** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8520** register an alternative page cache implementation by passing in an
8521** instance of the sqlite3_pcache_methods2 structure.)^
8522** In many applications, most of the heap memory allocated by
8523** SQLite is used for the page cache.
8524** By implementing a
8525** custom page cache using this API, an application can better control
8526** the amount of memory consumed by SQLite, the way in which
8527** that memory is allocated and released, and the policies used to
8528** determine exactly which parts of a database file are cached and for
8529** how long.
8530**
8531** The alternative page cache mechanism is an
8532** extreme measure that is only needed by the most demanding applications.
8533** The built-in page cache is recommended for most uses.
8534**
8535** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8536** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8537** the application may discard the parameter after the call to
8538** [sqlite3_config()] returns.)^
8539**
8540** [[the xInit() page cache method]]
8541** ^(The xInit() method is called once for each effective
8542** call to [sqlite3_initialize()])^
8543** (usually only once during the lifetime of the process). ^(The xInit()
8544** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8545** The intent of the xInit() method is to set up global data structures
8546** required by the custom page cache implementation.
8547** ^(If the xInit() method is NULL, then the
8548** built-in default page cache is used instead of the application defined
8549** page cache.)^
8550**
8551** [[the xShutdown() page cache method]]
8552** ^The xShutdown() method is called by [sqlite3_shutdown()].
8553** It can be used to clean up
8554** any outstanding resources before process shutdown, if required.
8555** ^The xShutdown() method may be NULL.
8556**
8557** ^SQLite automatically serializes calls to the xInit method,
8558** so the xInit method need not be threadsafe. ^The
8559** xShutdown method is only called from [sqlite3_shutdown()] so it does
8560** not need to be threadsafe either. All other methods must be threadsafe
8561** in multithreaded applications.
8562**
8563** ^SQLite will never invoke xInit() more than once without an intervening
8564** call to xShutdown().
8565**
8566** [[the xCreate() page cache methods]]
8567** ^SQLite invokes the xCreate() method to construct a new cache instance.
8568** SQLite will typically create one cache instance for each open database file,
8569** though this is not guaranteed. ^The
8570** first parameter, szPage, is the size in bytes of the pages that must
8571** be allocated by the cache. ^szPage will always a power of two. ^The
8572** second parameter szExtra is a number of bytes of extra storage
8573** associated with each page cache entry. ^The szExtra parameter will
8574** a number less than 250. SQLite will use the
8575** extra szExtra bytes on each page to store metadata about the underlying
8576** database page on disk. The value passed into szExtra depends
8577** on the SQLite version, the target platform, and how SQLite was compiled.
8578** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8579** created will be used to cache database pages of a file stored on disk, or
8580** false if it is used for an in-memory database. The cache implementation
8581** does not have to do anything special based with the value of bPurgeable;
8582** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8583** never invoke xUnpin() except to deliberately delete a page.
8584** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8585** false will always have the "discard" flag set to true.
8586** ^Hence, a cache created with bPurgeable false will
8587** never contain any unpinned pages.
8588**
8589** [[the xCachesize() page cache method]]
8590** ^(The xCachesize() method may be called at any time by SQLite to set the
8591** suggested maximum cache-size (number of pages stored by) the cache
8592** instance passed as the first argument. This is the value configured using
8593** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8594** parameter, the implementation is not required to do anything with this
8595** value; it is advisory only.
8596**
8597** [[the xPagecount() page cache methods]]
8598** The xPagecount() method must return the number of pages currently
8599** stored in the cache, both pinned and unpinned.
8600**
8601** [[the xFetch() page cache methods]]
8602** The xFetch() method locates a page in the cache and returns a pointer to
8603** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8604** The pBuf element of the returned sqlite3_pcache_page object will be a
8605** pointer to a buffer of szPage bytes used to store the content of a
8606** single database page. The pExtra element of sqlite3_pcache_page will be
8607** a pointer to the szExtra bytes of extra storage that SQLite has requested
8608** for each entry in the page cache.
8609**
8610** The page to be fetched is determined by the key. ^The minimum key value
8611** is 1. After it has been retrieved using xFetch, the page is considered
8612** to be "pinned".
8613**
8614** If the requested page is already in the page cache, then the page cache
8615** implementation must return a pointer to the page buffer with its content
8616** intact. If the requested page is not already in the cache, then the
8617** cache implementation should use the value of the createFlag
8618** parameter to help it determined what action to take:
8619**
8620** <table border=1 width=85% align=center>
8621** <tr><th> createFlag <th> Behavior when page is not already in cache
8622** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8623** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8624** Otherwise return NULL.
8625** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8626** NULL if allocating a new page is effectively impossible.
8627** </table>
8628**
8629** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8630** will only use a createFlag of 2 after a prior call with a createFlag of 1
8631** failed.)^ In between the xFetch() calls, SQLite may
8632** attempt to unpin one or more cache pages by spilling the content of
8633** pinned pages to disk and synching the operating system disk cache.
8634**
8635** [[the xUnpin() page cache method]]
8636** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8637** as its second argument. If the third parameter, discard, is non-zero,
8638** then the page must be evicted from the cache.
8639** ^If the discard parameter is
8640** zero, then the page may be discarded or retained at the discretion of
8641** page cache implementation. ^The page cache implementation
8642** may choose to evict unpinned pages at any time.
8643**
8644** The cache must not perform any reference counting. A single
8645** call to xUnpin() unpins the page regardless of the number of prior calls
8646** to xFetch().
8647**
8648** [[the xRekey() page cache methods]]
8649** The xRekey() method is used to change the key value associated with the
8650** page passed as the second argument. If the cache
8651** previously contains an entry associated with newKey, it must be
8652** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8653** to be pinned.
8654**
8655** When SQLite calls the xTruncate() method, the cache must discard all
8656** existing cache entries with page numbers (keys) greater than or equal
8657** to the value of the iLimit parameter passed to xTruncate(). If any
8658** of these pages are pinned, they are implicitly unpinned, meaning that
8659** they can be safely discarded.
8660**
8661** [[the xDestroy() page cache method]]
8662** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8663** All resources associated with the specified cache should be freed. ^After
8664** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8665** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8666** functions.
8667**
8668** [[the xShrink() page cache method]]
8669** ^SQLite invokes the xShrink() method when it wants the page cache to
8670** free up as much of heap memory as possible. The page cache implementation
8671** is not obligated to free any memory, but well-behaved implementations should
8672** do their best.
8673*/
8674typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8675struct sqlite3_pcache_methods2 {
8676 int iVersion;
8677 void *pArg;
8678 int (*xInit)(void*);
8679 void (*xShutdown)(void*);
8680 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8681 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8682 int (*xPagecount)(sqlite3_pcache*);
8683 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8684 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8685 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8686 unsigned oldKey, unsigned newKey);
8687 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8688 void (*xDestroy)(sqlite3_pcache*);
8689 void (*xShrink)(sqlite3_pcache*);
8690};
8691
8692/*
8693** This is the obsolete pcache_methods object that has now been replaced
8694** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8695** retained in the header file for backwards compatibility only.
8696*/
8697typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8698struct sqlite3_pcache_methods {
8699 void *pArg;
8700 int (*xInit)(void*);
8701 void (*xShutdown)(void*);
8702 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8703 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8704 int (*xPagecount)(sqlite3_pcache*);
8705 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8706 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8707 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8708 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8709 void (*xDestroy)(sqlite3_pcache*);
8710};
8711
8712
8713/*
8714** CAPI3REF: Online Backup Object
8715**
8716** The sqlite3_backup object records state information about an ongoing
8717** online backup operation. ^The sqlite3_backup object is created by
8718** a call to [sqlite3_backup_init()] and is destroyed by a call to
8719** [sqlite3_backup_finish()].
8720**
8721** See Also: [Using the SQLite Online Backup API]
8722*/
8723typedef struct sqlite3_backup sqlite3_backup;
8724
8725/*
8726** CAPI3REF: Online Backup API.
8727**
8728** The backup API copies the content of one database into another.
8729** It is useful either for creating backups of databases or
8730** for copying in-memory databases to or from persistent files.
8731**
8732** See Also: [Using the SQLite Online Backup API]
8733**
8734** ^SQLite holds a write transaction open on the destination database file
8735** for the duration of the backup operation.
8736** ^The source database is read-locked only while it is being read;
8737** it is not locked continuously for the entire backup operation.
8738** ^Thus, the backup may be performed on a live source database without
8739** preventing other database connections from
8740** reading or writing to the source database while the backup is underway.
8741**
8742** ^(To perform a backup operation:
8743** <ol>
8744** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8745** backup,
8746** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8747** the data between the two databases, and finally
8748** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8749** associated with the backup operation.
8750** </ol>)^
8751** There should be exactly one call to sqlite3_backup_finish() for each
8752** successful call to sqlite3_backup_init().
8753**
8754** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8755**
8756** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8757** [database connection] associated with the destination database
8758** and the database name, respectively.
8759** ^The database name is "main" for the main database, "temp" for the
8760** temporary database, or the name specified after the AS keyword in
8761** an [ATTACH] statement for an attached database.
8762** ^The S and M arguments passed to
8763** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8764** and database name of the source database, respectively.
8765** ^The source and destination [database connections] (parameters S and D)
8766** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8767** an error.
8768**
8769** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8770** there is already a read or read-write transaction open on the
8771** destination database.
8772**
8773** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8774** returned and an error code and error message are stored in the
8775** destination [database connection] D.
8776** ^The error code and message for the failed call to sqlite3_backup_init()
8777** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8778** [sqlite3_errmsg16()] functions.
8779** ^A successful call to sqlite3_backup_init() returns a pointer to an
8780** [sqlite3_backup] object.
8781** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8782** sqlite3_backup_finish() functions to perform the specified backup
8783** operation.
8784**
8785** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8786**
8787** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8788** the source and destination databases specified by [sqlite3_backup] object B.
8789** ^If N is negative, all remaining source pages are copied.
8790** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8791** are still more pages to be copied, then the function returns [SQLITE_OK].
8792** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8793** from source to destination, then it returns [SQLITE_DONE].
8794** ^If an error occurs while running sqlite3_backup_step(B,N),
8795** then an [error code] is returned. ^As well as [SQLITE_OK] and
8796** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8797** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8798** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8799**
8800** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8801** <ol>
8802** <li> the destination database was opened read-only, or
8803** <li> the destination database is using write-ahead-log journaling
8804** and the destination and source page sizes differ, or
8805** <li> the destination database is an in-memory database and the
8806** destination and source page sizes differ.
8807** </ol>)^
8808**
8809** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8810** the [sqlite3_busy_handler | busy-handler function]
8811** is invoked (if one is specified). ^If the
8812** busy-handler returns non-zero before the lock is available, then
8813** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8814** sqlite3_backup_step() can be retried later. ^If the source
8815** [database connection]
8816** is being used to write to the source database when sqlite3_backup_step()
8817** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8818** case the call to sqlite3_backup_step() can be retried later on. ^(If
8819** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8820** [SQLITE_READONLY] is returned, then
8821** there is no point in retrying the call to sqlite3_backup_step(). These
8822** errors are considered fatal.)^ The application must accept
8823** that the backup operation has failed and pass the backup operation handle
8824** to the sqlite3_backup_finish() to release associated resources.
8825**
8826** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8827** on the destination file. ^The exclusive lock is not released until either
8828** sqlite3_backup_finish() is called or the backup operation is complete
8829** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8830** sqlite3_backup_step() obtains a [shared lock] on the source database that
8831** lasts for the duration of the sqlite3_backup_step() call.
8832** ^Because the source database is not locked between calls to
8833** sqlite3_backup_step(), the source database may be modified mid-way
8834** through the backup process. ^If the source database is modified by an
8835** external process or via a database connection other than the one being
8836** used by the backup operation, then the backup will be automatically
8837** restarted by the next call to sqlite3_backup_step(). ^If the source
8838** database is modified by the using the same database connection as is used
8839** by the backup operation, then the backup database is automatically
8840** updated at the same time.
8841**
8842** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8843**
8844** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8845** application wishes to abandon the backup operation, the application
8846** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8847** ^The sqlite3_backup_finish() interfaces releases all
8848** resources associated with the [sqlite3_backup] object.
8849** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8850** active write-transaction on the destination database is rolled back.
8851** The [sqlite3_backup] object is invalid
8852** and may not be used following a call to sqlite3_backup_finish().
8853**
8854** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8855** sqlite3_backup_step() errors occurred, regardless or whether or not
8856** sqlite3_backup_step() completed.
8857** ^If an out-of-memory condition or IO error occurred during any prior
8858** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8859** sqlite3_backup_finish() returns the corresponding [error code].
8860**
8861** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8862** is not a permanent error and does not affect the return value of
8863** sqlite3_backup_finish().
8864**
8865** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8866** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8867**
8868** ^The sqlite3_backup_remaining() routine returns the number of pages still
8869** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8870** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8871** in the source database at the conclusion of the most recent
8872** sqlite3_backup_step().
8873** ^(The values returned by these functions are only updated by
8874** sqlite3_backup_step(). If the source database is modified in a way that
8875** changes the size of the source database or the number of pages remaining,
8876** those changes are not reflected in the output of sqlite3_backup_pagecount()
8877** and sqlite3_backup_remaining() until after the next
8878** sqlite3_backup_step().)^
8879**
8880** <b>Concurrent Usage of Database Handles</b>
8881**
8882** ^The source [database connection] may be used by the application for other
8883** purposes while a backup operation is underway or being initialized.
8884** ^If SQLite is compiled and configured to support threadsafe database
8885** connections, then the source database connection may be used concurrently
8886** from within other threads.
8887**
8888** However, the application must guarantee that the destination
8889** [database connection] is not passed to any other API (by any thread) after
8890** sqlite3_backup_init() is called and before the corresponding call to
8891** sqlite3_backup_finish(). SQLite does not currently check to see
8892** if the application incorrectly accesses the destination [database connection]
8893** and so no error code is reported, but the operations may malfunction
8894** nevertheless. Use of the destination database connection while a
8895** backup is in progress might also also cause a mutex deadlock.
8896**
8897** If running in [shared cache mode], the application must
8898** guarantee that the shared cache used by the destination database
8899** is not accessed while the backup is running. In practice this means
8900** that the application must guarantee that the disk file being
8901** backed up to is not accessed by any connection within the process,
8902** not just the specific connection that was passed to sqlite3_backup_init().
8903**
8904** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8905** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8906** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8907** APIs are not strictly speaking threadsafe. If they are invoked at the
8908** same time as another thread is invoking sqlite3_backup_step() it is
8909** possible that they return invalid values.
8910*/
8911SQLITE_API sqlite3_backup *sqlite3_backup_init(
8912 sqlite3 *pDest, /* Destination database handle */
8913 const char *zDestName, /* Destination database name */
8914 sqlite3 *pSource, /* Source database handle */
8915 const char *zSourceName /* Source database name */
8916);
8917SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8918SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8919SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8920SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8921
8922/*
8923** CAPI3REF: Unlock Notification
8924** METHOD: sqlite3
8925**
8926** ^When running in shared-cache mode, a database operation may fail with
8927** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8928** individual tables within the shared-cache cannot be obtained. See
8929** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8930** ^This API may be used to register a callback that SQLite will invoke
8931** when the connection currently holding the required lock relinquishes it.
8932** ^This API is only available if the library was compiled with the
8933** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8934**
8935** See Also: [Using the SQLite Unlock Notification Feature].
8936**
8937** ^Shared-cache locks are released when a database connection concludes
8938** its current transaction, either by committing it or rolling it back.
8939**
8940** ^When a connection (known as the blocked connection) fails to obtain a
8941** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8942** identity of the database connection (the blocking connection) that
8943** has locked the required resource is stored internally. ^After an
8944** application receives an SQLITE_LOCKED error, it may call the
8945** sqlite3_unlock_notify() method with the blocked connection handle as
8946** the first argument to register for a callback that will be invoked
8947** when the blocking connections current transaction is concluded. ^The
8948** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
8949** call that concludes the blocking connection's transaction.
8950**
8951** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8952** there is a chance that the blocking connection will have already
8953** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8954** If this happens, then the specified callback is invoked immediately,
8955** from within the call to sqlite3_unlock_notify().)^
8956**
8957** ^If the blocked connection is attempting to obtain a write-lock on a
8958** shared-cache table, and more than one other connection currently holds
8959** a read-lock on the same table, then SQLite arbitrarily selects one of
8960** the other connections to use as the blocking connection.
8961**
8962** ^(There may be at most one unlock-notify callback registered by a
8963** blocked connection. If sqlite3_unlock_notify() is called when the
8964** blocked connection already has a registered unlock-notify callback,
8965** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8966** called with a NULL pointer as its second argument, then any existing
8967** unlock-notify callback is canceled. ^The blocked connections
8968** unlock-notify callback may also be canceled by closing the blocked
8969** connection using [sqlite3_close()].
8970**
8971** The unlock-notify callback is not reentrant. If an application invokes
8972** any sqlite3_xxx API functions from within an unlock-notify callback, a
8973** crash or deadlock may be the result.
8974**
8975** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8976** returns SQLITE_OK.
8977**
8978** <b>Callback Invocation Details</b>
8979**
8980** When an unlock-notify callback is registered, the application provides a
8981** single void* pointer that is passed to the callback when it is invoked.
8982** However, the signature of the callback function allows SQLite to pass
8983** it an array of void* context pointers. The first argument passed to
8984** an unlock-notify callback is a pointer to an array of void* pointers,
8985** and the second is the number of entries in the array.
8986**
8987** When a blocking connection's transaction is concluded, there may be
8988** more than one blocked connection that has registered for an unlock-notify
8989** callback. ^If two or more such blocked connections have specified the
8990** same callback function, then instead of invoking the callback function
8991** multiple times, it is invoked once with the set of void* context pointers
8992** specified by the blocked connections bundled together into an array.
8993** This gives the application an opportunity to prioritize any actions
8994** related to the set of unblocked database connections.
8995**
8996** <b>Deadlock Detection</b>
8997**
8998** Assuming that after registering for an unlock-notify callback a
8999** database waits for the callback to be issued before taking any further
9000** action (a reasonable assumption), then using this API may cause the
9001** application to deadlock. For example, if connection X is waiting for
9002** connection Y's transaction to be concluded, and similarly connection
9003** Y is waiting on connection X's transaction, then neither connection
9004** will proceed and the system may remain deadlocked indefinitely.
