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** Provide the ability to override linkage features of the interface.
47*/
48#ifndef SQLITE_EXTERN
49# define SQLITE_EXTERN extern
50#endif
51#ifndef SQLITE_API
52# define SQLITE_API
53#endif
54#ifndef SQLITE_CDECL
55# define SQLITE_CDECL
56#endif
57#ifndef SQLITE_APICALL
58# define SQLITE_APICALL
59#endif
60#ifndef SQLITE_STDCALL
61# define SQLITE_STDCALL SQLITE_APICALL
62#endif
63#ifndef SQLITE_CALLBACK
64# define SQLITE_CALLBACK
65#endif
66#ifndef SQLITE_SYSAPI
67# define SQLITE_SYSAPI
68#endif
69
70/*
71** These no-op macros are used in front of interfaces to mark those
72** interfaces as either deprecated or experimental. New applications
73** should not use deprecated interfaces - they are supported for backwards
74** compatibility only. Application writers should be aware that
75** experimental interfaces are subject to change in point releases.
76**
77** These macros used to resolve to various kinds of compiler magic that
78** would generate warning messages when they were used. But that
79** compiler magic ended up generating such a flurry of bug reports
80** that we have taken it all out and gone back to using simple
81** noop macros.
82*/
83#define SQLITE_DEPRECATED
84#define SQLITE_EXPERIMENTAL
85
86/*
87** Ensure these symbols were not defined by some previous header file.
88*/
89#ifdef SQLITE_VERSION
90# undef SQLITE_VERSION
91#endif
92#ifdef SQLITE_VERSION_NUMBER
93# undef SQLITE_VERSION_NUMBER
94#endif
95
96/*
97** CAPI3REF: Compile-Time Library Version Numbers
98**
99** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
100** evaluates to a string literal that is the SQLite version in the
101** format "X.Y.Z" where X is the major version number (always 3 for
102** SQLite3) and Y is the minor version number and Z is the release number.)^
103** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
104** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
105** numbers used in [SQLITE_VERSION].)^
106** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
107** be larger than the release from which it is derived. Either Y will
108** be held constant and Z will be incremented or else Y will be incremented
109** and Z will be reset to zero.
110**
111** Since [version 3.6.18] ([dateof:3.6.18]),
112** SQLite source code has been stored in the
113** <a href="http://www.fossil-scm.org/">Fossil configuration management
114** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
115** a string which identifies a particular check-in of SQLite
116** within its configuration management system. ^The SQLITE_SOURCE_ID
117** string contains the date and time of the check-in (UTC) and a SHA1
118** or SHA3-256 hash of the entire source tree. If the source code has
119** been edited in any way since it was last checked in, then the last
120** four hexadecimal digits of the hash may be modified.
121**
122** See also: [sqlite3_libversion()],
123** [sqlite3_libversion_number()], [sqlite3_sourceid()],
124** [sqlite_version()] and [sqlite_source_id()].
125*/
126#define SQLITE_VERSION "3.26.0"
127#define SQLITE_VERSION_NUMBER 3026000
128#define SQLITE_SOURCE_ID "2018-12-01 12:34:55 bf8c1b2b7a5960c282e543b9c293686dccff272512d08865f4600fb58238b4f9"
129
130/*
131** CAPI3REF: Run-Time Library Version Numbers
132** KEYWORDS: sqlite3_version sqlite3_sourceid
133**
134** These interfaces provide the same information as the [SQLITE_VERSION],
135** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
136** but are associated with the library instead of the header file. ^(Cautious
137** programmers might include assert() statements in their application to
138** verify that values returned by these interfaces match the macros in
139** the header, and thus ensure that the application is
140** compiled with matching library and header files.
141**
142** <blockquote><pre>
143** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
144** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
145** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
146** </pre></blockquote>)^
147**
148** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
149** macro. ^The sqlite3_libversion() function returns a pointer to the
150** to the sqlite3_version[] string constant. The sqlite3_libversion()
151** function is provided for use in DLLs since DLL users usually do not have
152** direct access to string constants within the DLL. ^The
153** sqlite3_libversion_number() function returns an integer equal to
154** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
155** a pointer to a string constant whose value is the same as the
156** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
157** using an edited copy of [the amalgamation], then the last four characters
158** of the hash might be different from [SQLITE_SOURCE_ID].)^
159**
160** See also: [sqlite_version()] and [sqlite_source_id()].
161*/
162SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
163SQLITE_API const char *sqlite3_libversion(void);
164SQLITE_API const char *sqlite3_sourceid(void);
165SQLITE_API int sqlite3_libversion_number(void);
166
167/*
168** CAPI3REF: Run-Time Library Compilation Options Diagnostics
169**
170** ^The sqlite3_compileoption_used() function returns 0 or 1
171** indicating whether the specified option was defined at
172** compile time. ^The SQLITE_ prefix may be omitted from the
173** option name passed to sqlite3_compileoption_used().
174**
175** ^The sqlite3_compileoption_get() function allows iterating
176** over the list of options that were defined at compile time by
177** returning the N-th compile time option string. ^If N is out of range,
178** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
179** prefix is omitted from any strings returned by
180** sqlite3_compileoption_get().
181**
182** ^Support for the diagnostic functions sqlite3_compileoption_used()
183** and sqlite3_compileoption_get() may be omitted by specifying the
184** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
185**
186** See also: SQL functions [sqlite_compileoption_used()] and
187** [sqlite_compileoption_get()] and the [compile_options pragma].
188*/
189#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
190SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
191SQLITE_API const char *sqlite3_compileoption_get(int N);
192#endif
193
194/*
195** CAPI3REF: Test To See If The Library Is Threadsafe
196**
197** ^The sqlite3_threadsafe() function returns zero if and only if
198** SQLite was compiled with mutexing code omitted due to the
199** [SQLITE_THREADSAFE] compile-time option being set to 0.
200**
201** SQLite can be compiled with or without mutexes. When
202** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
203** are enabled and SQLite is threadsafe. When the
204** [SQLITE_THREADSAFE] macro is 0,
205** the mutexes are omitted. Without the mutexes, it is not safe
206** to use SQLite concurrently from more than one thread.
207**
208** Enabling mutexes incurs a measurable performance penalty.
209** So if speed is of utmost importance, it makes sense to disable
210** the mutexes. But for maximum safety, mutexes should be enabled.
211** ^The default behavior is for mutexes to be enabled.
212**
213** This interface can be used by an application to make sure that the
214** version of SQLite that it is linking against was compiled with
215** the desired setting of the [SQLITE_THREADSAFE] macro.
216**
217** This interface only reports on the compile-time mutex setting
218** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
219** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
220** can be fully or partially disabled using a call to [sqlite3_config()]
221** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
222** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
223** sqlite3_threadsafe() function shows only the compile-time setting of
224** thread safety, not any run-time changes to that setting made by
225** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
226** is unchanged by calls to sqlite3_config().)^
227**
228** See the [threading mode] documentation for additional information.
229*/
230SQLITE_API int sqlite3_threadsafe(void);
231
232/*
233** CAPI3REF: Database Connection Handle
234** KEYWORDS: {database connection} {database connections}
235**
236** Each open SQLite database is represented by a pointer to an instance of
237** the opaque structure named "sqlite3". It is useful to think of an sqlite3
238** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
239** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
240** and [sqlite3_close_v2()] are its destructors. There are many other
241** interfaces (such as
242** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
243** [sqlite3_busy_timeout()] to name but three) that are methods on an
244** sqlite3 object.
245*/
246typedef struct sqlite3 sqlite3;
247
248/*
249** CAPI3REF: 64-Bit Integer Types
250** KEYWORDS: sqlite_int64 sqlite_uint64
251**
252** Because there is no cross-platform way to specify 64-bit integer types
253** SQLite includes typedefs for 64-bit signed and unsigned integers.
254**
255** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
256** The sqlite_int64 and sqlite_uint64 types are supported for backwards
257** compatibility only.
258**
259** ^The sqlite3_int64 and sqlite_int64 types can store integer values
260** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
261** sqlite3_uint64 and sqlite_uint64 types can store integer values
262** between 0 and +18446744073709551615 inclusive.
263*/
264#ifdef SQLITE_INT64_TYPE
265 typedef SQLITE_INT64_TYPE sqlite_int64;
266# ifdef SQLITE_UINT64_TYPE
267 typedef SQLITE_UINT64_TYPE sqlite_uint64;
268# else
269 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
270# endif
271#elif defined(_MSC_VER) || defined(__BORLANDC__)
272 typedef __int64 sqlite_int64;
273 typedef unsigned __int64 sqlite_uint64;
274#else
275 typedef long long int sqlite_int64;
276 typedef unsigned long long int sqlite_uint64;
277#endif
278typedef sqlite_int64 sqlite3_int64;
279typedef sqlite_uint64 sqlite3_uint64;
280
281/*
282** If compiling for a processor that lacks floating point support,
283** substitute integer for floating-point.
284*/
285#ifdef SQLITE_OMIT_FLOATING_POINT
286# define double sqlite3_int64
287#endif
288
289/*
290** CAPI3REF: Closing A Database Connection
291** DESTRUCTOR: sqlite3
292**
293** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
294** for the [sqlite3] object.
295** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
296** the [sqlite3] object is successfully destroyed and all associated
297** resources are deallocated.
298**
299** ^If the database connection is associated with unfinalized prepared
300** statements or unfinished sqlite3_backup objects then sqlite3_close()
301** will leave the database connection open and return [SQLITE_BUSY].
302** ^If sqlite3_close_v2() is called with unfinalized prepared statements
303** and/or unfinished sqlite3_backups, then the database connection becomes
304** an unusable "zombie" which will automatically be deallocated when the
305** last prepared statement is finalized or the last sqlite3_backup is
306** finished. The sqlite3_close_v2() interface is intended for use with
307** host languages that are garbage collected, and where the order in which
308** destructors are called is arbitrary.
309**
310** Applications should [sqlite3_finalize | finalize] all [prepared statements],
311** [sqlite3_blob_close | close] all [BLOB handles], and
312** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
313** with the [sqlite3] object prior to attempting to close the object. ^If
314** sqlite3_close_v2() is called on a [database connection] that still has
315** outstanding [prepared statements], [BLOB handles], and/or
316** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
317** of resources is deferred until all [prepared statements], [BLOB handles],
318** and [sqlite3_backup] objects are also destroyed.
319**
320** ^If an [sqlite3] object is destroyed while a transaction is open,
321** the transaction is automatically rolled back.
322**
323** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
324** must be either a NULL
325** pointer or an [sqlite3] object pointer obtained
326** from [sqlite3_open()], [sqlite3_open16()], or
327** [sqlite3_open_v2()], and not previously closed.
328** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
329** argument is a harmless no-op.
330*/
331SQLITE_API int sqlite3_close(sqlite3*);
332SQLITE_API int sqlite3_close_v2(sqlite3*);
333
334/*
335** The type for a callback function.
336** This is legacy and deprecated. It is included for historical
337** compatibility and is not documented.
338*/
339typedef int (*sqlite3_callback)(void*,int,char**, char**);
340
341/*
342** CAPI3REF: One-Step Query Execution Interface
343** METHOD: sqlite3
344**
345** The sqlite3_exec() interface is a convenience wrapper around
346** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
347** that allows an application to run multiple statements of SQL
348** without having to use a lot of C code.
349**
350** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
351** semicolon-separate SQL statements passed into its 2nd argument,
352** in the context of the [database connection] passed in as its 1st
353** argument. ^If the callback function of the 3rd argument to
354** sqlite3_exec() is not NULL, then it is invoked for each result row
355** coming out of the evaluated SQL statements. ^The 4th argument to
356** sqlite3_exec() is relayed through to the 1st argument of each
357** callback invocation. ^If the callback pointer to sqlite3_exec()
358** is NULL, then no callback is ever invoked and result rows are
359** ignored.
360**
361** ^If an error occurs while evaluating the SQL statements passed into
362** sqlite3_exec(), then execution of the current statement stops and
363** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
364** is not NULL then any error message is written into memory obtained
365** from [sqlite3_malloc()] and passed back through the 5th parameter.
366** To avoid memory leaks, the application should invoke [sqlite3_free()]
367** on error message strings returned through the 5th parameter of
368** sqlite3_exec() after the error message string is no longer needed.
369** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
370** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
371** NULL before returning.
372**
373** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
374** routine returns SQLITE_ABORT without invoking the callback again and
375** without running any subsequent SQL statements.
376**
377** ^The 2nd argument to the sqlite3_exec() callback function is the
378** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
379** callback is an array of pointers to strings obtained as if from
380** [sqlite3_column_text()], one for each column. ^If an element of a
381** result row is NULL then the corresponding string pointer for the
382** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
383** sqlite3_exec() callback is an array of pointers to strings where each
384** entry represents the name of corresponding result column as obtained
385** from [sqlite3_column_name()].
386**
387** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
388** to an empty string, or a pointer that contains only whitespace and/or
389** SQL comments, then no SQL statements are evaluated and the database
390** is not changed.
391**
392** Restrictions:
393**
394** <ul>
395** <li> The application must ensure that the 1st parameter to sqlite3_exec()
396** is a valid and open [database connection].
397** <li> The application must not close the [database connection] specified by
398** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
399** <li> The application must not modify the SQL statement text passed into
400** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
401** </ul>
402*/
403SQLITE_API int sqlite3_exec(
404 sqlite3*, /* An open database */
405 const char *sql, /* SQL to be evaluated */
406 int (*callback)(void*,int,char**,char**), /* Callback function */
407 void *, /* 1st argument to callback */
408 char **errmsg /* Error msg written here */
409);
410
411/*
412** CAPI3REF: Result Codes
413** KEYWORDS: {result code definitions}
414**
415** Many SQLite functions return an integer result code from the set shown
416** here in order to indicate success or failure.
417**
418** New error codes may be added in future versions of SQLite.
419**
420** See also: [extended result code definitions]
421*/
422#define SQLITE_OK 0 /* Successful result */
423/* beginning-of-error-codes */
424#define SQLITE_ERROR 1 /* Generic error */
425#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
426#define SQLITE_PERM 3 /* Access permission denied */
427#define SQLITE_ABORT 4 /* Callback routine requested an abort */
428#define SQLITE_BUSY 5 /* The database file is locked */
429#define SQLITE_LOCKED 6 /* A table in the database is locked */
430#define SQLITE_NOMEM 7 /* A malloc() failed */
431#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
432#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
433#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
434#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
435#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
436#define SQLITE_FULL 13 /* Insertion failed because database is full */
437#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
438#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
439#define SQLITE_EMPTY 16 /* Internal use only */
440#define SQLITE_SCHEMA 17 /* The database schema changed */
441#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
442#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
443#define SQLITE_MISMATCH 20 /* Data type mismatch */
444#define SQLITE_MISUSE 21 /* Library used incorrectly */
445#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
446#define SQLITE_AUTH 23 /* Authorization denied */
447#define SQLITE_FORMAT 24 /* Not used */
448#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
449#define SQLITE_NOTADB 26 /* File opened that is not a database file */
450#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
451#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
452#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
453#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
454/* end-of-error-codes */
455
456/*
457** CAPI3REF: Extended Result Codes
458** KEYWORDS: {extended result code definitions}
459**
460** In its default configuration, SQLite API routines return one of 30 integer
461** [result codes]. However, experience has shown that many of
462** these result codes are too coarse-grained. They do not provide as
463** much information about problems as programmers might like. In an effort to
464** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
465** and later) include
466** support for additional result codes that provide more detailed information
467** about errors. These [extended result codes] are enabled or disabled
468** on a per database connection basis using the
469** [sqlite3_extended_result_codes()] API. Or, the extended code for
470** the most recent error can be obtained using
471** [sqlite3_extended_errcode()].
472*/
473#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
474#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
475#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
476#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
477#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
478#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
479#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
480#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
481#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
482#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
483#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
484#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
485#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
486#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
487#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
488#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
489#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
490#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
491#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
492#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
493#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
494#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
495#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
496#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
497#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
498#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
499#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
500#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
501#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
502#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
503#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
504#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
505#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
506#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
507#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
508#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
509#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
510#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
511#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
512#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
513#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
514#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
515#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
516#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
517#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
518#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
519#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
520#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
521#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
522#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
523#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
524#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
525#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
526#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
527#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
528#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
529#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
530#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
531#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
532#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
533#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
534#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
535#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
536#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
537#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
538#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
539#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
540
541/*
542** CAPI3REF: Flags For File Open Operations
543**
544** These bit values are intended for use in the
545** 3rd parameter to the [sqlite3_open_v2()] interface and
546** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
547*/
548#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
549#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
550#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
551#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
552#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
553#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
554#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
555#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
556#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
557#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
558#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
559#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
560#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
561#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
562#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
563#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
564#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
565#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
566#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
567#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
568
569/* Reserved: 0x00F00000 */
570
571/*
572** CAPI3REF: Device Characteristics
573**
574** The xDeviceCharacteristics method of the [sqlite3_io_methods]
575** object returns an integer which is a vector of these
576** bit values expressing I/O characteristics of the mass storage
577** device that holds the file that the [sqlite3_io_methods]
578** refers to.
579**
580** The SQLITE_IOCAP_ATOMIC property means that all writes of
581** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
582** mean that writes of blocks that are nnn bytes in size and
583** are aligned to an address which is an integer multiple of
584** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
585** that when data is appended to a file, the data is appended
586** first then the size of the file is extended, never the other
587** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
588** information is written to disk in the same order as calls
589** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
590** after reboot following a crash or power loss, the only bytes in a
591** file that were written at the application level might have changed
592** and that adjacent bytes, even bytes within the same sector are
593** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
594** flag indicates that a file cannot be deleted when open. The
595** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
596** read-only media and cannot be changed even by processes with
597** elevated privileges.
598**
599** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
600** filesystem supports doing multiple write operations atomically when those
601** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
602** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
603*/
604#define SQLITE_IOCAP_ATOMIC 0x00000001
605#define SQLITE_IOCAP_ATOMIC512 0x00000002
606#define SQLITE_IOCAP_ATOMIC1K 0x00000004
607#define SQLITE_IOCAP_ATOMIC2K 0x00000008
608#define SQLITE_IOCAP_ATOMIC4K 0x00000010
609#define SQLITE_IOCAP_ATOMIC8K 0x00000020
610#define SQLITE_IOCAP_ATOMIC16K 0x00000040
611#define SQLITE_IOCAP_ATOMIC32K 0x00000080
612#define SQLITE_IOCAP_ATOMIC64K 0x00000100
613#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
614#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
615#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
616#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
617#define SQLITE_IOCAP_IMMUTABLE 0x00002000
618#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
619
620/*
621** CAPI3REF: File Locking Levels
622**
623** SQLite uses one of these integer values as the second
624** argument to calls it makes to the xLock() and xUnlock() methods
625** of an [sqlite3_io_methods] object.
626*/
627#define SQLITE_LOCK_NONE 0
628#define SQLITE_LOCK_SHARED 1
629#define SQLITE_LOCK_RESERVED 2
630#define SQLITE_LOCK_PENDING 3
631#define SQLITE_LOCK_EXCLUSIVE 4
632
633/*
634** CAPI3REF: Synchronization Type Flags
635**
636** When SQLite invokes the xSync() method of an
637** [sqlite3_io_methods] object it uses a combination of
638** these integer values as the second argument.
639**
640** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
641** sync operation only needs to flush data to mass storage. Inode
642** information need not be flushed. If the lower four bits of the flag
643** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
644** If the lower four bits equal SQLITE_SYNC_FULL, that means
645** to use Mac OS X style fullsync instead of fsync().
646**
647** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
648** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
649** settings. The [synchronous pragma] determines when calls to the
650** xSync VFS method occur and applies uniformly across all platforms.
651** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
652** energetic or rigorous or forceful the sync operations are and
653** only make a difference on Mac OSX for the default SQLite code.
654** (Third-party VFS implementations might also make the distinction
655** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
656** operating systems natively supported by SQLite, only Mac OSX
657** cares about the difference.)
658*/
659#define SQLITE_SYNC_NORMAL 0x00002
660#define SQLITE_SYNC_FULL 0x00003
661#define SQLITE_SYNC_DATAONLY 0x00010
662
663/*
664** CAPI3REF: OS Interface Open File Handle
665**
666** An [sqlite3_file] object represents an open file in the
667** [sqlite3_vfs | OS interface layer]. Individual OS interface
668** implementations will
669** want to subclass this object by appending additional fields
670** for their own use. The pMethods entry is a pointer to an
671** [sqlite3_io_methods] object that defines methods for performing
672** I/O operations on the open file.
673*/
674typedef struct sqlite3_file sqlite3_file;
675struct sqlite3_file {
676 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
677};
678
679/*
680** CAPI3REF: OS Interface File Virtual Methods Object
681**
682** Every file opened by the [sqlite3_vfs.xOpen] method populates an
683** [sqlite3_file] object (or, more commonly, a subclass of the
684** [sqlite3_file] object) with a pointer to an instance of this object.
685** This object defines the methods used to perform various operations
686** against the open file represented by the [sqlite3_file] object.
687**
688** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
689** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
690** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
691** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
692** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
693** to NULL.
694**
695** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
696** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
697** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
698** flag may be ORed in to indicate that only the data of the file
699** and not its inode needs to be synced.
700**
701** The integer values to xLock() and xUnlock() are one of
702** <ul>
703** <li> [SQLITE_LOCK_NONE],
704** <li> [SQLITE_LOCK_SHARED],
705** <li> [SQLITE_LOCK_RESERVED],
706** <li> [SQLITE_LOCK_PENDING], or
707** <li> [SQLITE_LOCK_EXCLUSIVE].
708** </ul>
709** xLock() increases the lock. xUnlock() decreases the lock.
710** The xCheckReservedLock() method checks whether any database connection,
711** either in this process or in some other process, is holding a RESERVED,
712** PENDING, or EXCLUSIVE lock on the file. It returns true
713** if such a lock exists and false otherwise.
714**
715** The xFileControl() method is a generic interface that allows custom
716** VFS implementations to directly control an open file using the
717** [sqlite3_file_control()] interface. The second "op" argument is an
718** integer opcode. The third argument is a generic pointer intended to
719** point to a structure that may contain arguments or space in which to
720** write return values. Potential uses for xFileControl() might be
721** functions to enable blocking locks with timeouts, to change the
722** locking strategy (for example to use dot-file locks), to inquire
723** about the status of a lock, or to break stale locks. The SQLite
724** core reserves all opcodes less than 100 for its own use.
725** A [file control opcodes | list of opcodes] less than 100 is available.
726** Applications that define a custom xFileControl method should use opcodes
727** greater than 100 to avoid conflicts. VFS implementations should
728** return [SQLITE_NOTFOUND] for file control opcodes that they do not
729** recognize.
730**
731** The xSectorSize() method returns the sector size of the
732** device that underlies the file. The sector size is the
733** minimum write that can be performed without disturbing
734** other bytes in the file. The xDeviceCharacteristics()
735** method returns a bit vector describing behaviors of the
736** underlying device:
737**
738** <ul>
739** <li> [SQLITE_IOCAP_ATOMIC]
740** <li> [SQLITE_IOCAP_ATOMIC512]
741** <li> [SQLITE_IOCAP_ATOMIC1K]
742** <li> [SQLITE_IOCAP_ATOMIC2K]
743** <li> [SQLITE_IOCAP_ATOMIC4K]
744** <li> [SQLITE_IOCAP_ATOMIC8K]
745** <li> [SQLITE_IOCAP_ATOMIC16K]
746** <li> [SQLITE_IOCAP_ATOMIC32K]
747** <li> [SQLITE_IOCAP_ATOMIC64K]
748** <li> [SQLITE_IOCAP_SAFE_APPEND]
749** <li> [SQLITE_IOCAP_SEQUENTIAL]
750** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
751** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
752** <li> [SQLITE_IOCAP_IMMUTABLE]
753** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
754** </ul>
755**
756** The SQLITE_IOCAP_ATOMIC property means that all writes of
757** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
758** mean that writes of blocks that are nnn bytes in size and
759** are aligned to an address which is an integer multiple of
760** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
761** that when data is appended to a file, the data is appended
762** first then the size of the file is extended, never the other
763** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
764** information is written to disk in the same order as calls
765** to xWrite().
766**
767** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
768** in the unread portions of the buffer with zeros. A VFS that
769** fails to zero-fill short reads might seem to work. However,
770** failure to zero-fill short reads will eventually lead to
771** database corruption.
772*/
773typedef struct sqlite3_io_methods sqlite3_io_methods;
774struct sqlite3_io_methods {
775 int iVersion;
776 int (*xClose)(sqlite3_file*);
777 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
778 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
779 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
780 int (*xSync)(sqlite3_file*, int flags);
781 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
782 int (*xLock)(sqlite3_file*, int);
783 int (*xUnlock)(sqlite3_file*, int);
784 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
785 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
786 int (*xSectorSize)(sqlite3_file*);
787 int (*xDeviceCharacteristics)(sqlite3_file*);
788 /* Methods above are valid for version 1 */
789 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
790 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
791 void (*xShmBarrier)(sqlite3_file*);
792 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
793 /* Methods above are valid for version 2 */
794 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
795 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
796 /* Methods above are valid for version 3 */
797 /* Additional methods may be added in future releases */
798};
799
800/*
801** CAPI3REF: Standard File Control Opcodes
802** KEYWORDS: {file control opcodes} {file control opcode}
803**
804** These integer constants are opcodes for the xFileControl method
805** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
806** interface.
807**
808** <ul>
809** <li>[[SQLITE_FCNTL_LOCKSTATE]]
810** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
811** opcode causes the xFileControl method to write the current state of
812** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
813** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
814** into an integer that the pArg argument points to. This capability
815** is used during testing and is only available when the SQLITE_TEST
816** compile-time option is used.
817**
818** <li>[[SQLITE_FCNTL_SIZE_HINT]]
819** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
820** layer a hint of how large the database file will grow to be during the
821** current transaction. This hint is not guaranteed to be accurate but it
822** is often close. The underlying VFS might choose to preallocate database
823** file space based on this hint in order to help writes to the database
824** file run faster.
825**
826** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
827** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
828** extends and truncates the database file in chunks of a size specified
829** by the user. The fourth argument to [sqlite3_file_control()] should
830** point to an integer (type int) containing the new chunk-size to use
831** for the nominated database. Allocating database file space in large
832** chunks (say 1MB at a time), may reduce file-system fragmentation and
833** improve performance on some systems.
834**
835** <li>[[SQLITE_FCNTL_FILE_POINTER]]
836** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
837** to the [sqlite3_file] object associated with a particular database
838** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
839**
840** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
841** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
842** to the [sqlite3_file] object associated with the journal file (either
843** the [rollback journal] or the [write-ahead log]) for a particular database
844** connection. See also [SQLITE_FCNTL_FILE_POINTER].
845**
846** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
847** No longer in use.
848**
849** <li>[[SQLITE_FCNTL_SYNC]]
850** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
851** sent to the VFS immediately before the xSync method is invoked on a
852** database file descriptor. Or, if the xSync method is not invoked
853** because the user has configured SQLite with
854** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
855** of the xSync method. In most cases, the pointer argument passed with
856** this file-control is NULL. However, if the database file is being synced
857** as part of a multi-database commit, the argument points to a nul-terminated
858** string containing the transactions master-journal file name. VFSes that
859** do not need this signal should silently ignore this opcode. Applications
860** should not call [sqlite3_file_control()] with this opcode as doing so may
861** disrupt the operation of the specialized VFSes that do require it.
862**
863** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
864** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
865** and sent to the VFS after a transaction has been committed immediately
866** but before the database is unlocked. VFSes that do not need this signal
867** should silently ignore this opcode. Applications should not call
868** [sqlite3_file_control()] with this opcode as doing so may disrupt the
869** operation of the specialized VFSes that do require it.
870**
871** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
872** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
873** retry counts and intervals for certain disk I/O operations for the
874** windows [VFS] in order to provide robustness in the presence of
875** anti-virus programs. By default, the windows VFS will retry file read,
876** file write, and file delete operations up to 10 times, with a delay
877** of 25 milliseconds before the first retry and with the delay increasing
878** by an additional 25 milliseconds with each subsequent retry. This
879** opcode allows these two values (10 retries and 25 milliseconds of delay)
880** to be adjusted. The values are changed for all database connections
881** within the same process. The argument is a pointer to an array of two
882** integers where the first integer is the new retry count and the second
883** integer is the delay. If either integer is negative, then the setting
884** is not changed but instead the prior value of that setting is written
885** into the array entry, allowing the current retry settings to be
886** interrogated. The zDbName parameter is ignored.
887**
888** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
889** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
890** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
891** write ahead log ([WAL file]) and shared memory
892** files used for transaction control
893** are automatically deleted when the latest connection to the database
894** closes. Setting persistent WAL mode causes those files to persist after
895** close. Persisting the files is useful when other processes that do not
896** have write permission on the directory containing the database file want
897** to read the database file, as the WAL and shared memory files must exist
898** in order for the database to be readable. The fourth parameter to
899** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
900** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
901** WAL mode. If the integer is -1, then it is overwritten with the current
902** WAL persistence setting.
903**
904** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
905** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
906** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
907** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
908** xDeviceCharacteristics methods. The fourth parameter to
909** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
910** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
911** mode. If the integer is -1, then it is overwritten with the current
912** zero-damage mode setting.
913**
914** <li>[[SQLITE_FCNTL_OVERWRITE]]
915** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
916** a write transaction to indicate that, unless it is rolled back for some
917** reason, the entire database file will be overwritten by the current
918** transaction. This is used by VACUUM operations.
919**
920** <li>[[SQLITE_FCNTL_VFSNAME]]
921** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
922** all [VFSes] in the VFS stack. The names are of all VFS shims and the
923** final bottom-level VFS are written into memory obtained from
924** [sqlite3_malloc()] and the result is stored in the char* variable
925** that the fourth parameter of [sqlite3_file_control()] points to.
926** The caller is responsible for freeing the memory when done. As with
927** all file-control actions, there is no guarantee that this will actually
928** do anything. Callers should initialize the char* variable to a NULL
929** pointer in case this file-control is not implemented. This file-control
930** is intended for diagnostic use only.