9005**
9006** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9007** detection. ^If a given call to sqlite3_unlock_notify() would put the
9008** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9009** unlock-notify callback is registered. The system is said to be in
9010** a deadlocked state if connection A has registered for an unlock-notify
9011** callback on the conclusion of connection B's transaction, and connection
9012** B has itself registered for an unlock-notify callback when connection
9013** A's transaction is concluded. ^Indirect deadlock is also detected, so
9014** the system is also considered to be deadlocked if connection B has
9015** registered for an unlock-notify callback on the conclusion of connection
9016** C's transaction, where connection C is waiting on connection A. ^Any
9017** number of levels of indirection are allowed.
9018**
9019** <b>The "DROP TABLE" Exception</b>
9020**
9021** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9022** always appropriate to call sqlite3_unlock_notify(). There is however,
9023** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9024** SQLite checks if there are any currently executing SELECT statements
9025** that belong to the same connection. If there are, SQLITE_LOCKED is
9026** returned. In this case there is no "blocking connection", so invoking
9027** sqlite3_unlock_notify() results in the unlock-notify callback being
9028** invoked immediately. If the application then re-attempts the "DROP TABLE"
9029** or "DROP INDEX" query, an infinite loop might be the result.
9030**
9031** One way around this problem is to check the extended error code returned
9032** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9033** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9034** the special "DROP TABLE/INDEX" case, the extended error code is just
9035** SQLITE_LOCKED.)^
9036*/
9037SQLITE_API int sqlite3_unlock_notify(
9038 sqlite3 *pBlocked, /* Waiting connection */
9039 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9040 void *pNotifyArg /* Argument to pass to xNotify */
9041);
9042
9043
9044/*
9045** CAPI3REF: String Comparison
9046**
9047** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9048** and extensions to compare the contents of two buffers containing UTF-8
9049** strings in a case-independent fashion, using the same definition of "case
9050** independence" that SQLite uses internally when comparing identifiers.
9051*/
9052SQLITE_API int sqlite3_stricmp(const char *, const char *);
9053SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9054
9055/*
9056** CAPI3REF: String Globbing
9057*
9058** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9059** string X matches the [GLOB] pattern P.
9060** ^The definition of [GLOB] pattern matching used in
9061** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9062** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9063** is case sensitive.
9064**
9065** Note that this routine returns zero on a match and non-zero if the strings
9066** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9067**
9068** See also: [sqlite3_strlike()].
9069*/
9070SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9071
9072/*
9073** CAPI3REF: String LIKE Matching
9074*
9075** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9076** string X matches the [LIKE] pattern P with escape character E.
9077** ^The definition of [LIKE] pattern matching used in
9078** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9079** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9080** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9081** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9082** insensitive - equivalent upper and lower case ASCII characters match
9083** one another.
9084**
9085** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9086** only ASCII characters are case folded.
9087**
9088** Note that this routine returns zero on a match and non-zero if the strings
9089** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9090**
9091** See also: [sqlite3_strglob()].
9092*/
9093SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9094
9095/*
9096** CAPI3REF: Error Logging Interface
9097**
9098** ^The [sqlite3_log()] interface writes a message into the [error log]
9099** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9100** ^If logging is enabled, the zFormat string and subsequent arguments are
9101** used with [sqlite3_snprintf()] to generate the final output string.
9102**
9103** The sqlite3_log() interface is intended for use by extensions such as
9104** virtual tables, collating functions, and SQL functions. While there is
9105** nothing to prevent an application from calling sqlite3_log(), doing so
9106** is considered bad form.
9107**
9108** The zFormat string must not be NULL.
9109**
9110** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9111** will not use dynamically allocated memory. The log message is stored in
9112** a fixed-length buffer on the stack. If the log message is longer than
9113** a few hundred characters, it will be truncated to the length of the
9114** buffer.
9115*/
9116SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9117
9118/*
9119** CAPI3REF: Write-Ahead Log Commit Hook
9120** METHOD: sqlite3
9121**
9122** ^The [sqlite3_wal_hook()] function is used to register a callback that
9123** is invoked each time data is committed to a database in wal mode.
9124**
9125** ^(The callback is invoked by SQLite after the commit has taken place and
9126** the associated write-lock on the database released)^, so the implementation
9127** may read, write or [checkpoint] the database as required.
9128**
9129** ^The first parameter passed to the callback function when it is invoked
9130** is a copy of the third parameter passed to sqlite3_wal_hook() when
9131** registering the callback. ^The second is a copy of the database handle.
9132** ^The third parameter is the name of the database that was written to -
9133** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9134** is the number of pages currently in the write-ahead log file,
9135** including those that were just committed.
9136**
9137** The callback function should normally return [SQLITE_OK]. ^If an error
9138** code is returned, that error will propagate back up through the
9139** SQLite code base to cause the statement that provoked the callback
9140** to report an error, though the commit will have still occurred. If the
9141** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9142** that does not correspond to any valid SQLite error code, the results
9143** are undefined.
9144**
9145** A single database handle may have at most a single write-ahead log callback
9146** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9147** previously registered write-ahead log callback. ^The return value is
9148** a copy of the third parameter from the previous call, if any, or 0.
9149** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9150** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9151** overwrite any prior [sqlite3_wal_hook()] settings.
9152*/
9153SQLITE_API void *sqlite3_wal_hook(
9154 sqlite3*,
9155 int(*)(void *,sqlite3*,const char*,int),
9156 void*
9157);
9158
9159/*
9160** CAPI3REF: Configure an auto-checkpoint
9161** METHOD: sqlite3
9162**
9163** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9164** [sqlite3_wal_hook()] that causes any database on [database connection] D
9165** to automatically [checkpoint]
9166** after committing a transaction if there are N or
9167** more frames in the [write-ahead log] file. ^Passing zero or
9168** a negative value as the nFrame parameter disables automatic
9169** checkpoints entirely.
9170**
9171** ^The callback registered by this function replaces any existing callback
9172** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9173** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9174** configured by this function.
9175**
9176** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9177** from SQL.
9178**
9179** ^Checkpoints initiated by this mechanism are
9180** [sqlite3_wal_checkpoint_v2|PASSIVE].
9181**
9182** ^Every new [database connection] defaults to having the auto-checkpoint
9183** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9184** pages. The use of this interface
9185** is only necessary if the default setting is found to be suboptimal
9186** for a particular application.
9187*/
9188SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9189
9190/*
9191** CAPI3REF: Checkpoint a database
9192** METHOD: sqlite3
9193**
9194** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9195** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9196**
9197** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9198** [write-ahead log] for database X on [database connection] D to be
9199** transferred into the database file and for the write-ahead log to
9200** be reset. See the [checkpointing] documentation for addition
9201** information.
9202**
9203** This interface used to be the only way to cause a checkpoint to
9204** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9205** interface was added. This interface is retained for backwards
9206** compatibility and as a convenience for applications that need to manually
9207** start a callback but which do not need the full power (and corresponding
9208** complication) of [sqlite3_wal_checkpoint_v2()].
9209*/
9210SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9211
9212/*
9213** CAPI3REF: Checkpoint a database
9214** METHOD: sqlite3
9215**
9216** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9217** operation on database X of [database connection] D in mode M. Status
9218** information is written back into integers pointed to by L and C.)^
9219** ^(The M parameter must be a valid [checkpoint mode]:)^
9220**
9221** <dl>
9222** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9223** ^Checkpoint as many frames as possible without waiting for any database
9224** readers or writers to finish, then sync the database file if all frames
9225** in the log were checkpointed. ^The [busy-handler callback]
9226** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9227** ^On the other hand, passive mode might leave the checkpoint unfinished
9228** if there are concurrent readers or writers.
9229**
9230** <dt>SQLITE_CHECKPOINT_FULL<dd>
9231** ^This mode blocks (it invokes the
9232** [sqlite3_busy_handler|busy-handler callback]) until there is no
9233** database writer and all readers are reading from the most recent database
9234** snapshot. ^It then checkpoints all frames in the log file and syncs the
9235** database file. ^This mode blocks new database writers while it is pending,
9236** but new database readers are allowed to continue unimpeded.
9237**
9238** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9239** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9240** that after checkpointing the log file it blocks (calls the
9241** [busy-handler callback])
9242** until all readers are reading from the database file only. ^This ensures
9243** that the next writer will restart the log file from the beginning.
9244** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9245** database writer attempts while it is pending, but does not impede readers.
9246**
9247** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9248** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9249** addition that it also truncates the log file to zero bytes just prior
9250** to a successful return.
9251** </dl>
9252**
9253** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9254** the log file or to -1 if the checkpoint could not run because
9255** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9256** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9257** log file (including any that were already checkpointed before the function
9258** was called) or to -1 if the checkpoint could not run due to an error or
9259** because the database is not in WAL mode. ^Note that upon successful
9260** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9261** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9262**
9263** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9264** any other process is running a checkpoint operation at the same time, the
9265** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9266** busy-handler configured, it will not be invoked in this case.
9267**
9268** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9269** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9270** obtained immediately, and a busy-handler is configured, it is invoked and
9271** the writer lock retried until either the busy-handler returns 0 or the lock
9272** is successfully obtained. ^The busy-handler is also invoked while waiting for
9273** database readers as described above. ^If the busy-handler returns 0 before
9274** the writer lock is obtained or while waiting for database readers, the
9275** checkpoint operation proceeds from that point in the same way as
9276** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9277** without blocking any further. ^SQLITE_BUSY is returned in this case.
9278**
9279** ^If parameter zDb is NULL or points to a zero length string, then the
9280** specified operation is attempted on all WAL databases [attached] to
9281** [database connection] db. In this case the
9282** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9283** an SQLITE_BUSY error is encountered when processing one or more of the
9284** attached WAL databases, the operation is still attempted on any remaining
9285** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9286** error occurs while processing an attached database, processing is abandoned
9287** and the error code is returned to the caller immediately. ^If no error
9288** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9289** databases, SQLITE_OK is returned.
9290**
9291** ^If database zDb is the name of an attached database that is not in WAL
9292** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9293** zDb is not NULL (or a zero length string) and is not the name of any
9294** attached database, SQLITE_ERROR is returned to the caller.
9295**
9296** ^Unless it returns SQLITE_MISUSE,
9297** the sqlite3_wal_checkpoint_v2() interface
9298** sets the error information that is queried by
9299** [sqlite3_errcode()] and [sqlite3_errmsg()].
9300**
9301** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9302** from SQL.
9303*/
9304SQLITE_API int sqlite3_wal_checkpoint_v2(
9305 sqlite3 *db, /* Database handle */
9306 const char *zDb, /* Name of attached database (or NULL) */
9307 int eMode, /* SQLITE_CHECKPOINT_* value */
9308 int *pnLog, /* OUT: Size of WAL log in frames */
9309 int *pnCkpt /* OUT: Total number of frames checkpointed */
9310);
9311
9312/*
9313** CAPI3REF: Checkpoint Mode Values
9314** KEYWORDS: {checkpoint mode}
9315**
9316** These constants define all valid values for the "checkpoint mode" passed
9317** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9318** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9319** meaning of each of these checkpoint modes.
9320*/
9321#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9322#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9323#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
9324#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9325
9326/*
9327** CAPI3REF: Virtual Table Interface Configuration
9328**
9329** This function may be called by either the [xConnect] or [xCreate] method
9330** of a [virtual table] implementation to configure
9331** various facets of the virtual table interface.
9332**
9333** If this interface is invoked outside the context of an xConnect or
9334** xCreate virtual table method then the behavior is undefined.
9335**
9336** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9337** [database connection] in which the virtual table is being created and
9338** which is passed in as the first argument to the [xConnect] or [xCreate]
9339** method that is invoking sqlite3_vtab_config(). The C parameter is one
9340** of the [virtual table configuration options]. The presence and meaning
9341** of parameters after C depend on which [virtual table configuration option]
9342** is used.
9343*/
9344SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9345
9346/*
9347** CAPI3REF: Virtual Table Configuration Options
9348** KEYWORDS: {virtual table configuration options}
9349** KEYWORDS: {virtual table configuration option}
9350**
9351** These macros define the various options to the
9352** [sqlite3_vtab_config()] interface that [virtual table] implementations
9353** can use to customize and optimize their behavior.
9354**
9355** <dl>
9356** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9357** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9358** <dd>Calls of the form
9359** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9360** where X is an integer. If X is zero, then the [virtual table] whose
9361** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9362** support constraints. In this configuration (which is the default) if
9363** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9364** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9365** specified as part of the users SQL statement, regardless of the actual
9366** ON CONFLICT mode specified.
9367**
9368** If X is non-zero, then the virtual table implementation guarantees
9369** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9370** any modifications to internal or persistent data structures have been made.
9371** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9372** is able to roll back a statement or database transaction, and abandon
9373** or continue processing the current SQL statement as appropriate.
9374** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9375** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9376** had been ABORT.
9377**
9378** Virtual table implementations that are required to handle OR REPLACE
9379** must do so within the [xUpdate] method. If a call to the
9380** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9381** CONFLICT policy is REPLACE, the virtual table implementation should
9382** silently replace the appropriate rows within the xUpdate callback and
9383** return SQLITE_OK. Or, if this is not possible, it may return
9384** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9385** constraint handling.
9386** </dd>
9387**
9388** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9389** <dd>Calls of the form
9390** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9391** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9392** prohibits that virtual table from being used from within triggers and
9393** views.
9394** </dd>
9395**
9396** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9397** <dd>Calls of the form
9398** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9399** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9400** identify that virtual table as being safe to use from within triggers
9401** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9402** virtual table can do no serious harm even if it is controlled by a
9403** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9404** flag unless absolutely necessary.
9405** </dd>
9406** </dl>
9407*/
9408#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9409#define SQLITE_VTAB_INNOCUOUS 2
9410#define SQLITE_VTAB_DIRECTONLY 3
9411
9412/*
9413** CAPI3REF: Determine The Virtual Table Conflict Policy
9414**
9415** This function may only be called from within a call to the [xUpdate] method
9416** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9417** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9418** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9419** of the SQL statement that triggered the call to the [xUpdate] method of the
9420** [virtual table].
9421*/
9422SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9423
9424/*
9425** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9426**
9427** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9428** method of a [virtual table], then it might return true if the
9429** column is being fetched as part of an UPDATE operation during which the
9430** column value will not change. The virtual table implementation can use
9431** this hint as permission to substitute a return value that is less
9432** expensive to compute and that the corresponding
9433** [xUpdate] method understands as a "no-change" value.
9434**
9435** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9436** the column is not changed by the UPDATE statement, then the xColumn
9437** method can optionally return without setting a result, without calling
9438** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9439** In that case, [sqlite3_value_nochange(X)] will return true for the
9440** same column in the [xUpdate] method.
9441**
9442** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9443** implementations should continue to give a correct answer even if the
9444** sqlite3_vtab_nochange() interface were to always return false. In the
9445** current implementation, the sqlite3_vtab_nochange() interface does always
9446** returns false for the enhanced [UPDATE FROM] statement.
9447*/
9448SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9449
9450/*
9451** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9452**
9453** This function may only be called from within a call to the [xBestIndex]
9454** method of a [virtual table].
9455**
9456** The first argument must be the sqlite3_index_info object that is the
9457** first parameter to the xBestIndex() method. The second argument must be
9458** an index into the aConstraint[] array belonging to the sqlite3_index_info
9459** structure passed to xBestIndex. This function returns a pointer to a buffer
9460** containing the name of the collation sequence for the corresponding
9461** constraint.
9462*/
9463SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9464
9465/*
9466** CAPI3REF: Conflict resolution modes
9467** KEYWORDS: {conflict resolution mode}
9468**
9469** These constants are returned by [sqlite3_vtab_on_conflict()] to
9470** inform a [virtual table] implementation what the [ON CONFLICT] mode
9471** is for the SQL statement being evaluated.
9472**
9473** Note that the [SQLITE_IGNORE] constant is also used as a potential
9474** return value from the [sqlite3_set_authorizer()] callback and that
9475** [SQLITE_ABORT] is also a [result code].
9476*/
9477#define SQLITE_ROLLBACK 1
9478/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
9479#define SQLITE_FAIL 3
9480/* #define SQLITE_ABORT 4 // Also an error code */
9481#define SQLITE_REPLACE 5
9482
9483/*
9484** CAPI3REF: Prepared Statement Scan Status Opcodes
9485** KEYWORDS: {scanstatus options}
9486**
9487** The following constants can be used for the T parameter to the
9488** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
9489** different metric for sqlite3_stmt_scanstatus() to return.
9490**
9491** When the value returned to V is a string, space to hold that string is
9492** managed by the prepared statement S and will be automatically freed when
9493** S is finalized.
9494**
9495** <dl>
9496** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
9497** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
9498** set to the total number of times that the X-th loop has run.</dd>
9499**
9500** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
9501** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
9502** to the total number of rows examined by all iterations of the X-th loop.</dd>
9503**
9504** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
9505** <dd>^The "double" variable pointed to by the V parameter will be set to the
9506** query planner's estimate for the average number of rows output from each
9507** iteration of the X-th loop. If the query planner's estimates was accurate,
9508** then this value will approximate the quotient NVISIT/NLOOP and the
9509** product of this value for all prior loops with the same SELECTID will
9510** be the NLOOP value for the current loop.
9511**
9512** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
9513** <dd>^The "const char *" variable pointed to by the V parameter will be set
9514** to a zero-terminated UTF-8 string containing the name of the index or table
9515** used for the X-th loop.
9516**
9517** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
9518** <dd>^The "const char *" variable pointed to by the V parameter will be set
9519** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
9520** description for the X-th loop.
9521**
9522** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
9523** <dd>^The "int" variable pointed to by the V parameter will be set to the
9524** "select-id" for the X-th loop. The select-id identifies which query or
9525** subquery the loop is part of. The main query has a select-id of zero.
9526** The select-id is the same value as is output in the first column
9527** of an [EXPLAIN QUERY PLAN] query.