931**
932** <li>[[SQLITE_FCNTL_VFS_POINTER]]
933** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
934** [VFSes] currently in use. ^(The argument X in
935** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
936** of type "[sqlite3_vfs] **". This opcodes will set *X
937** to a pointer to the top-level VFS.)^
938** ^When there are multiple VFS shims in the stack, this opcode finds the
939** upper-most shim only.
940**
941** <li>[[SQLITE_FCNTL_PRAGMA]]
942** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
943** file control is sent to the open [sqlite3_file] object corresponding
944** to the database file to which the pragma statement refers. ^The argument
945** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
946** pointers to strings (char**) in which the second element of the array
947** is the name of the pragma and the third element is the argument to the
948** pragma or NULL if the pragma has no argument. ^The handler for an
949** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
950** of the char** argument point to a string obtained from [sqlite3_mprintf()]
951** or the equivalent and that string will become the result of the pragma or
952** the error message if the pragma fails. ^If the
953** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
954** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
955** file control returns [SQLITE_OK], then the parser assumes that the
956** VFS has handled the PRAGMA itself and the parser generates a no-op
957** prepared statement if result string is NULL, or that returns a copy
958** of the result string if the string is non-NULL.
959** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
960** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
961** that the VFS encountered an error while handling the [PRAGMA] and the
962** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
963** file control occurs at the beginning of pragma statement analysis and so
964** it is able to override built-in [PRAGMA] statements.
965**
966** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
967** ^The [SQLITE_FCNTL_BUSYHANDLER]
968** file-control may be invoked by SQLite on the database file handle
969** shortly after it is opened in order to provide a custom VFS with access
970** to the connections busy-handler callback. The argument is of type (void **)
971** - an array of two (void *) values. The first (void *) actually points
972** to a function of type (int (*)(void *)). In order to invoke the connections
973** busy-handler, this function should be invoked with the second (void *) in
974** the array as the only argument. If it returns non-zero, then the operation
975** should be retried. If it returns zero, the custom VFS should abandon the
976** current operation.
977**
978** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
979** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
980** to have SQLite generate a
981** temporary filename using the same algorithm that is followed to generate
982** temporary filenames for TEMP tables and other internal uses. The
983** argument should be a char** which will be filled with the filename
984** written into memory obtained from [sqlite3_malloc()]. The caller should
985** invoke [sqlite3_free()] on the result to avoid a memory leak.
986**
987** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
988** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
989** maximum number of bytes that will be used for memory-mapped I/O.
990** The argument is a pointer to a value of type sqlite3_int64 that
991** is an advisory maximum number of bytes in the file to memory map. The
992** pointer is overwritten with the old value. The limit is not changed if
993** the value originally pointed to is negative, and so the current limit
994** can be queried by passing in a pointer to a negative number. This
995** file-control is used internally to implement [PRAGMA mmap_size].
996**
997** <li>[[SQLITE_FCNTL_TRACE]]
998** The [SQLITE_FCNTL_TRACE] file control provides advisory information
999** to the VFS about what the higher layers of the SQLite stack are doing.
1000** This file control is used by some VFS activity tracing [shims].
1001** The argument is a zero-terminated string. Higher layers in the
1002** SQLite stack may generate instances of this file control if
1003** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1004**
1005** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1006** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1007** pointer to an integer and it writes a boolean into that integer depending
1008** on whether or not the file has been renamed, moved, or deleted since it
1009** was first opened.
1010**
1011** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1012** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1013** underlying native file handle associated with a file handle. This file
1014** control interprets its argument as a pointer to a native file handle and
1015** writes the resulting value there.
1016**
1017** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1018** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1019** opcode causes the xFileControl method to swap the file handle with the one
1020** pointed to by the pArg argument. This capability is used during testing
1021** and only needs to be supported when SQLITE_TEST is defined.
1022**
1023** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1024** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1025** be advantageous to block on the next WAL lock if the lock is not immediately
1026** available. The WAL subsystem issues this signal during rare
1027** circumstances in order to fix a problem with priority inversion.
1028** Applications should <em>not</em> use this file-control.
1029**
1030** <li>[[SQLITE_FCNTL_ZIPVFS]]
1031** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1032** VFS should return SQLITE_NOTFOUND for this opcode.
1033**
1034** <li>[[SQLITE_FCNTL_RBU]]
1035** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1036** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1037** this opcode.
1038**
1039** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1040** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1041** the file descriptor is placed in "batch write mode", which
1042** means all subsequent write operations will be deferred and done
1043** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1044** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1045** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1046** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1047** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1048** no VFS interface calls on the same [sqlite3_file] file descriptor
1049** except for calls to the xWrite method and the xFileControl method
1050** with [SQLITE_FCNTL_SIZE_HINT].
1051**
1052** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1053** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1054** operations since the previous successful call to
1055** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1056** This file control returns [SQLITE_OK] if and only if the writes were
1057** all performed successfully and have been committed to persistent storage.
1058** ^Regardless of whether or not it is successful, this file control takes
1059** the file descriptor out of batch write mode so that all subsequent
1060** write operations are independent.
1061** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1062** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1063**
1064** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1065** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1066** operations since the previous successful call to
1067** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1068** ^This file control takes the file descriptor out of batch write mode
1069** so that all subsequent write operations are independent.
1070** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1071** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1072**
1073** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1074** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain
1075** a file lock using the xLock or xShmLock methods of the VFS to wait
1076** for up to M milliseconds before failing, where M is the single
1077** unsigned integer parameter.
1078**
1079** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1080** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1081** a database file. The argument is a pointer to a 32-bit unsigned integer.
1082** The "data version" for the pager is written into the pointer. The
1083** "data version" changes whenever any change occurs to the corresponding
1084** database file, either through SQL statements on the same database
1085** connection or through transactions committed by separate database
1086** connections possibly in other processes. The [sqlite3_total_changes()]
1087** interface can be used to find if any database on the connection has changed,
1088** but that interface responds to changes on TEMP as well as MAIN and does
1089** not provide a mechanism to detect changes to MAIN only. Also, the
1090** [sqlite3_total_changes()] interface responds to internal changes only and
1091** omits changes made by other database connections. The
1092** [PRAGMA data_version] command provide a mechanism to detect changes to
1093** a single attached database that occur due to other database connections,
1094** but omits changes implemented by the database connection on which it is
1095** called. This file control is the only mechanism to detect changes that
1096** happen either internally or externally and that are associated with
1097** a particular attached database.
1098** </ul>
1099*/
1100#define SQLITE_FCNTL_LOCKSTATE 1
1101#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1102#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1103#define SQLITE_FCNTL_LAST_ERRNO 4
1104#define SQLITE_FCNTL_SIZE_HINT 5
1105#define SQLITE_FCNTL_CHUNK_SIZE 6
1106#define SQLITE_FCNTL_FILE_POINTER 7
1107#define SQLITE_FCNTL_SYNC_OMITTED 8
1108#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1109#define SQLITE_FCNTL_PERSIST_WAL 10
1110#define SQLITE_FCNTL_OVERWRITE 11
1111#define SQLITE_FCNTL_VFSNAME 12
1112#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1113#define SQLITE_FCNTL_PRAGMA 14
1114#define SQLITE_FCNTL_BUSYHANDLER 15
1115#define SQLITE_FCNTL_TEMPFILENAME 16
1116#define SQLITE_FCNTL_MMAP_SIZE 18
1117#define SQLITE_FCNTL_TRACE 19
1118#define SQLITE_FCNTL_HAS_MOVED 20
1119#define SQLITE_FCNTL_SYNC 21
1120#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1121#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1122#define SQLITE_FCNTL_WAL_BLOCK 24
1123#define SQLITE_FCNTL_ZIPVFS 25
1124#define SQLITE_FCNTL_RBU 26
1125#define SQLITE_FCNTL_VFS_POINTER 27
1126#define SQLITE_FCNTL_JOURNAL_POINTER 28
1127#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1128#define SQLITE_FCNTL_PDB 30
1129#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1130#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1131#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1132#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1133#define SQLITE_FCNTL_DATA_VERSION 35
1134
1135/* deprecated names */
1136#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1137#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1138#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1139
1140
1141/*
1142** CAPI3REF: Mutex Handle
1143**
1144** The mutex module within SQLite defines [sqlite3_mutex] to be an
1145** abstract type for a mutex object. The SQLite core never looks
1146** at the internal representation of an [sqlite3_mutex]. It only
1147** deals with pointers to the [sqlite3_mutex] object.
1148**
1149** Mutexes are created using [sqlite3_mutex_alloc()].
1150*/
1151typedef struct sqlite3_mutex sqlite3_mutex;
1152
1153/*
1154** CAPI3REF: Loadable Extension Thunk
1155**
1156** A pointer to the opaque sqlite3_api_routines structure is passed as
1157** the third parameter to entry points of [loadable extensions]. This
1158** structure must be typedefed in order to work around compiler warnings
1159** on some platforms.
1160*/
1161typedef struct sqlite3_api_routines sqlite3_api_routines;
1162
1163/*
1164** CAPI3REF: OS Interface Object
1165**
1166** An instance of the sqlite3_vfs object defines the interface between
1167** the SQLite core and the underlying operating system. The "vfs"
1168** in the name of the object stands for "virtual file system". See
1169** the [VFS | VFS documentation] for further information.
1170**
1171** The VFS interface is sometimes extended by adding new methods onto
1172** the end. Each time such an extension occurs, the iVersion field
1173** is incremented. The iVersion value started out as 1 in
1174** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1175** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1176** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1177** may be appended to the sqlite3_vfs object and the iVersion value
1178** may increase again in future versions of SQLite.
1179** Note that the structure
1180** of the sqlite3_vfs object changes in the transition from
1181** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1182** and yet the iVersion field was not modified.
1183**
1184** The szOsFile field is the size of the subclassed [sqlite3_file]
1185** structure used by this VFS. mxPathname is the maximum length of
1186** a pathname in this VFS.
1187**
1188** Registered sqlite3_vfs objects are kept on a linked list formed by
1189** the pNext pointer. The [sqlite3_vfs_register()]
1190** and [sqlite3_vfs_unregister()] interfaces manage this list
1191** in a thread-safe way. The [sqlite3_vfs_find()] interface
1192** searches the list. Neither the application code nor the VFS
1193** implementation should use the pNext pointer.
1194**
1195** The pNext field is the only field in the sqlite3_vfs
1196** structure that SQLite will ever modify. SQLite will only access
1197** or modify this field while holding a particular static mutex.
1198** The application should never modify anything within the sqlite3_vfs
1199** object once the object has been registered.
1200**
1201** The zName field holds the name of the VFS module. The name must
1202** be unique across all VFS modules.
1203**
1204** [[sqlite3_vfs.xOpen]]
1205** ^SQLite guarantees that the zFilename parameter to xOpen
1206** is either a NULL pointer or string obtained
1207** from xFullPathname() with an optional suffix added.
1208** ^If a suffix is added to the zFilename parameter, it will
1209** consist of a single "-" character followed by no more than
1210** 11 alphanumeric and/or "-" characters.
1211** ^SQLite further guarantees that
1212** the string will be valid and unchanged until xClose() is
1213** called. Because of the previous sentence,
1214** the [sqlite3_file] can safely store a pointer to the
1215** filename if it needs to remember the filename for some reason.
1216** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1217** must invent its own temporary name for the file. ^Whenever the
1218** xFilename parameter is NULL it will also be the case that the
1219** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1220**
1221** The flags argument to xOpen() includes all bits set in
1222** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1223** or [sqlite3_open16()] is used, then flags includes at least
1224** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1225** If xOpen() opens a file read-only then it sets *pOutFlags to
1226** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1227**
1228** ^(SQLite will also add one of the following flags to the xOpen()
1229** call, depending on the object being opened:
1230**
1231** <ul>
1232** <li> [SQLITE_OPEN_MAIN_DB]
1233** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1234** <li> [SQLITE_OPEN_TEMP_DB]
1235** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1236** <li> [SQLITE_OPEN_TRANSIENT_DB]
1237** <li> [SQLITE_OPEN_SUBJOURNAL]
1238** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1239** <li> [SQLITE_OPEN_WAL]
1240** </ul>)^
1241**
1242** The file I/O implementation can use the object type flags to
1243** change the way it deals with files. For example, an application
1244** that does not care about crash recovery or rollback might make
1245** the open of a journal file a no-op. Writes to this journal would
1246** also be no-ops, and any attempt to read the journal would return
1247** SQLITE_IOERR. Or the implementation might recognize that a database
1248** file will be doing page-aligned sector reads and writes in a random
1249** order and set up its I/O subsystem accordingly.
1250**
1251** SQLite might also add one of the following flags to the xOpen method:
1252**
1253** <ul>
1254** <li> [SQLITE_OPEN_DELETEONCLOSE]
1255** <li> [SQLITE_OPEN_EXCLUSIVE]
1256** </ul>
1257**
1258** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1259** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1260** will be set for TEMP databases and their journals, transient
1261** databases, and subjournals.
1262**
1263** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1264** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1265** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1266** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1267** SQLITE_OPEN_CREATE, is used to indicate that file should always
1268** be created, and that it is an error if it already exists.
1269** It is <i>not</i> used to indicate the file should be opened
1270** for exclusive access.
1271**
1272** ^At least szOsFile bytes of memory are allocated by SQLite
1273** to hold the [sqlite3_file] structure passed as the third
1274** argument to xOpen. The xOpen method does not have to
1275** allocate the structure; it should just fill it in. Note that
1276** the xOpen method must set the sqlite3_file.pMethods to either
1277** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1278** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1279** element will be valid after xOpen returns regardless of the success
1280** or failure of the xOpen call.
1281**
1282** [[sqlite3_vfs.xAccess]]
1283** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1284** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1285** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1286** to test whether a file is at least readable. The file can be a
1287** directory.
1288**
1289** ^SQLite will always allocate at least mxPathname+1 bytes for the
1290** output buffer xFullPathname. The exact size of the output buffer
1291** is also passed as a parameter to both methods. If the output buffer
1292** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1293** handled as a fatal error by SQLite, vfs implementations should endeavor
1294** to prevent this by setting mxPathname to a sufficiently large value.
1295**
1296** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1297** interfaces are not strictly a part of the filesystem, but they are
1298** included in the VFS structure for completeness.
1299** The xRandomness() function attempts to return nBytes bytes
1300** of good-quality randomness into zOut. The return value is
1301** the actual number of bytes of randomness obtained.
1302** The xSleep() method causes the calling thread to sleep for at
1303** least the number of microseconds given. ^The xCurrentTime()
1304** method returns a Julian Day Number for the current date and time as
1305** a floating point value.
1306** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1307** Day Number multiplied by 86400000 (the number of milliseconds in
1308** a 24-hour day).
1309** ^SQLite will use the xCurrentTimeInt64() method to get the current
1310** date and time if that method is available (if iVersion is 2 or
1311** greater and the function pointer is not NULL) and will fall back
1312** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1313**
1314** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1315** are not used by the SQLite core. These optional interfaces are provided
1316** by some VFSes to facilitate testing of the VFS code. By overriding
1317** system calls with functions under its control, a test program can
1318** simulate faults and error conditions that would otherwise be difficult
1319** or impossible to induce. The set of system calls that can be overridden
1320** varies from one VFS to another, and from one version of the same VFS to the
1321** next. Applications that use these interfaces must be prepared for any
1322** or all of these interfaces to be NULL or for their behavior to change
1323** from one release to the next. Applications must not attempt to access
1324** any of these methods if the iVersion of the VFS is less than 3.
1325*/
1326typedef struct sqlite3_vfs sqlite3_vfs;
1327typedef void (*sqlite3_syscall_ptr)(void);
1328struct sqlite3_vfs {
1329 int iVersion; /* Structure version number (currently 3) */
1330 int szOsFile; /* Size of subclassed sqlite3_file */
1331 int mxPathname; /* Maximum file pathname length */
1332 sqlite3_vfs *pNext; /* Next registered VFS */
1333 const char *zName; /* Name of this virtual file system */
1334 void *pAppData; /* Pointer to application-specific data */
1335 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1336 int flags, int *pOutFlags);
1337 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1338 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1339 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1340 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1341 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1342 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1343 void (*xDlClose)(sqlite3_vfs*, void*);
1344 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1345 int (*xSleep)(sqlite3_vfs*, int microseconds);
1346 int (*xCurrentTime)(sqlite3_vfs*, double*);
1347 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1348 /*
1349 ** The methods above are in version 1 of the sqlite_vfs object
1350 ** definition. Those that follow are added in version 2 or later
1351 */
1352 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1353 /*
1354 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1355 ** Those below are for version 3 and greater.
1356 */
1357 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1358 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1359 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1360 /*
1361 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1362 ** New fields may be appended in future versions. The iVersion
1363 ** value will increment whenever this happens.
1364 */
1365};
1366
1367/*
1368** CAPI3REF: Flags for the xAccess VFS method
1369**
1370** These integer constants can be used as the third parameter to
1371** the xAccess method of an [sqlite3_vfs] object. They determine
1372** what kind of permissions the xAccess method is looking for.
1373** With SQLITE_ACCESS_EXISTS, the xAccess method
1374** simply checks whether the file exists.
1375** With SQLITE_ACCESS_READWRITE, the xAccess method
1376** checks whether the named directory is both readable and writable
1377** (in other words, if files can be added, removed, and renamed within
1378** the directory).
1379** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1380** [temp_store_directory pragma], though this could change in a future
1381** release of SQLite.
1382** With SQLITE_ACCESS_READ, the xAccess method
1383** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1384** currently unused, though it might be used in a future release of
1385** SQLite.
1386*/
1387#define SQLITE_ACCESS_EXISTS 0
1388#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1389#define SQLITE_ACCESS_READ 2 /* Unused */
1390
1391/*
1392** CAPI3REF: Flags for the xShmLock VFS method
1393**
1394** These integer constants define the various locking operations
1395** allowed by the xShmLock method of [sqlite3_io_methods]. The
1396** following are the only legal combinations of flags to the
1397** xShmLock method:
1398**
1399** <ul>
1400** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1401** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1402** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1403** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1404** </ul>
1405**
1406** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1407** was given on the corresponding lock.
1408**
1409** The xShmLock method can transition between unlocked and SHARED or
1410** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1411** and EXCLUSIVE.
1412*/
1413#define SQLITE_SHM_UNLOCK 1
1414#define SQLITE_SHM_LOCK 2
1415#define SQLITE_SHM_SHARED 4
1416#define SQLITE_SHM_EXCLUSIVE 8
1417
1418/*
1419** CAPI3REF: Maximum xShmLock index
1420**
1421** The xShmLock method on [sqlite3_io_methods] may use values
1422** between 0 and this upper bound as its "offset" argument.
1423** The SQLite core will never attempt to acquire or release a
1424** lock outside of this range
1425*/
1426#define SQLITE_SHM_NLOCK 8
1427
1428
1429/*
1430** CAPI3REF: Initialize The SQLite Library
1431**
1432** ^The sqlite3_initialize() routine initializes the
1433** SQLite library. ^The sqlite3_shutdown() routine
1434** deallocates any resources that were allocated by sqlite3_initialize().
1435** These routines are designed to aid in process initialization and
1436** shutdown on embedded systems. Workstation applications using
1437** SQLite normally do not need to invoke either of these routines.
1438**
1439** A call to sqlite3_initialize() is an "effective" call if it is
1440** the first time sqlite3_initialize() is invoked during the lifetime of
1441** the process, or if it is the first time sqlite3_initialize() is invoked
1442** following a call to sqlite3_shutdown(). ^(Only an effective call
1443** of sqlite3_initialize() does any initialization. All other calls
1444** are harmless no-ops.)^
1445**
1446** A call to sqlite3_shutdown() is an "effective" call if it is the first
1447** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1448** an effective call to sqlite3_shutdown() does any deinitialization.
1449** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1450**
1451** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1452** is not. The sqlite3_shutdown() interface must only be called from a
1453** single thread. All open [database connections] must be closed and all
1454** other SQLite resources must be deallocated prior to invoking
1455** sqlite3_shutdown().
1456**
1457** Among other things, ^sqlite3_initialize() will invoke
1458** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1459** will invoke sqlite3_os_end().
1460**
1461** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1462** ^If for some reason, sqlite3_initialize() is unable to initialize
1463** the library (perhaps it is unable to allocate a needed resource such
1464** as a mutex) it returns an [error code] other than [SQLITE_OK].
1465**
1466** ^The sqlite3_initialize() routine is called internally by many other
1467** SQLite interfaces so that an application usually does not need to
1468** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1469** calls sqlite3_initialize() so the SQLite library will be automatically
1470** initialized when [sqlite3_open()] is called if it has not be initialized
1471** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1472** compile-time option, then the automatic calls to sqlite3_initialize()
1473** are omitted and the application must call sqlite3_initialize() directly
1474** prior to using any other SQLite interface. For maximum portability,
1475** it is recommended that applications always invoke sqlite3_initialize()
1476** directly prior to using any other SQLite interface. Future releases
1477** of SQLite may require this. In other words, the behavior exhibited
1478** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1479** default behavior in some future release of SQLite.
1480**
1481** The sqlite3_os_init() routine does operating-system specific
1482** initialization of the SQLite library. The sqlite3_os_end()
1483** routine undoes the effect of sqlite3_os_init(). Typical tasks
1484** performed by these routines include allocation or deallocation
1485** of static resources, initialization of global variables,
1486** setting up a default [sqlite3_vfs] module, or setting up
1487** a default configuration using [sqlite3_config()].
1488**
1489** The application should never invoke either sqlite3_os_init()
1490** or sqlite3_os_end() directly. The application should only invoke
1491** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1492** interface is called automatically by sqlite3_initialize() and
1493** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1494** implementations for sqlite3_os_init() and sqlite3_os_end()
1495** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1496** When [custom builds | built for other platforms]
1497** (using the [SQLITE_OS_OTHER=1] compile-time
1498** option) the application must supply a suitable implementation for
1499** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1500** implementation of sqlite3_os_init() or sqlite3_os_end()
1501** must return [SQLITE_OK] on success and some other [error code] upon
1502** failure.
1503*/
1504SQLITE_API int sqlite3_initialize(void);
1505SQLITE_API int sqlite3_shutdown(void);
1506SQLITE_API int sqlite3_os_init(void);
1507SQLITE_API int sqlite3_os_end(void);
1508
1509/*
1510** CAPI3REF: Configuring The SQLite Library
1511**
1512** The sqlite3_config() interface is used to make global configuration
1513** changes to SQLite in order to tune SQLite to the specific needs of
1514** the application. The default configuration is recommended for most
1515** applications and so this routine is usually not necessary. It is
1516** provided to support rare applications with unusual needs.
1517**
1518** <b>The sqlite3_config() interface is not threadsafe. The application
1519** must ensure that no other SQLite interfaces are invoked by other
1520** threads while sqlite3_config() is running.</b>
1521**
1522** The sqlite3_config() interface
1523** may only be invoked prior to library initialization using
1524** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1525** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1526** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1527** Note, however, that ^sqlite3_config() can be called as part of the
1528** implementation of an application-defined [sqlite3_os_init()].
1529**
1530** The first argument to sqlite3_config() is an integer
1531** [configuration option] that determines
1532** what property of SQLite is to be configured. Subsequent arguments
1533** vary depending on the [configuration option]
1534** in the first argument.
1535**
1536** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1537** ^If the option is unknown or SQLite is unable to set the option
1538** then this routine returns a non-zero [error code].
1539*/
1540SQLITE_API int sqlite3_config(int, ...);
1541
1542/*
1543** CAPI3REF: Configure database connections
1544** METHOD: sqlite3
1545**
1546** The sqlite3_db_config() interface is used to make configuration
1547** changes to a [database connection]. The interface is similar to
1548** [sqlite3_config()] except that the changes apply to a single
1549** [database connection] (specified in the first argument).
1550**
1551** The second argument to sqlite3_db_config(D,V,...) is the
1552** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1553** that indicates what aspect of the [database connection] is being configured.
1554** Subsequent arguments vary depending on the configuration verb.
1555**
1556** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1557** the call is considered successful.
1558*/
1559SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1560
1561/*
1562** CAPI3REF: Memory Allocation Routines
1563**
1564** An instance of this object defines the interface between SQLite
1565** and low-level memory allocation routines.
1566**
1567** This object is used in only one place in the SQLite interface.
1568** A pointer to an instance of this object is the argument to
1569** [sqlite3_config()] when the configuration option is
1570** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1571** By creating an instance of this object
1572** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1573** during configuration, an application can specify an alternative
1574** memory allocation subsystem for SQLite to use for all of its
1575** dynamic memory needs.
1576**
1577** Note that SQLite comes with several [built-in memory allocators]
1578** that are perfectly adequate for the overwhelming majority of applications
1579** and that this object is only useful to a tiny minority of applications
1580** with specialized memory allocation requirements. This object is
1581** also used during testing of SQLite in order to specify an alternative
1582** memory allocator that simulates memory out-of-memory conditions in
1583** order to verify that SQLite recovers gracefully from such
1584** conditions.
1585**
1586** The xMalloc, xRealloc, and xFree methods must work like the
1587** malloc(), realloc() and free() functions from the standard C library.
1588** ^SQLite guarantees that the second argument to
1589** xRealloc is always a value returned by a prior call to xRoundup.
1590**
1591** xSize should return the allocated size of a memory allocation
1592** previously obtained from xMalloc or xRealloc. The allocated size
1593** is always at least as big as the requested size but may be larger.
1594**
1595** The xRoundup method returns what would be the allocated size of
1596** a memory allocation given a particular requested size. Most memory
1597** allocators round up memory allocations at least to the next multiple
1598** of 8. Some allocators round up to a larger multiple or to a power of 2.
1599** Every memory allocation request coming in through [sqlite3_malloc()]
1600** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1601** that causes the corresponding memory allocation to fail.
1602**
1603** The xInit method initializes the memory allocator. For example,
1604** it might allocate any require mutexes or initialize internal data
1605** structures. The xShutdown method is invoked (indirectly) by
1606** [sqlite3_shutdown()] and should deallocate any resources acquired
1607** by xInit. The pAppData pointer is used as the only parameter to
1608** xInit and xShutdown.
1609**
1610** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1611** the xInit method, so the xInit method need not be threadsafe. The
1612** xShutdown method is only called from [sqlite3_shutdown()] so it does
1613** not need to be threadsafe either. For all other methods, SQLite
1614** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1615** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1616** it is by default) and so the methods are automatically serialized.
1617** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1618** methods must be threadsafe or else make their own arrangements for
1619** serialization.
1620**
1621** SQLite will never invoke xInit() more than once without an intervening
1622** call to xShutdown().
1623*/
1624typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1625struct sqlite3_mem_methods {
1626 void *(*xMalloc)(int); /* Memory allocation function */
1627 void (*xFree)(void*); /* Free a prior allocation */
1628 void *(*xRealloc)(void*,int); /* Resize an allocation */
1629 int (*xSize)(void*); /* Return the size of an allocation */
1630 int (*xRoundup)(int); /* Round up request size to allocation size */
1631 int (*xInit)(void*); /* Initialize the memory allocator */
1632 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1633 void *pAppData; /* Argument to xInit() and xShutdown() */
1634};
1635
1636/*
1637** CAPI3REF: Configuration Options
1638** KEYWORDS: {configuration option}
1639**
1640** These constants are the available integer configuration options that
1641** can be passed as the first argument to the [sqlite3_config()] interface.
1642**
1643** New configuration options may be added in future releases of SQLite.
1644** Existing configuration options might be discontinued. Applications
1645** should check the return code from [sqlite3_config()] to make sure that
1646** the call worked. The [sqlite3_config()] interface will return a
1647** non-zero [error code] if a discontinued or unsupported configuration option
1648** is invoked.
1649**
1650** <dl>
1651** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1652** <dd>There are no arguments to this option. ^This option sets the
1653** [threading mode] to Single-thread. In other words, it disables
1654** all mutexing and puts SQLite into a mode where it can only be used
1655** by a single thread. ^If SQLite is compiled with
1656** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1657** it is not possible to change the [threading mode] from its default
1658** value of Single-thread and so [sqlite3_config()] will return
1659** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1660** configuration option.</dd>
1661**
1662** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1663** <dd>There are no arguments to this option. ^This option sets the
1664** [threading mode] to Multi-thread. In other words, it disables
1665** mutexing on [database connection] and [prepared statement] objects.
1666** The application is responsible for serializing access to
1667** [database connections] and [prepared statements]. But other mutexes
1668** are enabled so that SQLite will be safe to use in a multi-threaded
1669** environment as long as no two threads attempt to use the same
1670** [database connection] at the same time. ^If SQLite is compiled with
1671** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1672** it is not possible to set the Multi-thread [threading mode] and
1673** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1674** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1675**
1676** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1677** <dd>There are no arguments to this option. ^This option sets the
1678** [threading mode] to Serialized. In other words, this option enables
1679** all mutexes including the recursive
1680** mutexes on [database connection] and [prepared statement] objects.
1681** In this mode (which is the default when SQLite is compiled with
1682** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1683** to [database connections] and [prepared statements] so that the
1684** application is free to use the same [database connection] or the
1685** same [prepared statement] in different threads at the same time.
1686** ^If SQLite is compiled with
1687** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1688** it is not possible to set the Serialized [threading mode] and
1689** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1690** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1691**
1692** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1693** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1694** a pointer to an instance of the [sqlite3_mem_methods] structure.
1695** The argument specifies
1696** alternative low-level memory allocation routines to be used in place of
1697** the memory allocation routines built into SQLite.)^ ^SQLite makes
1698** its own private copy of the content of the [sqlite3_mem_methods] structure
1699** before the [sqlite3_config()] call returns.</dd>
1700**
1701** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1702** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1703** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1704** The [sqlite3_mem_methods]
1705** structure is filled with the currently defined memory allocation routines.)^
1706** This option can be used to overload the default memory allocation
1707** routines with a wrapper that simulations memory allocation failure or
1708** tracks memory usage, for example. </dd>
1709**
1710** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1711** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1712** type int, interpreted as a boolean, which if true provides a hint to
1713** SQLite that it should avoid large memory allocations if possible.