9528** </dl>
9529*/
9530#define SQLITE_SCANSTAT_NLOOP 0
9531#define SQLITE_SCANSTAT_NVISIT 1
9532#define SQLITE_SCANSTAT_EST 2
9533#define SQLITE_SCANSTAT_NAME 3
9534#define SQLITE_SCANSTAT_EXPLAIN 4
9535#define SQLITE_SCANSTAT_SELECTID 5
9536
9537/*
9538** CAPI3REF: Prepared Statement Scan Status
9539** METHOD: sqlite3_stmt
9540**
9541** This interface returns information about the predicted and measured
9542** performance for pStmt. Advanced applications can use this
9543** interface to compare the predicted and the measured performance and
9544** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
9545**
9546** Since this interface is expected to be rarely used, it is only
9547** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
9548** compile-time option.
9549**
9550** The "iScanStatusOp" parameter determines which status information to return.
9551** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
9552** of this interface is undefined.
9553** ^The requested measurement is written into a variable pointed to by
9554** the "pOut" parameter.
9555** Parameter "idx" identifies the specific loop to retrieve statistics for.
9556** Loops are numbered starting from zero. ^If idx is out of range - less than
9557** zero or greater than or equal to the total number of loops used to implement
9558** the statement - a non-zero value is returned and the variable that pOut
9559** points to is unchanged.
9560**
9561** ^Statistics might not be available for all loops in all statements. ^In cases
9562** where there exist loops with no available statistics, this function behaves
9563** as if the loop did not exist - it returns non-zero and leave the variable
9564** that pOut points to unchanged.
9565**
9566** See also: [sqlite3_stmt_scanstatus_reset()]
9567*/
9568SQLITE_API int sqlite3_stmt_scanstatus(
9569 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
9570 int idx, /* Index of loop to report on */
9571 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
9572 void *pOut /* Result written here */
9573);
9574
9575/*
9576** CAPI3REF: Zero Scan-Status Counters
9577** METHOD: sqlite3_stmt
9578**
9579** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
9580**
9581** This API is only available if the library is built with pre-processor
9582** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
9583*/
9584SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
9585
9586/*
9587** CAPI3REF: Flush caches to disk mid-transaction
9588** METHOD: sqlite3
9589**
9590** ^If a write-transaction is open on [database connection] D when the
9591** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
9592** pages in the pager-cache that are not currently in use are written out
9593** to disk. A dirty page may be in use if a database cursor created by an
9594** active SQL statement is reading from it, or if it is page 1 of a database
9595** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
9596** interface flushes caches for all schemas - "main", "temp", and
9597** any [attached] databases.
9598**
9599** ^If this function needs to obtain extra database locks before dirty pages
9600** can be flushed to disk, it does so. ^If those locks cannot be obtained
9601** immediately and there is a busy-handler callback configured, it is invoked
9602** in the usual manner. ^If the required lock still cannot be obtained, then
9603** the database is skipped and an attempt made to flush any dirty pages
9604** belonging to the next (if any) database. ^If any databases are skipped
9605** because locks cannot be obtained, but no other error occurs, this
9606** function returns SQLITE_BUSY.
9607**
9608** ^If any other error occurs while flushing dirty pages to disk (for
9609** example an IO error or out-of-memory condition), then processing is
9610** abandoned and an SQLite [error code] is returned to the caller immediately.
9611**
9612** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
9613**
9614** ^This function does not set the database handle error code or message
9615** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
9616*/
9617SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
9618
9619/*
9620** CAPI3REF: The pre-update hook.
9621** METHOD: sqlite3
9622**
9623** ^These interfaces are only available if SQLite is compiled using the
9624** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
9625**
9626** ^The [sqlite3_preupdate_hook()] interface registers a callback function
9627** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
9628** on a database table.
9629** ^At most one preupdate hook may be registered at a time on a single
9630** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
9631** the previous setting.
9632** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
9633** with a NULL pointer as the second parameter.
9634** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
9635** the first parameter to callbacks.
9636**
9637** ^The preupdate hook only fires for changes to real database tables; the
9638** preupdate hook is not invoked for changes to [virtual tables] or to
9639** system tables like sqlite_sequence or sqlite_stat1.
9640**
9641** ^The second parameter to the preupdate callback is a pointer to
9642** the [database connection] that registered the preupdate hook.
9643** ^The third parameter to the preupdate callback is one of the constants
9644** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
9645** kind of update operation that is about to occur.
9646** ^(The fourth parameter to the preupdate callback is the name of the
9647** database within the database connection that is being modified. This
9648** will be "main" for the main database or "temp" for TEMP tables or
9649** the name given after the AS keyword in the [ATTACH] statement for attached
9650** databases.)^
9651** ^The fifth parameter to the preupdate callback is the name of the
9652** table that is being modified.
9653**
9654** For an UPDATE or DELETE operation on a [rowid table], the sixth
9655** parameter passed to the preupdate callback is the initial [rowid] of the
9656** row being modified or deleted. For an INSERT operation on a rowid table,
9657** or any operation on a WITHOUT ROWID table, the value of the sixth
9658** parameter is undefined. For an INSERT or UPDATE on a rowid table the
9659** seventh parameter is the final rowid value of the row being inserted
9660** or updated. The value of the seventh parameter passed to the callback
9661** function is not defined for operations on WITHOUT ROWID tables, or for
9662** DELETE operations on rowid tables.
9663**
9664** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
9665** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
9666** provide additional information about a preupdate event. These routines
9667** may only be called from within a preupdate callback. Invoking any of
9668** these routines from outside of a preupdate callback or with a
9669** [database connection] pointer that is different from the one supplied
9670** to the preupdate callback results in undefined and probably undesirable
9671** behavior.
9672**
9673** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
9674** in the row that is being inserted, updated, or deleted.
9675**
9676** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
9677** a [protected sqlite3_value] that contains the value of the Nth column of
9678** the table row before it is updated. The N parameter must be between 0
9679** and one less than the number of columns or the behavior will be
9680** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
9681** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
9682** behavior is undefined. The [sqlite3_value] that P points to
9683** will be destroyed when the preupdate callback returns.
9684**
9685** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
9686** a [protected sqlite3_value] that contains the value of the Nth column of
9687** the table row after it is updated. The N parameter must be between 0
9688** and one less than the number of columns or the behavior will be
9689** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
9690** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
9691** behavior is undefined. The [sqlite3_value] that P points to
9692** will be destroyed when the preupdate callback returns.
9693**
9694** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
9695** callback was invoked as a result of a direct insert, update, or delete
9696** operation; or 1 for inserts, updates, or deletes invoked by top-level
9697** triggers; or 2 for changes resulting from triggers called by top-level
9698** triggers; and so forth.
9699**
9700** When the [sqlite3_blob_write()] API is used to update a blob column,
9701** the pre-update hook is invoked with SQLITE_DELETE. This is because the
9702** in this case the new values are not available. In this case, when a
9703** callback made with op==SQLITE_DELETE is actuall a write using the
9704** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
9705** the index of the column being written. In other cases, where the
9706** pre-update hook is being invoked for some other reason, including a
9707** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
9708**
9709** See also: [sqlite3_update_hook()]
9710*/
9711#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
9712SQLITE_API void *sqlite3_preupdate_hook(
9713 sqlite3 *db,
9714 void(*xPreUpdate)(
9715 void *pCtx, /* Copy of third arg to preupdate_hook() */
9716 sqlite3 *db, /* Database handle */
9717 int op, /* SQLITE_UPDATE, DELETE or INSERT */
9718 char const *zDb, /* Database name */
9719 char const *zName, /* Table name */
9720 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
9721 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
9722 ),
9723 void*
9724);
9725SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
9726SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
9727SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
9728SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
9729SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
9730#endif
9731
9732/*
9733** CAPI3REF: Low-level system error code
9734** METHOD: sqlite3
9735**
9736** ^Attempt to return the underlying operating system error code or error
9737** number that caused the most recent I/O error or failure to open a file.
9738** The return value is OS-dependent. For example, on unix systems, after
9739** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
9740** called to get back the underlying "errno" that caused the problem, such
9741** as ENOSPC, EAUTH, EISDIR, and so forth.
9742*/
9743SQLITE_API int sqlite3_system_errno(sqlite3*);
9744
9745/*
9746** CAPI3REF: Database Snapshot
9747** KEYWORDS: {snapshot} {sqlite3_snapshot}
9748**
9749** An instance of the snapshot object records the state of a [WAL mode]
9750** database for some specific point in history.
9751**
9752** In [WAL mode], multiple [database connections] that are open on the
9753** same database file can each be reading a different historical version
9754** of the database file. When a [database connection] begins a read
9755** transaction, that connection sees an unchanging copy of the database
9756** as it existed for the point in time when the transaction first started.
9757** Subsequent changes to the database from other connections are not seen
9758** by the reader until a new read transaction is started.
9759**
9760** The sqlite3_snapshot object records state information about an historical
9761** version of the database file so that it is possible to later open a new read
9762** transaction that sees that historical version of the database rather than
9763** the most recent version.
9764*/
9765typedef struct sqlite3_snapshot {
9766 unsigned char hidden[48];
9767} sqlite3_snapshot;
9768
9769/*
9770** CAPI3REF: Record A Database Snapshot
9771** CONSTRUCTOR: sqlite3_snapshot
9772**
9773** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
9774** new [sqlite3_snapshot] object that records the current state of
9775** schema S in database connection D. ^On success, the
9776** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
9777** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
9778** If there is not already a read-transaction open on schema S when
9779** this function is called, one is opened automatically.
9780**
9781** The following must be true for this function to succeed. If any of
9782** the following statements are false when sqlite3_snapshot_get() is
9783** called, SQLITE_ERROR is returned. The final value of *P is undefined
9784** in this case.
9785**
9786** <ul>
9787** <li> The database handle must not be in [autocommit mode].
9788**
9789** <li> Schema S of [database connection] D must be a [WAL mode] database.
9790**
9791** <li> There must not be a write transaction open on schema S of database
9792** connection D.
9793**
9794** <li> One or more transactions must have been written to the current wal
9795** file since it was created on disk (by any connection). This means
9796** that a snapshot cannot be taken on a wal mode database with no wal
9797** file immediately after it is first opened. At least one transaction
9798** must be written to it first.
9799** </ul>
9800**
9801** This function may also return SQLITE_NOMEM. If it is called with the
9802** database handle in autocommit mode but fails for some other reason,
9803** whether or not a read transaction is opened on schema S is undefined.
9804**
9805** The [sqlite3_snapshot] object returned from a successful call to
9806** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9807** to avoid a memory leak.
9808**
9809** The [sqlite3_snapshot_get()] interface is only available when the
9810** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9811*/
9812SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9813 sqlite3 *db,
9814 const char *zSchema,
9815 sqlite3_snapshot **ppSnapshot
9816);
9817
9818/*
9819** CAPI3REF: Start a read transaction on an historical snapshot
9820** METHOD: sqlite3_snapshot
9821**
9822** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9823** transaction or upgrades an existing one for schema S of
9824** [database connection] D such that the read transaction refers to
9825** historical [snapshot] P, rather than the most recent change to the
9826** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9827** on success or an appropriate [error code] if it fails.
9828**
9829** ^In order to succeed, the database connection must not be in
9830** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9831** is already a read transaction open on schema S, then the database handle
9832** must have no active statements (SELECT statements that have been passed
9833** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9834** SQLITE_ERROR is returned if either of these conditions is violated, or
9835** if schema S does not exist, or if the snapshot object is invalid.
9836**
9837** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9838** snapshot has been overwritten by a [checkpoint]. In this case
9839** SQLITE_ERROR_SNAPSHOT is returned.
9840**
9841** If there is already a read transaction open when this function is
9842** invoked, then the same read transaction remains open (on the same
9843** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9844** is returned. If another error code - for example SQLITE_PROTOCOL or an
9845** SQLITE_IOERR error code - is returned, then the final state of the
9846** read transaction is undefined. If SQLITE_OK is returned, then the
9847** read transaction is now open on database snapshot P.
9848**
9849** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9850** database connection D does not know that the database file for
9851** schema S is in [WAL mode]. A database connection might not know
9852** that the database file is in [WAL mode] if there has been no prior
9853** I/O on that database connection, or if the database entered [WAL mode]
9854** after the most recent I/O on the database connection.)^
9855** (Hint: Run "[PRAGMA application_id]" against a newly opened
9856** database connection in order to make it ready to use snapshots.)
9857**
9858** The [sqlite3_snapshot_open()] interface is only available when the
9859** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9860*/
9861SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9862 sqlite3 *db,
9863 const char *zSchema,
9864 sqlite3_snapshot *pSnapshot
9865);
9866
9867/*
9868** CAPI3REF: Destroy a snapshot
9869** DESTRUCTOR: sqlite3_snapshot
9870**
9871** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9872** The application must eventually free every [sqlite3_snapshot] object
9873** using this routine to avoid a memory leak.
9874**
9875** The [sqlite3_snapshot_free()] interface is only available when the
9876** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9877*/
9878SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
9879
9880/*
9881** CAPI3REF: Compare the ages of two snapshot handles.
9882** METHOD: sqlite3_snapshot
9883**
9884** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
9885** of two valid snapshot handles.
9886**
9887** If the two snapshot handles are not associated with the same database
9888** file, the result of the comparison is undefined.
9889**
9890** Additionally, the result of the comparison is only valid if both of the
9891** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9892** last time the wal file was deleted. The wal file is deleted when the
9893** database is changed back to rollback mode or when the number of database
9894** clients drops to zero. If either snapshot handle was obtained before the
9895** wal file was last deleted, the value returned by this function
9896** is undefined.
9897**
9898** Otherwise, this API returns a negative value if P1 refers to an older
9899** snapshot than P2, zero if the two handles refer to the same database
9900** snapshot, and a positive value if P1 is a newer snapshot than P2.
9901**
9902** This interface is only available if SQLite is compiled with the
9903** [SQLITE_ENABLE_SNAPSHOT] option.
9904*/
9905SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9906 sqlite3_snapshot *p1,
9907 sqlite3_snapshot *p2
9908);
9909
9910/*
9911** CAPI3REF: Recover snapshots from a wal file
9912** METHOD: sqlite3_snapshot
9913**
9914** If a [WAL file] remains on disk after all database connections close
9915** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9916** or because the last process to have the database opened exited without
9917** calling [sqlite3_close()]) and a new connection is subsequently opened
9918** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9919** will only be able to open the last transaction added to the WAL file
9920** even though the WAL file contains other valid transactions.
9921**
9922** This function attempts to scan the WAL file associated with database zDb
9923** of database handle db and make all valid snapshots available to
9924** sqlite3_snapshot_open(). It is an error if there is already a read
9925** transaction open on the database, or if the database is not a WAL mode
9926** database.
9927**
9928** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9929**
9930** This interface is only available if SQLite is compiled with the
9931** [SQLITE_ENABLE_SNAPSHOT] option.
9932*/
9933SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9934
9935/*
9936** CAPI3REF: Serialize a database
9937**
9938** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9939** that is a serialization of the S database on [database connection] D.
9940** If P is not a NULL pointer, then the size of the database in bytes
9941** is written into *P.
9942**
9943** For an ordinary on-disk database file, the serialization is just a
9944** copy of the disk file. For an in-memory database or a "TEMP" database,
9945** the serialization is the same sequence of bytes which would be written
9946** to disk if that database where backed up to disk.
9947**
9948** The usual case is that sqlite3_serialize() copies the serialization of
9949** the database into memory obtained from [sqlite3_malloc64()] and returns
9950** a pointer to that memory. The caller is responsible for freeing the
9951** returned value to avoid a memory leak. However, if the F argument
9952** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9953** are made, and the sqlite3_serialize() function will return a pointer
9954** to the contiguous memory representation of the database that SQLite
9955** is currently using for that database, or NULL if the no such contiguous
9956** memory representation of the database exists. A contiguous memory
9957** representation of the database will usually only exist if there has
9958** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9959** values of D and S.
9960** The size of the database is written into *P even if the
9961** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9962** of the database exists.
9963**
9964** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9965** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9966** allocation error occurs.
9967**
9968** This interface is omitted if SQLite is compiled with the
9969** [SQLITE_OMIT_DESERIALIZE] option.
9970*/
9971SQLITE_API unsigned char *sqlite3_serialize(
9972 sqlite3 *db, /* The database connection */
9973 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9974 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9975 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9976);
9977
9978/*
9979** CAPI3REF: Flags for sqlite3_serialize
9980**
9981** Zero or more of the following constants can be OR-ed together for
9982** the F argument to [sqlite3_serialize(D,S,P,F)].
9983**
9984** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9985** a pointer to contiguous in-memory database that it is currently using,
9986** without making a copy of the database. If SQLite is not currently using
9987** a contiguous in-memory database, then this option causes
9988** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9989** using a contiguous in-memory database if it has been initialized by a
9990** prior call to [sqlite3_deserialize()].
9991*/
9992#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9993
9994/*
9995** CAPI3REF: Deserialize a database
9996**
9997** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9998** [database connection] D to disconnect from database S and then
9999** reopen S as an in-memory database based on the serialization contained
10000** in P. The serialized database P is N bytes in size. M is the size of
10001** the buffer P, which might be larger than N. If M is larger than N, and
10002** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10003** permitted to add content to the in-memory database as long as the total
10004** size does not exceed M bytes.
10005**
10006** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10007** invoke sqlite3_free() on the serialization buffer when the database
10008** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10009** SQLite will try to increase the buffer size using sqlite3_realloc64()
10010** if writes on the database cause it to grow larger than M bytes.
10011**
10012** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10013** database is currently in a read transaction or is involved in a backup
10014** operation.
10015**
10016** It is not possible to deserialized into the TEMP database. If the
10017** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10018** function returns SQLITE_ERROR.
10019**
10020** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10021** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10022** [sqlite3_free()] is invoked on argument P prior to returning.
10023**
10024** This interface is omitted if SQLite is compiled with the
10025** [SQLITE_OMIT_DESERIALIZE] option.
10026*/
10027SQLITE_API int sqlite3_deserialize(
10028 sqlite3 *db, /* The database connection */
10029 const char *zSchema, /* Which DB to reopen with the deserialization */
10030 unsigned char *pData, /* The serialized database content */
10031 sqlite3_int64 szDb, /* Number bytes in the deserialization */
10032 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10033 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10034);
10035
10036/*
10037** CAPI3REF: Flags for sqlite3_deserialize()
10038**
10039** The following are allowed values for 6th argument (the F argument) to
10040** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10041**
10042** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10043** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10044** and that SQLite should take ownership of this memory and automatically
10045** free it when it has finished using it. Without this flag, the caller
10046** is responsible for freeing any dynamically allocated memory.