1714** SQLite will run faster if it is free to make large memory allocations,
1715** but some application might prefer to run slower in exchange for
1716** guarantees about memory fragmentation that are possible if large
1717** allocations are avoided. This hint is normally off.
1718** </dd>
1719**
1720** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1721** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1722** interpreted as a boolean, which enables or disables the collection of
1723** memory allocation statistics. ^(When memory allocation statistics are
1724** disabled, the following SQLite interfaces become non-operational:
1725** <ul>
1726** <li> [sqlite3_memory_used()]
1727** <li> [sqlite3_memory_highwater()]
1728** <li> [sqlite3_soft_heap_limit64()]
1729** <li> [sqlite3_status64()]
1730** </ul>)^
1731** ^Memory allocation statistics are enabled by default unless SQLite is
1732** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1733** allocation statistics are disabled by default.
1734** </dd>
1735**
1736** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1737** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1738** </dd>
1739**
1740** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1741** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1742** that SQLite can use for the database page cache with the default page
1743** cache implementation.
1744** This configuration option is a no-op if an application-define page
1745** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1746** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1747** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1748** and the number of cache lines (N).
1749** The sz argument should be the size of the largest database page
1750** (a power of two between 512 and 65536) plus some extra bytes for each
1751** page header. ^The number of extra bytes needed by the page header
1752** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1753** ^It is harmless, apart from the wasted memory,
1754** for the sz parameter to be larger than necessary. The pMem
1755** argument must be either a NULL pointer or a pointer to an 8-byte
1756** aligned block of memory of at least sz*N bytes, otherwise
1757** subsequent behavior is undefined.
1758** ^When pMem is not NULL, SQLite will strive to use the memory provided
1759** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1760** a page cache line is larger than sz bytes or if all of the pMem buffer
1761** is exhausted.
1762** ^If pMem is NULL and N is non-zero, then each database connection
1763** does an initial bulk allocation for page cache memory
1764** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1765** of -1024*N bytes if N is negative, . ^If additional
1766** page cache memory is needed beyond what is provided by the initial
1767** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1768** additional cache line. </dd>
1769**
1770** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1771** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1772** that SQLite will use for all of its dynamic memory allocation needs
1773** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1774** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1775** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1776** [SQLITE_ERROR] if invoked otherwise.
1777** ^There are three arguments to SQLITE_CONFIG_HEAP:
1778** An 8-byte aligned pointer to the memory,
1779** the number of bytes in the memory buffer, and the minimum allocation size.
1780** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1781** to using its default memory allocator (the system malloc() implementation),
1782** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1783** memory pointer is not NULL then the alternative memory
1784** allocator is engaged to handle all of SQLites memory allocation needs.
1785** The first pointer (the memory pointer) must be aligned to an 8-byte
1786** boundary or subsequent behavior of SQLite will be undefined.
1787** The minimum allocation size is capped at 2**12. Reasonable values
1788** for the minimum allocation size are 2**5 through 2**8.</dd>
1789**
1790** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1791** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1792** pointer to an instance of the [sqlite3_mutex_methods] structure.
1793** The argument specifies alternative low-level mutex routines to be used
1794** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1795** the content of the [sqlite3_mutex_methods] structure before the call to
1796** [sqlite3_config()] returns. ^If SQLite is compiled with
1797** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1798** the entire mutexing subsystem is omitted from the build and hence calls to
1799** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1800** return [SQLITE_ERROR].</dd>
1801**
1802** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1803** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1804** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1805** [sqlite3_mutex_methods]
1806** structure is filled with the currently defined mutex routines.)^
1807** This option can be used to overload the default mutex allocation
1808** routines with a wrapper used to track mutex usage for performance
1809** profiling or testing, for example. ^If SQLite is compiled with
1810** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1811** the entire mutexing subsystem is omitted from the build and hence calls to
1812** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1813** return [SQLITE_ERROR].</dd>
1814**
1815** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1816** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1817** the default size of lookaside memory on each [database connection].
1818** The first argument is the
1819** size of each lookaside buffer slot and the second is the number of
1820** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1821** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1822** option to [sqlite3_db_config()] can be used to change the lookaside
1823** configuration on individual connections.)^ </dd>
1824**
1825** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1826** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1827** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1828** the interface to a custom page cache implementation.)^
1829** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1830**
1831** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1832** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1833** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1834** the current page cache implementation into that object.)^ </dd>
1835**
1836** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1837** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1838** global [error log].
1839** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1840** function with a call signature of void(*)(void*,int,const char*),
1841** and a pointer to void. ^If the function pointer is not NULL, it is
1842** invoked by [sqlite3_log()] to process each logging event. ^If the
1843** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1844** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1845** passed through as the first parameter to the application-defined logger
1846** function whenever that function is invoked. ^The second parameter to
1847** the logger function is a copy of the first parameter to the corresponding
1848** [sqlite3_log()] call and is intended to be a [result code] or an
1849** [extended result code]. ^The third parameter passed to the logger is
1850** log message after formatting via [sqlite3_snprintf()].
1851** The SQLite logging interface is not reentrant; the logger function
1852** supplied by the application must not invoke any SQLite interface.
1853** In a multi-threaded application, the application-defined logger
1854** function must be threadsafe. </dd>
1855**
1856** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1857** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1858** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1859** then URI handling is globally disabled.)^ ^If URI handling is globally
1860** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1861** [sqlite3_open16()] or
1862** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1863** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1864** connection is opened. ^If it is globally disabled, filenames are
1865** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1866** database connection is opened. ^(By default, URI handling is globally
1867** disabled. The default value may be changed by compiling with the
1868** [SQLITE_USE_URI] symbol defined.)^
1869**
1870** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1871** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1872** argument which is interpreted as a boolean in order to enable or disable
1873** the use of covering indices for full table scans in the query optimizer.
1874** ^The default setting is determined
1875** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1876** if that compile-time option is omitted.
1877** The ability to disable the use of covering indices for full table scans
1878** is because some incorrectly coded legacy applications might malfunction
1879** when the optimization is enabled. Providing the ability to
1880** disable the optimization allows the older, buggy application code to work
1881** without change even with newer versions of SQLite.
1882**
1883** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1884** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1885** <dd> These options are obsolete and should not be used by new code.
1886** They are retained for backwards compatibility but are now no-ops.
1887** </dd>
1888**
1889** [[SQLITE_CONFIG_SQLLOG]]
1890** <dt>SQLITE_CONFIG_SQLLOG
1891** <dd>This option is only available if sqlite is compiled with the
1892** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1893** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1894** The second should be of type (void*). The callback is invoked by the library
1895** in three separate circumstances, identified by the value passed as the
1896** fourth parameter. If the fourth parameter is 0, then the database connection
1897** passed as the second argument has just been opened. The third argument
1898** points to a buffer containing the name of the main database file. If the
1899** fourth parameter is 1, then the SQL statement that the third parameter
1900** points to has just been executed. Or, if the fourth parameter is 2, then
1901** the connection being passed as the second parameter is being closed. The
1902** third parameter is passed NULL In this case. An example of using this
1903** configuration option can be seen in the "test_sqllog.c" source file in
1904** the canonical SQLite source tree.</dd>
1905**
1906** [[SQLITE_CONFIG_MMAP_SIZE]]
1907** <dt>SQLITE_CONFIG_MMAP_SIZE
1908** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1909** that are the default mmap size limit (the default setting for
1910** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1911** ^The default setting can be overridden by each database connection using
1912** either the [PRAGMA mmap_size] command, or by using the
1913** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1914** will be silently truncated if necessary so that it does not exceed the
1915** compile-time maximum mmap size set by the
1916** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1917** ^If either argument to this option is negative, then that argument is
1918** changed to its compile-time default.
1919**
1920** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1921** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1922** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1923** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1924** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1925** that specifies the maximum size of the created heap.
1926**
1927** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1928** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1929** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1930** is a pointer to an integer and writes into that integer the number of extra
1931** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1932** The amount of extra space required can change depending on the compiler,
1933** target platform, and SQLite version.
1934**
1935** [[SQLITE_CONFIG_PMASZ]]
1936** <dt>SQLITE_CONFIG_PMASZ
1937** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1938** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1939** sorter to that integer. The default minimum PMA Size is set by the
1940** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1941** to help with sort operations when multithreaded sorting
1942** is enabled (using the [PRAGMA threads] command) and the amount of content
1943** to be sorted exceeds the page size times the minimum of the
1944** [PRAGMA cache_size] setting and this value.
1945**
1946** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1947** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1948** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1949** becomes the [statement journal] spill-to-disk threshold.
1950** [Statement journals] are held in memory until their size (in bytes)
1951** exceeds this threshold, at which point they are written to disk.
1952** Or if the threshold is -1, statement journals are always held
1953** exclusively in memory.
1954** Since many statement journals never become large, setting the spill
1955** threshold to a value such as 64KiB can greatly reduce the amount of
1956** I/O required to support statement rollback.
1957** The default value for this setting is controlled by the
1958** [SQLITE_STMTJRNL_SPILL] compile-time option.
1959**
1960** [[SQLITE_CONFIG_SORTERREF_SIZE]]
1961** <dt>SQLITE_CONFIG_SORTERREF_SIZE
1962** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
1963** of type (int) - the new value of the sorter-reference size threshold.
1964** Usually, when SQLite uses an external sort to order records according
1965** to an ORDER BY clause, all fields required by the caller are present in the
1966** sorted records. However, if SQLite determines based on the declared type
1967** of a table column that its values are likely to be very large - larger
1968** than the configured sorter-reference size threshold - then a reference
1969** is stored in each sorted record and the required column values loaded
1970** from the database as records are returned in sorted order. The default
1971** value for this option is to never use this optimization. Specifying a
1972** negative value for this option restores the default behaviour.
1973** This option is only available if SQLite is compiled with the
1974** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
1975** </dl>
1976*/
1977#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1978#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1979#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1980#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1981#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1982#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
1983#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1984#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1985#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1986#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1987#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1988/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1989#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1990#define SQLITE_CONFIG_PCACHE 14 /* no-op */
1991#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1992#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1993#define SQLITE_CONFIG_URI 17 /* int */
1994#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1995#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1996#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
1997#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
1998#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
1999#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2000#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2001#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2002#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2003#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2004#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2005
2006/*
2007** CAPI3REF: Database Connection Configuration Options
2008**
2009** These constants are the available integer configuration options that
2010** can be passed as the second argument to the [sqlite3_db_config()] interface.
2011**
2012** New configuration options may be added in future releases of SQLite.
2013** Existing configuration options might be discontinued. Applications
2014** should check the return code from [sqlite3_db_config()] to make sure that
2015** the call worked. ^The [sqlite3_db_config()] interface will return a
2016** non-zero [error code] if a discontinued or unsupported configuration option
2017** is invoked.
2018**
2019** <dl>
2020** [[SQLITE_DBCONFIG_LOOKASIDE]]
2021** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2022** <dd> ^This option takes three additional arguments that determine the
2023** [lookaside memory allocator] configuration for the [database connection].
2024** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2025** pointer to a memory buffer to use for lookaside memory.
2026** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2027** may be NULL in which case SQLite will allocate the
2028** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2029** size of each lookaside buffer slot. ^The third argument is the number of
2030** slots. The size of the buffer in the first argument must be greater than
2031** or equal to the product of the second and third arguments. The buffer
2032** must be aligned to an 8-byte boundary. ^If the second argument to
2033** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2034** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2035** configuration for a database connection can only be changed when that
2036** connection is not currently using lookaside memory, or in other words
2037** when the "current value" returned by
2038** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2039** Any attempt to change the lookaside memory configuration when lookaside
2040** memory is in use leaves the configuration unchanged and returns
2041** [SQLITE_BUSY].)^</dd>
2042**
2043** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2044** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2045** <dd> ^This option is used to enable or disable the enforcement of
2046** [foreign key constraints]. There should be two additional arguments.
2047** The first argument is an integer which is 0 to disable FK enforcement,
2048** positive to enable FK enforcement or negative to leave FK enforcement
2049** unchanged. The second parameter is a pointer to an integer into which
2050** is written 0 or 1 to indicate whether FK enforcement is off or on
2051** following this call. The second parameter may be a NULL pointer, in
2052** which case the FK enforcement setting is not reported back. </dd>
2053**
2054** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2055** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2056** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2057** There should be two additional arguments.
2058** The first argument is an integer which is 0 to disable triggers,
2059** positive to enable triggers or negative to leave the setting unchanged.
2060** The second parameter is a pointer to an integer into which
2061** is written 0 or 1 to indicate whether triggers are disabled or enabled
2062** following this call. The second parameter may be a NULL pointer, in
2063** which case the trigger setting is not reported back. </dd>
2064**
2065** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2066** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2067** <dd> ^This option is used to enable or disable the two-argument
2068** version of the [fts3_tokenizer()] function which is part of the
2069** [FTS3] full-text search engine extension.
2070** There should be two additional arguments.
2071** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2072** positive to enable fts3_tokenizer() or negative to leave the setting
2073** unchanged.
2074** The second parameter is a pointer to an integer into which
2075** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2076** following this call. The second parameter may be a NULL pointer, in
2077** which case the new setting is not reported back. </dd>
2078**
2079** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2080** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2081** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2082** interface independently of the [load_extension()] SQL function.
2083** The [sqlite3_enable_load_extension()] API enables or disables both the
2084** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2085** There should be two additional arguments.
2086** When the first argument to this interface is 1, then only the C-API is
2087** enabled and the SQL function remains disabled. If the first argument to
2088** this interface is 0, then both the C-API and the SQL function are disabled.
2089** If the first argument is -1, then no changes are made to state of either the
2090** C-API or the SQL function.
2091** The second parameter is a pointer to an integer into which
2092** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2093** is disabled or enabled following this call. The second parameter may
2094** be a NULL pointer, in which case the new setting is not reported back.
2095** </dd>
2096**
2097** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2098** <dd> ^This option is used to change the name of the "main" database
2099** schema. ^The sole argument is a pointer to a constant UTF8 string
2100** which will become the new schema name in place of "main". ^SQLite
2101** does not make a copy of the new main schema name string, so the application
2102** must ensure that the argument passed into this DBCONFIG option is unchanged
2103** until after the database connection closes.
2104** </dd>
2105**
2106** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2107** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2108** <dd> Usually, when a database in wal mode is closed or detached from a
2109** database handle, SQLite checks if this will mean that there are now no
2110** connections at all to the database. If so, it performs a checkpoint
2111** operation before closing the connection. This option may be used to
2112** override this behaviour. The first parameter passed to this operation
2113** is an integer - positive to disable checkpoints-on-close, or zero (the
2114** default) to enable them, and negative to leave the setting unchanged.
2115** The second parameter is a pointer to an integer
2116** into which is written 0 or 1 to indicate whether checkpoints-on-close
2117** have been disabled - 0 if they are not disabled, 1 if they are.
2118** </dd>
2119**
2120** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2121** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2122** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2123** a single SQL query statement will always use the same algorithm regardless
2124** of values of [bound parameters].)^ The QPSG disables some query optimizations
2125** that look at the values of bound parameters, which can make some queries
2126** slower. But the QPSG has the advantage of more predictable behavior. With
2127** the QPSG active, SQLite will always use the same query plan in the field as
2128** was used during testing in the lab.
2129** The first argument to this setting is an integer which is 0 to disable
2130** the QPSG, positive to enable QPSG, or negative to leave the setting
2131** unchanged. The second parameter is a pointer to an integer into which
2132** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2133** following this call.
2134** </dd>
2135**
2136** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2137** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2138** include output for any operations performed by trigger programs. This
2139** option is used to set or clear (the default) a flag that governs this
2140** behavior. The first parameter passed to this operation is an integer -
2141** positive to enable output for trigger programs, or zero to disable it,
2142** or negative to leave the setting unchanged.
2143** The second parameter is a pointer to an integer into which is written
2144** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2145** it is not disabled, 1 if it is.
2146** </dd>
2147**
2148** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2149** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2150** [VACUUM] in order to reset a database back to an empty database
2151** with no schema and no content. The following process works even for
2152** a badly corrupted database file:
2153** <ol>
2154** <li> If the database connection is newly opened, make sure it has read the
2155** database schema by preparing then discarding some query against the
2156** database, or calling sqlite3_table_column_metadata(), ignoring any
2157** errors. This step is only necessary if the application desires to keep
2158** the database in WAL mode after the reset if it was in WAL mode before
2159** the reset.
2160** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2161** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2162** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2163** </ol>
2164** Because resetting a database is destructive and irreversible, the
2165** process requires the use of this obscure API and multiple steps to help
2166** ensure that it does not happen by accident.
2167**
2168** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2169** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2170** "defensive" flag for a database connection. When the defensive
2171** flag is enabled, language features that allow ordinary SQL to
2172** deliberately corrupt the database file are disabled. The disabled
2173** features include but are not limited to the following:
2174** <ul>
2175** <li> The [PRAGMA writable_schema=ON] statement.
2176** <li> Writes to the [sqlite_dbpage] virtual table.
2177** <li> Direct writes to [shadow tables].
2178** </ul>
2179** </dd>
2180** </dl>
2181*/
2182#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2183#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2184#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2185#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2186#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2187#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2188#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2189#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2190#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2191#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2192#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2193#define SQLITE_DBCONFIG_MAX 1010 /* Largest DBCONFIG */
2194
2195/*
2196** CAPI3REF: Enable Or Disable Extended Result Codes
2197** METHOD: sqlite3
2198**
2199** ^The sqlite3_extended_result_codes() routine enables or disables the
2200** [extended result codes] feature of SQLite. ^The extended result
2201** codes are disabled by default for historical compatibility.
2202*/
2203SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2204
2205/*
2206** CAPI3REF: Last Insert Rowid
2207** METHOD: sqlite3
2208**
2209** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2210** has a unique 64-bit signed
2211** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2212** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2213** names are not also used by explicitly declared columns. ^If
2214** the table has a column of type [INTEGER PRIMARY KEY] then that column
2215** is another alias for the rowid.
2216**
2217** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2218** the most recent successful [INSERT] into a rowid table or [virtual table]
2219** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2220** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2221** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2222** zero.
2223**
2224** As well as being set automatically as rows are inserted into database
2225** tables, the value returned by this function may be set explicitly by
2226** [sqlite3_set_last_insert_rowid()]
2227**
2228** Some virtual table implementations may INSERT rows into rowid tables as
2229** part of committing a transaction (e.g. to flush data accumulated in memory
2230** to disk). In this case subsequent calls to this function return the rowid
2231** associated with these internal INSERT operations, which leads to
2232** unintuitive results. Virtual table implementations that do write to rowid
2233** tables in this way can avoid this problem by restoring the original
2234** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2235** control to the user.
2236**
2237** ^(If an [INSERT] occurs within a trigger then this routine will
2238** return the [rowid] of the inserted row as long as the trigger is
2239** running. Once the trigger program ends, the value returned
2240** by this routine reverts to what it was before the trigger was fired.)^
2241**
2242** ^An [INSERT] that fails due to a constraint violation is not a
2243** successful [INSERT] and does not change the value returned by this
2244** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2245** and INSERT OR ABORT make no changes to the return value of this
2246** routine when their insertion fails. ^(When INSERT OR REPLACE
2247** encounters a constraint violation, it does not fail. The
2248** INSERT continues to completion after deleting rows that caused
2249** the constraint problem so INSERT OR REPLACE will always change
2250** the return value of this interface.)^
2251**
2252** ^For the purposes of this routine, an [INSERT] is considered to
2253** be successful even if it is subsequently rolled back.
2254**
2255** This function is accessible to SQL statements via the
2256** [last_insert_rowid() SQL function].
2257**
2258** If a separate thread performs a new [INSERT] on the same
2259** database connection while the [sqlite3_last_insert_rowid()]
2260** function is running and thus changes the last insert [rowid],
2261** then the value returned by [sqlite3_last_insert_rowid()] is
2262** unpredictable and might not equal either the old or the new
2263** last insert [rowid].
2264*/
2265SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2266
2267/*
2268** CAPI3REF: Set the Last Insert Rowid value.
2269** METHOD: sqlite3
2270**
2271** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2272** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2273** without inserting a row into the database.
2274*/
2275SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2276
2277/*
2278** CAPI3REF: Count The Number Of Rows Modified
2279** METHOD: sqlite3
2280**
2281** ^This function returns the number of rows modified, inserted or
2282** deleted by the most recently completed INSERT, UPDATE or DELETE
2283** statement on the database connection specified by the only parameter.
2284** ^Executing any other type of SQL statement does not modify the value
2285** returned by this function.
2286**
2287** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2288** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2289** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2290**
2291** Changes to a view that are intercepted by
2292** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2293** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2294** DELETE statement run on a view is always zero. Only changes made to real
2295** tables are counted.
2296**
2297** Things are more complicated if the sqlite3_changes() function is
2298** executed while a trigger program is running. This may happen if the
2299** program uses the [changes() SQL function], or if some other callback
2300** function invokes sqlite3_changes() directly. Essentially:
2301**
2302** <ul>
2303** <li> ^(Before entering a trigger program the value returned by
2304** sqlite3_changes() function is saved. After the trigger program
2305** has finished, the original value is restored.)^
2306**
2307** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2308** statement sets the value returned by sqlite3_changes()
2309** upon completion as normal. Of course, this value will not include
2310** any changes performed by sub-triggers, as the sqlite3_changes()
2311** value will be saved and restored after each sub-trigger has run.)^
2312** </ul>
2313**
2314** ^This means that if the changes() SQL function (or similar) is used
2315** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2316** returns the value as set when the calling statement began executing.
2317** ^If it is used by the second or subsequent such statement within a trigger
2318** program, the value returned reflects the number of rows modified by the
2319** previous INSERT, UPDATE or DELETE statement within the same trigger.
2320**
2321** If a separate thread makes changes on the same database connection
2322** while [sqlite3_changes()] is running then the value returned
2323** is unpredictable and not meaningful.
2324**
2325** See also:
2326** <ul>
2327** <li> the [sqlite3_total_changes()] interface
2328** <li> the [count_changes pragma]
2329** <li> the [changes() SQL function]
2330** <li> the [data_version pragma]
2331** </ul>
2332*/
2333SQLITE_API int sqlite3_changes(sqlite3*);
2334
2335/*
2336** CAPI3REF: Total Number Of Rows Modified
2337** METHOD: sqlite3
2338**
2339** ^This function returns the total number of rows inserted, modified or
2340** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2341** since the database connection was opened, including those executed as
2342** part of trigger programs. ^Executing any other type of SQL statement
2343** does not affect the value returned by sqlite3_total_changes().
2344**
2345** ^Changes made as part of [foreign key actions] are included in the
2346** count, but those made as part of REPLACE constraint resolution are
2347** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2348** are not counted.
2349**
2350** This the [sqlite3_total_changes(D)] interface only reports the number
2351** of rows that changed due to SQL statement run against database
2352** connection D. Any changes by other database connections are ignored.
2353** To detect changes against a database file from other database
2354** connections use the [PRAGMA data_version] command or the
2355** [SQLITE_FCNTL_DATA_VERSION] [file control].
2356**
2357** If a separate thread makes changes on the same database connection
2358** while [sqlite3_total_changes()] is running then the value
2359** returned is unpredictable and not meaningful.
2360**
2361** See also:
2362** <ul>
2363** <li> the [sqlite3_changes()] interface
2364** <li> the [count_changes pragma]
2365** <li> the [changes() SQL function]
2366** <li> the [data_version pragma]
2367** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2368** </ul>
2369*/
2370SQLITE_API int sqlite3_total_changes(sqlite3*);
2371
2372/*
2373** CAPI3REF: Interrupt A Long-Running Query
2374** METHOD: sqlite3
2375**
2376** ^This function causes any pending database operation to abort and
2377** return at its earliest opportunity. This routine is typically
2378** called in response to a user action such as pressing "Cancel"
2379** or Ctrl-C where the user wants a long query operation to halt
2380** immediately.
2381**
2382** ^It is safe to call this routine from a thread different from the
2383** thread that is currently running the database operation. But it
2384** is not safe to call this routine with a [database connection] that
2385** is closed or might close before sqlite3_interrupt() returns.
2386**
2387** ^If an SQL operation is very nearly finished at the time when
2388** sqlite3_interrupt() is called, then it might not have an opportunity
2389** to be interrupted and might continue to completion.
2390**
2391** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2392** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2393** that is inside an explicit transaction, then the entire transaction
2394** will be rolled back automatically.
2395**
2396** ^The sqlite3_interrupt(D) call is in effect until all currently running
2397** SQL statements on [database connection] D complete. ^Any new SQL statements
2398** that are started after the sqlite3_interrupt() call and before the
2399** running statements reaches zero are interrupted as if they had been
2400** running prior to the sqlite3_interrupt() call. ^New SQL statements
2401** that are started after the running statement count reaches zero are
2402** not effected by the sqlite3_interrupt().
2403** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2404** SQL statements is a no-op and has no effect on SQL statements
2405** that are started after the sqlite3_interrupt() call returns.
2406*/
2407SQLITE_API void sqlite3_interrupt(sqlite3*);
2408
2409/*
2410** CAPI3REF: Determine If An SQL Statement Is Complete
2411**
2412** These routines are useful during command-line input to determine if the
2413** currently entered text seems to form a complete SQL statement or
2414** if additional input is needed before sending the text into
2415** SQLite for parsing. ^These routines return 1 if the input string
2416** appears to be a complete SQL statement. ^A statement is judged to be
2417** complete if it ends with a semicolon token and is not a prefix of a
2418** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2419** string literals or quoted identifier names or comments are not
2420** independent tokens (they are part of the token in which they are
2421** embedded) and thus do not count as a statement terminator. ^Whitespace
2422** and comments that follow the final semicolon are ignored.
2423**
2424** ^These routines return 0 if the statement is incomplete. ^If a
2425** memory allocation fails, then SQLITE_NOMEM is returned.
2426**
2427** ^These routines do not parse the SQL statements thus
2428** will not detect syntactically incorrect SQL.
2429**
2430** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2431** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2432** automatically by sqlite3_complete16(). If that initialization fails,
2433** then the return value from sqlite3_complete16() will be non-zero
2434** regardless of whether or not the input SQL is complete.)^
2435**
2436** The input to [sqlite3_complete()] must be a zero-terminated
2437** UTF-8 string.
2438**
2439** The input to [sqlite3_complete16()] must be a zero-terminated
2440** UTF-16 string in native byte order.
2441*/
2442SQLITE_API int sqlite3_complete(const char *sql);
2443SQLITE_API int sqlite3_complete16(const void *sql);
2444
2445/*
2446** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2447** KEYWORDS: {busy-handler callback} {busy handler}
2448** METHOD: sqlite3
2449**
2450** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2451** that might be invoked with argument P whenever
2452** an attempt is made to access a database table associated with
2453** [database connection] D when another thread
2454** or process has the table locked.
2455** The sqlite3_busy_handler() interface is used to implement
2456** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2457**
2458** ^If the busy callback is NULL, then [SQLITE_BUSY]
2459** is returned immediately upon encountering the lock. ^If the busy callback
2460** is not NULL, then the callback might be invoked with two arguments.
2461**
2462** ^The first argument to the busy handler is a copy of the void* pointer which
2463** is the third argument to sqlite3_busy_handler(). ^The second argument to
2464** the busy handler callback is the number of times that the busy handler has
2465** been invoked previously for the same locking event. ^If the
2466** busy callback returns 0, then no additional attempts are made to
2467** access the database and [SQLITE_BUSY] is returned
2468** to the application.
2469** ^If the callback returns non-zero, then another attempt
2470** is made to access the database and the cycle repeats.
2471**
2472** The presence of a busy handler does not guarantee that it will be invoked
2473** when there is lock contention. ^If SQLite determines that invoking the busy
2474** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2475** to the application instead of invoking the
2476** busy handler.
2477** Consider a scenario where one process is holding a read lock that
2478** it is trying to promote to a reserved lock and
2479** a second process is holding a reserved lock that it is trying
2480** to promote to an exclusive lock. The first process cannot proceed
2481** because it is blocked by the second and the second process cannot
2482** proceed because it is blocked by the first. If both processes
2483** invoke the busy handlers, neither will make any progress. Therefore,
2484** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2485** will induce the first process to release its read lock and allow
2486** the second process to proceed.
2487**
2488** ^The default busy callback is NULL.
2489**
2490** ^(There can only be a single busy handler defined for each
2491** [database connection]. Setting a new busy handler clears any
2492** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2493** or evaluating [PRAGMA busy_timeout=N] will change the
2494** busy handler and thus clear any previously set busy handler.
2495**
2496** The busy callback should not take any actions which modify the
2497** database connection that invoked the busy handler. In other words,
2498** the busy handler is not reentrant. Any such actions
2499** result in undefined behavior.
2500**
2501** A busy handler must not close the database connection
2502** or [prepared statement] that invoked the busy handler.
2503*/
2504SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2505
2506/*
2507** CAPI3REF: Set A Busy Timeout
2508** METHOD: sqlite3
2509**
2510** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2511** for a specified amount of time when a table is locked. ^The handler
2512** will sleep multiple times until at least "ms" milliseconds of sleeping
2513** have accumulated. ^After at least "ms" milliseconds of sleeping,
2514** the handler returns 0 which causes [sqlite3_step()] to return
2515** [SQLITE_BUSY].
2516**
2517** ^Calling this routine with an argument less than or equal to zero
2518** turns off all busy handlers.
2519**
2520** ^(There can only be a single busy handler for a particular
2521** [database connection] at any given moment. If another busy handler
2522** was defined (using [sqlite3_busy_handler()]) prior to calling
2523** this routine, that other busy handler is cleared.)^
2524**
2525** See also: [PRAGMA busy_timeout]
2526*/
2527SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2528
2529/*
2530** CAPI3REF: Convenience Routines For Running Queries
2531** METHOD: sqlite3
2532**
2533** This is a legacy interface that is preserved for backwards compatibility.