10047**
10048** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10049** grow the size of the database using calls to [sqlite3_realloc64()]. This
10050** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10051** Without this flag, the deserialized database cannot increase in size beyond
10052** the number of bytes specified by the M parameter.
10053**
10054** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10055** should be treated as read-only.
10056*/
10057#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10058#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10059#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10060
10061/*
10062** Undo the hack that converts floating point types to integer for
10063** builds on processors without floating point support.
10064*/
10065#ifdef SQLITE_OMIT_FLOATING_POINT
10066# undef double
10067#endif
10068
10069#ifdef __cplusplus
10070} /* End of the 'extern "C"' block */
10071#endif
10072#endif /* SQLITE3_H */
10073
10074/******** Begin file sqlite3rtree.h *********/
10075/*
10076** 2010 August 30
10077**
10078** The author disclaims copyright to this source code. In place of
10079** a legal notice, here is a blessing:
10080**
10081** May you do good and not evil.
10082** May you find forgiveness for yourself and forgive others.
10083** May you share freely, never taking more than you give.
10084**
10085*************************************************************************
10086*/
10087
10088#ifndef _SQLITE3RTREE_H_
10089#define _SQLITE3RTREE_H_
10090
10091
10092#ifdef __cplusplus
10093extern "C" {
10094#endif
10095
10096typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10097typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10098
10099/* The double-precision datatype used by RTree depends on the
10100** SQLITE_RTREE_INT_ONLY compile-time option.
10101*/
10102#ifdef SQLITE_RTREE_INT_ONLY
10103 typedef sqlite3_int64 sqlite3_rtree_dbl;
10104#else
10105 typedef double sqlite3_rtree_dbl;
10106#endif
10107
10108/*
10109** Register a geometry callback named zGeom that can be used as part of an
10110** R-Tree geometry query as follows:
10111**
10112** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10113*/
10114SQLITE_API int sqlite3_rtree_geometry_callback(
10115 sqlite3 *db,
10116 const char *zGeom,
10117 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10118 void *pContext
10119);
10120
10121
10122/*
10123** A pointer to a structure of the following type is passed as the first
10124** argument to callbacks registered using rtree_geometry_callback().
10125*/
10126struct sqlite3_rtree_geometry {
10127 void *pContext; /* Copy of pContext passed to s_r_g_c() */
10128 int nParam; /* Size of array aParam[] */
10129 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10130 void *pUser; /* Callback implementation user data */
10131 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10132};
10133
10134/*
10135** Register a 2nd-generation geometry callback named zScore that can be
10136** used as part of an R-Tree geometry query as follows:
10137**
10138** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10139*/
10140SQLITE_API int sqlite3_rtree_query_callback(
10141 sqlite3 *db,
10142 const char *zQueryFunc,
10143 int (*xQueryFunc)(sqlite3_rtree_query_info*),
10144 void *pContext,
10145 void (*xDestructor)(void*)
10146);
10147
10148
10149/*
10150** A pointer to a structure of the following type is passed as the
10151** argument to scored geometry callback registered using
10152** sqlite3_rtree_query_callback().
10153**
10154** Note that the first 5 fields of this structure are identical to
10155** sqlite3_rtree_geometry. This structure is a subclass of
10156** sqlite3_rtree_geometry.
10157*/
10158struct sqlite3_rtree_query_info {
10159 void *pContext; /* pContext from when function registered */
10160 int nParam; /* Number of function parameters */
10161 sqlite3_rtree_dbl *aParam; /* value of function parameters */
10162 void *pUser; /* callback can use this, if desired */
10163 void (*xDelUser)(void*); /* function to free pUser */
10164 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10165 unsigned int *anQueue; /* Number of pending entries in the queue */
10166 int nCoord; /* Number of coordinates */
10167 int iLevel; /* Level of current node or entry */
10168 int mxLevel; /* The largest iLevel value in the tree */
10169 sqlite3_int64 iRowid; /* Rowid for current entry */
10170 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10171 int eParentWithin; /* Visibility of parent node */
10172 int eWithin; /* OUT: Visibility */
10173 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10174 /* The following fields are only available in 3.8.11 and later */
10175 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10176};
10177
10178/*
10179** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10180*/
10181#define NOT_WITHIN 0 /* Object completely outside of query region */
10182#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10183#define FULLY_WITHIN 2 /* Object fully contained within query region */
10184
10185
10186#ifdef __cplusplus
10187} /* end of the 'extern "C"' block */
10188#endif
10189
10190#endif /* ifndef _SQLITE3RTREE_H_ */
10191
10192/******** End of sqlite3rtree.h *********/
10193/******** Begin file sqlite3session.h *********/
10194
10195#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10196#define __SQLITESESSION_H_ 1
10197
10198/*
10199** Make sure we can call this stuff from C++.
10200*/
10201#ifdef __cplusplus
10202extern "C" {
10203#endif
10204
10205
10206/*
10207** CAPI3REF: Session Object Handle
10208**
10209** An instance of this object is a [session] that can be used to
10210** record changes to a database.
10211*/
10212typedef struct sqlite3_session sqlite3_session;
10213
10214/*
10215** CAPI3REF: Changeset Iterator Handle
10216**
10217** An instance of this object acts as a cursor for iterating
10218** over the elements of a [changeset] or [patchset].
10219*/
10220typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10221
10222/*
10223** CAPI3REF: Create A New Session Object
10224** CONSTRUCTOR: sqlite3_session
10225**
10226** Create a new session object attached to database handle db. If successful,
10227** a pointer to the new object is written to *ppSession and SQLITE_OK is
10228** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10229** error code (e.g. SQLITE_NOMEM) is returned.
10230**
10231** It is possible to create multiple session objects attached to a single
10232** database handle.
10233**
10234** Session objects created using this function should be deleted using the
10235** [sqlite3session_delete()] function before the database handle that they
10236** are attached to is itself closed. If the database handle is closed before
10237** the session object is deleted, then the results of calling any session
10238** module function, including [sqlite3session_delete()] on the session object
10239** are undefined.
10240**
10241** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10242** is not possible for an application to register a pre-update hook on a
10243** database handle that has one or more session objects attached. Nor is
10244** it possible to create a session object attached to a database handle for
10245** which a pre-update hook is already defined. The results of attempting
10246** either of these things are undefined.
10247**
10248** The session object will be used to create changesets for tables in
10249** database zDb, where zDb is either "main", or "temp", or the name of an
10250** attached database. It is not an error if database zDb is not attached
10251** to the database when the session object is created.
10252*/
10253SQLITE_API int sqlite3session_create(
10254 sqlite3 *db, /* Database handle */
10255 const char *zDb, /* Name of db (e.g. "main") */
10256 sqlite3_session **ppSession /* OUT: New session object */
10257);
10258
10259/*
10260** CAPI3REF: Delete A Session Object
10261** DESTRUCTOR: sqlite3_session
10262**
10263** Delete a session object previously allocated using
10264** [sqlite3session_create()]. Once a session object has been deleted, the
10265** results of attempting to use pSession with any other session module
10266** function are undefined.
10267**
10268** Session objects must be deleted before the database handle to which they
10269** are attached is closed. Refer to the documentation for
10270** [sqlite3session_create()] for details.
10271*/
10272SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
10273
10274/*
10275** CAPIREF: Conigure a Session Object
10276** METHOD: sqlite3_session
10277**
10278** This method is used to configure a session object after it has been
10279** created. At present the only valid value for the second parameter is
10280** [SQLITE_SESSION_OBJCONFIG_SIZE].
10281**
10282** Arguments for sqlite3session_object_config()
10283**
10284** The following values may passed as the the 4th parameter to
10285** sqlite3session_object_config().
10286**
10287** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
10288** This option is used to set, clear or query the flag that enables
10289** the [sqlite3session_changeset_size()] API. Because it imposes some
10290** computational overhead, this API is disabled by default. Argument
10291** pArg must point to a value of type (int). If the value is initially
10292** 0, then the sqlite3session_changeset_size() API is disabled. If it
10293** is greater than 0, then the same API is enabled. Or, if the initial
10294** value is less than zero, no change is made. In all cases the (int)
10295** variable is set to 1 if the sqlite3session_changeset_size() API is
10296** enabled following the current call, or 0 otherwise.
10297**
10298** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
10299** the first table has been attached to the session object.
10300*/
10301SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
10302
10303/*
10304*/
10305#define SQLITE_SESSION_OBJCONFIG_SIZE 1
10306
10307/*
10308** CAPI3REF: Enable Or Disable A Session Object
10309** METHOD: sqlite3_session
10310**
10311** Enable or disable the recording of changes by a session object. When
10312** enabled, a session object records changes made to the database. When
10313** disabled - it does not. A newly created session object is enabled.
10314** Refer to the documentation for [sqlite3session_changeset()] for further
10315** details regarding how enabling and disabling a session object affects
10316** the eventual changesets.
10317**
10318** Passing zero to this function disables the session. Passing a value
10319** greater than zero enables it. Passing a value less than zero is a
10320** no-op, and may be used to query the current state of the session.
10321**
10322** The return value indicates the final state of the session object: 0 if
10323** the session is disabled, or 1 if it is enabled.
10324*/
10325SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
10326
10327/*
10328** CAPI3REF: Set Or Clear the Indirect Change Flag
10329** METHOD: sqlite3_session
10330**
10331** Each change recorded by a session object is marked as either direct or
10332** indirect. A change is marked as indirect if either:
10333**
10334** <ul>
10335** <li> The session object "indirect" flag is set when the change is
10336** made, or
10337** <li> The change is made by an SQL trigger or foreign key action
10338** instead of directly as a result of a users SQL statement.
10339** </ul>
10340**
10341** If a single row is affected by more than one operation within a session,
10342** then the change is considered indirect if all operations meet the criteria
10343** for an indirect change above, or direct otherwise.
10344**
10345** This function is used to set, clear or query the session object indirect
10346** flag. If the second argument passed to this function is zero, then the
10347** indirect flag is cleared. If it is greater than zero, the indirect flag
10348** is set. Passing a value less than zero does not modify the current value
10349** of the indirect flag, and may be used to query the current state of the
10350** indirect flag for the specified session object.
10351**
10352** The return value indicates the final state of the indirect flag: 0 if
10353** it is clear, or 1 if it is set.
10354*/
10355SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
10356
10357/*
10358** CAPI3REF: Attach A Table To A Session Object
10359** METHOD: sqlite3_session
10360**
10361** If argument zTab is not NULL, then it is the name of a table to attach
10362** to the session object passed as the first argument. All subsequent changes
10363** made to the table while the session object is enabled will be recorded. See
10364** documentation for [sqlite3session_changeset()] for further details.
10365**
10366** Or, if argument zTab is NULL, then changes are recorded for all tables
10367** in the database. If additional tables are added to the database (by
10368** executing "CREATE TABLE" statements) after this call is made, changes for
10369** the new tables are also recorded.
10370**
10371** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
10372** defined as part of their CREATE TABLE statement. It does not matter if the
10373** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10374** KEY may consist of a single column, or may be a composite key.
10375**
10376** It is not an error if the named table does not exist in the database. Nor
10377** is it an error if the named table does not have a PRIMARY KEY. However,
10378** no changes will be recorded in either of these scenarios.
10379**
10380** Changes are not recorded for individual rows that have NULL values stored
10381** in one or more of their PRIMARY KEY columns.
10382**
10383** SQLITE_OK is returned if the call completes without error. Or, if an error
10384** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
10385**
10386** <h3>Special sqlite_stat1 Handling</h3>
10387**
10388** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
10389** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
10390** <pre>
10391** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
10392** </pre>
10393**
10394** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
10395** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
10396** are recorded for rows for which (idx IS NULL) is true. However, for such
10397** rows a zero-length blob (SQL value X'') is stored in the changeset or
10398** patchset instead of a NULL value. This allows such changesets to be
10399** manipulated by legacy implementations of sqlite3changeset_invert(),
10400** concat() and similar.
10401**
10402** The sqlite3changeset_apply() function automatically converts the
10403** zero-length blob back to a NULL value when updating the sqlite_stat1
10404** table. However, if the application calls sqlite3changeset_new(),
10405** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
10406** iterator directly (including on a changeset iterator passed to a
10407** conflict-handler callback) then the X'' value is returned. The application
10408** must translate X'' to NULL itself if required.
10409**
10410** Legacy (older than 3.22.0) versions of the sessions module cannot capture
10411** changes made to the sqlite_stat1 table. Legacy versions of the
10412** sqlite3changeset_apply() function silently ignore any modifications to the
10413** sqlite_stat1 table that are part of a changeset or patchset.
10414*/
10415SQLITE_API int sqlite3session_attach(
10416 sqlite3_session *pSession, /* Session object */
10417 const char *zTab /* Table name */
10418);
10419
10420/*
10421** CAPI3REF: Set a table filter on a Session Object.
10422** METHOD: sqlite3_session
10423**
10424** The second argument (xFilter) is the "filter callback". For changes to rows
10425** in tables that are not attached to the Session object, the filter is called
10426** to determine whether changes to the table's rows should be tracked or not.
10427** If xFilter returns 0, changes are not tracked. Note that once a table is
10428** attached, xFilter will not be called again.
10429*/
10430SQLITE_API void sqlite3session_table_filter(
10431 sqlite3_session *pSession, /* Session object */
10432 int(*xFilter)(
10433 void *pCtx, /* Copy of third arg to _filter_table() */
10434 const char *zTab /* Table name */
10435 ),
10436 void *pCtx /* First argument passed to xFilter */
10437);
10438
10439/*
10440** CAPI3REF: Generate A Changeset From A Session Object
10441** METHOD: sqlite3_session
10442**
10443** Obtain a changeset containing changes to the tables attached to the
10444** session object passed as the first argument. If successful,
10445** set *ppChangeset to point to a buffer containing the changeset
10446** and *pnChangeset to the size of the changeset in bytes before returning
10447** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
10448** zero and return an SQLite error code.
10449**
10450** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
10451** each representing a change to a single row of an attached table. An INSERT
10452** change contains the values of each field of a new database row. A DELETE
10453** contains the original values of each field of a deleted database row. An
10454** UPDATE change contains the original values of each field of an updated
10455** database row along with the updated values for each updated non-primary-key
10456** column. It is not possible for an UPDATE change to represent a change that
10457** modifies the values of primary key columns. If such a change is made, it
10458** is represented in a changeset as a DELETE followed by an INSERT.
10459**
10460** Changes are not recorded for rows that have NULL values stored in one or
10461** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
10462** no corresponding change is present in the changesets returned by this
10463** function. If an existing row with one or more NULL values stored in
10464** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
10465** only an INSERT is appears in the changeset. Similarly, if an existing row
10466** with non-NULL PRIMARY KEY values is updated so that one or more of its
10467** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
10468** DELETE change only.
10469**
10470** The contents of a changeset may be traversed using an iterator created
10471** using the [sqlite3changeset_start()] API. A changeset may be applied to
10472** a database with a compatible schema using the [sqlite3changeset_apply()]
10473** API.
10474**
10475** Within a changeset generated by this function, all changes related to a
10476** single table are grouped together. In other words, when iterating through
10477** a changeset or when applying a changeset to a database, all changes related
10478** to a single table are processed before moving on to the next table. Tables
10479** are sorted in the same order in which they were attached (or auto-attached)
10480** to the sqlite3_session object. The order in which the changes related to
10481** a single table are stored is undefined.
10482**
10483** Following a successful call to this function, it is the responsibility of
10484** the caller to eventually free the buffer that *ppChangeset points to using
10485** [sqlite3_free()].
10486**
10487** <h3>Changeset Generation</h3>
10488**
10489** Once a table has been attached to a session object, the session object
10490** records the primary key values of all new rows inserted into the table.
10491** It also records the original primary key and other column values of any
10492** deleted or updated rows. For each unique primary key value, data is only
10493** recorded once - the first time a row with said primary key is inserted,
10494** updated or deleted in the lifetime of the session.
10495**
10496** There is one exception to the previous paragraph: when a row is inserted,
10497** updated or deleted, if one or more of its primary key columns contain a
10498** NULL value, no record of the change is made.
10499**
10500** The session object therefore accumulates two types of records - those
10501** that consist of primary key values only (created when the user inserts
10502** a new record) and those that consist of the primary key values and the
10503** original values of other table columns (created when the users deletes
10504** or updates a record).
10505**
10506** When this function is called, the requested changeset is created using
10507** both the accumulated records and the current contents of the database
10508** file. Specifically:
10509**
10510** <ul>
10511** <li> For each record generated by an insert, the database is queried
10512** for a row with a matching primary key. If one is found, an INSERT
10513** change is added to the changeset. If no such row is found, no change
10514** is added to the changeset.
10515**
10516** <li> For each record generated by an update or delete, the database is
10517** queried for a row with a matching primary key. If such a row is
10518** found and one or more of the non-primary key fields have been
10519** modified from their original values, an UPDATE change is added to
10520** the changeset. Or, if no such row is found in the table, a DELETE
10521** change is added to the changeset. If there is a row with a matching
10522** primary key in the database, but all fields contain their original
10523** values, no change is added to the changeset.
10524** </ul>
10525**
10526** This means, amongst other things, that if a row is inserted and then later
10527** deleted while a session object is active, neither the insert nor the delete
10528** will be present in the changeset. Or if a row is deleted and then later a
10529** row with the same primary key values inserted while a session object is
10530** active, the resulting changeset will contain an UPDATE change instead of
10531** a DELETE and an INSERT.
10532**
10533** When a session object is disabled (see the [sqlite3session_enable()] API),
10534** it does not accumulate records when rows are inserted, updated or deleted.
10535** This may appear to have some counter-intuitive effects if a single row
10536** is written to more than once during a session. For example, if a row
10537** is inserted while a session object is enabled, then later deleted while
10538** the same session object is disabled, no INSERT record will appear in the
10539** changeset, even though the delete took place while the session was disabled.
10540** Or, if one field of a row is updated while a session is disabled, and
10541** another field of the same row is updated while the session is enabled, the
10542** resulting changeset will contain an UPDATE change that updates both fields.
10543*/
10544SQLITE_API int sqlite3session_changeset(
10545 sqlite3_session *pSession, /* Session object */
10546 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
10547 void **ppChangeset /* OUT: Buffer containing changeset */
10548);
10549
10550/*
10551** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
10552** METHOD: sqlite3_session
10553**
10554** By default, this function always returns 0. For it to return
10555** a useful result, the sqlite3_session object must have been configured
10556** to enable this API using sqlite3session_object_config() with the
10557** SQLITE_SESSION_OBJCONFIG_SIZE verb.
10558**
10559** When enabled, this function returns an upper limit, in bytes, for the size
10560** of the changeset that might be produced if sqlite3session_changeset() were
10561** called. The final changeset size might be equal to or smaller than the
10562** size in bytes returned by this function.
10563*/
10564SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
10565
10566/*
10567** CAPI3REF: Load The Difference Between Tables Into A Session
10568** METHOD: sqlite3_session
10569**
10570** If it is not already attached to the session object passed as the first
10571** argument, this function attaches table zTbl in the same manner as the
10572** [sqlite3session_attach()] function. If zTbl does not exist, or if it
10573** does not have a primary key, this function is a no-op (but does not return
10574** an error).
10575**
10576** Argument zFromDb must be the name of a database ("main", "temp" etc.)
10577** attached to the same database handle as the session object that contains
10578** a table compatible with the table attached to the session by this function.
10579** A table is considered compatible if it:
10580**
10581** <ul>
10582** <li> Has the same name,
10583** <li> Has the same set of columns declared in the same order, and
10584** <li> Has the same PRIMARY KEY definition.
10585** </ul>
10586**
10587** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
10588** are compatible but do not have any PRIMARY KEY columns, it is not an error
10589** but no changes are added to the session object. As with other session
10590** APIs, tables without PRIMARY KEYs are simply ignored.
10591**
10592** This function adds a set of changes to the session object that could be
10593** used to update the table in database zFrom (call this the "from-table")
10594** so that its content is the same as the table attached to the session
10595** object (call this the "to-table"). Specifically:
10596**
10597** <ul>
10598** <li> For each row (primary key) that exists in the to-table but not in
10599** the from-table, an INSERT record is added to the session object.
10600**
10601** <li> For each row (primary key) that exists in the to-table but not in
10602** the from-table, a DELETE record is added to the session object.
10603**
10604** <li> For each row (primary key) that exists in both tables, but features
10605** different non-PK values in each, an UPDATE record is added to the
10606** session.
10607** </ul>
10608**
10609** To clarify, if this function is called and then a changeset constructed
10610** using [sqlite3session_changeset()], then after applying that changeset to
10611** database zFrom the contents of the two compatible tables would be
10612** identical.
10613**
10614** It an error if database zFrom does not exist or does not contain the
10615** required compatible table.
10616**
10617** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
10618** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
10619** may be set to point to a buffer containing an English language error
10620** message. It is the responsibility of the caller to free this buffer using
10621** sqlite3_free().
10622*/
10623SQLITE_API int sqlite3session_diff(
10624 sqlite3_session *pSession,
10625 const char *zFromDb,
10626 const char *zTbl,
10627 char **pzErrMsg
10628);
10629
10630
10631/*
10632** CAPI3REF: Generate A Patchset From A Session Object
10633** METHOD: sqlite3_session
10634**
10635** The differences between a patchset and a changeset are that:
10636**
10637** <ul>
10638** <li> DELETE records consist of the primary key fields only. The
10639** original values of other fields are omitted.
10640** <li> The original values of any modified fields are omitted from
10641** UPDATE records.
10642** </ul>
10643**
10644** A patchset blob may be used with up to date versions of all
10645** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
10646** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
10647** attempting to use a patchset blob with old versions of the
10648** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
10649**
10650** Because the non-primary key "old.*" fields are omitted, no
10651** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
10652** is passed to the sqlite3changeset_apply() API. Other conflict types work
10653** in the same way as for changesets.
10654**
10655** Changes within a patchset are ordered in the same way as for changesets
10656** generated by the sqlite3session_changeset() function (i.e. all changes for
10657** a single table are grouped together, tables appear in the order in which
10658** they were attached to the session object).
10659*/
10660SQLITE_API int sqlite3session_patchset(
10661 sqlite3_session *pSession, /* Session object */
10662 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
10663 void **ppPatchset /* OUT: Buffer containing patchset */
10664);
10665
10666/*
10667** CAPI3REF: Test if a changeset has recorded any changes.
10668**
10669** Return non-zero if no changes to attached tables have been recorded by
10670** the session object passed as the first argument. Otherwise, if one or
10671** more changes have been recorded, return zero.
10672**
10673** Even if this function returns zero, it is possible that calling
10674** [sqlite3session_changeset()] on the session handle may still return a
10675** changeset that contains no changes. This can happen when a row in
10676** an attached table is modified and then later on the original values
10677** are restored. However, if this function returns non-zero, then it is
10678** guaranteed that a call to sqlite3session_changeset() will return a
10679** changeset containing zero changes.
10680*/
10681SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
10682
10683/*
10684** CAPI3REF: Query for the amount of heap memory used by a session object.
10685**
10686** This API returns the total amount of heap memory in bytes currently
10687** used by the session object passed as the only argument.
10688*/
10689SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
10690
10691/*
10692** CAPI3REF: Create An Iterator To Traverse A Changeset
10693** CONSTRUCTOR: sqlite3_changeset_iter
10694**
10695** Create an iterator used to iterate through the contents of a changeset.
10696** If successful, *pp is set to point to the iterator handle and SQLITE_OK
10697** is returned. Otherwise, if an error occurs, *pp is set to zero and an
10698** SQLite error code is returned.
10699**
10700** The following functions can be used to advance and query a changeset
10701** iterator created by this function:
10702**
10703** <ul>
10704** <li> [sqlite3changeset_next()]
10705** <li> [sqlite3changeset_op()]
10706** <li> [sqlite3changeset_new()]
10707** <li> [sqlite3changeset_old()]
10708** </ul>
10709**
10710** It is the responsibility of the caller to eventually destroy the iterator
10711** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
10712** changeset (pChangeset) must remain valid until after the iterator is
10713** destroyed.
10714**
10715** Assuming the changeset blob was created by one of the
10716** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
10717** [sqlite3changeset_invert()] functions, all changes within the changeset
10718** that apply to a single table are grouped together. This means that when
10719** an application iterates through a changeset using an iterator created by
10720** this function, all changes that relate to a single table are visited
10721** consecutively. There is no chance that the iterator will visit a change
10722** the applies to table X, then one for table Y, and then later on visit
10723** another change for table X.
10724**
10725** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
10726** may be modified by passing a combination of
10727** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
10728**
10729** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
10730** and therefore subject to change.
10731*/
10732SQLITE_API int sqlite3changeset_start(
10733 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10734 int nChangeset, /* Size of changeset blob in bytes */
10735 void *pChangeset /* Pointer to blob containing changeset */
10736);
10737SQLITE_API int sqlite3changeset_start_v2(
10738 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
10739 int nChangeset, /* Size of changeset blob in bytes */
10740 void *pChangeset, /* Pointer to blob containing changeset */
10741 int flags /* SESSION_CHANGESETSTART_* flags */
10742);
10743
10744/*
10745** CAPI3REF: Flags for sqlite3changeset_start_v2
10746**
10747** The following flags may passed via the 4th parameter to
10748** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
10749**
10750** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10751** Invert the changeset while iterating through it. This is equivalent to
10752** inverting a changeset using sqlite3changeset_invert() before applying it.
10753** It is an error to specify this flag with a patchset.
10754*/
10755#define SQLITE_CHANGESETSTART_INVERT 0x0002
10756
10757
10758/*
10759** CAPI3REF: Advance A Changeset Iterator
10760** METHOD: sqlite3_changeset_iter
10761**
10762** This function may only be used with iterators created by the function
10763** [sqlite3changeset_start()]. If it is called on an iterator passed to
10764** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
10765** is returned and the call has no effect.
10766**
10767** Immediately after an iterator is created by sqlite3changeset_start(), it
10768** does not point to any change in the changeset. Assuming the changeset
10769** is not empty, the first call to this function advances the iterator to
10770** point to the first change in the changeset. Each subsequent call advances
10771** the iterator to point to the next change in the changeset (if any). If
10772** no error occurs and the iterator points to a valid change after a call
10773** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
10774** Otherwise, if all changes in the changeset have already been visited,
10775** SQLITE_DONE is returned.
10776**
10777** If an error occurs, an SQLite error code is returned. Possible error
10778** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
10779** SQLITE_NOMEM.
10780*/
10781SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
10782
10783/*
10784** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
10785** METHOD: sqlite3_changeset_iter
10786**
10787** The pIter argument passed to this function may either be an iterator
10788** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10789** created by [sqlite3changeset_start()]. In the latter case, the most recent
10790** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
10791** is not the case, this function returns [SQLITE_MISUSE].
10792**
10793** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
10794** outputs are set through these pointers:
10795**
10796** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
10797** depending on the type of change that the iterator currently points to;
10798**
10799** *pnCol is set to the number of columns in the table affected by the change; and
10800**
10801** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
10802** the name of the table affected by the current change. The buffer remains
10803** valid until either sqlite3changeset_next() is called on the iterator
10804** or until the conflict-handler function returns.
10805**
10806** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
10807** is an indirect change, or false (0) otherwise. See the documentation for
10808** [sqlite3session_indirect()] for a description of direct and indirect
10809** changes.
10810**
10811** If no error occurs, SQLITE_OK is returned. If an error does occur, an
10812** SQLite error code is returned. The values of the output variables may not
10813** be trusted in this case.
10814*/
10815SQLITE_API int sqlite3changeset_op(
10816 sqlite3_changeset_iter *pIter, /* Iterator object */
10817 const char **pzTab, /* OUT: Pointer to table name */
10818 int *pnCol, /* OUT: Number of columns in table */
10819 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
10820 int *pbIndirect /* OUT: True for an 'indirect' change */
10821);
10822
10823/*
10824** CAPI3REF: Obtain The Primary Key Definition Of A Table
10825** METHOD: sqlite3_changeset_iter
10826**
10827** For each modified table, a changeset includes the following:
10828**
10829** <ul>
10830** <li> The number of columns in the table, and
10831** <li> Which of those columns make up the tables PRIMARY KEY.
10832** </ul>
10833**
10834** This function is used to find which columns comprise the PRIMARY KEY of
10835** the table modified by the change that iterator pIter currently points to.
10836** If successful, *pabPK is set to point to an array of nCol entries, where
10837** nCol is the number of columns in the table. Elements of *pabPK are set to
10838** 0x01 if the corresponding column is part of the tables primary key, or
10839** 0x00 if it is not.
10840**
10841** If argument pnCol is not NULL, then *pnCol is set to the number of columns
10842** in the table.
10843**
10844** If this function is called when the iterator does not point to a valid
10845** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
10846** SQLITE_OK is returned and the output variables populated as described
10847** above.
10848*/
10849SQLITE_API int sqlite3changeset_pk(
10850 sqlite3_changeset_iter *pIter, /* Iterator object */
10851 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
10852 int *pnCol /* OUT: Number of entries in output array */
10853);
10854
10855/*
10856** CAPI3REF: Obtain old.* Values From A Changeset Iterator
10857** METHOD: sqlite3_changeset_iter
10858**
10859** The pIter argument passed to this function may either be an iterator
10860** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10861** created by [sqlite3changeset_start()]. In the latter case, the most recent
10862** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10863** Furthermore, it may only be called if the type of change that the iterator
10864** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
10865** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10866**
10867** Argument iVal must be greater than or equal to 0, and less than the number
10868** of columns in the table affected by the current change. Otherwise,
10869** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10870**
10871** If successful, this function sets *ppValue to point to a protected
10872** sqlite3_value object containing the iVal'th value from the vector of
10873** original row values stored as part of the UPDATE or DELETE change and
10874** returns SQLITE_OK. The name of the function comes from the fact that this
10875** is similar to the "old.*" columns available to update or delete triggers.
10876**
10877** If some other error occurs (e.g. an OOM condition), an SQLite error code
10878** is returned and *ppValue is set to NULL.
10879*/
10880SQLITE_API int sqlite3changeset_old(
10881 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10882 int iVal, /* Column number */
10883 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10884);
10885
10886/*
10887** CAPI3REF: Obtain new.* Values From A Changeset Iterator
10888** METHOD: sqlite3_changeset_iter
10889**
10890** The pIter argument passed to this function may either be an iterator
10891** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10892** created by [sqlite3changeset_start()]. In the latter case, the most recent
10893** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10894** Furthermore, it may only be called if the type of change that the iterator
10895** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10896** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10897**
10898** Argument iVal must be greater than or equal to 0, and less than the number
10899** of columns in the table affected by the current change. Otherwise,
10900** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10901**
10902** If successful, this function sets *ppValue to point to a protected
10903** sqlite3_value object containing the iVal'th value from the vector of
10904** new row values stored as part of the UPDATE or INSERT change and
10905** returns SQLITE_OK. If the change is an UPDATE and does not include
10906** a new value for the requested column, *ppValue is set to NULL and
10907** SQLITE_OK returned. The name of the function comes from the fact that
10908** this is similar to the "new.*" columns available to update or delete
10909** triggers.
10910**
10911** If some other error occurs (e.g. an OOM condition), an SQLite error code
10912** is returned and *ppValue is set to NULL.
10913*/
10914SQLITE_API int sqlite3changeset_new(
10915 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10916 int iVal, /* Column number */
10917 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10918);
10919
10920/*
10921** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
10922** METHOD: sqlite3_changeset_iter
10923**
10924** This function should only be used with iterator objects passed to a
10925** conflict-handler callback by [sqlite3changeset_apply()] with either
10926** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10927** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10928** is set to NULL.
10929**
10930** Argument iVal must be greater than or equal to 0, and less than the number
10931** of columns in the table affected by the current change. Otherwise,
10932** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10933**
10934** If successful, this function sets *ppValue to point to a protected
10935** sqlite3_value object containing the iVal'th value from the
10936** "conflicting row" associated with the current conflict-handler callback
10937** and returns SQLITE_OK.
10938**
10939** If some other error occurs (e.g. an OOM condition), an SQLite error code
10940** is returned and *ppValue is set to NULL.
10941*/
10942SQLITE_API int sqlite3changeset_conflict(
10943 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10944 int iVal, /* Column number */
10945 sqlite3_value **ppValue /* OUT: Value from conflicting row */
10946);
10947
10948/*
10949** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
10950** METHOD: sqlite3_changeset_iter
10951**
10952** This function may only be called with an iterator passed to an
10953** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10954** it sets the output variable to the total number of known foreign key
10955** violations in the destination database and returns SQLITE_OK.
10956**
10957** In all other cases this function returns SQLITE_MISUSE.
10958*/
10959SQLITE_API int sqlite3changeset_fk_conflicts(
10960 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10961 int *pnOut /* OUT: Number of FK violations */
10962);
10963
10964
10965/*
10966** CAPI3REF: Finalize A Changeset Iterator
10967** METHOD: sqlite3_changeset_iter
10968**
10969** This function is used to finalize an iterator allocated with
10970** [sqlite3changeset_start()].
10971**
10972** This function should only be called on iterators created using the
10973** [sqlite3changeset_start()] function. If an application calls this
10974** function with an iterator passed to a conflict-handler by
10975** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10976** call has no effect.
10977**
10978** If an error was encountered within a call to an sqlite3changeset_xxx()
10979** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
10980** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10981** to that error is returned by this function. Otherwise, SQLITE_OK is
10982** returned. This is to allow the following pattern (pseudo-code):
10983**
10984** <pre>
10985** sqlite3changeset_start();
10986** while( SQLITE_ROW==sqlite3changeset_next() ){
10987** // Do something with change.
10988** }
10989** rc = sqlite3changeset_finalize();
10990** if( rc!=SQLITE_OK ){
10991** // An error has occurred
10992** }
10993** </pre>
10994*/
10995SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
10996
10997/*
10998** CAPI3REF: Invert A Changeset
10999**
11000** This function is used to "invert" a changeset object. Applying an inverted
11001** changeset to a database reverses the effects of applying the uninverted
11002** changeset. Specifically:
11003**
11004** <ul>
11005** <li> Each DELETE change is changed to an INSERT, and
11006** <li> Each INSERT change is changed to a DELETE, and
11007** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11008** </ul>
11009**
11010** This function does not change the order in which changes appear within
11011** the changeset. It merely reverses the sense of each individual change.
11012**
11013** If successful, a pointer to a buffer containing the inverted changeset
11014** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11015** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11016** zeroed and an SQLite error code returned.
11017**
11018** It is the responsibility of the caller to eventually call sqlite3_free()
11019** on the *ppOut pointer to free the buffer allocation following a successful
11020** call to this function.
11021**
11022** WARNING/TODO: This function currently assumes that the input is a valid
11023** changeset. If it is not, the results are undefined.
11024*/
11025SQLITE_API int sqlite3changeset_invert(
11026 int nIn, const void *pIn, /* Input changeset */
11027 int *pnOut, void **ppOut /* OUT: Inverse of input */
11028);
11029
11030/*
11031** CAPI3REF: Concatenate Two Changeset Objects
11032**
11033** This function is used to concatenate two changesets, A and B, into a
11034** single changeset. The result is a changeset equivalent to applying
11035** changeset A followed by changeset B.
11036**
11037** This function combines the two input changesets using an
11038** sqlite3_changegroup object. Calling it produces similar results as the
11039** following code fragment:
11040**
11041** <pre>
11042** sqlite3_changegroup *pGrp;
11043** rc = sqlite3_changegroup_new(&pGrp);
11044** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11045** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11046** if( rc==SQLITE_OK ){
11047** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11048** }else{
11049** *ppOut = 0;
11050** *pnOut = 0;
11051** }
11052** </pre>
11053**
11054** Refer to the sqlite3_changegroup documentation below for details.