2534** Use of this interface is not recommended.
2535**
2536** Definition: A <b>result table</b> is memory data structure created by the
2537** [sqlite3_get_table()] interface. A result table records the
2538** complete query results from one or more queries.
2539**
2540** The table conceptually has a number of rows and columns. But
2541** these numbers are not part of the result table itself. These
2542** numbers are obtained separately. Let N be the number of rows
2543** and M be the number of columns.
2544**
2545** A result table is an array of pointers to zero-terminated UTF-8 strings.
2546** There are (N+1)*M elements in the array. The first M pointers point
2547** to zero-terminated strings that contain the names of the columns.
2548** The remaining entries all point to query results. NULL values result
2549** in NULL pointers. All other values are in their UTF-8 zero-terminated
2550** string representation as returned by [sqlite3_column_text()].
2551**
2552** A result table might consist of one or more memory allocations.
2553** It is not safe to pass a result table directly to [sqlite3_free()].
2554** A result table should be deallocated using [sqlite3_free_table()].
2555**
2556** ^(As an example of the result table format, suppose a query result
2557** is as follows:
2558**
2559** <blockquote><pre>
2560** Name | Age
2561** -----------------------
2562** Alice | 43
2563** Bob | 28
2564** Cindy | 21
2565** </pre></blockquote>
2566**
2567** There are two column (M==2) and three rows (N==3). Thus the
2568** result table has 8 entries. Suppose the result table is stored
2569** in an array names azResult. Then azResult holds this content:
2570**
2571** <blockquote><pre>
2572** azResult&#91;0] = "Name";
2573** azResult&#91;1] = "Age";
2574** azResult&#91;2] = "Alice";
2575** azResult&#91;3] = "43";
2576** azResult&#91;4] = "Bob";
2577** azResult&#91;5] = "28";
2578** azResult&#91;6] = "Cindy";
2579** azResult&#91;7] = "21";
2580** </pre></blockquote>)^
2581**
2582** ^The sqlite3_get_table() function evaluates one or more
2583** semicolon-separated SQL statements in the zero-terminated UTF-8
2584** string of its 2nd parameter and returns a result table to the
2585** pointer given in its 3rd parameter.
2586**
2587** After the application has finished with the result from sqlite3_get_table(),
2588** it must pass the result table pointer to sqlite3_free_table() in order to
2589** release the memory that was malloced. Because of the way the
2590** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2591** function must not try to call [sqlite3_free()] directly. Only
2592** [sqlite3_free_table()] is able to release the memory properly and safely.
2593**
2594** The sqlite3_get_table() interface is implemented as a wrapper around
2595** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2596** to any internal data structures of SQLite. It uses only the public
2597** interface defined here. As a consequence, errors that occur in the
2598** wrapper layer outside of the internal [sqlite3_exec()] call are not
2599** reflected in subsequent calls to [sqlite3_errcode()] or
2600** [sqlite3_errmsg()].
2601*/
2602SQLITE_API int sqlite3_get_table(
2603 sqlite3 *db, /* An open database */
2604 const char *zSql, /* SQL to be evaluated */
2605 char ***pazResult, /* Results of the query */
2606 int *pnRow, /* Number of result rows written here */
2607 int *pnColumn, /* Number of result columns written here */
2608 char **pzErrmsg /* Error msg written here */
2609);
2610SQLITE_API void sqlite3_free_table(char **result);
2611
2612/*
2613** CAPI3REF: Formatted String Printing Functions
2614**
2615** These routines are work-alikes of the "printf()" family of functions
2616** from the standard C library.
2617** These routines understand most of the common formatting options from
2618** the standard library printf()
2619** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2620** See the [built-in printf()] documentation for details.
2621**
2622** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2623** results into memory obtained from [sqlite3_malloc64()].
2624** The strings returned by these two routines should be
2625** released by [sqlite3_free()]. ^Both routines return a
2626** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2627** memory to hold the resulting string.
2628**
2629** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2630** the standard C library. The result is written into the
2631** buffer supplied as the second parameter whose size is given by
2632** the first parameter. Note that the order of the
2633** first two parameters is reversed from snprintf().)^ This is an
2634** historical accident that cannot be fixed without breaking
2635** backwards compatibility. ^(Note also that sqlite3_snprintf()
2636** returns a pointer to its buffer instead of the number of
2637** characters actually written into the buffer.)^ We admit that
2638** the number of characters written would be a more useful return
2639** value but we cannot change the implementation of sqlite3_snprintf()
2640** now without breaking compatibility.
2641**
2642** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2643** guarantees that the buffer is always zero-terminated. ^The first
2644** parameter "n" is the total size of the buffer, including space for
2645** the zero terminator. So the longest string that can be completely
2646** written will be n-1 characters.
2647**
2648** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2649**
2650** See also: [built-in printf()], [printf() SQL function]
2651*/
2652SQLITE_API char *sqlite3_mprintf(const char*,...);
2653SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2654SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2655SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2656
2657/*
2658** CAPI3REF: Memory Allocation Subsystem
2659**
2660** The SQLite core uses these three routines for all of its own
2661** internal memory allocation needs. "Core" in the previous sentence
2662** does not include operating-system specific VFS implementation. The
2663** Windows VFS uses native malloc() and free() for some operations.
2664**
2665** ^The sqlite3_malloc() routine returns a pointer to a block
2666** of memory at least N bytes in length, where N is the parameter.
2667** ^If sqlite3_malloc() is unable to obtain sufficient free
2668** memory, it returns a NULL pointer. ^If the parameter N to
2669** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2670** a NULL pointer.
2671**
2672** ^The sqlite3_malloc64(N) routine works just like
2673** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2674** of a signed 32-bit integer.
2675**
2676** ^Calling sqlite3_free() with a pointer previously returned
2677** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2678** that it might be reused. ^The sqlite3_free() routine is
2679** a no-op if is called with a NULL pointer. Passing a NULL pointer
2680** to sqlite3_free() is harmless. After being freed, memory
2681** should neither be read nor written. Even reading previously freed
2682** memory might result in a segmentation fault or other severe error.
2683** Memory corruption, a segmentation fault, or other severe error
2684** might result if sqlite3_free() is called with a non-NULL pointer that
2685** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2686**
2687** ^The sqlite3_realloc(X,N) interface attempts to resize a
2688** prior memory allocation X to be at least N bytes.
2689** ^If the X parameter to sqlite3_realloc(X,N)
2690** is a NULL pointer then its behavior is identical to calling
2691** sqlite3_malloc(N).
2692** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2693** negative then the behavior is exactly the same as calling
2694** sqlite3_free(X).
2695** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2696** of at least N bytes in size or NULL if insufficient memory is available.
2697** ^If M is the size of the prior allocation, then min(N,M) bytes
2698** of the prior allocation are copied into the beginning of buffer returned
2699** by sqlite3_realloc(X,N) and the prior allocation is freed.
2700** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2701** prior allocation is not freed.
2702**
2703** ^The sqlite3_realloc64(X,N) interfaces works the same as
2704** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2705** of a 32-bit signed integer.
2706**
2707** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2708** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2709** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2710** ^The value returned by sqlite3_msize(X) might be larger than the number
2711** of bytes requested when X was allocated. ^If X is a NULL pointer then
2712** sqlite3_msize(X) returns zero. If X points to something that is not
2713** the beginning of memory allocation, or if it points to a formerly
2714** valid memory allocation that has now been freed, then the behavior
2715** of sqlite3_msize(X) is undefined and possibly harmful.
2716**
2717** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2718** sqlite3_malloc64(), and sqlite3_realloc64()
2719** is always aligned to at least an 8 byte boundary, or to a
2720** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2721** option is used.
2722**
2723** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2724** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2725** implementation of these routines to be omitted. That capability
2726** is no longer provided. Only built-in memory allocators can be used.
2727**
2728** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2729** the system malloc() and free() directly when converting
2730** filenames between the UTF-8 encoding used by SQLite
2731** and whatever filename encoding is used by the particular Windows
2732** installation. Memory allocation errors were detected, but
2733** they were reported back as [SQLITE_CANTOPEN] or
2734** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2735**
2736** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2737** must be either NULL or else pointers obtained from a prior
2738** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2739** not yet been released.
2740**
2741** The application must not read or write any part of
2742** a block of memory after it has been released using
2743** [sqlite3_free()] or [sqlite3_realloc()].
2744*/
2745SQLITE_API void *sqlite3_malloc(int);
2746SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2747SQLITE_API void *sqlite3_realloc(void*, int);
2748SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2749SQLITE_API void sqlite3_free(void*);
2750SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2751
2752/*
2753** CAPI3REF: Memory Allocator Statistics
2754**
2755** SQLite provides these two interfaces for reporting on the status
2756** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2757** routines, which form the built-in memory allocation subsystem.
2758**
2759** ^The [sqlite3_memory_used()] routine returns the number of bytes
2760** of memory currently outstanding (malloced but not freed).
2761** ^The [sqlite3_memory_highwater()] routine returns the maximum
2762** value of [sqlite3_memory_used()] since the high-water mark
2763** was last reset. ^The values returned by [sqlite3_memory_used()] and
2764** [sqlite3_memory_highwater()] include any overhead
2765** added by SQLite in its implementation of [sqlite3_malloc()],
2766** but not overhead added by the any underlying system library
2767** routines that [sqlite3_malloc()] may call.
2768**
2769** ^The memory high-water mark is reset to the current value of
2770** [sqlite3_memory_used()] if and only if the parameter to
2771** [sqlite3_memory_highwater()] is true. ^The value returned
2772** by [sqlite3_memory_highwater(1)] is the high-water mark
2773** prior to the reset.
2774*/
2775SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2776SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2777
2778/*
2779** CAPI3REF: Pseudo-Random Number Generator
2780**
2781** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2782** select random [ROWID | ROWIDs] when inserting new records into a table that
2783** already uses the largest possible [ROWID]. The PRNG is also used for
2784** the build-in random() and randomblob() SQL functions. This interface allows
2785** applications to access the same PRNG for other purposes.
2786**
2787** ^A call to this routine stores N bytes of randomness into buffer P.
2788** ^The P parameter can be a NULL pointer.
2789**
2790** ^If this routine has not been previously called or if the previous
2791** call had N less than one or a NULL pointer for P, then the PRNG is
2792** seeded using randomness obtained from the xRandomness method of
2793** the default [sqlite3_vfs] object.
2794** ^If the previous call to this routine had an N of 1 or more and a
2795** non-NULL P then the pseudo-randomness is generated
2796** internally and without recourse to the [sqlite3_vfs] xRandomness
2797** method.
2798*/
2799SQLITE_API void sqlite3_randomness(int N, void *P);
2800
2801/*
2802** CAPI3REF: Compile-Time Authorization Callbacks
2803** METHOD: sqlite3
2804** KEYWORDS: {authorizer callback}
2805**
2806** ^This routine registers an authorizer callback with a particular
2807** [database connection], supplied in the first argument.
2808** ^The authorizer callback is invoked as SQL statements are being compiled
2809** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2810** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
2811** and [sqlite3_prepare16_v3()]. ^At various
2812** points during the compilation process, as logic is being created
2813** to perform various actions, the authorizer callback is invoked to
2814** see if those actions are allowed. ^The authorizer callback should
2815** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2816** specific action but allow the SQL statement to continue to be
2817** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2818** rejected with an error. ^If the authorizer callback returns
2819** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2820** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2821** the authorizer will fail with an error message.
2822**
2823** When the callback returns [SQLITE_OK], that means the operation
2824** requested is ok. ^When the callback returns [SQLITE_DENY], the
2825** [sqlite3_prepare_v2()] or equivalent call that triggered the
2826** authorizer will fail with an error message explaining that
2827** access is denied.
2828**
2829** ^The first parameter to the authorizer callback is a copy of the third
2830** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2831** to the callback is an integer [SQLITE_COPY | action code] that specifies
2832** the particular action to be authorized. ^The third through sixth parameters
2833** to the callback are either NULL pointers or zero-terminated strings
2834** that contain additional details about the action to be authorized.
2835** Applications must always be prepared to encounter a NULL pointer in any
2836** of the third through the sixth parameters of the authorization callback.
2837**
2838** ^If the action code is [SQLITE_READ]
2839** and the callback returns [SQLITE_IGNORE] then the
2840** [prepared statement] statement is constructed to substitute
2841** a NULL value in place of the table column that would have
2842** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2843** return can be used to deny an untrusted user access to individual
2844** columns of a table.
2845** ^When a table is referenced by a [SELECT] but no column values are
2846** extracted from that table (for example in a query like
2847** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
2848** is invoked once for that table with a column name that is an empty string.
2849** ^If the action code is [SQLITE_DELETE] and the callback returns
2850** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2851** [truncate optimization] is disabled and all rows are deleted individually.
2852**
2853** An authorizer is used when [sqlite3_prepare | preparing]
2854** SQL statements from an untrusted source, to ensure that the SQL statements
2855** do not try to access data they are not allowed to see, or that they do not
2856** try to execute malicious statements that damage the database. For
2857** example, an application may allow a user to enter arbitrary
2858** SQL queries for evaluation by a database. But the application does
2859** not want the user to be able to make arbitrary changes to the
2860** database. An authorizer could then be put in place while the
2861** user-entered SQL is being [sqlite3_prepare | prepared] that
2862** disallows everything except [SELECT] statements.
2863**
2864** Applications that need to process SQL from untrusted sources
2865** might also consider lowering resource limits using [sqlite3_limit()]
2866** and limiting database size using the [max_page_count] [PRAGMA]
2867** in addition to using an authorizer.
2868**
2869** ^(Only a single authorizer can be in place on a database connection
2870** at a time. Each call to sqlite3_set_authorizer overrides the
2871** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2872** The authorizer is disabled by default.
2873**
2874** The authorizer callback must not do anything that will modify
2875** the database connection that invoked the authorizer callback.
2876** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2877** database connections for the meaning of "modify" in this paragraph.
2878**
2879** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2880** statement might be re-prepared during [sqlite3_step()] due to a
2881** schema change. Hence, the application should ensure that the
2882** correct authorizer callback remains in place during the [sqlite3_step()].
2883**
2884** ^Note that the authorizer callback is invoked only during
2885** [sqlite3_prepare()] or its variants. Authorization is not
2886** performed during statement evaluation in [sqlite3_step()], unless
2887** as stated in the previous paragraph, sqlite3_step() invokes
2888** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2889*/
2890SQLITE_API int sqlite3_set_authorizer(
2891 sqlite3*,
2892 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2893 void *pUserData
2894);
2895
2896/*
2897** CAPI3REF: Authorizer Return Codes
2898**
2899** The [sqlite3_set_authorizer | authorizer callback function] must
2900** return either [SQLITE_OK] or one of these two constants in order
2901** to signal SQLite whether or not the action is permitted. See the
2902** [sqlite3_set_authorizer | authorizer documentation] for additional
2903** information.
2904**
2905** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2906** returned from the [sqlite3_vtab_on_conflict()] interface.
2907*/
2908#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2909#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2910
2911/*
2912** CAPI3REF: Authorizer Action Codes
2913**
2914** The [sqlite3_set_authorizer()] interface registers a callback function
2915** that is invoked to authorize certain SQL statement actions. The
2916** second parameter to the callback is an integer code that specifies
2917** what action is being authorized. These are the integer action codes that
2918** the authorizer callback may be passed.
2919**
2920** These action code values signify what kind of operation is to be
2921** authorized. The 3rd and 4th parameters to the authorization
2922** callback function will be parameters or NULL depending on which of these
2923** codes is used as the second parameter. ^(The 5th parameter to the
2924** authorizer callback is the name of the database ("main", "temp",
2925** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2926** is the name of the inner-most trigger or view that is responsible for
2927** the access attempt or NULL if this access attempt is directly from
2928** top-level SQL code.
2929*/
2930/******************************************* 3rd ************ 4th ***********/
2931#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2932#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2933#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2934#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2935#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2936#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2937#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2938#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2939#define SQLITE_DELETE 9 /* Table Name NULL */
2940#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2941#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2942#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2943#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2944#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2945#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2946#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2947#define SQLITE_DROP_VIEW 17 /* View Name NULL */
2948#define SQLITE_INSERT 18 /* Table Name NULL */
2949#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2950#define SQLITE_READ 20 /* Table Name Column Name */
2951#define SQLITE_SELECT 21 /* NULL NULL */
2952#define SQLITE_TRANSACTION 22 /* Operation NULL */
2953#define SQLITE_UPDATE 23 /* Table Name Column Name */
2954#define SQLITE_ATTACH 24 /* Filename NULL */
2955#define SQLITE_DETACH 25 /* Database Name NULL */
2956#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2957#define SQLITE_REINDEX 27 /* Index Name NULL */
2958#define SQLITE_ANALYZE 28 /* Table Name NULL */
2959#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2960#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2961#define SQLITE_FUNCTION 31 /* NULL Function Name */
2962#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2963#define SQLITE_COPY 0 /* No longer used */
2964#define SQLITE_RECURSIVE 33 /* NULL NULL */
2965
2966/*
2967** CAPI3REF: Tracing And Profiling Functions
2968** METHOD: sqlite3
2969**
2970** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
2971** instead of the routines described here.
2972**
2973** These routines register callback functions that can be used for
2974** tracing and profiling the execution of SQL statements.
2975**
2976** ^The callback function registered by sqlite3_trace() is invoked at
2977** various times when an SQL statement is being run by [sqlite3_step()].
2978** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2979** SQL statement text as the statement first begins executing.
2980** ^(Additional sqlite3_trace() callbacks might occur
2981** as each triggered subprogram is entered. The callbacks for triggers
2982** contain a UTF-8 SQL comment that identifies the trigger.)^
2983**
2984** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2985** the length of [bound parameter] expansion in the output of sqlite3_trace().
2986**
2987** ^The callback function registered by sqlite3_profile() is invoked
2988** as each SQL statement finishes. ^The profile callback contains
2989** the original statement text and an estimate of wall-clock time
2990** of how long that statement took to run. ^The profile callback
2991** time is in units of nanoseconds, however the current implementation
2992** is only capable of millisecond resolution so the six least significant
2993** digits in the time are meaningless. Future versions of SQLite
2994** might provide greater resolution on the profiler callback. The
2995** sqlite3_profile() function is considered experimental and is
2996** subject to change in future versions of SQLite.
2997*/
2998SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
2999 void(*xTrace)(void*,const char*), void*);
3000SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3001 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3002
3003/*
3004** CAPI3REF: SQL Trace Event Codes
3005** KEYWORDS: SQLITE_TRACE
3006**
3007** These constants identify classes of events that can be monitored
3008** using the [sqlite3_trace_v2()] tracing logic. The M argument
3009** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3010** the following constants. ^The first argument to the trace callback
3011** is one of the following constants.
3012**
3013** New tracing constants may be added in future releases.
3014**
3015** ^A trace callback has four arguments: xCallback(T,C,P,X).
3016** ^The T argument is one of the integer type codes above.
3017** ^The C argument is a copy of the context pointer passed in as the
3018** fourth argument to [sqlite3_trace_v2()].
3019** The P and X arguments are pointers whose meanings depend on T.
3020**
3021** <dl>
3022** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3023** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3024** first begins running and possibly at other times during the
3025** execution of the prepared statement, such as at the start of each
3026** trigger subprogram. ^The P argument is a pointer to the
3027** [prepared statement]. ^The X argument is a pointer to a string which
3028** is the unexpanded SQL text of the prepared statement or an SQL comment
3029** that indicates the invocation of a trigger. ^The callback can compute
3030** the same text that would have been returned by the legacy [sqlite3_trace()]
3031** interface by using the X argument when X begins with "--" and invoking
3032** [sqlite3_expanded_sql(P)] otherwise.
3033**
3034** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3035** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3036** information as is provided by the [sqlite3_profile()] callback.
3037** ^The P argument is a pointer to the [prepared statement] and the
3038** X argument points to a 64-bit integer which is the estimated of
3039** the number of nanosecond that the prepared statement took to run.
3040** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3041**
3042** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3043** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3044** statement generates a single row of result.
3045** ^The P argument is a pointer to the [prepared statement] and the
3046** X argument is unused.
3047**
3048** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3049** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3050** connection closes.
3051** ^The P argument is a pointer to the [database connection] object
3052** and the X argument is unused.
3053** </dl>
3054*/
3055#define SQLITE_TRACE_STMT 0x01
3056#define SQLITE_TRACE_PROFILE 0x02
3057#define SQLITE_TRACE_ROW 0x04
3058#define SQLITE_TRACE_CLOSE 0x08
3059
3060/*
3061** CAPI3REF: SQL Trace Hook
3062** METHOD: sqlite3
3063**
3064** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3065** function X against [database connection] D, using property mask M
3066** and context pointer P. ^If the X callback is
3067** NULL or if the M mask is zero, then tracing is disabled. The
3068** M argument should be the bitwise OR-ed combination of
3069** zero or more [SQLITE_TRACE] constants.
3070**
3071** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3072** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3073**
3074** ^The X callback is invoked whenever any of the events identified by
3075** mask M occur. ^The integer return value from the callback is currently
3076** ignored, though this may change in future releases. Callback
3077** implementations should return zero to ensure future compatibility.
3078**
3079** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3080** ^The T argument is one of the [SQLITE_TRACE]
3081** constants to indicate why the callback was invoked.
3082** ^The C argument is a copy of the context pointer.
3083** The P and X arguments are pointers whose meanings depend on T.
3084**
3085** The sqlite3_trace_v2() interface is intended to replace the legacy
3086** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3087** are deprecated.
3088*/
3089SQLITE_API int sqlite3_trace_v2(
3090 sqlite3*,
3091 unsigned uMask,
3092 int(*xCallback)(unsigned,void*,void*,void*),
3093 void *pCtx
3094);
3095
3096/*
3097** CAPI3REF: Query Progress Callbacks
3098** METHOD: sqlite3
3099**
3100** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3101** function X to be invoked periodically during long running calls to
3102** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3103** database connection D. An example use for this
3104** interface is to keep a GUI updated during a large query.
3105**
3106** ^The parameter P is passed through as the only parameter to the
3107** callback function X. ^The parameter N is the approximate number of
3108** [virtual machine instructions] that are evaluated between successive
3109** invocations of the callback X. ^If N is less than one then the progress
3110** handler is disabled.
3111**
3112** ^Only a single progress handler may be defined at one time per
3113** [database connection]; setting a new progress handler cancels the
3114** old one. ^Setting parameter X to NULL disables the progress handler.
3115** ^The progress handler is also disabled by setting N to a value less
3116** than 1.
3117**
3118** ^If the progress callback returns non-zero, the operation is
3119** interrupted. This feature can be used to implement a
3120** "Cancel" button on a GUI progress dialog box.
3121**
3122** The progress handler callback must not do anything that will modify
3123** the database connection that invoked the progress handler.
3124** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3125** database connections for the meaning of "modify" in this paragraph.
3126**
3127*/
3128SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3129
3130/*
3131** CAPI3REF: Opening A New Database Connection
3132** CONSTRUCTOR: sqlite3
3133**
3134** ^These routines open an SQLite database file as specified by the
3135** filename argument. ^The filename argument is interpreted as UTF-8 for
3136** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3137** order for sqlite3_open16(). ^(A [database connection] handle is usually
3138** returned in *ppDb, even if an error occurs. The only exception is that
3139** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3140** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3141** object.)^ ^(If the database is opened (and/or created) successfully, then
3142** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3143** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3144** an English language description of the error following a failure of any
3145** of the sqlite3_open() routines.
3146**
3147** ^The default encoding will be UTF-8 for databases created using
3148** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3149** created using sqlite3_open16() will be UTF-16 in the native byte order.
3150**
3151** Whether or not an error occurs when it is opened, resources
3152** associated with the [database connection] handle should be released by
3153** passing it to [sqlite3_close()] when it is no longer required.
3154**
3155** The sqlite3_open_v2() interface works like sqlite3_open()
3156** except that it accepts two additional parameters for additional control
3157** over the new database connection. ^(The flags parameter to
3158** sqlite3_open_v2() can take one of
3159** the following three values, optionally combined with the
3160** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
3161** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
3162**
3163** <dl>
3164** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3165** <dd>The database is opened in read-only mode. If the database does not
3166** already exist, an error is returned.</dd>)^
3167**
3168** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3169** <dd>The database is opened for reading and writing if possible, or reading
3170** only if the file is write protected by the operating system. In either
3171** case the database must already exist, otherwise an error is returned.</dd>)^
3172**
3173** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3174** <dd>The database is opened for reading and writing, and is created if
3175** it does not already exist. This is the behavior that is always used for
3176** sqlite3_open() and sqlite3_open16().</dd>)^
3177** </dl>
3178**
3179** If the 3rd parameter to sqlite3_open_v2() is not one of the
3180** combinations shown above optionally combined with other
3181** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3182** then the behavior is undefined.
3183**
3184** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
3185** opens in the multi-thread [threading mode] as long as the single-thread
3186** mode has not been set at compile-time or start-time. ^If the
3187** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
3188** in the serialized [threading mode] unless single-thread was
3189** previously selected at compile-time or start-time.
3190** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
3191** eligible to use [shared cache mode], regardless of whether or not shared
3192** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
3193** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
3194** participate in [shared cache mode] even if it is enabled.
3195**
3196** ^The fourth parameter to sqlite3_open_v2() is the name of the
3197** [sqlite3_vfs] object that defines the operating system interface that
3198** the new database connection should use. ^If the fourth parameter is
3199** a NULL pointer then the default [sqlite3_vfs] object is used.
3200**
3201** ^If the filename is ":memory:", then a private, temporary in-memory database
3202** is created for the connection. ^This in-memory database will vanish when
3203** the database connection is closed. Future versions of SQLite might
3204** make use of additional special filenames that begin with the ":" character.
3205** It is recommended that when a database filename actually does begin with
3206** a ":" character you should prefix the filename with a pathname such as
3207** "./" to avoid ambiguity.
3208**
3209** ^If the filename is an empty string, then a private, temporary
3210** on-disk database will be created. ^This private database will be
3211** automatically deleted as soon as the database connection is closed.
3212**
3213** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3214**
3215** ^If [URI filename] interpretation is enabled, and the filename argument
3216** begins with "file:", then the filename is interpreted as a URI. ^URI
3217** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3218** set in the third argument to sqlite3_open_v2(), or if it has
3219** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3220** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3221** URI filename interpretation is turned off
3222** by default, but future releases of SQLite might enable URI filename
3223** interpretation by default. See "[URI filenames]" for additional
3224** information.
3225**
3226** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3227** authority, then it must be either an empty string or the string
3228** "localhost". ^If the authority is not an empty string or "localhost", an
3229** error is returned to the caller. ^The fragment component of a URI, if
3230** present, is ignored.
3231**
3232** ^SQLite uses the path component of the URI as the name of the disk file
3233** which contains the database. ^If the path begins with a '/' character,
3234** then it is interpreted as an absolute path. ^If the path does not begin
3235** with a '/' (meaning that the authority section is omitted from the URI)
3236** then the path is interpreted as a relative path.
3237** ^(On windows, the first component of an absolute path
3238** is a drive specification (e.g. "C:").)^
3239**
3240** [[core URI query parameters]]
3241** The query component of a URI may contain parameters that are interpreted
3242** either by SQLite itself, or by a [VFS | custom VFS implementation].
3243** SQLite and its built-in [VFSes] interpret the
3244** following query parameters:
3245**
3246** <ul>
3247** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3248** a VFS object that provides the operating system interface that should
3249** be used to access the database file on disk. ^If this option is set to
3250** an empty string the default VFS object is used. ^Specifying an unknown
3251** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3252** present, then the VFS specified by the option takes precedence over
3253** the value passed as the fourth parameter to sqlite3_open_v2().
3254**
3255** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3256** "rwc", or "memory". Attempting to set it to any other value is
3257** an error)^.
3258** ^If "ro" is specified, then the database is opened for read-only
3259** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3260** third argument to sqlite3_open_v2(). ^If the mode option is set to
3261** "rw", then the database is opened for read-write (but not create)
3262** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3263** been set. ^Value "rwc" is equivalent to setting both
3264** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3265** set to "memory" then a pure [in-memory database] that never reads
3266** or writes from disk is used. ^It is an error to specify a value for
3267** the mode parameter that is less restrictive than that specified by
3268** the flags passed in the third parameter to sqlite3_open_v2().
3269**
3270** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3271** "private". ^Setting it to "shared" is equivalent to setting the
3272** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3273** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3274** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3275** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3276** a URI filename, its value overrides any behavior requested by setting
3277** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3278**
3279** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3280** [powersafe overwrite] property does or does not apply to the
3281** storage media on which the database file resides.
3282**
3283** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3284** which if set disables file locking in rollback journal modes. This
3285** is useful for accessing a database on a filesystem that does not
3286** support locking. Caution: Database corruption might result if two
3287** or more processes write to the same database and any one of those
3288** processes uses nolock=1.
3289**
3290** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3291** parameter that indicates that the database file is stored on
3292** read-only media. ^When immutable is set, SQLite assumes that the
3293** database file cannot be changed, even by a process with higher
3294** privilege, and so the database is opened read-only and all locking
3295** and change detection is disabled. Caution: Setting the immutable
3296** property on a database file that does in fact change can result
3297** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3298** See also: [SQLITE_IOCAP_IMMUTABLE].
3299**
3300** </ul>
3301**
3302** ^Specifying an unknown parameter in the query component of a URI is not an
3303** error. Future versions of SQLite might understand additional query
3304** parameters. See "[query parameters with special meaning to SQLite]" for
3305** additional information.
3306**
3307** [[URI filename examples]] <h3>URI filename examples</h3>
3308**
3309** <table border="1" align=center cellpadding=5>
3310** <tr><th> URI filenames <th> Results
3311** <tr><td> file:data.db <td>
3312** Open the file "data.db" in the current directory.
3313** <tr><td> file:/home/fred/data.db<br>
3314** file:///home/fred/data.db <br>
3315** file://localhost/home/fred/data.db <br> <td>
3316** Open the database file "/home/fred/data.db".