11055*/
11056SQLITE_API int sqlite3changeset_concat(
11057 int nA, /* Number of bytes in buffer pA */
11058 void *pA, /* Pointer to buffer containing changeset A */
11059 int nB, /* Number of bytes in buffer pB */
11060 void *pB, /* Pointer to buffer containing changeset B */
11061 int *pnOut, /* OUT: Number of bytes in output changeset */
11062 void **ppOut /* OUT: Buffer containing output changeset */
11063);
11064
11065
11066/*
11067** CAPI3REF: Changegroup Handle
11068**
11069** A changegroup is an object used to combine two or more
11070** [changesets] or [patchsets]
11071*/
11072typedef struct sqlite3_changegroup sqlite3_changegroup;
11073
11074/*
11075** CAPI3REF: Create A New Changegroup Object
11076** CONSTRUCTOR: sqlite3_changegroup
11077**
11078** An sqlite3_changegroup object is used to combine two or more changesets
11079** (or patchsets) into a single changeset (or patchset). A single changegroup
11080** object may combine changesets or patchsets, but not both. The output is
11081** always in the same format as the input.
11082**
11083** If successful, this function returns SQLITE_OK and populates (*pp) with
11084** a pointer to a new sqlite3_changegroup object before returning. The caller
11085** should eventually free the returned object using a call to
11086** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11087** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11088**
11089** The usual usage pattern for an sqlite3_changegroup object is as follows:
11090**
11091** <ul>
11092** <li> It is created using a call to sqlite3changegroup_new().
11093**
11094** <li> Zero or more changesets (or patchsets) are added to the object
11095** by calling sqlite3changegroup_add().
11096**
11097** <li> The result of combining all input changesets together is obtained
11098** by the application via a call to sqlite3changegroup_output().
11099**
11100** <li> The object is deleted using a call to sqlite3changegroup_delete().
11101** </ul>
11102**
11103** Any number of calls to add() and output() may be made between the calls to
11104** new() and delete(), and in any order.
11105**
11106** As well as the regular sqlite3changegroup_add() and
11107** sqlite3changegroup_output() functions, also available are the streaming
11108** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11109*/
11110SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11111
11112/*
11113** CAPI3REF: Add A Changeset To A Changegroup
11114** METHOD: sqlite3_changegroup
11115**
11116** Add all changes within the changeset (or patchset) in buffer pData (size
11117** nData bytes) to the changegroup.
11118**
11119** If the buffer contains a patchset, then all prior calls to this function
11120** on the same changegroup object must also have specified patchsets. Or, if
11121** the buffer contains a changeset, so must have the earlier calls to this
11122** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11123** to the changegroup.
11124**
11125** Rows within the changeset and changegroup are identified by the values in
11126** their PRIMARY KEY columns. A change in the changeset is considered to
11127** apply to the same row as a change already present in the changegroup if
11128** the two rows have the same primary key.
11129**
11130** Changes to rows that do not already appear in the changegroup are
11131** simply copied into it. Or, if both the new changeset and the changegroup
11132** contain changes that apply to a single row, the final contents of the
11133** changegroup depends on the type of each change, as follows:
11134**
11135** <table border=1 style="margin-left:8ex;margin-right:8ex">
11136** <tr><th style="white-space:pre">Existing Change </th>
11137** <th style="white-space:pre">New Change </th>
11138** <th>Output Change
11139** <tr><td>INSERT <td>INSERT <td>
11140** The new change is ignored. This case does not occur if the new
11141** changeset was recorded immediately after the changesets already
11142** added to the changegroup.
11143** <tr><td>INSERT <td>UPDATE <td>
11144** The INSERT change remains in the changegroup. The values in the
11145** INSERT change are modified as if the row was inserted by the
11146** existing change and then updated according to the new change.
11147** <tr><td>INSERT <td>DELETE <td>
11148** The existing INSERT is removed from the changegroup. The DELETE is
11149** not added.
11150** <tr><td>UPDATE <td>INSERT <td>
11151** The new change is ignored. This case does not occur if the new
11152** changeset was recorded immediately after the changesets already
11153** added to the changegroup.
11154** <tr><td>UPDATE <td>UPDATE <td>
11155** The existing UPDATE remains within the changegroup. It is amended
11156** so that the accompanying values are as if the row was updated once
11157** by the existing change and then again by the new change.
11158** <tr><td>UPDATE <td>DELETE <td>
11159** The existing UPDATE is replaced by the new DELETE within the
11160** changegroup.
11161** <tr><td>DELETE <td>INSERT <td>
11162** If one or more of the column values in the row inserted by the
11163** new change differ from those in the row deleted by the existing
11164** change, the existing DELETE is replaced by an UPDATE within the
11165** changegroup. Otherwise, if the inserted row is exactly the same
11166** as the deleted row, the existing DELETE is simply discarded.
11167** <tr><td>DELETE <td>UPDATE <td>
11168** The new change is ignored. This case does not occur if the new
11169** changeset was recorded immediately after the changesets already
11170** added to the changegroup.
11171** <tr><td>DELETE <td>DELETE <td>
11172** The new change is ignored. This case does not occur if the new
11173** changeset was recorded immediately after the changesets already
11174** added to the changegroup.
11175** </table>
11176**
11177** If the new changeset contains changes to a table that is already present
11178** in the changegroup, then the number of columns and the position of the
11179** primary key columns for the table must be consistent. If this is not the
11180** case, this function fails with SQLITE_SCHEMA. If the input changeset
11181** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
11182** returned. Or, if an out-of-memory condition occurs during processing, this
11183** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
11184** of the final contents of the changegroup is undefined.
11185**
11186** If no error occurs, SQLITE_OK is returned.
11187*/
11188SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
11189
11190/*
11191** CAPI3REF: Obtain A Composite Changeset From A Changegroup
11192** METHOD: sqlite3_changegroup
11193**
11194** Obtain a buffer containing a changeset (or patchset) representing the
11195** current contents of the changegroup. If the inputs to the changegroup
11196** were themselves changesets, the output is a changeset. Or, if the
11197** inputs were patchsets, the output is also a patchset.
11198**
11199** As with the output of the sqlite3session_changeset() and
11200** sqlite3session_patchset() functions, all changes related to a single
11201** table are grouped together in the output of this function. Tables appear
11202** in the same order as for the very first changeset added to the changegroup.
11203** If the second or subsequent changesets added to the changegroup contain
11204** changes for tables that do not appear in the first changeset, they are
11205** appended onto the end of the output changeset, again in the order in
11206** which they are first encountered.
11207**
11208** If an error occurs, an SQLite error code is returned and the output
11209** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
11210** is returned and the output variables are set to the size of and a
11211** pointer to the output buffer, respectively. In this case it is the
11212** responsibility of the caller to eventually free the buffer using a
11213** call to sqlite3_free().
11214*/
11215SQLITE_API int sqlite3changegroup_output(
11216 sqlite3_changegroup*,
11217 int *pnData, /* OUT: Size of output buffer in bytes */
11218 void **ppData /* OUT: Pointer to output buffer */
11219);
11220
11221/*
11222** CAPI3REF: Delete A Changegroup Object
11223** DESTRUCTOR: sqlite3_changegroup
11224*/
11225SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
11226
11227/*
11228** CAPI3REF: Apply A Changeset To A Database
11229**
11230** Apply a changeset or patchset to a database. These functions attempt to
11231** update the "main" database attached to handle db with the changes found in
11232** the changeset passed via the second and third arguments.
11233**
11234** The fourth argument (xFilter) passed to these functions is the "filter
11235** callback". If it is not NULL, then for each table affected by at least one
11236** change in the changeset, the filter callback is invoked with
11237** the table name as the second argument, and a copy of the context pointer
11238** passed as the sixth argument as the first. If the "filter callback"
11239** returns zero, then no attempt is made to apply any changes to the table.
11240** Otherwise, if the return value is non-zero or the xFilter argument to
11241** is NULL, all changes related to the table are attempted.
11242**
11243** For each table that is not excluded by the filter callback, this function
11244** tests that the target database contains a compatible table. A table is
11245** considered compatible if all of the following are true:
11246**
11247** <ul>
11248** <li> The table has the same name as the name recorded in the
11249** changeset, and
11250** <li> The table has at least as many columns as recorded in the
11251** changeset, and
11252** <li> The table has primary key columns in the same position as
11253** recorded in the changeset.
11254** </ul>
11255**
11256** If there is no compatible table, it is not an error, but none of the
11257** changes associated with the table are applied. A warning message is issued
11258** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
11259** one such warning is issued for each table in the changeset.
11260**
11261** For each change for which there is a compatible table, an attempt is made
11262** to modify the table contents according to the UPDATE, INSERT or DELETE
11263** change. If a change cannot be applied cleanly, the conflict handler
11264** function passed as the fifth argument to sqlite3changeset_apply() may be
11265** invoked. A description of exactly when the conflict handler is invoked for
11266** each type of change is below.
11267**
11268** Unlike the xFilter argument, xConflict may not be passed NULL. The results
11269** of passing anything other than a valid function pointer as the xConflict
11270** argument are undefined.
11271**
11272** Each time the conflict handler function is invoked, it must return one
11273** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
11274** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
11275** if the second argument passed to the conflict handler is either
11276** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
11277** returns an illegal value, any changes already made are rolled back and
11278** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
11279** actions are taken by sqlite3changeset_apply() depending on the value
11280** returned by each invocation of the conflict-handler function. Refer to
11281** the documentation for the three
11282** [SQLITE_CHANGESET_OMIT|available return values] for details.
11283**
11284** <dl>
11285** <dt>DELETE Changes<dd>
11286** For each DELETE change, the function checks if the target database
11287** contains a row with the same primary key value (or values) as the
11288** original row values stored in the changeset. If it does, and the values
11289** stored in all non-primary key columns also match the values stored in
11290** the changeset the row is deleted from the target database.
11291**
11292** If a row with matching primary key values is found, but one or more of
11293** the non-primary key fields contains a value different from the original
11294** row value stored in the changeset, the conflict-handler function is
11295** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
11296** database table has more columns than are recorded in the changeset,
11297** only the values of those non-primary key fields are compared against
11298** the current database contents - any trailing database table columns
11299** are ignored.
11300**
11301** If no row with matching primary key values is found in the database,
11302** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11303** passed as the second argument.
11304**
11305** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
11306** (which can only happen if a foreign key constraint is violated), the
11307** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
11308** passed as the second argument. This includes the case where the DELETE
11309** operation is attempted because an earlier call to the conflict handler
11310** function returned [SQLITE_CHANGESET_REPLACE].
11311**
11312** <dt>INSERT Changes<dd>
11313** For each INSERT change, an attempt is made to insert the new row into
11314** the database. If the changeset row contains fewer fields than the
11315** database table, the trailing fields are populated with their default
11316** values.
11317**
11318** If the attempt to insert the row fails because the database already
11319** contains a row with the same primary key values, the conflict handler
11320** function is invoked with the second argument set to
11321** [SQLITE_CHANGESET_CONFLICT].
11322**
11323** If the attempt to insert the row fails because of some other constraint
11324** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
11325** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
11326** This includes the case where the INSERT operation is re-attempted because
11327** an earlier call to the conflict handler function returned
11328** [SQLITE_CHANGESET_REPLACE].
11329**
11330** <dt>UPDATE Changes<dd>
11331** For each UPDATE change, the function checks if the target database
11332** contains a row with the same primary key value (or values) as the
11333** original row values stored in the changeset. If it does, and the values
11334** stored in all modified non-primary key columns also match the values
11335** stored in the changeset the row is updated within the target database.
11336**
11337** If a row with matching primary key values is found, but one or more of
11338** the modified non-primary key fields contains a value different from an
11339** original row value stored in the changeset, the conflict-handler function
11340** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
11341** UPDATE changes only contain values for non-primary key fields that are
11342** to be modified, only those fields need to match the original values to
11343** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11344**
11345** If no row with matching primary key values is found in the database,
11346** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11347** passed as the second argument.
11348**
11349** If the UPDATE operation is attempted, but SQLite returns
11350** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
11351** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
11352** This includes the case where the UPDATE operation is attempted after
11353** an earlier call to the conflict handler function returned
11354** [SQLITE_CHANGESET_REPLACE].
11355** </dl>
11356**
11357** It is safe to execute SQL statements, including those that write to the
11358** table that the callback related to, from within the xConflict callback.
11359** This can be used to further customize the application's conflict
11360** resolution strategy.
11361**
11362** All changes made by these functions are enclosed in a savepoint transaction.
11363** If any other error (aside from a constraint failure when attempting to
11364** write to the target database) occurs, then the savepoint transaction is
11365** rolled back, restoring the target database to its original state, and an
11366** SQLite error code returned.
11367**
11368** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11369** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11370** may set (*ppRebase) to point to a "rebase" that may be used with the
11371** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11372** is set to the size of the buffer in bytes. It is the responsibility of the
11373** caller to eventually free any such buffer using sqlite3_free(). The buffer
11374** is only allocated and populated if one or more conflicts were encountered
11375** while applying the patchset. See comments surrounding the sqlite3_rebaser
11376** APIs for further details.
11377**
11378** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11379** may be modified by passing a combination of
11380** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11381**
11382** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11383** and therefore subject to change.
11384*/
11385SQLITE_API int sqlite3changeset_apply(
11386 sqlite3 *db, /* Apply change to "main" db of this handle */
11387 int nChangeset, /* Size of changeset in bytes */
11388 void *pChangeset, /* Changeset blob */
11389 int(*xFilter)(
11390 void *pCtx, /* Copy of sixth arg to _apply() */
11391 const char *zTab /* Table name */
11392 ),
11393 int(*xConflict)(
11394 void *pCtx, /* Copy of sixth arg to _apply() */
11395 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11396 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11397 ),
11398 void *pCtx /* First argument passed to xConflict */
11399);
11400SQLITE_API int sqlite3changeset_apply_v2(
11401 sqlite3 *db, /* Apply change to "main" db of this handle */
11402 int nChangeset, /* Size of changeset in bytes */
11403 void *pChangeset, /* Changeset blob */
11404 int(*xFilter)(
11405 void *pCtx, /* Copy of sixth arg to _apply() */
11406 const char *zTab /* Table name */
11407 ),
11408 int(*xConflict)(
11409 void *pCtx, /* Copy of sixth arg to _apply() */
11410 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11411 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11412 ),
11413 void *pCtx, /* First argument passed to xConflict */
11414 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
11415 int flags /* SESSION_CHANGESETAPPLY_* flags */
11416);
11417
11418/*
11419** CAPI3REF: Flags for sqlite3changeset_apply_v2
11420**
11421** The following flags may passed via the 9th parameter to
11422** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
11423**
11424** <dl>
11425** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
11426** Usually, the sessions module encloses all operations performed by
11427** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
11428** SAVEPOINT is committed if the changeset or patchset is successfully
11429** applied, or rolled back if an error occurs. Specifying this flag
11430** causes the sessions module to omit this savepoint. In this case, if the
11431** caller has an open transaction or savepoint when apply_v2() is called,
11432** it may revert the partially applied changeset by rolling it back.
11433**
11434** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11435** Invert the changeset before applying it. This is equivalent to inverting
11436** a changeset using sqlite3changeset_invert() before applying it. It is
11437** an error to specify this flag with a patchset.
11438*/
11439#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
11440#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
11441
11442/*
11443** CAPI3REF: Constants Passed To The Conflict Handler
11444**
11445** Values that may be passed as the second argument to a conflict-handler.
11446**
11447** <dl>
11448** <dt>SQLITE_CHANGESET_DATA<dd>
11449** The conflict handler is invoked with CHANGESET_DATA as the second argument
11450** when processing a DELETE or UPDATE change if a row with the required
11451** PRIMARY KEY fields is present in the database, but one or more other
11452** (non primary-key) fields modified by the update do not contain the
11453** expected "before" values.
11454**
11455** The conflicting row, in this case, is the database row with the matching
11456** primary key.
11457**
11458** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
11459** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
11460** argument when processing a DELETE or UPDATE change if a row with the
11461** required PRIMARY KEY fields is not present in the database.
11462**
11463** There is no conflicting row in this case. The results of invoking the
11464** sqlite3changeset_conflict() API are undefined.
11465**
11466** <dt>SQLITE_CHANGESET_CONFLICT<dd>
11467** CHANGESET_CONFLICT is passed as the second argument to the conflict
11468** handler while processing an INSERT change if the operation would result
11469** in duplicate primary key values.
11470**
11471** The conflicting row in this case is the database row with the matching
11472** primary key.
11473**
11474** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
11475** If foreign key handling is enabled, and applying a changeset leaves the
11476** database in a state containing foreign key violations, the conflict
11477** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
11478** exactly once before the changeset is committed. If the conflict handler
11479** returns CHANGESET_OMIT, the changes, including those that caused the
11480** foreign key constraint violation, are committed. Or, if it returns
11481** CHANGESET_ABORT, the changeset is rolled back.
11482**
11483** No current or conflicting row information is provided. The only function
11484** it is possible to call on the supplied sqlite3_changeset_iter handle
11485** is sqlite3changeset_fk_conflicts().
11486**
11487** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
11488** If any other constraint violation occurs while applying a change (i.e.
11489** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
11490** invoked with CHANGESET_CONSTRAINT as the second argument.
11491**
11492** There is no conflicting row in this case. The results of invoking the
11493** sqlite3changeset_conflict() API are undefined.
11494**
11495** </dl>
11496*/
11497#define SQLITE_CHANGESET_DATA 1
11498#define SQLITE_CHANGESET_NOTFOUND 2
11499#define SQLITE_CHANGESET_CONFLICT 3
11500#define SQLITE_CHANGESET_CONSTRAINT 4
11501#define SQLITE_CHANGESET_FOREIGN_KEY 5
11502
11503/*
11504** CAPI3REF: Constants Returned By The Conflict Handler
11505**
11506** A conflict handler callback must return one of the following three values.
11507**
11508** <dl>
11509** <dt>SQLITE_CHANGESET_OMIT<dd>
11510** If a conflict handler returns this value no special action is taken. The
11511** change that caused the conflict is not applied. The session module
11512** continues to the next change in the changeset.
11513**
11514** <dt>SQLITE_CHANGESET_REPLACE<dd>
11515** This value may only be returned if the second argument to the conflict
11516** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
11517** is not the case, any changes applied so far are rolled back and the
11518** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
11519**
11520** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
11521** handler, then the conflicting row is either updated or deleted, depending
11522** on the type of change.
11523**
11524** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
11525** handler, then the conflicting row is removed from the database and a
11526** second attempt to apply the change is made. If this second attempt fails,
11527** the original row is restored to the database before continuing.