3317** <tr><td> file://darkstar/home/fred/data.db <td>
3318** An error. "darkstar" is not a recognized authority.
3319** <tr><td style="white-space:nowrap">
3320** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3321** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3322** C:. Note that the %20 escaping in this example is not strictly
3323** necessary - space characters can be used literally
3324** in URI filenames.
3325** <tr><td> file:data.db?mode=ro&cache=private <td>
3326** Open file "data.db" in the current directory for read-only access.
3327** Regardless of whether or not shared-cache mode is enabled by
3328** default, use a private cache.
3329** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3330** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3331** that uses dot-files in place of posix advisory locking.
3332** <tr><td> file:data.db?mode=readonly <td>
3333** An error. "readonly" is not a valid option for the "mode" parameter.
3334** </table>
3335**
3336** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3337** query components of a URI. A hexadecimal escape sequence consists of a
3338** percent sign - "%" - followed by exactly two hexadecimal digits
3339** specifying an octet value. ^Before the path or query components of a
3340** URI filename are interpreted, they are encoded using UTF-8 and all
3341** hexadecimal escape sequences replaced by a single byte containing the
3342** corresponding octet. If this process generates an invalid UTF-8 encoding,
3343** the results are undefined.
3344**
3345** <b>Note to Windows users:</b> The encoding used for the filename argument
3346** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3347** codepage is currently defined. Filenames containing international
3348** characters must be converted to UTF-8 prior to passing them into
3349** sqlite3_open() or sqlite3_open_v2().
3350**
3351** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3352** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3353** features that require the use of temporary files may fail.
3354**
3355** See also: [sqlite3_temp_directory]
3356*/
3357SQLITE_API int sqlite3_open(
3358 const char *filename, /* Database filename (UTF-8) */
3359 sqlite3 **ppDb /* OUT: SQLite db handle */
3360);
3361SQLITE_API int sqlite3_open16(
3362 const void *filename, /* Database filename (UTF-16) */
3363 sqlite3 **ppDb /* OUT: SQLite db handle */
3364);
3365SQLITE_API int sqlite3_open_v2(
3366 const char *filename, /* Database filename (UTF-8) */
3367 sqlite3 **ppDb, /* OUT: SQLite db handle */
3368 int flags, /* Flags */
3369 const char *zVfs /* Name of VFS module to use */
3370);
3371
3372/*
3373** CAPI3REF: Obtain Values For URI Parameters
3374**
3375** These are utility routines, useful to VFS implementations, that check
3376** to see if a database file was a URI that contained a specific query
3377** parameter, and if so obtains the value of that query parameter.
3378**
3379** If F is the database filename pointer passed into the xOpen() method of
3380** a VFS implementation when the flags parameter to xOpen() has one or
3381** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3382** P is the name of the query parameter, then
3383** sqlite3_uri_parameter(F,P) returns the value of the P
3384** parameter if it exists or a NULL pointer if P does not appear as a
3385** query parameter on F. If P is a query parameter of F
3386** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3387** a pointer to an empty string.
3388**
3389** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3390** parameter and returns true (1) or false (0) according to the value
3391** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3392** value of query parameter P is one of "yes", "true", or "on" in any
3393** case or if the value begins with a non-zero number. The
3394** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3395** query parameter P is one of "no", "false", or "off" in any case or
3396** if the value begins with a numeric zero. If P is not a query
3397** parameter on F or if the value of P is does not match any of the
3398** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3399**
3400** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3401** 64-bit signed integer and returns that integer, or D if P does not
3402** exist. If the value of P is something other than an integer, then
3403** zero is returned.
3404**
3405** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3406** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3407** is not a database file pathname pointer that SQLite passed into the xOpen
3408** VFS method, then the behavior of this routine is undefined and probably
3409** undesirable.
3410*/
3411SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3412SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3413SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3414
3415
3416/*
3417** CAPI3REF: Error Codes And Messages
3418** METHOD: sqlite3
3419**
3420** ^If the most recent sqlite3_* API call associated with
3421** [database connection] D failed, then the sqlite3_errcode(D) interface
3422** returns the numeric [result code] or [extended result code] for that
3423** API call.
3424** ^The sqlite3_extended_errcode()
3425** interface is the same except that it always returns the
3426** [extended result code] even when extended result codes are
3427** disabled.
3428**
3429** The values returned by sqlite3_errcode() and/or
3430** sqlite3_extended_errcode() might change with each API call.
3431** Except, there are some interfaces that are guaranteed to never
3432** change the value of the error code. The error-code preserving
3433** interfaces are:
3434**
3435** <ul>
3436** <li> sqlite3_errcode()
3437** <li> sqlite3_extended_errcode()
3438** <li> sqlite3_errmsg()
3439** <li> sqlite3_errmsg16()
3440** </ul>
3441**
3442** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3443** text that describes the error, as either UTF-8 or UTF-16 respectively.
3444** ^(Memory to hold the error message string is managed internally.
3445** The application does not need to worry about freeing the result.
3446** However, the error string might be overwritten or deallocated by
3447** subsequent calls to other SQLite interface functions.)^
3448**
3449** ^The sqlite3_errstr() interface returns the English-language text
3450** that describes the [result code], as UTF-8.
3451** ^(Memory to hold the error message string is managed internally
3452** and must not be freed by the application)^.
3453**
3454** When the serialized [threading mode] is in use, it might be the
3455** case that a second error occurs on a separate thread in between
3456** the time of the first error and the call to these interfaces.
3457** When that happens, the second error will be reported since these
3458** interfaces always report the most recent result. To avoid
3459** this, each thread can obtain exclusive use of the [database connection] D
3460** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3461** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3462** all calls to the interfaces listed here are completed.
3463**
3464** If an interface fails with SQLITE_MISUSE, that means the interface
3465** was invoked incorrectly by the application. In that case, the
3466** error code and message may or may not be set.
3467*/
3468SQLITE_API int sqlite3_errcode(sqlite3 *db);
3469SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3470SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3471SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3472SQLITE_API const char *sqlite3_errstr(int);
3473
3474/*
3475** CAPI3REF: Prepared Statement Object
3476** KEYWORDS: {prepared statement} {prepared statements}
3477**
3478** An instance of this object represents a single SQL statement that
3479** has been compiled into binary form and is ready to be evaluated.
3480**
3481** Think of each SQL statement as a separate computer program. The
3482** original SQL text is source code. A prepared statement object
3483** is the compiled object code. All SQL must be converted into a
3484** prepared statement before it can be run.
3485**
3486** The life-cycle of a prepared statement object usually goes like this:
3487**
3488** <ol>
3489** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3490** <li> Bind values to [parameters] using the sqlite3_bind_*()
3491** interfaces.
3492** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3493** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3494** to step 2. Do this zero or more times.
3495** <li> Destroy the object using [sqlite3_finalize()].
3496** </ol>
3497*/
3498typedef struct sqlite3_stmt sqlite3_stmt;
3499
3500/*
3501** CAPI3REF: Run-time Limits
3502** METHOD: sqlite3
3503**
3504** ^(This interface allows the size of various constructs to be limited
3505** on a connection by connection basis. The first parameter is the
3506** [database connection] whose limit is to be set or queried. The
3507** second parameter is one of the [limit categories] that define a
3508** class of constructs to be size limited. The third parameter is the
3509** new limit for that construct.)^
3510**
3511** ^If the new limit is a negative number, the limit is unchanged.
3512** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3513** [limits | hard upper bound]
3514** set at compile-time by a C preprocessor macro called
3515** [limits | SQLITE_MAX_<i>NAME</i>].
3516** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3517** ^Attempts to increase a limit above its hard upper bound are
3518** silently truncated to the hard upper bound.
3519**
3520** ^Regardless of whether or not the limit was changed, the
3521** [sqlite3_limit()] interface returns the prior value of the limit.
3522** ^Hence, to find the current value of a limit without changing it,
3523** simply invoke this interface with the third parameter set to -1.
3524**
3525** Run-time limits are intended for use in applications that manage
3526** both their own internal database and also databases that are controlled
3527** by untrusted external sources. An example application might be a
3528** web browser that has its own databases for storing history and
3529** separate databases controlled by JavaScript applications downloaded
3530** off the Internet. The internal databases can be given the
3531** large, default limits. Databases managed by external sources can
3532** be given much smaller limits designed to prevent a denial of service
3533** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3534** interface to further control untrusted SQL. The size of the database
3535** created by an untrusted script can be contained using the
3536** [max_page_count] [PRAGMA].
3537**
3538** New run-time limit categories may be added in future releases.
3539*/
3540SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3541
3542/*
3543** CAPI3REF: Run-Time Limit Categories
3544** KEYWORDS: {limit category} {*limit categories}
3545**
3546** These constants define various performance limits
3547** that can be lowered at run-time using [sqlite3_limit()].
3548** The synopsis of the meanings of the various limits is shown below.
3549** Additional information is available at [limits | Limits in SQLite].
3550**
3551** <dl>
3552** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3553** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3554**
3555** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3556** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3557**
3558** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3559** <dd>The maximum number of columns in a table definition or in the
3560** result set of a [SELECT] or the maximum number of columns in an index
3561** or in an ORDER BY or GROUP BY clause.</dd>)^
3562**
3563** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3564** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3565**
3566** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3567** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3568**
3569** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3570** <dd>The maximum number of instructions in a virtual machine program
3571** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3572** the equivalent tries to allocate space for more than this many opcodes
3573** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3574**
3575** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3576** <dd>The maximum number of arguments on a function.</dd>)^
3577**
3578** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3579** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3580**
3581** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3582** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3583** <dd>The maximum length of the pattern argument to the [LIKE] or
3584** [GLOB] operators.</dd>)^
3585**
3586** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3587** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3588** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3589**
3590** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3591** <dd>The maximum depth of recursion for triggers.</dd>)^
3592**
3593** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3594** <dd>The maximum number of auxiliary worker threads that a single
3595** [prepared statement] may start.</dd>)^
3596** </dl>
3597*/
3598#define SQLITE_LIMIT_LENGTH 0
3599#define SQLITE_LIMIT_SQL_LENGTH 1
3600#define SQLITE_LIMIT_COLUMN 2
3601#define SQLITE_LIMIT_EXPR_DEPTH 3
3602#define SQLITE_LIMIT_COMPOUND_SELECT 4
3603#define SQLITE_LIMIT_VDBE_OP 5
3604#define SQLITE_LIMIT_FUNCTION_ARG 6
3605#define SQLITE_LIMIT_ATTACHED 7
3606#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3607#define SQLITE_LIMIT_VARIABLE_NUMBER 9
3608#define SQLITE_LIMIT_TRIGGER_DEPTH 10
3609#define SQLITE_LIMIT_WORKER_THREADS 11
3610
3611/*
3612** CAPI3REF: Prepare Flags
3613**
3614** These constants define various flags that can be passed into
3615** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
3616** [sqlite3_prepare16_v3()] interfaces.
3617**
3618** New flags may be added in future releases of SQLite.
3619**
3620** <dl>
3621** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
3622** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
3623** that the prepared statement will be retained for a long time and
3624** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
3625** and [sqlite3_prepare16_v3()] assume that the prepared statement will
3626** be used just once or at most a few times and then destroyed using
3627** [sqlite3_finalize()] relatively soon. The current implementation acts
3628** on this hint by avoiding the use of [lookaside memory] so as not to
3629** deplete the limited store of lookaside memory. Future versions of
3630** SQLite may act on this hint differently.
3631**
3632** [[SQLITE_PREPARE_NORMALIZE]] ^(<dt>SQLITE_PREPARE_NORMALIZE</dt>
3633** <dd>The SQLITE_PREPARE_NORMALIZE flag indicates that a normalized
3634** representation of the SQL statement should be calculated and then
3635** associated with the prepared statement, which can be obtained via
3636** the [sqlite3_normalized_sql()] interface.)^ The semantics used to
3637** normalize a SQL statement are unspecified and subject to change.
3638** At a minimum, literal values will be replaced with suitable
3639** placeholders.
3640** </dl>
3641*/
3642#define SQLITE_PREPARE_PERSISTENT 0x01
3643#define SQLITE_PREPARE_NORMALIZE 0x02
3644
3645/*
3646** CAPI3REF: Compiling An SQL Statement
3647** KEYWORDS: {SQL statement compiler}
3648** METHOD: sqlite3
3649** CONSTRUCTOR: sqlite3_stmt
3650**
3651** To execute an SQL statement, it must first be compiled into a byte-code
3652** program using one of these routines. Or, in other words, these routines
3653** are constructors for the [prepared statement] object.
3654**
3655** The preferred routine to use is [sqlite3_prepare_v2()]. The
3656** [sqlite3_prepare()] interface is legacy and should be avoided.
3657** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
3658** for special purposes.
3659**
3660** The use of the UTF-8 interfaces is preferred, as SQLite currently
3661** does all parsing using UTF-8. The UTF-16 interfaces are provided
3662** as a convenience. The UTF-16 interfaces work by converting the
3663** input text into UTF-8, then invoking the corresponding UTF-8 interface.
3664**
3665** The first argument, "db", is a [database connection] obtained from a
3666** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3667** [sqlite3_open16()]. The database connection must not have been closed.
3668**
3669** The second argument, "zSql", is the statement to be compiled, encoded
3670** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
3671** and sqlite3_prepare_v3()
3672** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
3673** and sqlite3_prepare16_v3() use UTF-16.
3674**
3675** ^If the nByte argument is negative, then zSql is read up to the
3676** first zero terminator. ^If nByte is positive, then it is the
3677** number of bytes read from zSql. ^If nByte is zero, then no prepared
3678** statement is generated.
3679** If the caller knows that the supplied string is nul-terminated, then
3680** there is a small performance advantage to passing an nByte parameter that
3681** is the number of bytes in the input string <i>including</i>
3682** the nul-terminator.
3683**
3684** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3685** past the end of the first SQL statement in zSql. These routines only
3686** compile the first statement in zSql, so *pzTail is left pointing to
3687** what remains uncompiled.
3688**
3689** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3690** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3691** to NULL. ^If the input text contains no SQL (if the input is an empty
3692** string or a comment) then *ppStmt is set to NULL.
3693** The calling procedure is responsible for deleting the compiled
3694** SQL statement using [sqlite3_finalize()] after it has finished with it.
3695** ppStmt may not be NULL.
3696**
3697** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3698** otherwise an [error code] is returned.
3699**
3700** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
3701** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
3702** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
3703** are retained for backwards compatibility, but their use is discouraged.
3704** ^In the "vX" interfaces, the prepared statement
3705** that is returned (the [sqlite3_stmt] object) contains a copy of the
3706** original SQL text. This causes the [sqlite3_step()] interface to
3707** behave differently in three ways:
3708**
3709** <ol>
3710** <li>
3711** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3712** always used to do, [sqlite3_step()] will automatically recompile the SQL
3713** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3714** retries will occur before sqlite3_step() gives up and returns an error.
3715** </li>
3716**
3717** <li>
3718** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3719** [error codes] or [extended error codes]. ^The legacy behavior was that
3720** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3721** and the application would have to make a second call to [sqlite3_reset()]
3722** in order to find the underlying cause of the problem. With the "v2" prepare
3723** interfaces, the underlying reason for the error is returned immediately.
3724** </li>
3725**
3726** <li>
3727** ^If the specific value bound to [parameter | host parameter] in the
3728** WHERE clause might influence the choice of query plan for a statement,
3729** then the statement will be automatically recompiled, as if there had been
3730** a schema change, on the first [sqlite3_step()] call following any change
3731** to the [sqlite3_bind_text | bindings] of that [parameter].
3732** ^The specific value of WHERE-clause [parameter] might influence the
3733** choice of query plan if the parameter is the left-hand side of a [LIKE]
3734** or [GLOB] operator or if the parameter is compared to an indexed column
3735** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3736** </li>
3737** </ol>
3738**
3739** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
3740** the extra prepFlags parameter, which is a bit array consisting of zero or
3741** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
3742** sqlite3_prepare_v2() interface works exactly the same as
3743** sqlite3_prepare_v3() with a zero prepFlags parameter.
3744*/
3745SQLITE_API int sqlite3_prepare(
3746 sqlite3 *db, /* Database handle */
3747 const char *zSql, /* SQL statement, UTF-8 encoded */
3748 int nByte, /* Maximum length of zSql in bytes. */
3749 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3750 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3751);
3752SQLITE_API int sqlite3_prepare_v2(
3753 sqlite3 *db, /* Database handle */
3754 const char *zSql, /* SQL statement, UTF-8 encoded */
3755 int nByte, /* Maximum length of zSql in bytes. */
3756 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3757 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3758);
3759SQLITE_API int sqlite3_prepare_v3(
3760 sqlite3 *db, /* Database handle */
3761 const char *zSql, /* SQL statement, UTF-8 encoded */
3762 int nByte, /* Maximum length of zSql in bytes. */
3763 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3764 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3765 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3766);
3767SQLITE_API int sqlite3_prepare16(
3768 sqlite3 *db, /* Database handle */
3769 const void *zSql, /* SQL statement, UTF-16 encoded */
3770 int nByte, /* Maximum length of zSql in bytes. */
3771 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3772 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3773);
3774SQLITE_API int sqlite3_prepare16_v2(
3775 sqlite3 *db, /* Database handle */
3776 const void *zSql, /* SQL statement, UTF-16 encoded */
3777 int nByte, /* Maximum length of zSql in bytes. */
3778 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3779 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3780);
3781SQLITE_API int sqlite3_prepare16_v3(
3782 sqlite3 *db, /* Database handle */
3783 const void *zSql, /* SQL statement, UTF-16 encoded */
3784 int nByte, /* Maximum length of zSql in bytes. */
3785 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
3786 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3787 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3788);
3789
3790/*
3791** CAPI3REF: Retrieving Statement SQL
3792** METHOD: sqlite3_stmt
3793**
3794** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
3795** SQL text used to create [prepared statement] P if P was
3796** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
3797** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
3798** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
3799** string containing the SQL text of prepared statement P with
3800** [bound parameters] expanded.
3801** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
3802** string containing the normalized SQL text of prepared statement P. The
3803** semantics used to normalize a SQL statement are unspecified and subject
3804** to change. At a minimum, literal values will be replaced with suitable
3805** placeholders.
3806**
3807** ^(For example, if a prepared statement is created using the SQL
3808** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
3809** and parameter :xyz is unbound, then sqlite3_sql() will return
3810** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
3811** will return "SELECT 2345,NULL".)^
3812**
3813** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
3814** is available to hold the result, or if the result would exceed the
3815** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
3816**
3817** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
3818** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
3819** option causes sqlite3_expanded_sql() to always return NULL.
3820**
3821** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
3822** are managed by SQLite and are automatically freed when the prepared
3823** statement is finalized.
3824** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
3825** is obtained from [sqlite3_malloc()] and must be free by the application
3826** by passing it to [sqlite3_free()].
3827*/
3828SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
3829SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
3830SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
3831
3832/*
3833** CAPI3REF: Determine If An SQL Statement Writes The Database
3834** METHOD: sqlite3_stmt
3835**
3836** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3837** and only if the [prepared statement] X makes no direct changes to
3838** the content of the database file.
3839**
3840** Note that [application-defined SQL functions] or
3841** [virtual tables] might change the database indirectly as a side effect.
3842** ^(For example, if an application defines a function "eval()" that
3843** calls [sqlite3_exec()], then the following SQL statement would
3844** change the database file through side-effects:
3845**
3846** <blockquote><pre>
3847** SELECT eval('DELETE FROM t1') FROM t2;
3848** </pre></blockquote>
3849**
3850** But because the [SELECT] statement does not change the database file
3851** directly, sqlite3_stmt_readonly() would still return true.)^
3852**
3853** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3854** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3855** since the statements themselves do not actually modify the database but
3856** rather they control the timing of when other statements modify the
3857** database. ^The [ATTACH] and [DETACH] statements also cause
3858** sqlite3_stmt_readonly() to return true since, while those statements
3859** change the configuration of a database connection, they do not make
3860** changes to the content of the database files on disk.
3861** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
3862** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
3863** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
3864** sqlite3_stmt_readonly() returns false for those commands.
3865*/
3866SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3867
3868/*
3869** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3870** METHOD: sqlite3_stmt
3871**
3872** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3873** [prepared statement] S has been stepped at least once using
3874** [sqlite3_step(S)] but has neither run to completion (returned
3875** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3876** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3877** interface returns false if S is a NULL pointer. If S is not a
3878** NULL pointer and is not a pointer to a valid [prepared statement]
3879** object, then the behavior is undefined and probably undesirable.
3880**
3881** This interface can be used in combination [sqlite3_next_stmt()]
3882** to locate all prepared statements associated with a database
3883** connection that are in need of being reset. This can be used,
3884** for example, in diagnostic routines to search for prepared
3885** statements that are holding a transaction open.
3886*/
3887SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
3888
3889/*
3890** CAPI3REF: Dynamically Typed Value Object
3891** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3892**
3893** SQLite uses the sqlite3_value object to represent all values
3894** that can be stored in a database table. SQLite uses dynamic typing
3895** for the values it stores. ^Values stored in sqlite3_value objects
3896** can be integers, floating point values, strings, BLOBs, or NULL.
3897**
3898** An sqlite3_value object may be either "protected" or "unprotected".
3899** Some interfaces require a protected sqlite3_value. Other interfaces
3900** will accept either a protected or an unprotected sqlite3_value.
3901** Every interface that accepts sqlite3_value arguments specifies
3902** whether or not it requires a protected sqlite3_value. The
3903** [sqlite3_value_dup()] interface can be used to construct a new
3904** protected sqlite3_value from an unprotected sqlite3_value.
3905**
3906** The terms "protected" and "unprotected" refer to whether or not
3907** a mutex is held. An internal mutex is held for a protected
3908** sqlite3_value object but no mutex is held for an unprotected
3909** sqlite3_value object. If SQLite is compiled to be single-threaded
3910** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3911** or if SQLite is run in one of reduced mutex modes
3912** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3913** then there is no distinction between protected and unprotected
3914** sqlite3_value objects and they can be used interchangeably. However,
3915** for maximum code portability it is recommended that applications
3916** still make the distinction between protected and unprotected
3917** sqlite3_value objects even when not strictly required.
3918**
3919** ^The sqlite3_value objects that are passed as parameters into the
3920** implementation of [application-defined SQL functions] are protected.
3921** ^The sqlite3_value object returned by
3922** [sqlite3_column_value()] is unprotected.
3923** Unprotected sqlite3_value objects may only be used as arguments
3924** to [sqlite3_result_value()], [sqlite3_bind_value()], and
3925** [sqlite3_value_dup()].
3926** The [sqlite3_value_blob | sqlite3_value_type()] family of
3927** interfaces require protected sqlite3_value objects.
3928*/
3929typedef struct sqlite3_value sqlite3_value;
3930
3931/*
3932** CAPI3REF: SQL Function Context Object
3933**
3934** The context in which an SQL function executes is stored in an
3935** sqlite3_context object. ^A pointer to an sqlite3_context object
3936** is always first parameter to [application-defined SQL functions].
3937** The application-defined SQL function implementation will pass this
3938** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3939** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3940** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3941** and/or [sqlite3_set_auxdata()].
3942*/
3943typedef struct sqlite3_context sqlite3_context;
3944
3945/*
3946** CAPI3REF: Binding Values To Prepared Statements
3947** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3948** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3949** METHOD: sqlite3_stmt
3950**
3951** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3952** literals may be replaced by a [parameter] that matches one of following
3953** templates:
3954**
3955** <ul>
3956** <li> ?
3957** <li> ?NNN
3958** <li> :VVV
3959** <li> @VVV
3960** <li> $VVV
3961** </ul>
3962**
3963** In the templates above, NNN represents an integer literal,
3964** and VVV represents an alphanumeric identifier.)^ ^The values of these
3965** parameters (also called "host parameter names" or "SQL parameters")
3966** can be set using the sqlite3_bind_*() routines defined here.
3967**
3968** ^The first argument to the sqlite3_bind_*() routines is always
3969** a pointer to the [sqlite3_stmt] object returned from
3970** [sqlite3_prepare_v2()] or its variants.
3971**
3972** ^The second argument is the index of the SQL parameter to be set.
3973** ^The leftmost SQL parameter has an index of 1. ^When the same named
3974** SQL parameter is used more than once, second and subsequent
3975** occurrences have the same index as the first occurrence.
3976** ^The index for named parameters can be looked up using the
3977** [sqlite3_bind_parameter_index()] API if desired. ^The index
3978** for "?NNN" parameters is the value of NNN.
3979** ^The NNN value must be between 1 and the [sqlite3_limit()]
3980** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3981**
3982** ^The third argument is the value to bind to the parameter.
3983** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3984** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3985** is ignored and the end result is the same as sqlite3_bind_null().
3986**
3987** ^(In those routines that have a fourth argument, its value is the
3988** number of bytes in the parameter. To be clear: the value is the
3989** number of <u>bytes</u> in the value, not the number of characters.)^
3990** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3991** is negative, then the length of the string is
3992** the number of bytes up to the first zero terminator.
3993** If the fourth parameter to sqlite3_bind_blob() is negative, then
3994** the behavior is undefined.
3995** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3996** or sqlite3_bind_text16() or sqlite3_bind_text64() then
3997** that parameter must be the byte offset
3998** where the NUL terminator would occur assuming the string were NUL
3999** terminated. If any NUL characters occur at byte offsets less than
4000** the value of the fourth parameter then the resulting string value will
4001** contain embedded NULs. The result of expressions involving strings
4002** with embedded NULs is undefined.
4003**
4004** ^The fifth argument to the BLOB and string binding interfaces
4005** is a destructor used to dispose of the BLOB or
4006** string after SQLite has finished with it. ^The destructor is called
4007** to dispose of the BLOB or string even if the call to bind API fails.
4008** ^If the fifth argument is
4009** the special value [SQLITE_STATIC], then SQLite assumes that the
4010** information is in static, unmanaged space and does not need to be freed.
4011** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
4012** SQLite makes its own private copy of the data immediately, before
4013** the sqlite3_bind_*() routine returns.
4014**
4015** ^The sixth argument to sqlite3_bind_text64() must be one of
4016** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4017** to specify the encoding of the text in the third parameter. If
4018** the sixth argument to sqlite3_bind_text64() is not one of the
4019** allowed values shown above, or if the text encoding is different
4020** from the encoding specified by the sixth parameter, then the behavior
4021** is undefined.
4022**
4023** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4024** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4025** (just an integer to hold its size) while it is being processed.
4026** Zeroblobs are intended to serve as placeholders for BLOBs whose
4027** content is later written using
4028** [sqlite3_blob_open | incremental BLOB I/O] routines.
4029** ^A negative value for the zeroblob results in a zero-length BLOB.
4030**
4031** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4032** [prepared statement] S to have an SQL value of NULL, but to also be
4033** associated with the pointer P of type T. ^D is either a NULL pointer or
4034** a pointer to a destructor function for P. ^SQLite will invoke the
4035** destructor D with a single argument of P when it is finished using
4036** P. The T parameter should be a static string, preferably a string
4037** literal. The sqlite3_bind_pointer() routine is part of the
4038** [pointer passing interface] added for SQLite 3.20.0.
4039**
4040** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4041** for the [prepared statement] or with a prepared statement for which
4042** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4043** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4044** routine is passed a [prepared statement] that has been finalized, the
4045** result is undefined and probably harmful.
4046**
4047** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4048** ^Unbound parameters are interpreted as NULL.
4049**
4050** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4051** [error code] if anything goes wrong.
4052** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4053** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4054** [SQLITE_MAX_LENGTH].
4055** ^[SQLITE_RANGE] is returned if the parameter
4056** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4057**
4058** See also: [sqlite3_bind_parameter_count()],
4059** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4060*/
4061SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4062SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4063 void(*)(void*));
4064SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4065SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4066SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4067SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4068SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4069SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4070SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4071 void(*)(void*), unsigned char encoding);
4072SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4073SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4074SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4075SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4076
4077/*
4078** CAPI3REF: Number Of SQL Parameters
4079** METHOD: sqlite3_stmt
4080**
4081** ^This routine can be used to find the number of [SQL parameters]
4082** in a [prepared statement]. SQL parameters are tokens of the
4083** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4084** placeholders for values that are [sqlite3_bind_blob | bound]
4085** to the parameters at a later time.
4086**
4087** ^(This routine actually returns the index of the largest (rightmost)
4088** parameter. For all forms except ?NNN, this will correspond to the
4089** number of unique parameters. If parameters of the ?NNN form are used,
4090** there may be gaps in the list.)^
4091**
4092** See also: [sqlite3_bind_blob|sqlite3_bind()],
4093** [sqlite3_bind_parameter_name()], and
4094** [sqlite3_bind_parameter_index()].
4095*/
4096SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4097
4098/*
4099** CAPI3REF: Name Of A Host Parameter
4100** METHOD: sqlite3_stmt
4101**
4102** ^The sqlite3_bind_parameter_name(P,N) interface returns
4103** the name of the N-th [SQL parameter] in the [prepared statement] P.
4104** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4105** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4106** respectively.
4107** In other words, the initial ":" or "$" or "@" or "?"
4108** is included as part of the name.)^
4109** ^Parameters of the form "?" without a following integer have no name
4110** and are referred to as "nameless" or "anonymous parameters".
4111**
4112** ^The first host parameter has an index of 1, not 0.
4113**
4114** ^If the value N is out of range or if the N-th parameter is
4115** nameless, then NULL is returned. ^The returned string is
4116** always in UTF-8 encoding even if the named parameter was
4117** originally specified as UTF-16 in [sqlite3_prepare16()],
4118** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4119**
4120** See also: [sqlite3_bind_blob|sqlite3_bind()],
4121** [sqlite3_bind_parameter_count()], and
4122** [sqlite3_bind_parameter_index()].
4123*/
4124SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4125
4126/*
4127** CAPI3REF: Index Of A Parameter With A Given Name
4128** METHOD: sqlite3_stmt
4129**
4130** ^Return the index of an SQL parameter given its name. ^The
4131** index value returned is suitable for use as the second
4132** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4133** is returned if no matching parameter is found. ^The parameter
4134** name must be given in UTF-8 even if the original statement
4135** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4136** [sqlite3_prepare16_v3()].
4137**
4138** See also: [sqlite3_bind_blob|sqlite3_bind()],
4139** [sqlite3_bind_parameter_count()], and
4140** [sqlite3_bind_parameter_name()].
4141*/
4142SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4143
4144/*
4145** CAPI3REF: Reset All Bindings On A Prepared Statement
4146** METHOD: sqlite3_stmt
4147**
4148** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4149** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4150** ^Use this routine to reset all host parameters to NULL.
4151*/
4152SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4153
4154/*
4155** CAPI3REF: Number Of Columns In A Result Set
4156** METHOD: sqlite3_stmt
4157**
4158** ^Return the number of columns in the result set returned by the
4159** [prepared statement]. ^If this routine returns 0, that means the
4160** [prepared statement] returns no data (for example an [UPDATE]).
4161** ^However, just because this routine returns a positive number does not
4162** mean that one or more rows of data will be returned. ^A SELECT statement
4163** will always have a positive sqlite3_column_count() but depending on the
4164** WHERE clause constraints and the table content, it might return no rows.
4165**
4166** See also: [sqlite3_data_count()]
4167*/
4168SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4169
4170/*
4171** CAPI3REF: Column Names In A Result Set
4172** METHOD: sqlite3_stmt
4173**
4174** ^These routines return the name assigned to a particular column
4175** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4176** interface returns a pointer to a zero-terminated UTF-8 string
4177** and sqlite3_column_name16() returns a pointer to a zero-terminated
4178** UTF-16 string. ^The first parameter is the [prepared statement]
4179** that implements the [SELECT] statement. ^The second parameter is the
4180** column number. ^The leftmost column is number 0.
4181**
4182** ^The returned string pointer is valid until either the [prepared statement]
4183** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4184** reprepared by the first call to [sqlite3_step()] for a particular run
4185** or until the next call to
4186** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4187**
4188** ^If sqlite3_malloc() fails during the processing of either routine
4189** (for example during a conversion from UTF-8 to UTF-16) then a
4190** NULL pointer is returned.
4191**
4192** ^The name of a result column is the value of the "AS" clause for
4193** that column, if there is an AS clause. If there is no AS clause
4194** then the name of the column is unspecified and may change from
4195** one release of SQLite to the next.
4196*/
4197SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4198SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4199
4200/*
4201** CAPI3REF: Source Of Data In A Query Result
4202** METHOD: sqlite3_stmt
4203**
4204** ^These routines provide a means to determine the database, table, and
4205** table column that is the origin of a particular result column in
4206** [SELECT] statement.
4207** ^The name of the database or table or column can be returned as
4208** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4209** the database name, the _table_ routines return the table name, and
4210** the origin_ routines return the column name.
4211** ^The returned string is valid until the [prepared statement] is destroyed
4212** using [sqlite3_finalize()] or until the statement is automatically
4213** reprepared by the first call to [sqlite3_step()] for a particular run
4214** or until the same information is requested
4215** again in a different encoding.
4216**
4217** ^The names returned are the original un-aliased names of the
4218** database, table, and column.
4219**
4220** ^The first argument to these interfaces is a [prepared statement].
4221** ^These functions return information about the Nth result column returned by
4222** the statement, where N is the second function argument.
4223** ^The left-most column is column 0 for these routines.
4224**
4225** ^If the Nth column returned by the statement is an expression or
4226** subquery and is not a column value, then all of these functions return
4227** NULL. ^These routine might also return NULL if a memory allocation error
4228** occurs. ^Otherwise, they return the name of the attached database, table,
4229** or column that query result column was extracted from.
4230**
4231** ^As with all other SQLite APIs, those whose names end with "16" return
4232** UTF-16 encoded strings and the other functions return UTF-8.
4233**
4234** ^These APIs are only available if the library was compiled with the
4235** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4236**
4237** If two or more threads call one or more of these routines against the same
4238** prepared statement and column at the same time then the results are
4239** undefined.
4240**
4241** If two or more threads call one or more
4242** [sqlite3_column_database_name | column metadata interfaces]
4243** for the same [prepared statement] and result column
4244** at the same time then the results are undefined.
4245*/
4246SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4247SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4248SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4249SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4250SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4251SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4252
4253/*
4254** CAPI3REF: Declared Datatype Of A Query Result
4255** METHOD: sqlite3_stmt
4256**
4257** ^(The first parameter is a [prepared statement].
4258** If this statement is a [SELECT] statement and the Nth column of the
4259** returned result set of that [SELECT] is a table column (not an
4260** expression or subquery) then the declared type of the table
4261** column is returned.)^ ^If the Nth column of the result set is an
4262** expression or subquery, then a NULL pointer is returned.
4263** ^The returned string is always UTF-8 encoded.
4264**
4265** ^(For example, given the database schema:
4266**
4267** CREATE TABLE t1(c1 VARIANT);
4268**
4269** and the following statement to be compiled:
4270**
4271** SELECT c1 + 1, c1 FROM t1;
4272**
4273** this routine would return the string "VARIANT" for the second result
4274** column (i==1), and a NULL pointer for the first result column (i==0).)^
4275**
4276** ^SQLite uses dynamic run-time typing. ^So just because a column
4277** is declared to contain a particular type does not mean that the
4278** data stored in that column is of the declared type. SQLite is
4279** strongly typed, but the typing is dynamic not static. ^Type
4280** is associated with individual values, not with the containers
4281** used to hold those values.
4282*/
4283SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4284SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4285
4286/*
4287** CAPI3REF: Evaluate An SQL Statement
4288** METHOD: sqlite3_stmt
4289**
4290** After a [prepared statement] has been prepared using any of
4291** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4292** or [sqlite3_prepare16_v3()] or one of the legacy
4293** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4294** must be called one or more times to evaluate the statement.
4295**
4296** The details of the behavior of the sqlite3_step() interface depend
4297** on whether the statement was prepared using the newer "vX" interfaces
4298** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4299** [sqlite3_prepare16_v2()] or the older legacy
4300** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4301** new "vX" interface is recommended for new applications but the legacy
4302** interface will continue to be supported.
4303**
4304** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4305** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4306** ^With the "v2" interface, any of the other [result codes] or
4307** [extended result codes] might be returned as well.
4308**
4309** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4310** database locks it needs to do its job. ^If the statement is a [COMMIT]
4311** or occurs outside of an explicit transaction, then you can retry the
4312** statement. If the statement is not a [COMMIT] and occurs within an
4313** explicit transaction then you should rollback the transaction before
4314** continuing.
4315**
4316** ^[SQLITE_DONE] means that the statement has finished executing
4317** successfully. sqlite3_step() should not be called again on this virtual
4318** machine without first calling [sqlite3_reset()] to reset the virtual
4319** machine back to its initial state.
4320**
4321** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4322** is returned each time a new row of data is ready for processing by the
4323** caller. The values may be accessed using the [column access functions].
4324** sqlite3_step() is called again to retrieve the next row of data.
4325**
4326** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4327** violation) has occurred. sqlite3_step() should not be called again on
4328** the VM. More information may be found by calling [sqlite3_errmsg()].
4329** ^With the legacy interface, a more specific error code (for example,
4330** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4331** can be obtained by calling [sqlite3_reset()] on the
4332** [prepared statement]. ^In the "v2" interface,
4333** the more specific error code is returned directly by sqlite3_step().
4334**
4335** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4336** Perhaps it was called on a [prepared statement] that has
4337** already been [sqlite3_finalize | finalized] or on one that had
4338** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4339** be the case that the same database connection is being used by two or
4340** more threads at the same moment in time.
4341**
4342** For all versions of SQLite up to and including 3.6.23.1, a call to
4343** [sqlite3_reset()] was required after sqlite3_step() returned anything
4344** other than [SQLITE_ROW] before any subsequent invocation of
4345** sqlite3_step(). Failure to reset the prepared statement using
4346** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4347** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4348** sqlite3_step() began
4349** calling [sqlite3_reset()] automatically in this circumstance rather
4350** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4351** break because any application that ever receives an SQLITE_MISUSE error
4352** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4353** can be used to restore the legacy behavior.
4354**
4355** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4356** API always returns a generic error code, [SQLITE_ERROR], following any
4357** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4358** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4359** specific [error codes] that better describes the error.
4360** We admit that this is a goofy design. The problem has been fixed
4361** with the "v2" interface. If you prepare all of your SQL statements
4362** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4363** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4364** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4365** then the more specific [error codes] are returned directly
4366** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4367*/
4368SQLITE_API int sqlite3_step(sqlite3_stmt*);
4369
4370/*
4371** CAPI3REF: Number of columns in a result set
4372** METHOD: sqlite3_stmt
4373**
4374** ^The sqlite3_data_count(P) interface returns the number of columns in the
4375** current row of the result set of [prepared statement] P.
4376** ^If prepared statement P does not have results ready to return
4377** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
4378** interfaces) then sqlite3_data_count(P) returns 0.
4379** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4380** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4381** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4382** will return non-zero if previous call to [sqlite3_step](P) returned
4383** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4384** where it always returns zero since each step of that multi-step
4385** pragma returns 0 columns of data.
4386**
4387** See also: [sqlite3_column_count()]
4388*/
4389SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4390
4391/*
4392** CAPI3REF: Fundamental Datatypes
4393** KEYWORDS: SQLITE_TEXT
4394**
4395** ^(Every value in SQLite has one of five fundamental datatypes:
4396**
4397** <ul>
4398** <li> 64-bit signed integer
4399** <li> 64-bit IEEE floating point number
4400** <li> string
4401** <li> BLOB
4402** <li> NULL
4403** </ul>)^
4404**
4405** These constants are codes for each of those types.
4406**
4407** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4408** for a completely different meaning. Software that links against both
4409** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4410** SQLITE_TEXT.
4411*/
4412#define SQLITE_INTEGER 1
4413#define SQLITE_FLOAT 2
4414#define SQLITE_BLOB 4
4415#define SQLITE_NULL 5
4416#ifdef SQLITE_TEXT
4417# undef SQLITE_TEXT
4418#else
4419# define SQLITE_TEXT 3
4420#endif
4421#define SQLITE3_TEXT 3
4422
4423/*
4424** CAPI3REF: Result Values From A Query
4425** KEYWORDS: {column access functions}
4426** METHOD: sqlite3_stmt
4427**
4428** <b>Summary:</b>
4429** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4430** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4431** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4432** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4433** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4434** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4435** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4436** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4437** [sqlite3_value|unprotected sqlite3_value] object.
4438** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4439** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4440** or a UTF-8 TEXT result in bytes
4441** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4442** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4443** TEXT in bytes
4444** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4445** datatype of the result
4446** </table></blockquote>
4447**
4448** <b>Details:</b>
4449**
4450** ^These routines return information about a single column of the current
4451** result row of a query. ^In every case the first argument is a pointer
4452** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4453** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4454** and the second argument is the index of the column for which information
4455** should be returned. ^The leftmost column of the result set has the index 0.
4456** ^The number of columns in the result can be determined using
4457** [sqlite3_column_count()].
4458**
4459** If the SQL statement does not currently point to a valid row, or if the
4460** column index is out of range, the result is undefined.
4461** These routines may only be called when the most recent call to
4462** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4463** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4464** If any of these routines are called after [sqlite3_reset()] or
4465** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4466** something other than [SQLITE_ROW], the results are undefined.
4467** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4468** are called from a different thread while any of these routines
4469** are pending, then the results are undefined.
4470**
4471** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4472** each return the value of a result column in a specific data format. If
4473** the result column is not initially in the requested format (for example,
4474** if the query returns an integer but the sqlite3_column_text() interface
4475** is used to extract the value) then an automatic type conversion is performed.
4476**
4477** ^The sqlite3_column_type() routine returns the
4478** [SQLITE_INTEGER | datatype code] for the initial data type
4479** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4480** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4481** The return value of sqlite3_column_type() can be used to decide which
4482** of the first six interface should be used to extract the column value.
4483** The value returned by sqlite3_column_type() is only meaningful if no
4484** automatic type conversions have occurred for the value in question.
4485** After a type conversion, the result of calling sqlite3_column_type()
4486** is undefined, though harmless. Future
4487** versions of SQLite may change the behavior of sqlite3_column_type()
4488** following a type conversion.
4489**
4490** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4491** or sqlite3_column_bytes16() interfaces can be used to determine the size
4492** of that BLOB or string.
4493**
4494** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4495** routine returns the number of bytes in that BLOB or string.
4496** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4497** the string to UTF-8 and then returns the number of bytes.
4498** ^If the result is a numeric value then sqlite3_column_bytes() uses
4499** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4500** the number of bytes in that string.
4501** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4502**
4503** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4504** routine returns the number of bytes in that BLOB or string.
4505** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4506** the string to UTF-16 and then returns the number of bytes.
4507** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4508** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4509** the number of bytes in that string.
4510** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4511**
4512** ^The values returned by [sqlite3_column_bytes()] and
4513** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4514** of the string. ^For clarity: the values returned by
4515** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4516** bytes in the string, not the number of characters.
4517**
4518** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4519** even empty strings, are always zero-terminated. ^The return
4520** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4521**
4522** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4523** [unprotected sqlite3_value] object. In a multithreaded environment,
4524** an unprotected sqlite3_value object may only be used safely with
4525** [sqlite3_bind_value()] and [sqlite3_result_value()].
4526** If the [unprotected sqlite3_value] object returned by
4527** [sqlite3_column_value()] is used in any other way, including calls
4528** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4529** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4530** Hence, the sqlite3_column_value() interface
4531** is normally only useful within the implementation of
4532** [application-defined SQL functions] or [virtual tables], not within
4533** top-level application code.
4534**
4535** The these routines may attempt to convert the datatype of the result.
4536** ^For example, if the internal representation is FLOAT and a text result
4537** is requested, [sqlite3_snprintf()] is used internally to perform the
4538** conversion automatically. ^(The following table details the conversions
4539** that are applied:
4540**
4541** <blockquote>
4542** <table border="1">
4543** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4544**
4545** <tr><td> NULL <td> INTEGER <td> Result is 0
4546** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4547** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4548** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4549** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4550** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4551** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4552** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4553** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4554** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4555** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4556** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4557** <tr><td> TEXT <td> BLOB <td> No change
4558** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4559** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4560** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4561** </table>
4562** </blockquote>)^
4563**
4564** Note that when type conversions occur, pointers returned by prior
4565** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4566** sqlite3_column_text16() may be invalidated.
4567** Type conversions and pointer invalidations might occur
4568** in the following cases:
4569**
4570** <ul>
4571** <li> The initial content is a BLOB and sqlite3_column_text() or
4572** sqlite3_column_text16() is called. A zero-terminator might
4573** need to be added to the string.</li>
4574** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4575** sqlite3_column_text16() is called. The content must be converted
4576** to UTF-16.</li>
4577** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4578** sqlite3_column_text() is called. The content must be converted
4579** to UTF-8.</li>
4580** </ul>
4581**
4582** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4583** not invalidate a prior pointer, though of course the content of the buffer
4584** that the prior pointer references will have been modified. Other kinds
4585** of conversion are done in place when it is possible, but sometimes they
4586** are not possible and in those cases prior pointers are invalidated.
4587**
4588** The safest policy is to invoke these routines
4589** in one of the following ways:
4590**
4591** <ul>
4592** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4593** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4594** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4595** </ul>
4596**
4597** In other words, you should call sqlite3_column_text(),
4598** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4599** into the desired format, then invoke sqlite3_column_bytes() or
4600** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4601** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4602** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4603** with calls to sqlite3_column_bytes().
4604**
4605** ^The pointers returned are valid until a type conversion occurs as
4606** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4607** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4608** and BLOBs is freed automatically. Do not pass the pointers returned
4609** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4610** [sqlite3_free()].
4611**
4612** As long as the input parameters are correct, these routines will only
4613** fail if an out-of-memory error occurs during a format conversion.
4614** Only the following subset of interfaces are subject to out-of-memory
4615** errors:
4616**
4617** <ul>
4618** <li> sqlite3_column_blob()
4619** <li> sqlite3_column_text()
4620** <li> sqlite3_column_text16()
4621** <li> sqlite3_column_bytes()
4622** <li> sqlite3_column_bytes16()
4623** </ul>
4624**
4625** If an out-of-memory error occurs, then the return value from these
4626** routines is the same as if the column had contained an SQL NULL value.
4627** Valid SQL NULL returns can be distinguished from out-of-memory errors
4628** by invoking the [sqlite3_errcode()] immediately after the suspect
4629** return value is obtained and before any
4630** other SQLite interface is called on the same [database connection].
4631*/
4632SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
4633SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
4634SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
4635SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
4636SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
4637SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
4638SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
4639SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4640SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4641SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
4642
4643/*
4644** CAPI3REF: Destroy A Prepared Statement Object
4645** DESTRUCTOR: sqlite3_stmt
4646**
4647** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4648** ^If the most recent evaluation of the statement encountered no errors
4649** or if the statement is never been evaluated, then sqlite3_finalize() returns
4650** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4651** sqlite3_finalize(S) returns the appropriate [error code] or
4652** [extended error code].
4653**
4654** ^The sqlite3_finalize(S) routine can be called at any point during
4655** the life cycle of [prepared statement] S:
4656** before statement S is ever evaluated, after
4657** one or more calls to [sqlite3_reset()], or after any call
4658** to [sqlite3_step()] regardless of whether or not the statement has
4659** completed execution.
4660**
4661** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4662**
4663** The application must finalize every [prepared statement] in order to avoid
4664** resource leaks. It is a grievous error for the application to try to use
4665** a prepared statement after it has been finalized. Any use of a prepared
4666** statement after it has been finalized can result in undefined and
4667** undesirable behavior such as segfaults and heap corruption.
4668*/
4669SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
4670
4671/*
4672** CAPI3REF: Reset A Prepared Statement Object
4673** METHOD: sqlite3_stmt
4674**
4675** The sqlite3_reset() function is called to reset a [prepared statement]
4676** object back to its initial state, ready to be re-executed.
4677** ^Any SQL statement variables that had values bound to them using
4678** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4679** Use [sqlite3_clear_bindings()] to reset the bindings.
4680**
4681** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4682** back to the beginning of its program.
4683**
4684** ^If the most recent call to [sqlite3_step(S)] for the
4685** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4686** or if [sqlite3_step(S)] has never before been called on S,
4687** then [sqlite3_reset(S)] returns [SQLITE_OK].
4688**
4689** ^If the most recent call to [sqlite3_step(S)] for the
4690** [prepared statement] S indicated an error, then
4691** [sqlite3_reset(S)] returns an appropriate [error code].
4692**
4693** ^The [sqlite3_reset(S)] interface does not change the values
4694** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4695*/
4696SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
4697
4698/*
4699** CAPI3REF: Create Or Redefine SQL Functions
4700** KEYWORDS: {function creation routines}
4701** KEYWORDS: {application-defined SQL function}
4702** KEYWORDS: {application-defined SQL functions}
4703** METHOD: sqlite3
4704**
4705** ^These functions (collectively known as "function creation routines")
4706** are used to add SQL functions or aggregates or to redefine the behavior
4707** of existing SQL functions or aggregates. The only differences between
4708** the three "sqlite3_create_function*" routines are the text encoding
4709** expected for the second parameter (the name of the function being
4710** created) and the presence or absence of a destructor callback for
4711** the application data pointer. Function sqlite3_create_window_function()
4712** is similar, but allows the user to supply the extra callback functions
4713** needed by [aggregate window functions].
4714**
4715** ^The first parameter is the [database connection] to which the SQL
4716** function is to be added. ^If an application uses more than one database
4717** connection then application-defined SQL functions must be added
4718** to each database connection separately.
4719**
4720** ^The second parameter is the name of the SQL function to be created or
4721** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
4722** representation, exclusive of the zero-terminator. ^Note that the name
4723** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4724** ^Any attempt to create a function with a longer name
4725** will result in [SQLITE_MISUSE] being returned.
4726**
4727** ^The third parameter (nArg)
4728** is the number of arguments that the SQL function or
4729** aggregate takes. ^If this parameter is -1, then the SQL function or
4730** aggregate may take any number of arguments between 0 and the limit
4731** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
4732** parameter is less than -1 or greater than 127 then the behavior is
4733** undefined.
4734**
4735** ^The fourth parameter, eTextRep, specifies what
4736** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4737** its parameters. The application should set this parameter to
4738** [SQLITE_UTF16LE] if the function implementation invokes
4739** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4740** implementation invokes [sqlite3_value_text16be()] on an input, or
4741** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4742** otherwise. ^The same SQL function may be registered multiple times using
4743** different preferred text encodings, with different implementations for
4744** each encoding.
4745** ^When multiple implementations of the same function are available, SQLite
4746** will pick the one that involves the least amount of data conversion.
4747**
4748** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4749** to signal that the function will always return the same result given
4750** the same inputs within a single SQL statement. Most SQL functions are
4751** deterministic. The built-in [random()] SQL function is an example of a
4752** function that is not deterministic. The SQLite query planner is able to
4753** perform additional optimizations on deterministic functions, so use
4754** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4755**
4756** ^(The fifth parameter is an arbitrary pointer. The implementation of the
4757** function can gain access to this pointer using [sqlite3_user_data()].)^
4758**
4759** ^The sixth, seventh and eighth parameters passed to the three
4760** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
4761** pointers to C-language functions that implement the SQL function or
4762** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4763** callback only; NULL pointers must be passed as the xStep and xFinal
4764** parameters. ^An aggregate SQL function requires an implementation of xStep
4765** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4766** SQL function or aggregate, pass NULL pointers for all three function
4767** callbacks.
4768**
4769** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
4770** and xInverse) passed to sqlite3_create_window_function are pointers to
4771** C-language callbacks that implement the new function. xStep and xFinal
4772** must both be non-NULL. xValue and xInverse may either both be NULL, in
4773** which case a regular aggregate function is created, or must both be
4774** non-NULL, in which case the new function may be used as either an aggregate
4775** or aggregate window function. More details regarding the implementation
4776** of aggregate window functions are
4777** [user-defined window functions|available here].
4778**
4779** ^(If the final parameter to sqlite3_create_function_v2() or
4780** sqlite3_create_window_function() is not NULL, then it is destructor for
4781** the application data pointer. The destructor is invoked when the function
4782** is deleted, either by being overloaded or when the database connection
4783** closes.)^ ^The destructor is also invoked if the call to
4784** sqlite3_create_function_v2() fails. ^When the destructor callback is
4785** invoked, it is passed a single argument which is a copy of the application
4786** data pointer which was the fifth parameter to sqlite3_create_function_v2().
4787**
4788** ^It is permitted to register multiple implementations of the same
4789** functions with the same name but with either differing numbers of
4790** arguments or differing preferred text encodings. ^SQLite will use
4791** the implementation that most closely matches the way in which the
4792** SQL function is used. ^A function implementation with a non-negative
4793** nArg parameter is a better match than a function implementation with
4794** a negative nArg. ^A function where the preferred text encoding
4795** matches the database encoding is a better
4796** match than a function where the encoding is different.
4797** ^A function where the encoding difference is between UTF16le and UTF16be
4798** is a closer match than a function where the encoding difference is
4799** between UTF8 and UTF16.
4800**
4801** ^Built-in functions may be overloaded by new application-defined functions.
4802**
4803** ^An application-defined function is permitted to call other
4804** SQLite interfaces. However, such calls must not
4805** close the database connection nor finalize or reset the prepared
4806** statement in which the function is running.
4807*/
4808SQLITE_API int sqlite3_create_function(
4809 sqlite3 *db,
4810 const char *zFunctionName,
4811 int nArg,
4812 int eTextRep,
4813 void *pApp,
4814 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4815 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4816 void (*xFinal)(sqlite3_context*)
4817);
4818SQLITE_API int sqlite3_create_function16(
4819 sqlite3 *db,
4820 const void *zFunctionName,
4821 int nArg,
4822 int eTextRep,
4823 void *pApp,
4824 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4825 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4826 void (*xFinal)(sqlite3_context*)
4827);
4828SQLITE_API int sqlite3_create_function_v2(
4829 sqlite3 *db,
4830 const char *zFunctionName,
4831 int nArg,
4832 int eTextRep,
4833 void *pApp,
4834 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4835 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4836 void (*xFinal)(sqlite3_context*),
4837 void(*xDestroy)(void*)
4838);
4839SQLITE_API int sqlite3_create_window_function(
4840 sqlite3 *db,
4841 const char *zFunctionName,
4842 int nArg,
4843 int eTextRep,
4844 void *pApp,
4845 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4846 void (*xFinal)(sqlite3_context*),
4847 void (*xValue)(sqlite3_context*),
4848 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
4849 void(*xDestroy)(void*)
4850);
4851
4852/*
4853** CAPI3REF: Text Encodings
4854**
4855** These constant define integer codes that represent the various
4856** text encodings supported by SQLite.
4857*/
4858#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
4859#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
4860#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
4861#define SQLITE_UTF16 4 /* Use native byte order */
4862#define SQLITE_ANY 5 /* Deprecated */
4863#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4864
4865/*
4866** CAPI3REF: Function Flags
4867**
4868** These constants may be ORed together with the
4869** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4870** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4871** [sqlite3_create_function_v2()].
4872*/
4873#define SQLITE_DETERMINISTIC 0x800
4874
4875/*
4876** CAPI3REF: Deprecated Functions
4877** DEPRECATED
4878**
4879** These functions are [deprecated]. In order to maintain
4880** backwards compatibility with older code, these functions continue
4881** to be supported. However, new applications should avoid
4882** the use of these functions. To encourage programmers to avoid
4883** these functions, we will not explain what they do.
4884*/
4885#ifndef SQLITE_OMIT_DEPRECATED
4886SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
4887SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
4888SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4889SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
4890SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
4891SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4892 void*,sqlite3_int64);
4893#endif
4894
4895/*
4896** CAPI3REF: Obtaining SQL Values
4897** METHOD: sqlite3_value
4898**
4899** <b>Summary:</b>
4900** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4901** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
4902** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
4903** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
4904** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
4905** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
4906** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
4907** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
4908** the native byteorder
4909** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
4910** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
4911** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4912** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
4913** or a UTF-8 TEXT in bytes
4914** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
4915** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4916** TEXT in bytes
4917** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
4918** datatype of the value
4919** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
4920** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
4921** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
4922** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
4923** against a virtual table.
4924** </table></blockquote>
4925**
4926** <b>Details:</b>
4927**
4928** These routines extract type, size, and content information from
4929** [protected sqlite3_value] objects. Protected sqlite3_value objects
4930** are used to pass parameter information into implementation of
4931** [application-defined SQL functions] and [virtual tables].
4932**
4933** These routines work only with [protected sqlite3_value] objects.
4934** Any attempt to use these routines on an [unprotected sqlite3_value]
4935** is not threadsafe.
4936**
4937** ^These routines work just like the corresponding [column access functions]
4938** except that these routines take a single [protected sqlite3_value] object
4939** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4940**
4941** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4942** in the native byte-order of the host machine. ^The
4943** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4944** extract UTF-16 strings as big-endian and little-endian respectively.
4945**
4946** ^If [sqlite3_value] object V was initialized
4947** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
4948** and if X and Y are strings that compare equal according to strcmp(X,Y),
4949** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
4950** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
4951** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
4952**
4953** ^(The sqlite3_value_type(V) interface returns the
4954** [SQLITE_INTEGER | datatype code] for the initial datatype of the
4955** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
4956** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
4957** Other interfaces might change the datatype for an sqlite3_value object.
4958** For example, if the datatype is initially SQLITE_INTEGER and
4959** sqlite3_value_text(V) is called to extract a text value for that
4960** integer, then subsequent calls to sqlite3_value_type(V) might return
4961** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
4962** occurs is undefined and may change from one release of SQLite to the next.
4963**
4964** ^(The sqlite3_value_numeric_type() interface attempts to apply
4965** numeric affinity to the value. This means that an attempt is
4966** made to convert the value to an integer or floating point. If
4967** such a conversion is possible without loss of information (in other
4968** words, if the value is a string that looks like a number)
4969** then the conversion is performed. Otherwise no conversion occurs.
4970** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4971**
4972** ^Within the [xUpdate] method of a [virtual table], the
4973** sqlite3_value_nochange(X) interface returns true if and only if
4974** the column corresponding to X is unchanged by the UPDATE operation
4975** that the xUpdate method call was invoked to implement and if
4976** and the prior [xColumn] method call that was invoked to extracted
4977** the value for that column returned without setting a result (probably
4978** because it queried [sqlite3_vtab_nochange()] and found that the column
4979** was unchanging). ^Within an [xUpdate] method, any value for which
4980** sqlite3_value_nochange(X) is true will in all other respects appear
4981** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
4982** than within an [xUpdate] method call for an UPDATE statement, then
4983** the return value is arbitrary and meaningless.
4984**
4985** Please pay particular attention to the fact that the pointer returned
4986** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4987** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4988** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4989** or [sqlite3_value_text16()].
4990**
4991** These routines must be called from the same thread as
4992** the SQL function that supplied the [sqlite3_value*] parameters.
4993**
4994** As long as the input parameter is correct, these routines can only
4995** fail if an out-of-memory error occurs during a format conversion.
4996** Only the following subset of interfaces are subject to out-of-memory
4997** errors:
4998**
4999** <ul>
5000** <li> sqlite3_value_blob()
5001** <li> sqlite3_value_text()
5002** <li> sqlite3_value_text16()
5003** <li> sqlite3_value_text16le()
5004** <li> sqlite3_value_text16be()
5005** <li> sqlite3_value_bytes()
5006** <li> sqlite3_value_bytes16()
5007** </ul>
5008**
5009** If an out-of-memory error occurs, then the return value from these
5010** routines is the same as if the column had contained an SQL NULL value.
5011** Valid SQL NULL returns can be distinguished from out-of-memory errors
5012** by invoking the [sqlite3_errcode()] immediately after the suspect
5013** return value is obtained and before any
5014** other SQLite interface is called on the same [database connection].