11528**
11529** <dt>SQLITE_CHANGESET_ABORT<dd>
11530** If this value is returned, any changes applied so far are rolled back
11531** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
11532** </dl>
11533*/
11534#define SQLITE_CHANGESET_OMIT 0
11535#define SQLITE_CHANGESET_REPLACE 1
11536#define SQLITE_CHANGESET_ABORT 2
11537
11538/*
11539** CAPI3REF: Rebasing changesets
11540** EXPERIMENTAL
11541**
11542** Suppose there is a site hosting a database in state S0. And that
11543** modifications are made that move that database to state S1 and a
11544** changeset recorded (the "local" changeset). Then, a changeset based
11545** on S0 is received from another site (the "remote" changeset) and
11546** applied to the database. The database is then in state
11547** (S1+"remote"), where the exact state depends on any conflict
11548** resolution decisions (OMIT or REPLACE) made while applying "remote".
11549** Rebasing a changeset is to update it to take those conflict
11550** resolution decisions into account, so that the same conflicts
11551** do not have to be resolved elsewhere in the network.
11552**
11553** For example, if both the local and remote changesets contain an
11554** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
11555**
11556** local: INSERT INTO t1 VALUES(1, 'v1');
11557** remote: INSERT INTO t1 VALUES(1, 'v2');
11558**
11559** and the conflict resolution is REPLACE, then the INSERT change is
11560** removed from the local changeset (it was overridden). Or, if the
11561** conflict resolution was "OMIT", then the local changeset is modified
11562** to instead contain:
11563**
11564** UPDATE t1 SET b = 'v2' WHERE a=1;
11565**
11566** Changes within the local changeset are rebased as follows:
11567**
11568** <dl>
11569** <dt>Local INSERT<dd>
11570** This may only conflict with a remote INSERT. If the conflict
11571** resolution was OMIT, then add an UPDATE change to the rebased
11572** changeset. Or, if the conflict resolution was REPLACE, add
11573** nothing to the rebased changeset.
11574**
11575** <dt>Local DELETE<dd>
11576** This may conflict with a remote UPDATE or DELETE. In both cases the
11577** only possible resolution is OMIT. If the remote operation was a
11578** DELETE, then add no change to the rebased changeset. If the remote
11579** operation was an UPDATE, then the old.* fields of change are updated
11580** to reflect the new.* values in the UPDATE.
11581**
11582** <dt>Local UPDATE<dd>
11583** This may conflict with a remote UPDATE or DELETE. If it conflicts
11584** with a DELETE, and the conflict resolution was OMIT, then the update
11585** is changed into an INSERT. Any undefined values in the new.* record
11586** from the update change are filled in using the old.* values from
11587** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
11588** the UPDATE change is simply omitted from the rebased changeset.
11589**
11590** If conflict is with a remote UPDATE and the resolution is OMIT, then
11591** the old.* values are rebased using the new.* values in the remote
11592** change. Or, if the resolution is REPLACE, then the change is copied
11593** into the rebased changeset with updates to columns also updated by
11594** the conflicting remote UPDATE removed. If this means no columns would
11595** be updated, the change is omitted.
11596** </dl>
11597**
11598** A local change may be rebased against multiple remote changes
11599** simultaneously. If a single key is modified by multiple remote
11600** changesets, they are combined as follows before the local changeset
11601** is rebased:
11602**
11603** <ul>
11604** <li> If there has been one or more REPLACE resolutions on a
11605** key, it is rebased according to a REPLACE.
11606**
11607** <li> If there have been no REPLACE resolutions on a key, then
11608** the local changeset is rebased according to the most recent
11609** of the OMIT resolutions.
11610** </ul>
11611**
11612** Note that conflict resolutions from multiple remote changesets are
11613** combined on a per-field basis, not per-row. This means that in the
11614** case of multiple remote UPDATE operations, some fields of a single
11615** local change may be rebased for REPLACE while others are rebased for
11616** OMIT.
11617**
11618** In order to rebase a local changeset, the remote changeset must first
11619** be applied to the local database using sqlite3changeset_apply_v2() and
11620** the buffer of rebase information captured. Then:
11621**
11622** <ol>
11623** <li> An sqlite3_rebaser object is created by calling
11624** sqlite3rebaser_create().
11625** <li> The new object is configured with the rebase buffer obtained from
11626** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
11627** If the local changeset is to be rebased against multiple remote
11628** changesets, then sqlite3rebaser_configure() should be called
11629** multiple times, in the same order that the multiple
11630** sqlite3changeset_apply_v2() calls were made.
11631** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
11632** <li> The sqlite3_rebaser object is deleted by calling
11633** sqlite3rebaser_delete().
11634** </ol>
11635*/
11636typedef struct sqlite3_rebaser sqlite3_rebaser;
11637
11638/*
11639** CAPI3REF: Create a changeset rebaser object.
11640** EXPERIMENTAL
11641**
11642** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
11643** point to the new object and return SQLITE_OK. Otherwise, if an error
11644** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
11645** to NULL.
11646*/
11647SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
11648
11649/*
11650** CAPI3REF: Configure a changeset rebaser object.
11651** EXPERIMENTAL
11652**
11653** Configure the changeset rebaser object to rebase changesets according
11654** to the conflict resolutions described by buffer pRebase (size nRebase
11655** bytes), which must have been obtained from a previous call to
11656** sqlite3changeset_apply_v2().
11657*/
11658SQLITE_API int sqlite3rebaser_configure(
11659 sqlite3_rebaser*,
11660 int nRebase, const void *pRebase
11661);
11662
11663/*
11664** CAPI3REF: Rebase a changeset
11665** EXPERIMENTAL
11666**
11667** Argument pIn must point to a buffer containing a changeset nIn bytes
11668** in size. This function allocates and populates a buffer with a copy
11669** of the changeset rebased according to the configuration of the
11670** rebaser object passed as the first argument. If successful, (*ppOut)
11671** is set to point to the new buffer containing the rebased changeset and
11672** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
11673** responsibility of the caller to eventually free the new buffer using
11674** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
11675** are set to zero and an SQLite error code returned.
11676*/
11677SQLITE_API int sqlite3rebaser_rebase(
11678 sqlite3_rebaser*,
11679 int nIn, const void *pIn,
11680 int *pnOut, void **ppOut
11681);
11682
11683/*
11684** CAPI3REF: Delete a changeset rebaser object.
11685** EXPERIMENTAL
11686**
11687** Delete the changeset rebaser object and all associated resources. There
11688** should be one call to this function for each successful invocation
11689** of sqlite3rebaser_create().
11690*/
11691SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
11692
11693/*
11694** CAPI3REF: Streaming Versions of API functions.
11695**
11696** The six streaming API xxx_strm() functions serve similar purposes to the
11697** corresponding non-streaming API functions:
11698**
11699** <table border=1 style="margin-left:8ex;margin-right:8ex">
11700** <tr><th>Streaming function<th>Non-streaming equivalent</th>
11701** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
11702** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
11703** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
11704** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
11705** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
11706** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
11707** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
11708** </table>
11709**
11710** Non-streaming functions that accept changesets (or patchsets) as input
11711** require that the entire changeset be stored in a single buffer in memory.
11712** Similarly, those that return a changeset or patchset do so by returning
11713** a pointer to a single large buffer allocated using sqlite3_malloc().
11714** Normally this is convenient. However, if an application running in a
11715** low-memory environment is required to handle very large changesets, the
11716** large contiguous memory allocations required can become onerous.
11717**
11718** In order to avoid this problem, instead of a single large buffer, input
11719** is passed to a streaming API functions by way of a callback function that
11720** the sessions module invokes to incrementally request input data as it is
11721** required. In all cases, a pair of API function parameters such as
11722**
11723** <pre>
11724** &nbsp; int nChangeset,
11725** &nbsp; void *pChangeset,
11726** </pre>
11727**
11728** Is replaced by:
11729**
11730** <pre>
11731** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
11732** &nbsp; void *pIn,
11733** </pre>
11734**
11735** Each time the xInput callback is invoked by the sessions module, the first
11736** argument passed is a copy of the supplied pIn context pointer. The second
11737** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
11738** error occurs the xInput method should copy up to (*pnData) bytes of data
11739** into the buffer and set (*pnData) to the actual number of bytes copied
11740** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
11741** should be set to zero to indicate this. Or, if an error occurs, an SQLite
11742** error code should be returned. In all cases, if an xInput callback returns
11743** an error, all processing is abandoned and the streaming API function
11744** returns a copy of the error code to the caller.
11745**
11746** In the case of sqlite3changeset_start_strm(), the xInput callback may be
11747** invoked by the sessions module at any point during the lifetime of the
11748** iterator. If such an xInput callback returns an error, the iterator enters
11749** an error state, whereby all subsequent calls to iterator functions
11750** immediately fail with the same error code as returned by xInput.
11751**
11752** Similarly, streaming API functions that return changesets (or patchsets)
11753** return them in chunks by way of a callback function instead of via a
11754** pointer to a single large buffer. In this case, a pair of parameters such
11755** as:
11756**
11757** <pre>
11758** &nbsp; int *pnChangeset,
11759** &nbsp; void **ppChangeset,
11760** </pre>
11761**
11762** Is replaced by:
11763**
11764** <pre>
11765** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
11766** &nbsp; void *pOut
11767** </pre>
11768**
11769** The xOutput callback is invoked zero or more times to return data to
11770** the application. The first parameter passed to each call is a copy of the
11771** pOut pointer supplied by the application. The second parameter, pData,
11772** points to a buffer nData bytes in size containing the chunk of output
11773** data being returned. If the xOutput callback successfully processes the
11774** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
11775** it should return some other SQLite error code. In this case processing
11776** is immediately abandoned and the streaming API function returns a copy
11777** of the xOutput error code to the application.
11778**
11779** The sessions module never invokes an xOutput callback with the third
11780** parameter set to a value less than or equal to zero. Other than this,
11781** no guarantees are made as to the size of the chunks of data returned.
11782*/
11783SQLITE_API int sqlite3changeset_apply_strm(
11784 sqlite3 *db, /* Apply change to "main" db of this handle */
11785 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11786 void *pIn, /* First arg for xInput */
11787 int(*xFilter)(
11788 void *pCtx, /* Copy of sixth arg to _apply() */
11789 const char *zTab /* Table name */
11790 ),
11791 int(*xConflict)(
11792 void *pCtx, /* Copy of sixth arg to _apply() */
11793 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11794 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11795 ),
11796 void *pCtx /* First argument passed to xConflict */
11797);
11798SQLITE_API int sqlite3changeset_apply_v2_strm(
11799 sqlite3 *db, /* Apply change to "main" db of this handle */
11800 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
11801 void *pIn, /* First arg for xInput */
11802 int(*xFilter)(
11803 void *pCtx, /* Copy of sixth arg to _apply() */
11804 const char *zTab /* Table name */
11805 ),
11806 int(*xConflict)(
11807 void *pCtx, /* Copy of sixth arg to _apply() */
11808 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11809 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11810 ),
11811 void *pCtx, /* First argument passed to xConflict */
11812 void **ppRebase, int *pnRebase,
11813 int flags
11814);
11815SQLITE_API int sqlite3changeset_concat_strm(
11816 int (*xInputA)(void *pIn, void *pData, int *pnData),
11817 void *pInA,
11818 int (*xInputB)(void *pIn, void *pData, int *pnData),
11819 void *pInB,
11820 int (*xOutput)(void *pOut, const void *pData, int nData),
11821 void *pOut
11822);
11823SQLITE_API int sqlite3changeset_invert_strm(
11824 int (*xInput)(void *pIn, void *pData, int *pnData),
11825 void *pIn,
11826 int (*xOutput)(void *pOut, const void *pData, int nData),
11827 void *pOut
11828);
11829SQLITE_API int sqlite3changeset_start_strm(
11830 sqlite3_changeset_iter **pp,
11831 int (*xInput)(void *pIn, void *pData, int *pnData),
11832 void *pIn
11833);
11834SQLITE_API int sqlite3changeset_start_v2_strm(
11835 sqlite3_changeset_iter **pp,
11836 int (*xInput)(void *pIn, void *pData, int *pnData),
11837 void *pIn,
11838 int flags
11839);
11840SQLITE_API int sqlite3session_changeset_strm(
11841 sqlite3_session *pSession,
11842 int (*xOutput)(void *pOut, const void *pData, int nData),
11843 void *pOut
11844);
11845SQLITE_API int sqlite3session_patchset_strm(
11846 sqlite3_session *pSession,
11847 int (*xOutput)(void *pOut, const void *pData, int nData),
11848 void *pOut
11849);
11850SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
11851 int (*xInput)(void *pIn, void *pData, int *pnData),
11852 void *pIn
11853);
11854SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
11855 int (*xOutput)(void *pOut, const void *pData, int nData),
11856 void *pOut
11857);
11858SQLITE_API int sqlite3rebaser_rebase_strm(
11859 sqlite3_rebaser *pRebaser,
11860 int (*xInput)(void *pIn, void *pData, int *pnData),
11861 void *pIn,
11862 int (*xOutput)(void *pOut, const void *pData, int nData),
11863 void *pOut
11864);
11865
11866/*
11867** CAPI3REF: Configure global parameters
11868**
11869** The sqlite3session_config() interface is used to make global configuration
11870** changes to the sessions module in order to tune it to the specific needs
11871** of the application.
11872**
11873** The sqlite3session_config() interface is not threadsafe. If it is invoked
11874** while any other thread is inside any other sessions method then the
11875** results are undefined. Furthermore, if it is invoked after any sessions
11876** related objects have been created, the results are also undefined.
11877**
11878** The first argument to the sqlite3session_config() function must be one
11879** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
11880** interpretation of the (void*) value passed as the second parameter and
11881** the effect of calling this function depends on the value of the first
11882** parameter.
11883**
11884** <dl>
11885** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
11886** By default, the sessions module streaming interfaces attempt to input
11887** and output data in approximately 1 KiB chunks. This operand may be used
11888** to set and query the value of this configuration setting. The pointer
11889** passed as the second argument must point to a value of type (int).
11890** If this value is greater than 0, it is used as the new streaming data
11891** chunk size for both input and output. Before returning, the (int) value
11892** pointed to by pArg is set to the final value of the streaming interface
11893** chunk size.
11894** </dl>
11895**
11896** This function returns SQLITE_OK if successful, or an SQLite error code
11897** otherwise.
11898*/
11899SQLITE_API int sqlite3session_config(int op, void *pArg);
11900
11901/*
11902** CAPI3REF: Values for sqlite3session_config().
11903*/
11904#define SQLITE_SESSION_CONFIG_STRMSIZE 1
11905
11906/*
11907** Make sure we can call this stuff from C++.
11908*/
11909#ifdef __cplusplus
11910}
11911#endif
11912
11913#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
11914
11915/******** End of sqlite3session.h *********/
11916/******** Begin file fts5.h *********/
11917/*
11918** 2014 May 31
11919**
11920** The author disclaims copyright to this source code. In place of
11921** a legal notice, here is a blessing:
11922**
11923** May you do good and not evil.
11924** May you find forgiveness for yourself and forgive others.
11925** May you share freely, never taking more than you give.
11926**
11927******************************************************************************
11928**
11929** Interfaces to extend FTS5. Using the interfaces defined in this file,
11930** FTS5 may be extended with:
11931**
11932** * custom tokenizers, and
11933** * custom auxiliary functions.
11934*/
11935
11936
11937#ifndef _FTS5_H
11938#define _FTS5_H
11939
11940
11941#ifdef __cplusplus
11942extern "C" {
11943#endif
11944
11945/*************************************************************************
11946** CUSTOM AUXILIARY FUNCTIONS
11947**
11948** Virtual table implementations may overload SQL functions by implementing
11949** the sqlite3_module.xFindFunction() method.
11950*/
11951
11952typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11953typedef struct Fts5Context Fts5Context;
11954typedef struct Fts5PhraseIter Fts5PhraseIter;
11955
11956typedef void (*fts5_extension_function)(
11957 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11958 Fts5Context *pFts, /* First arg to pass to pApi functions */
11959 sqlite3_context *pCtx, /* Context for returning result/error */
11960 int nVal, /* Number of values in apVal[] array */
11961 sqlite3_value **apVal /* Array of trailing arguments */
11962);
11963
11964struct Fts5PhraseIter {
11965 const unsigned char *a;
11966 const unsigned char *b;
11967};
11968
11969/*
11970** EXTENSION API FUNCTIONS
11971**
11972** xUserData(pFts):
11973** Return a copy of the context pointer the extension function was
11974** registered with.
11975**
11976** xColumnTotalSize(pFts, iCol, pnToken):
11977** If parameter iCol is less than zero, set output variable *pnToken
11978** to the total number of tokens in the FTS5 table. Or, if iCol is
11979** non-negative but less than the number of columns in the table, return
11980** the total number of tokens in column iCol, considering all rows in
11981** the FTS5 table.
11982**
11983** If parameter iCol is greater than or equal to the number of columns
11984** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11985** an OOM condition or IO error), an appropriate SQLite error code is
11986** returned.
11987**
11988** xColumnCount(pFts):
11989** Return the number of columns in the table.
11990**
11991** xColumnSize(pFts, iCol, pnToken):
11992** If parameter iCol is less than zero, set output variable *pnToken
11993** to the total number of tokens in the current row. Or, if iCol is
11994** non-negative but less than the number of columns in the table, set
11995** *pnToken to the number of tokens in column iCol of the current row.
11996**
11997** If parameter iCol is greater than or equal to the number of columns
11998** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11999** an OOM condition or IO error), an appropriate SQLite error code is
12000** returned.
12001**
12002** This function may be quite inefficient if used with an FTS5 table
12003** created with the "columnsize=0" option.
12004**
12005** xColumnText:
12006** This function attempts to retrieve the text of column iCol of the
12007** current document. If successful, (*pz) is set to point to a buffer
12008** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12009** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12010** if an error occurs, an SQLite error code is returned and the final values
12011** of (*pz) and (*pn) are undefined.
12012**
12013** xPhraseCount:
12014** Returns the number of phrases in the current query expression.
12015**
12016** xPhraseSize:
12017** Returns the number of tokens in phrase iPhrase of the query. Phrases
12018** are numbered starting from zero.