5015*/
5016SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5017SQLITE_API double sqlite3_value_double(sqlite3_value*);
5018SQLITE_API int sqlite3_value_int(sqlite3_value*);
5019SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5020SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5021SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5022SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5023SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5024SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5025SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5026SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5027SQLITE_API int sqlite3_value_type(sqlite3_value*);
5028SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5029SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5030
5031/*
5032** CAPI3REF: Finding The Subtype Of SQL Values
5033** METHOD: sqlite3_value
5034**
5035** The sqlite3_value_subtype(V) function returns the subtype for
5036** an [application-defined SQL function] argument V. The subtype
5037** information can be used to pass a limited amount of context from
5038** one SQL function to another. Use the [sqlite3_result_subtype()]
5039** routine to set the subtype for the return value of an SQL function.
5040*/
5041SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5042
5043/*
5044** CAPI3REF: Copy And Free SQL Values
5045** METHOD: sqlite3_value
5046**
5047** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5048** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5049** is a [protected sqlite3_value] object even if the input is not.
5050** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5051** memory allocation fails.
5052**
5053** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5054** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5055** then sqlite3_value_free(V) is a harmless no-op.
5056*/
5057SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5058SQLITE_API void sqlite3_value_free(sqlite3_value*);
5059
5060/*
5061** CAPI3REF: Obtain Aggregate Function Context
5062** METHOD: sqlite3_context
5063**
5064** Implementations of aggregate SQL functions use this
5065** routine to allocate memory for storing their state.
5066**
5067** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5068** for a particular aggregate function, SQLite
5069** allocates N of memory, zeroes out that memory, and returns a pointer
5070** to the new memory. ^On second and subsequent calls to
5071** sqlite3_aggregate_context() for the same aggregate function instance,
5072** the same buffer is returned. Sqlite3_aggregate_context() is normally
5073** called once for each invocation of the xStep callback and then one
5074** last time when the xFinal callback is invoked. ^(When no rows match
5075** an aggregate query, the xStep() callback of the aggregate function
5076** implementation is never called and xFinal() is called exactly once.
5077** In those cases, sqlite3_aggregate_context() might be called for the
5078** first time from within xFinal().)^
5079**
5080** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5081** when first called if N is less than or equal to zero or if a memory
5082** allocate error occurs.
5083**
5084** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5085** determined by the N parameter on first successful call. Changing the
5086** value of N in subsequent call to sqlite3_aggregate_context() within
5087** the same aggregate function instance will not resize the memory
5088** allocation.)^ Within the xFinal callback, it is customary to set
5089** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5090** pointless memory allocations occur.
5091**
5092** ^SQLite automatically frees the memory allocated by
5093** sqlite3_aggregate_context() when the aggregate query concludes.
5094**
5095** The first parameter must be a copy of the
5096** [sqlite3_context | SQL function context] that is the first parameter
5097** to the xStep or xFinal callback routine that implements the aggregate
5098** function.
5099**
5100** This routine must be called from the same thread in which
5101** the aggregate SQL function is running.
5102*/
5103SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5104
5105/*
5106** CAPI3REF: User Data For Functions
5107** METHOD: sqlite3_context
5108**
5109** ^The sqlite3_user_data() interface returns a copy of
5110** the pointer that was the pUserData parameter (the 5th parameter)
5111** of the [sqlite3_create_function()]
5112** and [sqlite3_create_function16()] routines that originally
5113** registered the application defined function.
5114**
5115** This routine must be called from the same thread in which
5116** the application-defined function is running.
5117*/
5118SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5119
5120/*
5121** CAPI3REF: Database Connection For Functions
5122** METHOD: sqlite3_context
5123**
5124** ^The sqlite3_context_db_handle() interface returns a copy of
5125** the pointer to the [database connection] (the 1st parameter)
5126** of the [sqlite3_create_function()]
5127** and [sqlite3_create_function16()] routines that originally
5128** registered the application defined function.
5129*/
5130SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5131
5132/*
5133** CAPI3REF: Function Auxiliary Data
5134** METHOD: sqlite3_context
5135**
5136** These functions may be used by (non-aggregate) SQL functions to
5137** associate metadata with argument values. If the same value is passed to
5138** multiple invocations of the same SQL function during query execution, under
5139** some circumstances the associated metadata may be preserved. An example
5140** of where this might be useful is in a regular-expression matching
5141** function. The compiled version of the regular expression can be stored as
5142** metadata associated with the pattern string.
5143** Then as long as the pattern string remains the same,
5144** the compiled regular expression can be reused on multiple
5145** invocations of the same function.
5146**
5147** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5148** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5149** value to the application-defined function. ^N is zero for the left-most
5150** function argument. ^If there is no metadata
5151** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5152** returns a NULL pointer.
5153**
5154** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5155** argument of the application-defined function. ^Subsequent
5156** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5157** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5158** NULL if the metadata has been discarded.
5159** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5160** SQLite will invoke the destructor function X with parameter P exactly
5161** once, when the metadata is discarded.
5162** SQLite is free to discard the metadata at any time, including: <ul>
5163** <li> ^(when the corresponding function parameter changes)^, or
5164** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5165** SQL statement)^, or
5166** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5167** parameter)^, or
5168** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5169** allocation error occurs.)^ </ul>
5170**
5171** Note the last bullet in particular. The destructor X in
5172** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5173** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5174** should be called near the end of the function implementation and the
5175** function implementation should not make any use of P after
5176** sqlite3_set_auxdata() has been called.
5177**
5178** ^(In practice, metadata is preserved between function calls for
5179** function parameters that are compile-time constants, including literal
5180** values and [parameters] and expressions composed from the same.)^
5181**
5182** The value of the N parameter to these interfaces should be non-negative.
5183** Future enhancements may make use of negative N values to define new
5184** kinds of function caching behavior.
5185**
5186** These routines must be called from the same thread in which
5187** the SQL function is running.
5188*/
5189SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5190SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5191
5192
5193/*
5194** CAPI3REF: Constants Defining Special Destructor Behavior
5195**
5196** These are special values for the destructor that is passed in as the
5197** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5198** argument is SQLITE_STATIC, it means that the content pointer is constant
5199** and will never change. It does not need to be destroyed. ^The
5200** SQLITE_TRANSIENT value means that the content will likely change in
5201** the near future and that SQLite should make its own private copy of
5202** the content before returning.
5203**
5204** The typedef is necessary to work around problems in certain
5205** C++ compilers.
5206*/
5207typedef void (*sqlite3_destructor_type)(void*);
5208#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5209#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5210
5211/*
5212** CAPI3REF: Setting The Result Of An SQL Function
5213** METHOD: sqlite3_context
5214**
5215** These routines are used by the xFunc or xFinal callbacks that
5216** implement SQL functions and aggregates. See
5217** [sqlite3_create_function()] and [sqlite3_create_function16()]
5218** for additional information.
5219**
5220** These functions work very much like the [parameter binding] family of
5221** functions used to bind values to host parameters in prepared statements.
5222** Refer to the [SQL parameter] documentation for additional information.
5223**
5224** ^The sqlite3_result_blob() interface sets the result from
5225** an application-defined function to be the BLOB whose content is pointed
5226** to by the second parameter and which is N bytes long where N is the
5227** third parameter.
5228**
5229** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5230** interfaces set the result of the application-defined function to be
5231** a BLOB containing all zero bytes and N bytes in size.
5232**
5233** ^The sqlite3_result_double() interface sets the result from
5234** an application-defined function to be a floating point value specified
5235** by its 2nd argument.
5236**
5237** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5238** cause the implemented SQL function to throw an exception.
5239** ^SQLite uses the string pointed to by the
5240** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5241** as the text of an error message. ^SQLite interprets the error
5242** message string from sqlite3_result_error() as UTF-8. ^SQLite
5243** interprets the string from sqlite3_result_error16() as UTF-16 in native
5244** byte order. ^If the third parameter to sqlite3_result_error()
5245** or sqlite3_result_error16() is negative then SQLite takes as the error
5246** message all text up through the first zero character.
5247** ^If the third parameter to sqlite3_result_error() or
5248** sqlite3_result_error16() is non-negative then SQLite takes that many
5249** bytes (not characters) from the 2nd parameter as the error message.
5250** ^The sqlite3_result_error() and sqlite3_result_error16()
5251** routines make a private copy of the error message text before
5252** they return. Hence, the calling function can deallocate or
5253** modify the text after they return without harm.
5254** ^The sqlite3_result_error_code() function changes the error code
5255** returned by SQLite as a result of an error in a function. ^By default,
5256** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5257** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5258**
5259** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5260** error indicating that a string or BLOB is too long to represent.
5261**
5262** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5263** error indicating that a memory allocation failed.
5264**
5265** ^The sqlite3_result_int() interface sets the return value
5266** of the application-defined function to be the 32-bit signed integer
5267** value given in the 2nd argument.
5268** ^The sqlite3_result_int64() interface sets the return value
5269** of the application-defined function to be the 64-bit signed integer
5270** value given in the 2nd argument.
5271**
5272** ^The sqlite3_result_null() interface sets the return value
5273** of the application-defined function to be NULL.
5274**
5275** ^The sqlite3_result_text(), sqlite3_result_text16(),
5276** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5277** set the return value of the application-defined function to be
5278** a text string which is represented as UTF-8, UTF-16 native byte order,
5279** UTF-16 little endian, or UTF-16 big endian, respectively.
5280** ^The sqlite3_result_text64() interface sets the return value of an
5281** application-defined function to be a text string in an encoding
5282** specified by the fifth (and last) parameter, which must be one
5283** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5284** ^SQLite takes the text result from the application from
5285** the 2nd parameter of the sqlite3_result_text* interfaces.
5286** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5287** is negative, then SQLite takes result text from the 2nd parameter
5288** through the first zero character.
5289** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5290** is non-negative, then as many bytes (not characters) of the text
5291** pointed to by the 2nd parameter are taken as the application-defined
5292** function result. If the 3rd parameter is non-negative, then it
5293** must be the byte offset into the string where the NUL terminator would
5294** appear if the string where NUL terminated. If any NUL characters occur
5295** in the string at a byte offset that is less than the value of the 3rd
5296** parameter, then the resulting string will contain embedded NULs and the
5297** result of expressions operating on strings with embedded NULs is undefined.
5298** ^If the 4th parameter to the sqlite3_result_text* interfaces
5299** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5300** function as the destructor on the text or BLOB result when it has
5301** finished using that result.
5302** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5303** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5304** assumes that the text or BLOB result is in constant space and does not
5305** copy the content of the parameter nor call a destructor on the content
5306** when it has finished using that result.
5307** ^If the 4th parameter to the sqlite3_result_text* interfaces
5308** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5309** then SQLite makes a copy of the result into space obtained
5310** from [sqlite3_malloc()] before it returns.
5311**
5312** ^The sqlite3_result_value() interface sets the result of
5313** the application-defined function to be a copy of the
5314** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5315** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5316** so that the [sqlite3_value] specified in the parameter may change or
5317** be deallocated after sqlite3_result_value() returns without harm.
5318** ^A [protected sqlite3_value] object may always be used where an
5319** [unprotected sqlite3_value] object is required, so either
5320** kind of [sqlite3_value] object can be used with this interface.
5321**
5322** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5323** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5324** also associates the host-language pointer P or type T with that
5325** NULL value such that the pointer can be retrieved within an
5326** [application-defined SQL function] using [sqlite3_value_pointer()].
5327** ^If the D parameter is not NULL, then it is a pointer to a destructor
5328** for the P parameter. ^SQLite invokes D with P as its only argument
5329** when SQLite is finished with P. The T parameter should be a static
5330** string and preferably a string literal. The sqlite3_result_pointer()
5331** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5332**
5333** If these routines are called from within the different thread
5334** than the one containing the application-defined function that received
5335** the [sqlite3_context] pointer, the results are undefined.
5336*/
5337SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5338SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5339 sqlite3_uint64,void(*)(void*));
5340SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5341SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5342SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5343SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5344SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5345SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5346SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5347SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5348SQLITE_API void sqlite3_result_null(sqlite3_context*);
5349SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5350SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5351 void(*)(void*), unsigned char encoding);
5352SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5353SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5354SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5355SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5356SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5357SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5358SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5359
5360
5361/*
5362** CAPI3REF: Setting The Subtype Of An SQL Function
5363** METHOD: sqlite3_context
5364**
5365** The sqlite3_result_subtype(C,T) function causes the subtype of
5366** the result from the [application-defined SQL function] with
5367** [sqlite3_context] C to be the value T. Only the lower 8 bits
5368** of the subtype T are preserved in current versions of SQLite;
5369** higher order bits are discarded.
5370** The number of subtype bytes preserved by SQLite might increase
5371** in future releases of SQLite.
5372*/
5373SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5374
5375/*
5376** CAPI3REF: Define New Collating Sequences
5377** METHOD: sqlite3
5378**
5379** ^These functions add, remove, or modify a [collation] associated
5380** with the [database connection] specified as the first argument.
5381**
5382** ^The name of the collation is a UTF-8 string
5383** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5384** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5385** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5386** considered to be the same name.
5387**
5388** ^(The third argument (eTextRep) must be one of the constants:
5389** <ul>
5390** <li> [SQLITE_UTF8],
5391** <li> [SQLITE_UTF16LE],
5392** <li> [SQLITE_UTF16BE],
5393** <li> [SQLITE_UTF16], or
5394** <li> [SQLITE_UTF16_ALIGNED].
5395** </ul>)^
5396** ^The eTextRep argument determines the encoding of strings passed
5397** to the collating function callback, xCallback.
5398** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5399** force strings to be UTF16 with native byte order.
5400** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5401** on an even byte address.
5402**
5403** ^The fourth argument, pArg, is an application data pointer that is passed
5404** through as the first argument to the collating function callback.
5405**
5406** ^The fifth argument, xCallback, is a pointer to the collating function.
5407** ^Multiple collating functions can be registered using the same name but
5408** with different eTextRep parameters and SQLite will use whichever
5409** function requires the least amount of data transformation.
5410** ^If the xCallback argument is NULL then the collating function is
5411** deleted. ^When all collating functions having the same name are deleted,
5412** that collation is no longer usable.
5413**
5414** ^The collating function callback is invoked with a copy of the pArg
5415** application data pointer and with two strings in the encoding specified
5416** by the eTextRep argument. The collating function must return an
5417** integer that is negative, zero, or positive
5418** if the first string is less than, equal to, or greater than the second,
5419** respectively. A collating function must always return the same answer
5420** given the same inputs. If two or more collating functions are registered
5421** to the same collation name (using different eTextRep values) then all
5422** must give an equivalent answer when invoked with equivalent strings.
5423** The collating function must obey the following properties for all
5424** strings A, B, and C:
5425**
5426** <ol>
5427** <li> If A==B then B==A.
5428** <li> If A==B and B==C then A==C.
5429** <li> If A&lt;B THEN B&gt;A.
5430** <li> If A&lt;B and B&lt;C then A&lt;C.
5431** </ol>
5432**
5433** If a collating function fails any of the above constraints and that
5434** collating function is registered and used, then the behavior of SQLite
5435** is undefined.
5436**
5437** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
5438** with the addition that the xDestroy callback is invoked on pArg when
5439** the collating function is deleted.
5440** ^Collating functions are deleted when they are overridden by later
5441** calls to the collation creation functions or when the
5442** [database connection] is closed using [sqlite3_close()].
5443**
5444** ^The xDestroy callback is <u>not</u> called if the
5445** sqlite3_create_collation_v2() function fails. Applications that invoke
5446** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
5447** check the return code and dispose of the application data pointer
5448** themselves rather than expecting SQLite to deal with it for them.
5449** This is different from every other SQLite interface. The inconsistency
5450** is unfortunate but cannot be changed without breaking backwards
5451** compatibility.
5452**
5453** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
5454*/
5455SQLITE_API int sqlite3_create_collation(
5456 sqlite3*,
5457 const char *zName,
5458 int eTextRep,
5459 void *pArg,
5460 int(*xCompare)(void*,int,const void*,int,const void*)
5461);
5462SQLITE_API int sqlite3_create_collation_v2(
5463 sqlite3*,
5464 const char *zName,
5465 int eTextRep,
5466 void *pArg,
5467 int(*xCompare)(void*,int,const void*,int,const void*),
5468 void(*xDestroy)(void*)
5469);
5470SQLITE_API int sqlite3_create_collation16(
5471 sqlite3*,
5472 const void *zName,
5473 int eTextRep,
5474 void *pArg,
5475 int(*xCompare)(void*,int,const void*,int,const void*)
5476);
5477
5478/*
5479** CAPI3REF: Collation Needed Callbacks
5480** METHOD: sqlite3
5481**
5482** ^To avoid having to register all collation sequences before a database
5483** can be used, a single callback function may be registered with the
5484** [database connection] to be invoked whenever an undefined collation
5485** sequence is required.
5486**
5487** ^If the function is registered using the sqlite3_collation_needed() API,
5488** then it is passed the names of undefined collation sequences as strings
5489** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
5490** the names are passed as UTF-16 in machine native byte order.
5491** ^A call to either function replaces the existing collation-needed callback.
5492**
5493** ^(When the callback is invoked, the first argument passed is a copy
5494** of the second argument to sqlite3_collation_needed() or
5495** sqlite3_collation_needed16(). The second argument is the database
5496** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
5497** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
5498** sequence function required. The fourth parameter is the name of the
5499** required collation sequence.)^
5500**
5501** The callback function should register the desired collation using
5502** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
5503** [sqlite3_create_collation_v2()].
5504*/
5505SQLITE_API int sqlite3_collation_needed(
5506 sqlite3*,
5507 void*,
5508 void(*)(void*,sqlite3*,int eTextRep,const char*)
5509);
5510SQLITE_API int sqlite3_collation_needed16(
5511 sqlite3*,
5512 void*,
5513 void(*)(void*,sqlite3*,int eTextRep,const void*)
5514);
5515
5516#ifdef SQLITE_HAS_CODEC
5517/*
5518** Specify the key for an encrypted database. This routine should be
5519** called right after sqlite3_open().
5520**
5521** The code to implement this API is not available in the public release
5522** of SQLite.
5523*/
5524SQLITE_API int sqlite3_key(
5525 sqlite3 *db, /* Database to be rekeyed */
5526 const void *pKey, int nKey /* The key */
5527);
5528SQLITE_API int sqlite3_key_v2(
5529 sqlite3 *db, /* Database to be rekeyed */
5530 const char *zDbName, /* Name of the database */
5531 const void *pKey, int nKey /* The key */
5532);
5533
5534/*
5535** Change the key on an open database. If the current database is not
5536** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
5537** database is decrypted.
5538**
5539** The code to implement this API is not available in the public release
5540** of SQLite.
5541*/
5542SQLITE_API int sqlite3_rekey(
5543 sqlite3 *db, /* Database to be rekeyed */
5544 const void *pKey, int nKey /* The new key */
5545);
5546SQLITE_API int sqlite3_rekey_v2(
5547 sqlite3 *db, /* Database to be rekeyed */
5548 const char *zDbName, /* Name of the database */
5549 const void *pKey, int nKey /* The new key */
5550);
5551
5552/*
5553** Specify the activation key for a SEE database. Unless
5554** activated, none of the SEE routines will work.
5555*/
5556SQLITE_API void sqlite3_activate_see(
5557 const char *zPassPhrase /* Activation phrase */
5558);
5559#endif
5560
5561#ifdef SQLITE_ENABLE_CEROD
5562/*
5563** Specify the activation key for a CEROD database. Unless
5564** activated, none of the CEROD routines will work.
5565*/
5566SQLITE_API void sqlite3_activate_cerod(
5567 const char *zPassPhrase /* Activation phrase */
5568);
5569#endif
5570
5571/*
5572** CAPI3REF: Suspend Execution For A Short Time
5573**
5574** The sqlite3_sleep() function causes the current thread to suspend execution
5575** for at least a number of milliseconds specified in its parameter.
5576**
5577** If the operating system does not support sleep requests with
5578** millisecond time resolution, then the time will be rounded up to
5579** the nearest second. The number of milliseconds of sleep actually
5580** requested from the operating system is returned.
5581**
5582** ^SQLite implements this interface by calling the xSleep()
5583** method of the default [sqlite3_vfs] object. If the xSleep() method
5584** of the default VFS is not implemented correctly, or not implemented at
5585** all, then the behavior of sqlite3_sleep() may deviate from the description
5586** in the previous paragraphs.
5587*/
5588SQLITE_API int sqlite3_sleep(int);
5589
5590/*
5591** CAPI3REF: Name Of The Folder Holding Temporary Files
5592**
5593** ^(If this global variable is made to point to a string which is
5594** the name of a folder (a.k.a. directory), then all temporary files
5595** created by SQLite when using a built-in [sqlite3_vfs | VFS]
5596** will be placed in that directory.)^ ^If this variable
5597** is a NULL pointer, then SQLite performs a search for an appropriate
5598** temporary file directory.
5599**
5600** Applications are strongly discouraged from using this global variable.
5601** It is required to set a temporary folder on Windows Runtime (WinRT).
5602** But for all other platforms, it is highly recommended that applications
5603** neither read nor write this variable. This global variable is a relic
5604** that exists for backwards compatibility of legacy applications and should
5605** be avoided in new projects.
5606**
5607** It is not safe to read or modify this variable in more than one
5608** thread at a time. It is not safe to read or modify this variable
5609** if a [database connection] is being used at the same time in a separate
5610** thread.
5611** It is intended that this variable be set once
5612** as part of process initialization and before any SQLite interface
5613** routines have been called and that this variable remain unchanged
5614** thereafter.
5615**
5616** ^The [temp_store_directory pragma] may modify this variable and cause
5617** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5618** the [temp_store_directory pragma] always assumes that any string
5619** that this variable points to is held in memory obtained from
5620** [sqlite3_malloc] and the pragma may attempt to free that memory
5621** using [sqlite3_free].
5622** Hence, if this variable is modified directly, either it should be
5623** made NULL or made to point to memory obtained from [sqlite3_malloc]
5624** or else the use of the [temp_store_directory pragma] should be avoided.
5625** Except when requested by the [temp_store_directory pragma], SQLite
5626** does not free the memory that sqlite3_temp_directory points to. If
5627** the application wants that memory to be freed, it must do
5628** so itself, taking care to only do so after all [database connection]
5629** objects have been destroyed.
5630**
5631** <b>Note to Windows Runtime users:</b> The temporary directory must be set
5632** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
5633** features that require the use of temporary files may fail. Here is an
5634** example of how to do this using C++ with the Windows Runtime:
5635**
5636** <blockquote><pre>
5637** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5638** &nbsp; TemporaryFolder->Path->Data();
5639** char zPathBuf&#91;MAX_PATH + 1&#93;;
5640** memset(zPathBuf, 0, sizeof(zPathBuf));
5641** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5642** &nbsp; NULL, NULL);
5643** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5644** </pre></blockquote>
5645*/
5646SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
5647
5648/*
5649** CAPI3REF: Name Of The Folder Holding Database Files
5650**
5651** ^(If this global variable is made to point to a string which is
5652** the name of a folder (a.k.a. directory), then all database files
5653** specified with a relative pathname and created or accessed by
5654** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5655** to be relative to that directory.)^ ^If this variable is a NULL
5656** pointer, then SQLite assumes that all database files specified
5657** with a relative pathname are relative to the current directory
5658** for the process. Only the windows VFS makes use of this global
5659** variable; it is ignored by the unix VFS.
5660**
5661** Changing the value of this variable while a database connection is
5662** open can result in a corrupt database.
5663**
5664** It is not safe to read or modify this variable in more than one
5665** thread at a time. It is not safe to read or modify this variable
5666** if a [database connection] is being used at the same time in a separate
5667** thread.
5668** It is intended that this variable be set once
5669** as part of process initialization and before any SQLite interface
5670** routines have been called and that this variable remain unchanged
5671** thereafter.
5672**
5673** ^The [data_store_directory pragma] may modify this variable and cause
5674** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5675** the [data_store_directory pragma] always assumes that any string
5676** that this variable points to is held in memory obtained from
5677** [sqlite3_malloc] and the pragma may attempt to free that memory
5678** using [sqlite3_free].
5679** Hence, if this variable is modified directly, either it should be
5680** made NULL or made to point to memory obtained from [sqlite3_malloc]
5681** or else the use of the [data_store_directory pragma] should be avoided.
5682*/
5683SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
5684
5685/*
5686** CAPI3REF: Win32 Specific Interface
5687**
5688** These interfaces are available only on Windows. The
5689** [sqlite3_win32_set_directory] interface is used to set the value associated
5690** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
5691** zValue, depending on the value of the type parameter. The zValue parameter
5692** should be NULL to cause the previous value to be freed via [sqlite3_free];
5693** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
5694** prior to being used. The [sqlite3_win32_set_directory] interface returns
5695** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
5696** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
5697** [sqlite3_data_directory] variable is intended to act as a replacement for
5698** the current directory on the sub-platforms of Win32 where that concept is
5699** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
5700** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
5701** sqlite3_win32_set_directory interface except the string parameter must be
5702** UTF-8 or UTF-16, respectively.
5703*/
5704SQLITE_API int sqlite3_win32_set_directory(
5705 unsigned long type, /* Identifier for directory being set or reset */
5706 void *zValue /* New value for directory being set or reset */
5707);
5708SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
5709SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
5710
5711/*
5712** CAPI3REF: Win32 Directory Types
5713**
5714** These macros are only available on Windows. They define the allowed values
5715** for the type argument to the [sqlite3_win32_set_directory] interface.
5716*/
5717#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
5718#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
5719
5720/*
5721** CAPI3REF: Test For Auto-Commit Mode
5722** KEYWORDS: {autocommit mode}
5723** METHOD: sqlite3
5724**
5725** ^The sqlite3_get_autocommit() interface returns non-zero or
5726** zero if the given database connection is or is not in autocommit mode,
5727** respectively. ^Autocommit mode is on by default.
5728** ^Autocommit mode is disabled by a [BEGIN] statement.
5729** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5730**
5731** If certain kinds of errors occur on a statement within a multi-statement
5732** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5733** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
5734** transaction might be rolled back automatically. The only way to
5735** find out whether SQLite automatically rolled back the transaction after
5736** an error is to use this function.
5737**
5738** If another thread changes the autocommit status of the database
5739** connection while this routine is running, then the return value
5740** is undefined.
5741*/
5742SQLITE_API int sqlite3_get_autocommit(sqlite3*);
5743
5744/*
5745** CAPI3REF: Find The Database Handle Of A Prepared Statement
5746** METHOD: sqlite3_stmt
5747**
5748** ^The sqlite3_db_handle interface returns the [database connection] handle
5749** to which a [prepared statement] belongs. ^The [database connection]
5750** returned by sqlite3_db_handle is the same [database connection]
5751** that was the first argument
5752** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5753** create the statement in the first place.
5754*/
5755SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
5756
5757/*
5758** CAPI3REF: Return The Filename For A Database Connection
5759** METHOD: sqlite3
5760**
5761** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5762** associated with database N of connection D. ^The main database file
5763** has the name "main". If there is no attached database N on the database
5764** connection D, or if database N is a temporary or in-memory database, then
5765** a NULL pointer is returned.
5766**
5767** ^The filename returned by this function is the output of the
5768** xFullPathname method of the [VFS]. ^In other words, the filename
5769** will be an absolute pathname, even if the filename used
5770** to open the database originally was a URI or relative pathname.
5771*/
5772SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5773
5774/*
5775** CAPI3REF: Determine if a database is read-only
5776** METHOD: sqlite3
5777**
5778** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5779** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5780** the name of a database on connection D.
5781*/
5782SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5783
5784/*
5785** CAPI3REF: Find the next prepared statement
5786** METHOD: sqlite3
5787**
5788** ^This interface returns a pointer to the next [prepared statement] after
5789** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
5790** then this interface returns a pointer to the first prepared statement
5791** associated with the database connection pDb. ^If no prepared statement
5792** satisfies the conditions of this routine, it returns NULL.
5793**
5794** The [database connection] pointer D in a call to
5795** [sqlite3_next_stmt(D,S)] must refer to an open database
5796** connection and in particular must not be a NULL pointer.
5797*/
5798SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5799
5800/*
5801** CAPI3REF: Commit And Rollback Notification Callbacks
5802** METHOD: sqlite3
5803**
5804** ^The sqlite3_commit_hook() interface registers a callback
5805** function to be invoked whenever a transaction is [COMMIT | committed].
5806** ^Any callback set by a previous call to sqlite3_commit_hook()
5807** for the same database connection is overridden.
5808** ^The sqlite3_rollback_hook() interface registers a callback
5809** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5810** ^Any callback set by a previous call to sqlite3_rollback_hook()
5811** for the same database connection is overridden.
5812** ^The pArg argument is passed through to the callback.
5813** ^If the callback on a commit hook function returns non-zero,
5814** then the commit is converted into a rollback.
5815**
5816** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5817** return the P argument from the previous call of the same function
5818** on the same [database connection] D, or NULL for
5819** the first call for each function on D.
5820**
5821** The commit and rollback hook callbacks are not reentrant.
5822** The callback implementation must not do anything that will modify
5823** the database connection that invoked the callback. Any actions
5824** to modify the database connection must be deferred until after the
5825** completion of the [sqlite3_step()] call that triggered the commit
5826** or rollback hook in the first place.
5827** Note that running any other SQL statements, including SELECT statements,
5828** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5829** the database connections for the meaning of "modify" in this paragraph.
5830**
5831** ^Registering a NULL function disables the callback.
5832**
5833** ^When the commit hook callback routine returns zero, the [COMMIT]
5834** operation is allowed to continue normally. ^If the commit hook
5835** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5836** ^The rollback hook is invoked on a rollback that results from a commit
5837** hook returning non-zero, just as it would be with any other rollback.
5838**
5839** ^For the purposes of this API, a transaction is said to have been
5840** rolled back if an explicit "ROLLBACK" statement is executed, or
5841** an error or constraint causes an implicit rollback to occur.
5842** ^The rollback callback is not invoked if a transaction is
5843** automatically rolled back because the database connection is closed.