12019**
12020** xInstCount:
12021** Set *pnInst to the total number of occurrences of all phrases within
12022** the query within the current row. Return SQLITE_OK if successful, or
12023** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12024**
12025** This API can be quite slow if used with an FTS5 table created with the
12026** "detail=none" or "detail=column" option. If the FTS5 table is created
12027** with either "detail=none" or "detail=column" and "content=" option
12028** (i.e. if it is a contentless table), then this API always returns 0.
12029**
12030** xInst:
12031** Query for the details of phrase match iIdx within the current row.
12032** Phrase matches are numbered starting from zero, so the iIdx argument
12033** should be greater than or equal to zero and smaller than the value
12034** output by xInstCount().
12035**
12036** Usually, output parameter *piPhrase is set to the phrase number, *piCol
12037** to the column in which it occurs and *piOff the token offset of the
12038** first token of the phrase. Returns SQLITE_OK if successful, or an error
12039** code (i.e. SQLITE_NOMEM) if an error occurs.
12040**
12041** This API can be quite slow if used with an FTS5 table created with the
12042** "detail=none" or "detail=column" option.
12043**
12044** xRowid:
12045** Returns the rowid of the current row.
12046**
12047** xTokenize:
12048** Tokenize text using the tokenizer belonging to the FTS5 table.
12049**
12050** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12051** This API function is used to query the FTS table for phrase iPhrase
12052** of the current query. Specifically, a query equivalent to:
12053**
12054** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12055**
12056** with $p set to a phrase equivalent to the phrase iPhrase of the
12057** current query is executed. Any column filter that applies to
12058** phrase iPhrase of the current query is included in $p. For each
12059** row visited, the callback function passed as the fourth argument
12060** is invoked. The context and API objects passed to the callback
12061** function may be used to access the properties of each matched row.
12062** Invoking Api.xUserData() returns a copy of the pointer passed as
12063** the third argument to pUserData.
12064**
12065** If the callback function returns any value other than SQLITE_OK, the
12066** query is abandoned and the xQueryPhrase function returns immediately.
12067** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12068** Otherwise, the error code is propagated upwards.
12069**
12070** If the query runs to completion without incident, SQLITE_OK is returned.
12071** Or, if some error occurs before the query completes or is aborted by
12072** the callback, an SQLite error code is returned.
12073**
12074**
12075** xSetAuxdata(pFts5, pAux, xDelete)
12076**
12077** Save the pointer passed as the second argument as the extension function's
12078** "auxiliary data". The pointer may then be retrieved by the current or any
12079** future invocation of the same fts5 extension function made as part of
12080** the same MATCH query using the xGetAuxdata() API.
12081**
12082** Each extension function is allocated a single auxiliary data slot for
12083** each FTS query (MATCH expression). If the extension function is invoked
12084** more than once for a single FTS query, then all invocations share a
12085** single auxiliary data context.
12086**
12087** If there is already an auxiliary data pointer when this function is
12088** invoked, then it is replaced by the new pointer. If an xDelete callback
12089** was specified along with the original pointer, it is invoked at this
12090** point.
12091**
12092** The xDelete callback, if one is specified, is also invoked on the
12093** auxiliary data pointer after the FTS5 query has finished.
12094**
12095** If an error (e.g. an OOM condition) occurs within this function,
12096** the auxiliary data is set to NULL and an error code returned. If the
12097** xDelete parameter was not NULL, it is invoked on the auxiliary data
12098** pointer before returning.
12099**
12100**
12101** xGetAuxdata(pFts5, bClear)
12102**
12103** Returns the current auxiliary data pointer for the fts5 extension
12104** function. See the xSetAuxdata() method for details.
12105**
12106** If the bClear argument is non-zero, then the auxiliary data is cleared
12107** (set to NULL) before this function returns. In this case the xDelete,
12108** if any, is not invoked.
12109**
12110**
12111** xRowCount(pFts5, pnRow)
12112**
12113** This function is used to retrieve the total number of rows in the table.
12114** In other words, the same value that would be returned by:
12115**
12116** SELECT count(*) FROM ftstable;
12117**
12118** xPhraseFirst()
12119** This function is used, along with type Fts5PhraseIter and the xPhraseNext
12120** method, to iterate through all instances of a single query phrase within
12121** the current row. This is the same information as is accessible via the
12122** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
12123** to use, this API may be faster under some circumstances. To iterate
12124** through instances of phrase iPhrase, use the following code:
12125**
12126** Fts5PhraseIter iter;
12127** int iCol, iOff;
12128** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
12129** iCol>=0;
12130** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
12131** ){
12132** // An instance of phrase iPhrase at offset iOff of column iCol
12133** }
12134**
12135** The Fts5PhraseIter structure is defined above. Applications should not
12136** modify this structure directly - it should only be used as shown above
12137** with the xPhraseFirst() and xPhraseNext() API methods (and by
12138** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
12139**
12140** This API can be quite slow if used with an FTS5 table created with the
12141** "detail=none" or "detail=column" option. If the FTS5 table is created
12142** with either "detail=none" or "detail=column" and "content=" option
12143** (i.e. if it is a contentless table), then this API always iterates
12144** through an empty set (all calls to xPhraseFirst() set iCol to -1).
12145**
12146** xPhraseNext()
12147** See xPhraseFirst above.
12148**
12149** xPhraseFirstColumn()
12150** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
12151** and xPhraseNext() APIs described above. The difference is that instead
12152** of iterating through all instances of a phrase in the current row, these
12153** APIs are used to iterate through the set of columns in the current row
12154** that contain one or more instances of a specified phrase. For example:
12155**
12156** Fts5PhraseIter iter;
12157** int iCol;
12158** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
12159** iCol>=0;
12160** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
12161** ){
12162** // Column iCol contains at least one instance of phrase iPhrase
12163** }
12164**
12165** This API can be quite slow if used with an FTS5 table created with the
12166** "detail=none" option. If the FTS5 table is created with either
12167** "detail=none" "content=" option (i.e. if it is a contentless table),
12168** then this API always iterates through an empty set (all calls to
12169** xPhraseFirstColumn() set iCol to -1).
12170**
12171** The information accessed using this API and its companion
12172** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
12173** (or xInst/xInstCount). The chief advantage of this API is that it is
12174** significantly more efficient than those alternatives when used with
12175** "detail=column" tables.
12176**
12177** xPhraseNextColumn()
12178** See xPhraseFirstColumn above.
12179*/
12180struct Fts5ExtensionApi {
12181 int iVersion; /* Currently always set to 3 */
12182
12183 void *(*xUserData)(Fts5Context*);
12184
12185 int (*xColumnCount)(Fts5Context*);
12186 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
12187 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
12188
12189 int (*xTokenize)(Fts5Context*,
12190 const char *pText, int nText, /* Text to tokenize */
12191 void *pCtx, /* Context passed to xToken() */
12192 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
12193 );
12194
12195 int (*xPhraseCount)(Fts5Context*);
12196 int (*xPhraseSize)(Fts5Context*, int iPhrase);
12197
12198 int (*xInstCount)(Fts5Context*, int *pnInst);
12199 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
12200
12201 sqlite3_int64 (*xRowid)(Fts5Context*);
12202 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
12203 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
12204
12205 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
12206 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
12207 );
12208 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
12209 void *(*xGetAuxdata)(Fts5Context*, int bClear);
12210
12211 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
12212 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
12213
12214 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
12215 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
12216};
12217
12218/*
12219** CUSTOM AUXILIARY FUNCTIONS
12220*************************************************************************/
12221
12222/*************************************************************************
12223** CUSTOM TOKENIZERS
12224**
12225** Applications may also register custom tokenizer types. A tokenizer
12226** is registered by providing fts5 with a populated instance of the
12227** following structure. All structure methods must be defined, setting
12228** any member of the fts5_tokenizer struct to NULL leads to undefined
12229** behaviour. The structure methods are expected to function as follows:
12230**
12231** xCreate:
12232** This function is used to allocate and initialize a tokenizer instance.
12233** A tokenizer instance is required to actually tokenize text.
12234**
12235** The first argument passed to this function is a copy of the (void*)
12236** pointer provided by the application when the fts5_tokenizer object
12237** was registered with FTS5 (the third argument to xCreateTokenizer()).
12238** The second and third arguments are an array of nul-terminated strings
12239** containing the tokenizer arguments, if any, specified following the
12240** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
12241** to create the FTS5 table.
12242**
12243** The final argument is an output variable. If successful, (*ppOut)
12244** should be set to point to the new tokenizer handle and SQLITE_OK
12245** returned. If an error occurs, some value other than SQLITE_OK should
12246** be returned. In this case, fts5 assumes that the final value of *ppOut
12247** is undefined.
12248**
12249** xDelete:
12250** This function is invoked to delete a tokenizer handle previously
12251** allocated using xCreate(). Fts5 guarantees that this function will
12252** be invoked exactly once for each successful call to xCreate().
12253**
12254** xTokenize:
12255** This function is expected to tokenize the nText byte string indicated
12256** by argument pText. pText may or may not be nul-terminated. The first
12257** argument passed to this function is a pointer to an Fts5Tokenizer object
12258** returned by an earlier call to xCreate().
12259**
12260** The second argument indicates the reason that FTS5 is requesting
12261** tokenization of the supplied text. This is always one of the following
12262** four values:
12263**
12264** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
12265** or removed from the FTS table. The tokenizer is being invoked to
12266** determine the set of tokens to add to (or delete from) the
12267** FTS index.
12268**
12269** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
12270** against the FTS index. The tokenizer is being called to tokenize
12271** a bareword or quoted string specified as part of the query.
12272**
12273** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
12274** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
12275** followed by a "*" character, indicating that the last token
12276** returned by the tokenizer will be treated as a token prefix.
12277**
12278** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
12279** satisfy an fts5_api.xTokenize() request made by an auxiliary
12280** function. Or an fts5_api.xColumnSize() request made by the same
12281** on a columnsize=0 database.
12282** </ul>
12283**
12284** For each token in the input string, the supplied callback xToken() must
12285** be invoked. The first argument to it should be a copy of the pointer
12286** passed as the second argument to xTokenize(). The third and fourth
12287** arguments are a pointer to a buffer containing the token text, and the
12288** size of the token in bytes. The 4th and 5th arguments are the byte offsets
12289** of the first byte of and first byte immediately following the text from
12290** which the token is derived within the input.
12291**
12292** The second argument passed to the xToken() callback ("tflags") should
12293** normally be set to 0. The exception is if the tokenizer supports
12294** synonyms. In this case see the discussion below for details.
12295**
12296** FTS5 assumes the xToken() callback is invoked for each token in the
12297** order that they occur within the input text.
12298**
12299** If an xToken() callback returns any value other than SQLITE_OK, then
12300** the tokenization should be abandoned and the xTokenize() method should
12301** immediately return a copy of the xToken() return value. Or, if the
12302** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
12303** if an error occurs with the xTokenize() implementation itself, it
12304** may abandon the tokenization and return any error code other than
12305** SQLITE_OK or SQLITE_DONE.
12306**
12307** SYNONYM SUPPORT
12308**
12309** Custom tokenizers may also support synonyms. Consider a case in which a
12310** user wishes to query for a phrase such as "first place". Using the
12311** built-in tokenizers, the FTS5 query 'first + place' will match instances
12312** of "first place" within the document set, but not alternative forms
12313** such as "1st place". In some applications, it would be better to match
12314** all instances of "first place" or "1st place" regardless of which form
12315** the user specified in the MATCH query text.
12316**
12317** There are several ways to approach this in FTS5:
12318**
12319** <ol><li> By mapping all synonyms to a single token. In this case, using
12320** the above example, this means that the tokenizer returns the
12321** same token for inputs "first" and "1st". Say that token is in
12322** fact "first", so that when the user inserts the document "I won
12323** 1st place" entries are added to the index for tokens "i", "won",
12324** "first" and "place". If the user then queries for '1st + place',
12325** the tokenizer substitutes "first" for "1st" and the query works
12326** as expected.
12327**
12328** <li> By querying the index for all synonyms of each query term
12329** separately. In this case, when tokenizing query text, the
12330** tokenizer may provide multiple synonyms for a single term
12331** within the document. FTS5 then queries the index for each
12332** synonym individually. For example, faced with the query:
12333**
12334** <codeblock>
12335** ... MATCH 'first place'</codeblock>
12336**
12337** the tokenizer offers both "1st" and "first" as synonyms for the
12338** first token in the MATCH query and FTS5 effectively runs a query
12339** similar to:
12340**
12341** <codeblock>
12342** ... MATCH '(first OR 1st) place'</codeblock>
12343**
12344** except that, for the purposes of auxiliary functions, the query
12345** still appears to contain just two phrases - "(first OR 1st)"
12346** being treated as a single phrase.
12347**
12348** <li> By adding multiple synonyms for a single term to the FTS index.
12349** Using this method, when tokenizing document text, the tokenizer
12350** provides multiple synonyms for each token. So that when a
12351** document such as "I won first place" is tokenized, entries are
12352** added to the FTS index for "i", "won", "first", "1st" and
12353** "place".
12354**
12355** This way, even if the tokenizer does not provide synonyms
12356** when tokenizing query text (it should not - to do so would be
12357** inefficient), it doesn't matter if the user queries for
12358** 'first + place' or '1st + place', as there are entries in the
12359** FTS index corresponding to both forms of the first token.
12360** </ol>
12361**
12362** Whether it is parsing document or query text, any call to xToken that
12363** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12364** is considered to supply a synonym for the previous token. For example,
12365** when parsing the document "I won first place", a tokenizer that supports
12366** synonyms would call xToken() 5 times, as follows:
12367**
12368** <codeblock>
12369** xToken(pCtx, 0, "i", 1, 0, 1);
12370** xToken(pCtx, 0, "won", 3, 2, 5);
12371** xToken(pCtx, 0, "first", 5, 6, 11);
12372** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
12373** xToken(pCtx, 0, "place", 5, 12, 17);
12374**</codeblock>
12375**
12376** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
12377** xToken() is called. Multiple synonyms may be specified for a single token
12378** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
12379** There is no limit to the number of synonyms that may be provided for a
12380** single token.
12381**
12382** In many cases, method (1) above is the best approach. It does not add
12383** extra data to the FTS index or require FTS5 to query for multiple terms,
12384** so it is efficient in terms of disk space and query speed. However, it
12385** does not support prefix queries very well. If, as suggested above, the
12386** token "first" is substituted for "1st" by the tokenizer, then the query:
12387**
12388** <codeblock>
12389** ... MATCH '1s*'</codeblock>
12390**
12391** will not match documents that contain the token "1st" (as the tokenizer
12392** will probably not map "1s" to any prefix of "first").
12393**
12394** For full prefix support, method (3) may be preferred. In this case,
12395** because the index contains entries for both "first" and "1st", prefix
12396** queries such as 'fi*' or '1s*' will match correctly. However, because
12397** extra entries are added to the FTS index, this method uses more space
12398** within the database.
12399**
12400** Method (2) offers a midpoint between (1) and (3). Using this method,
12401** a query such as '1s*' will match documents that contain the literal
12402** token "1st", but not "first" (assuming the tokenizer is not able to
12403** provide synonyms for prefixes). However, a non-prefix query like '1st'
12404** will match against "1st" and "first". This method does not require
12405** extra disk space, as no extra entries are added to the FTS index.
12406** On the other hand, it may require more CPU cycles to run MATCH queries,
12407** as separate queries of the FTS index are required for each synonym.
12408**
12409** When using methods (2) or (3), it is important that the tokenizer only
12410** provide synonyms when tokenizing document text (method (2)) or query
12411** text (method (3)), not both. Doing so will not cause any errors, but is
12412** inefficient.
12413*/
12414typedef struct Fts5Tokenizer Fts5Tokenizer;
12415typedef struct fts5_tokenizer fts5_tokenizer;
12416struct fts5_tokenizer {
12417 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
12418 void (*xDelete)(Fts5Tokenizer*);
12419 int (*xTokenize)(Fts5Tokenizer*,
12420 void *pCtx,
12421 int flags, /* Mask of FTS5_TOKENIZE_* flags */
12422 const char *pText, int nText,
12423 int (*xToken)(
12424 void *pCtx, /* Copy of 2nd argument to xTokenize() */
12425 int tflags, /* Mask of FTS5_TOKEN_* flags */
12426 const char *pToken, /* Pointer to buffer containing token */
12427 int nToken, /* Size of token in bytes */
12428 int iStart, /* Byte offset of token within input text */
12429 int iEnd /* Byte offset of end of token within input text */
12430 )
12431 );
12432};
12433
12434/* Flags that may be passed as the third argument to xTokenize() */
12435#define FTS5_TOKENIZE_QUERY 0x0001
12436#define FTS5_TOKENIZE_PREFIX 0x0002
12437#define FTS5_TOKENIZE_DOCUMENT 0x0004
12438#define FTS5_TOKENIZE_AUX 0x0008
12439
12440/* Flags that may be passed by the tokenizer implementation back to FTS5
12441** as the third argument to the supplied xToken callback. */
12442#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
12443
12444/*
12445** END OF CUSTOM TOKENIZERS
12446*************************************************************************/
12447
12448/*************************************************************************
12449** FTS5 EXTENSION REGISTRATION API
12450*/
12451typedef struct fts5_api fts5_api;
12452struct fts5_api {
12453 int iVersion; /* Currently always set to 2 */
12454
12455 /* Create a new tokenizer */
12456 int (*xCreateTokenizer)(
12457 fts5_api *pApi,
12458 const char *zName,
12459 void *pContext,
12460 fts5_tokenizer *pTokenizer,
12461 void (*xDestroy)(void*)
12462 );
12463
12464 /* Find an existing tokenizer */
12465 int (*xFindTokenizer)(
12466 fts5_api *pApi,
12467 const char *zName,
12468 void **ppContext,
12469 fts5_tokenizer *pTokenizer
12470 );
12471
12472 /* Create a new auxiliary function */
12473 int (*xCreateFunction)(
12474 fts5_api *pApi,
12475 const char *zName,
12476 void *pContext,
12477 fts5_extension_function xFunction,
12478 void (*xDestroy)(void*)
12479 );
12480};
12481
12482/*
12483** END OF REGISTRATION API
12484*************************************************************************/
12485
12486#ifdef __cplusplus
12487} /* end of the 'extern "C"' block */
12488#endif
12489
12490#endif /* _FTS5_H */
12491
12492/******** End of fts5.h *********/
12493

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