5844**
5845** See also the [sqlite3_update_hook()] interface.
5846*/
5847SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5848SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5849
5850/*
5851** CAPI3REF: Data Change Notification Callbacks
5852** METHOD: sqlite3
5853**
5854** ^The sqlite3_update_hook() interface registers a callback function
5855** with the [database connection] identified by the first argument
5856** to be invoked whenever a row is updated, inserted or deleted in
5857** a [rowid table].
5858** ^Any callback set by a previous call to this function
5859** for the same database connection is overridden.
5860**
5861** ^The second argument is a pointer to the function to invoke when a
5862** row is updated, inserted or deleted in a rowid table.
5863** ^The first argument to the callback is a copy of the third argument
5864** to sqlite3_update_hook().
5865** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5866** or [SQLITE_UPDATE], depending on the operation that caused the callback
5867** to be invoked.
5868** ^The third and fourth arguments to the callback contain pointers to the
5869** database and table name containing the affected row.
5870** ^The final callback parameter is the [rowid] of the row.
5871** ^In the case of an update, this is the [rowid] after the update takes place.
5872**
5873** ^(The update hook is not invoked when internal system tables are
5874** modified (i.e. sqlite_master and sqlite_sequence).)^
5875** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5876**
5877** ^In the current implementation, the update hook
5878** is not invoked when conflicting rows are deleted because of an
5879** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
5880** invoked when rows are deleted using the [truncate optimization].
5881** The exceptions defined in this paragraph might change in a future
5882** release of SQLite.
5883**
5884** The update hook implementation must not do anything that will modify
5885** the database connection that invoked the update hook. Any actions
5886** to modify the database connection must be deferred until after the
5887** completion of the [sqlite3_step()] call that triggered the update hook.
5888** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5889** database connections for the meaning of "modify" in this paragraph.
5890**
5891** ^The sqlite3_update_hook(D,C,P) function
5892** returns the P argument from the previous call
5893** on the same [database connection] D, or NULL for
5894** the first call on D.
5895**
5896** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
5897** and [sqlite3_preupdate_hook()] interfaces.
5898*/
5899SQLITE_API void *sqlite3_update_hook(
5900 sqlite3*,
5901 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5902 void*
5903);
5904
5905/*
5906** CAPI3REF: Enable Or Disable Shared Pager Cache
5907**
5908** ^(This routine enables or disables the sharing of the database cache
5909** and schema data structures between [database connection | connections]
5910** to the same database. Sharing is enabled if the argument is true
5911** and disabled if the argument is false.)^
5912**
5913** ^Cache sharing is enabled and disabled for an entire process.
5914** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
5915** In prior versions of SQLite,
5916** sharing was enabled or disabled for each thread separately.
5917**
5918** ^(The cache sharing mode set by this interface effects all subsequent
5919** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5920** Existing database connections continue use the sharing mode
5921** that was in effect at the time they were opened.)^
5922**
5923** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5924** successfully. An [error code] is returned otherwise.)^
5925**
5926** ^Shared cache is disabled by default. But this might change in
5927** future releases of SQLite. Applications that care about shared
5928** cache setting should set it explicitly.
5929**
5930** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5931** and will always return SQLITE_MISUSE. On those systems,
5932** shared cache mode should be enabled per-database connection via
5933** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
5934**
5935** This interface is threadsafe on processors where writing a
5936** 32-bit integer is atomic.
5937**
5938** See Also: [SQLite Shared-Cache Mode]
5939*/
5940SQLITE_API int sqlite3_enable_shared_cache(int);
5941
5942/*
5943** CAPI3REF: Attempt To Free Heap Memory
5944**
5945** ^The sqlite3_release_memory() interface attempts to free N bytes
5946** of heap memory by deallocating non-essential memory allocations
5947** held by the database library. Memory used to cache database
5948** pages to improve performance is an example of non-essential memory.
5949** ^sqlite3_release_memory() returns the number of bytes actually freed,
5950** which might be more or less than the amount requested.
5951** ^The sqlite3_release_memory() routine is a no-op returning zero
5952** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5953**
5954** See also: [sqlite3_db_release_memory()]
5955*/
5956SQLITE_API int sqlite3_release_memory(int);
5957
5958/*
5959** CAPI3REF: Free Memory Used By A Database Connection
5960** METHOD: sqlite3
5961**
5962** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5963** memory as possible from database connection D. Unlike the
5964** [sqlite3_release_memory()] interface, this interface is in effect even
5965** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5966** omitted.
5967**
5968** See also: [sqlite3_release_memory()]
5969*/
5970SQLITE_API int sqlite3_db_release_memory(sqlite3*);
5971
5972/*
5973** CAPI3REF: Impose A Limit On Heap Size
5974**
5975** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5976** soft limit on the amount of heap memory that may be allocated by SQLite.
5977** ^SQLite strives to keep heap memory utilization below the soft heap
5978** limit by reducing the number of pages held in the page cache
5979** as heap memory usages approaches the limit.
5980** ^The soft heap limit is "soft" because even though SQLite strives to stay
5981** below the limit, it will exceed the limit rather than generate
5982** an [SQLITE_NOMEM] error. In other words, the soft heap limit
5983** is advisory only.
5984**
5985** ^The return value from sqlite3_soft_heap_limit64() is the size of
5986** the soft heap limit prior to the call, or negative in the case of an
5987** error. ^If the argument N is negative
5988** then no change is made to the soft heap limit. Hence, the current
5989** size of the soft heap limit can be determined by invoking
5990** sqlite3_soft_heap_limit64() with a negative argument.
5991**
5992** ^If the argument N is zero then the soft heap limit is disabled.
5993**
5994** ^(The soft heap limit is not enforced in the current implementation
5995** if one or more of following conditions are true:
5996**
5997** <ul>
5998** <li> The soft heap limit is set to zero.
5999** <li> Memory accounting is disabled using a combination of the
6000** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6001** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6002** <li> An alternative page cache implementation is specified using
6003** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6004** <li> The page cache allocates from its own memory pool supplied
6005** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6006** from the heap.
6007** </ul>)^
6008**
6009** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]),
6010** the soft heap limit is enforced
6011** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
6012** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
6013** the soft heap limit is enforced on every memory allocation. Without
6014** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
6015** when memory is allocated by the page cache. Testing suggests that because
6016** the page cache is the predominate memory user in SQLite, most
6017** applications will achieve adequate soft heap limit enforcement without
6018** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6019**
6020** The circumstances under which SQLite will enforce the soft heap limit may
6021** changes in future releases of SQLite.
6022*/
6023SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6024
6025/*
6026** CAPI3REF: Deprecated Soft Heap Limit Interface
6027** DEPRECATED
6028**
6029** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6030** interface. This routine is provided for historical compatibility
6031** only. All new applications should use the
6032** [sqlite3_soft_heap_limit64()] interface rather than this one.
6033*/
6034SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6035
6036
6037/*
6038** CAPI3REF: Extract Metadata About A Column Of A Table
6039** METHOD: sqlite3
6040**
6041** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6042** information about column C of table T in database D
6043** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6044** interface returns SQLITE_OK and fills in the non-NULL pointers in
6045** the final five arguments with appropriate values if the specified
6046** column exists. ^The sqlite3_table_column_metadata() interface returns
6047** SQLITE_ERROR and if the specified column does not exist.
6048** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6049** NULL pointer, then this routine simply checks for the existence of the
6050** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6051** does not. If the table name parameter T in a call to
6052** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6053** undefined behavior.
6054**
6055** ^The column is identified by the second, third and fourth parameters to
6056** this function. ^(The second parameter is either the name of the database
6057** (i.e. "main", "temp", or an attached database) containing the specified
6058** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6059** for the table using the same algorithm used by the database engine to
6060** resolve unqualified table references.
6061**
6062** ^The third and fourth parameters to this function are the table and column
6063** name of the desired column, respectively.
6064**
6065** ^Metadata is returned by writing to the memory locations passed as the 5th
6066** and subsequent parameters to this function. ^Any of these arguments may be
6067** NULL, in which case the corresponding element of metadata is omitted.
6068**
6069** ^(<blockquote>
6070** <table border="1">
6071** <tr><th> Parameter <th> Output<br>Type <th> Description
6072**
6073** <tr><td> 5th <td> const char* <td> Data type
6074** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6075** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6076** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6077** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6078** </table>
6079** </blockquote>)^
6080**
6081** ^The memory pointed to by the character pointers returned for the
6082** declaration type and collation sequence is valid until the next
6083** call to any SQLite API function.
6084**
6085** ^If the specified table is actually a view, an [error code] is returned.
6086**
6087** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6088** is not a [WITHOUT ROWID] table and an
6089** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6090** parameters are set for the explicitly declared column. ^(If there is no
6091** [INTEGER PRIMARY KEY] column, then the outputs
6092** for the [rowid] are set as follows:
6093**
6094** <pre>
6095** data type: "INTEGER"
6096** collation sequence: "BINARY"
6097** not null: 0
6098** primary key: 1
6099** auto increment: 0
6100** </pre>)^
6101**
6102** ^This function causes all database schemas to be read from disk and
6103** parsed, if that has not already been done, and returns an error if
6104** any errors are encountered while loading the schema.
6105*/
6106SQLITE_API int sqlite3_table_column_metadata(
6107 sqlite3 *db, /* Connection handle */
6108 const char *zDbName, /* Database name or NULL */
6109 const char *zTableName, /* Table name */
6110 const char *zColumnName, /* Column name */
6111 char const **pzDataType, /* OUTPUT: Declared data type */
6112 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6113 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6114 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6115 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6116);
6117
6118/*
6119** CAPI3REF: Load An Extension
6120** METHOD: sqlite3
6121**
6122** ^This interface loads an SQLite extension library from the named file.
6123**
6124** ^The sqlite3_load_extension() interface attempts to load an
6125** [SQLite extension] library contained in the file zFile. If
6126** the file cannot be loaded directly, attempts are made to load
6127** with various operating-system specific extensions added.
6128** So for example, if "samplelib" cannot be loaded, then names like
6129** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6130** be tried also.
6131**
6132** ^The entry point is zProc.
6133** ^(zProc may be 0, in which case SQLite will try to come up with an
6134** entry point name on its own. It first tries "sqlite3_extension_init".
6135** If that does not work, it constructs a name "sqlite3_X_init" where the
6136** X is consists of the lower-case equivalent of all ASCII alphabetic
6137** characters in the filename from the last "/" to the first following
6138** "." and omitting any initial "lib".)^
6139** ^The sqlite3_load_extension() interface returns
6140** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6141** ^If an error occurs and pzErrMsg is not 0, then the
6142** [sqlite3_load_extension()] interface shall attempt to
6143** fill *pzErrMsg with error message text stored in memory
6144** obtained from [sqlite3_malloc()]. The calling function
6145** should free this memory by calling [sqlite3_free()].
6146**
6147** ^Extension loading must be enabled using
6148** [sqlite3_enable_load_extension()] or
6149** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6150** prior to calling this API,
6151** otherwise an error will be returned.
6152**
6153** <b>Security warning:</b> It is recommended that the
6154** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6155** interface. The use of the [sqlite3_enable_load_extension()] interface
6156** should be avoided. This will keep the SQL function [load_extension()]
6157** disabled and prevent SQL injections from giving attackers
6158** access to extension loading capabilities.
6159**
6160** See also the [load_extension() SQL function].
6161*/
6162SQLITE_API int sqlite3_load_extension(
6163 sqlite3 *db, /* Load the extension into this database connection */
6164 const char *zFile, /* Name of the shared library containing extension */
6165 const char *zProc, /* Entry point. Derived from zFile if 0 */
6166 char **pzErrMsg /* Put error message here if not 0 */
6167);
6168
6169/*
6170** CAPI3REF: Enable Or Disable Extension Loading
6171** METHOD: sqlite3
6172**
6173** ^So as not to open security holes in older applications that are
6174** unprepared to deal with [extension loading], and as a means of disabling
6175** [extension loading] while evaluating user-entered SQL, the following API
6176** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6177**
6178** ^Extension loading is off by default.
6179** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6180** to turn extension loading on and call it with onoff==0 to turn
6181** it back off again.
6182**
6183** ^This interface enables or disables both the C-API
6184** [sqlite3_load_extension()] and the SQL function [load_extension()].
6185** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6186** to enable or disable only the C-API.)^
6187**
6188** <b>Security warning:</b> It is recommended that extension loading
6189** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6190** rather than this interface, so the [load_extension()] SQL function
6191** remains disabled. This will prevent SQL injections from giving attackers
6192** access to extension loading capabilities.
6193*/
6194SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6195
6196/*
6197** CAPI3REF: Automatically Load Statically Linked Extensions
6198**
6199** ^This interface causes the xEntryPoint() function to be invoked for
6200** each new [database connection] that is created. The idea here is that
6201** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6202** that is to be automatically loaded into all new database connections.
6203**
6204** ^(Even though the function prototype shows that xEntryPoint() takes
6205** no arguments and returns void, SQLite invokes xEntryPoint() with three
6206** arguments and expects an integer result as if the signature of the
6207** entry point where as follows:
6208**
6209** <blockquote><pre>
6210** &nbsp; int xEntryPoint(
6211** &nbsp; sqlite3 *db,
6212** &nbsp; const char **pzErrMsg,
6213** &nbsp; const struct sqlite3_api_routines *pThunk
6214** &nbsp; );
6215** </pre></blockquote>)^
6216**
6217** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6218** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6219** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6220** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6221** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6222** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6223** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6224**
6225** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6226** on the list of automatic extensions is a harmless no-op. ^No entry point
6227** will be called more than once for each database connection that is opened.
6228**
6229** See also: [sqlite3_reset_auto_extension()]
6230** and [sqlite3_cancel_auto_extension()]
6231*/
6232SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6233
6234/*
6235** CAPI3REF: Cancel Automatic Extension Loading
6236**
6237** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6238** initialization routine X that was registered using a prior call to
6239** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6240** routine returns 1 if initialization routine X was successfully
6241** unregistered and it returns 0 if X was not on the list of initialization
6242** routines.
6243*/
6244SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6245
6246/*
6247** CAPI3REF: Reset Automatic Extension Loading
6248**
6249** ^This interface disables all automatic extensions previously
6250** registered using [sqlite3_auto_extension()].
6251*/
6252SQLITE_API void sqlite3_reset_auto_extension(void);
6253
6254/*
6255** The interface to the virtual-table mechanism is currently considered
6256** to be experimental. The interface might change in incompatible ways.
6257** If this is a problem for you, do not use the interface at this time.
6258**
6259** When the virtual-table mechanism stabilizes, we will declare the
6260** interface fixed, support it indefinitely, and remove this comment.
6261*/
6262
6263/*
6264** Structures used by the virtual table interface
6265*/
6266typedef struct sqlite3_vtab sqlite3_vtab;
6267typedef struct sqlite3_index_info sqlite3_index_info;
6268typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6269typedef struct sqlite3_module sqlite3_module;
6270
6271/*
6272** CAPI3REF: Virtual Table Object
6273** KEYWORDS: sqlite3_module {virtual table module}
6274**
6275** This structure, sometimes called a "virtual table module",
6276** defines the implementation of a [virtual tables].
6277** This structure consists mostly of methods for the module.
6278**
6279** ^A virtual table module is created by filling in a persistent
6280** instance of this structure and passing a pointer to that instance
6281** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6282** ^The registration remains valid until it is replaced by a different
6283** module or until the [database connection] closes. The content
6284** of this structure must not change while it is registered with
6285** any database connection.
6286*/
6287struct sqlite3_module {
6288 int iVersion;
6289 int (*xCreate)(sqlite3*, void *pAux,
6290 int argc, const char *const*argv,
6291 sqlite3_vtab **ppVTab, char**);
6292 int (*xConnect)(sqlite3*, void *pAux,
6293 int argc, const char *const*argv,
6294 sqlite3_vtab **ppVTab, char**);
6295 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6296 int (*xDisconnect)(sqlite3_vtab *pVTab);
6297 int (*xDestroy)(sqlite3_vtab *pVTab);
6298 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6299 int (*xClose)(sqlite3_vtab_cursor*);
6300 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6301 int argc, sqlite3_value **argv);
6302 int (*xNext)(sqlite3_vtab_cursor*);
6303 int (*xEof)(sqlite3_vtab_cursor*);
6304 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6305 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
6306 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
6307 int (*xBegin)(sqlite3_vtab *pVTab);
6308 int (*xSync)(sqlite3_vtab *pVTab);
6309 int (*xCommit)(sqlite3_vtab *pVTab);
6310 int (*xRollback)(sqlite3_vtab *pVTab);
6311 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
6312 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
6313 void **ppArg);
6314 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
6315 /* The methods above are in version 1 of the sqlite_module object. Those
6316 ** below are for version 2 and greater. */
6317 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
6318 int (*xRelease)(sqlite3_vtab *pVTab, int);
6319 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
6320 /* The methods above are in versions 1 and 2 of the sqlite_module object.
6321 ** Those below are for version 3 and greater. */
6322 int (*xShadowName)(const char*);
6323};
6324
6325/*
6326** CAPI3REF: Virtual Table Indexing Information
6327** KEYWORDS: sqlite3_index_info
6328**
6329** The sqlite3_index_info structure and its substructures is used as part
6330** of the [virtual table] interface to
6331** pass information into and receive the reply from the [xBestIndex]
6332** method of a [virtual table module]. The fields under **Inputs** are the
6333** inputs to xBestIndex and are read-only. xBestIndex inserts its
6334** results into the **Outputs** fields.
6335**
6336** ^(The aConstraint[] array records WHERE clause constraints of the form:
6337**
6338** <blockquote>column OP expr</blockquote>
6339**
6340** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
6341** stored in aConstraint[].op using one of the
6342** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
6343** ^(The index of the column is stored in
6344** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
6345** expr on the right-hand side can be evaluated (and thus the constraint
6346** is usable) and false if it cannot.)^
6347**
6348** ^The optimizer automatically inverts terms of the form "expr OP column"
6349** and makes other simplifications to the WHERE clause in an attempt to
6350** get as many WHERE clause terms into the form shown above as possible.
6351** ^The aConstraint[] array only reports WHERE clause terms that are
6352** relevant to the particular virtual table being queried.
6353**
6354** ^Information about the ORDER BY clause is stored in aOrderBy[].
6355** ^Each term of aOrderBy records a column of the ORDER BY clause.
6356**
6357** The colUsed field indicates which columns of the virtual table may be
6358** required by the current scan. Virtual table columns are numbered from
6359** zero in the order in which they appear within the CREATE TABLE statement
6360** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
6361** the corresponding bit is set within the colUsed mask if the column may be
6362** required by SQLite. If the table has at least 64 columns and any column
6363** to the right of the first 63 is required, then bit 63 of colUsed is also
6364** set. In other words, column iCol may be required if the expression
6365** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
6366** non-zero.
6367**
6368** The [xBestIndex] method must fill aConstraintUsage[] with information
6369** about what parameters to pass to xFilter. ^If argvIndex>0 then
6370** the right-hand side of the corresponding aConstraint[] is evaluated
6371** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
6372** is true, then the constraint is assumed to be fully handled by the
6373** virtual table and is not checked again by SQLite.)^
6374**
6375** ^The idxNum and idxPtr values are recorded and passed into the
6376** [xFilter] method.
6377** ^[sqlite3_free()] is used to free idxPtr if and only if
6378** needToFreeIdxPtr is true.
6379**
6380** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
6381** the correct order to satisfy the ORDER BY clause so that no separate
6382** sorting step is required.
6383**
6384** ^The estimatedCost value is an estimate of the cost of a particular
6385** strategy. A cost of N indicates that the cost of the strategy is similar
6386** to a linear scan of an SQLite table with N rows. A cost of log(N)
6387** indicates that the expense of the operation is similar to that of a
6388** binary search on a unique indexed field of an SQLite table with N rows.
6389**
6390** ^The estimatedRows value is an estimate of the number of rows that
6391** will be returned by the strategy.
6392**
6393** The xBestIndex method may optionally populate the idxFlags field with a
6394** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
6395** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
6396** assumes that the strategy may visit at most one row.
6397**
6398** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
6399** SQLite also assumes that if a call to the xUpdate() method is made as
6400** part of the same statement to delete or update a virtual table row and the
6401** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
6402** any database changes. In other words, if the xUpdate() returns
6403** SQLITE_CONSTRAINT, the database contents must be exactly as they were
6404** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
6405** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
6406** the xUpdate method are automatically rolled back by SQLite.
6407**
6408** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
6409** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
6410** If a virtual table extension is
6411** used with an SQLite version earlier than 3.8.2, the results of attempting
6412** to read or write the estimatedRows field are undefined (but are likely
6413** to included crashing the application). The estimatedRows field should
6414** therefore only be used if [sqlite3_libversion_number()] returns a
6415** value greater than or equal to 3008002. Similarly, the idxFlags field
6416** was added for [version 3.9.0] ([dateof:3.9.0]).
6417** It may therefore only be used if
6418** sqlite3_libversion_number() returns a value greater than or equal to
6419** 3009000.
6420*/
6421struct sqlite3_index_info {
6422 /* Inputs */
6423 int nConstraint; /* Number of entries in aConstraint */
6424 struct sqlite3_index_constraint {
6425 int iColumn; /* Column constrained. -1 for ROWID */
6426 unsigned char op; /* Constraint operator */
6427 unsigned char usable; /* True if this constraint is usable */
6428 int iTermOffset; /* Used internally - xBestIndex should ignore */
6429 } *aConstraint; /* Table of WHERE clause constraints */
6430 int nOrderBy; /* Number of terms in the ORDER BY clause */
6431 struct sqlite3_index_orderby {
6432 int iColumn; /* Column number */
6433 unsigned char desc; /* True for DESC. False for ASC. */
6434 } *aOrderBy; /* The ORDER BY clause */
6435 /* Outputs */
6436 struct sqlite3_index_constraint_usage {
6437 int argvIndex; /* if >0, constraint is part of argv to xFilter */
6438 unsigned char omit; /* Do not code a test for this constraint */
6439 } *aConstraintUsage;
6440 int idxNum; /* Number used to identify the index */
6441 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
6442 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
6443 int orderByConsumed; /* True if output is already ordered */
6444 double estimatedCost; /* Estimated cost of using this index */
6445 /* Fields below are only available in SQLite 3.8.2 and later */
6446 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
6447 /* Fields below are only available in SQLite 3.9.0 and later */
6448 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
6449 /* Fields below are only available in SQLite 3.10.0 and later */
6450 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
6451};
6452
6453/*
6454** CAPI3REF: Virtual Table Scan Flags
6455**
6456** Virtual table implementations are allowed to set the
6457** [sqlite3_index_info].idxFlags field to some combination of
6458** these bits.
6459*/
6460#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
6461
6462/*
6463** CAPI3REF: Virtual Table Constraint Operator Codes
6464**
6465** These macros defined the allowed values for the
6466** [sqlite3_index_info].aConstraint[].op field. Each value represents
6467** an operator that is part of a constraint term in the wHERE clause of
6468** a query that uses a [virtual table].
6469*/
6470#define SQLITE_INDEX_CONSTRAINT_EQ 2
6471#define SQLITE_INDEX_CONSTRAINT_GT 4
6472#define SQLITE_INDEX_CONSTRAINT_LE 8
6473#define SQLITE_INDEX_CONSTRAINT_LT 16
6474#define SQLITE_INDEX_CONSTRAINT_GE 32
6475#define SQLITE_INDEX_CONSTRAINT_MATCH 64
6476#define SQLITE_INDEX_CONSTRAINT_LIKE 65
6477#define SQLITE_INDEX_CONSTRAINT_GLOB 66
6478#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
6479#define SQLITE_INDEX_CONSTRAINT_NE 68
6480#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
6481#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
6482#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
6483#define SQLITE_INDEX_CONSTRAINT_IS 72
6484#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
6485
6486/*
6487** CAPI3REF: Register A Virtual Table Implementation
6488** METHOD: sqlite3
6489**
6490** ^These routines are used to register a new [virtual table module] name.
6491** ^Module names must be registered before
6492** creating a new [virtual table] using the module and before using a
6493** preexisting [virtual table] for the module.
6494**
6495** ^The module name is registered on the [database connection] specified
6496** by the first parameter. ^The name of the module is given by the
6497** second parameter. ^The third parameter is a pointer to
6498** the implementation of the [virtual table module]. ^The fourth
6499** parameter is an arbitrary client data pointer that is passed through
6500** into the [xCreate] and [xConnect] methods of the virtual table module
6501** when a new virtual table is be being created or reinitialized.
6502**
6503** ^The sqlite3_create_module_v2() interface has a fifth parameter which
6504** is a pointer to a destructor for the pClientData. ^SQLite will
6505** invoke the destructor function (if it is not NULL) when SQLite
6506** no longer needs the pClientData pointer. ^The destructor will also
6507** be invoked if the call to sqlite3_create_module_v2() fails.
6508** ^The sqlite3_create_module()
6509** interface is equivalent to sqlite3_create_module_v2() with a NULL
6510** destructor.
6511*/
6512SQLITE_API int sqlite3_create_module(
6513 sqlite3 *db, /* SQLite connection to register module with */
6514 const char *zName, /* Name of the module */
6515 const sqlite3_module *p, /* Methods for the module */
6516 void *pClientData /* Client data for xCreate/xConnect */
6517);
6518SQLITE_API int sqlite3_create_module_v2(
6519 sqlite3 *db, /* SQLite connection to register module with */
6520 const char *zName, /* Name of the module */
6521 const sqlite3_module *p, /* Methods for the module */
6522 void *pClientData, /* Client data for xCreate/xConnect */
6523 void(*xDestroy)(void*) /* Module destructor function */
6524);
6525
6526/*
6527** CAPI3REF: Virtual Table Instance Object
6528** KEYWORDS: sqlite3_vtab
6529**
6530** Every [virtual table module] implementation uses a subclass
6531** of this object to describe a particular instance
6532** of the [virtual table]. Each subclass will
6533** be tailored to the specific needs of the module implementation.
6534** The purpose of this superclass is to define certain fields that are
6535** common to all module implementations.
6536**
6537** ^Virtual tables methods can set an error message by assigning a
6538** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
6539** take care that any prior string is freed by a call to [sqlite3_free()]
6540** prior to assigning a new string to zErrMsg. ^After the error message
6541** is delivered up to the client application, the string will be automatically
6542** freed by sqlite3_free() and the zErrMsg field will be zeroed.
6543*/
6544struct sqlite3_vtab {
6545 const sqlite3_module *pModule; /* The module for this virtual table */
6546 int nRef; /* Number of open cursors */
6547 char *zErrMsg; /* Error message from sqlite3_mprintf() */
6548 /* Virtual table implementations will typically add additional fields */
6549};
6550
6551/*
6552** CAPI3REF: Virtual Table Cursor Object
6553** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
6554**
6555** Every [virtual table module] implementation uses a subclass of the
6556** following structure to describe cursors that point into the
6557** [virtual table] and are used
6558** to loop through the virtual table. Cursors are created using the
6559** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
6560** by the [sqlite3_module.xClose | xClose] method. Cursors are used
6561** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
6562** of the module. Each module implementation will define
6563** the content of a cursor structure to suit its own needs.
6564**
6565** This superclass exists in order to define fields of the cursor that
6566** are common to all implementations.
6567*/
6568struct sqlite3_vtab_cursor {
6569 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
6570 /* Virtual table implementations will typically add additional fields */
6571};
6572
6573/*
6574** CAPI3REF: Declare The Schema Of A Virtual Table
6575**
6576** ^The [xCreate] and [xConnect] methods of a
6577** [virtual table module] call this interface
6578** to declare the format (the names and datatypes of the columns) of
6579** the virtual tables they implement.
6580*/
6581SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
6582
6583/*
6584** CAPI3REF: Overload A Function For A Virtual Table
6585** METHOD: sqlite3
6586**
6587** ^(Virtual tables can provide alternative implementations of functions
6588** using the [xFindFunction] method of the [virtual table module].
6589** But global versions of those functions
6590** must exist in order to be overloaded.)^
6591**
6592** ^(This API makes sure a global version of a function with a particular
6593** name and number of parameters exists. If no such function exists
6594** before this API is called, a new function is created.)^ ^The implementation
6595** of the new function always causes an exception to be thrown. So
6596** the new function is not good for anything by itself. Its only
6597** purpose is to be a placeholder function that can be overloaded
6598** by a [virtual table].
6599*/
6600SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
6601
6602/*
6603** The interface to the virtual-table mechanism defined above (back up
6604** to a comment remarkably similar to this one) is currently considered
6605** to be experimental. The interface might change in incompatible ways.
6606** If this is a problem for you, do not use the interface at this time.
6607**
6608** When the virtual-table mechanism stabilizes, we will declare the
6609** interface fixed, support it indefinitely, and remove this comment.
6610*/
6611
6612/*
6613** CAPI3REF: A Handle To An Open BLOB
6614** KEYWORDS: {BLOB handle} {BLOB handles}
6615**
6616** An instance of this object represents an open BLOB on which
6617** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
6618** ^Objects of this type are created by [sqlite3_blob_open()]
6619** and destroyed by [sqlite3_blob_close()].
6620** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
6621** can be used to read or write small subsections of the BLOB.
6622** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
6623*/
6624typedef struct sqlite3_blob sqlite3_blob;
6625
6626/*
6627** CAPI3REF: Open A BLOB For Incremental I/O
6628** METHOD: sqlite3
6629** CONSTRUCTOR: sqlite3_blob
6630**
6631** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
6632** in row iRow, column zColumn, table zTable in database zDb;
6633** in other words, the same BLOB that would be selected by:
6634**
6635** <pre>
6636** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
6637** </pre>)^
6638**
6639** ^(Parameter zDb is not the filename that contains the database, but
6640** rather the symbolic name of the database. For attached databases, this is
6641** the name that appears after the AS keyword in the [ATTACH] statement.
6642** For the main database file, the database name is "main". For TEMP
6643** tables, the database name is "temp".)^
6644**
6645** ^If the flags parameter is non-zero, then the BLOB is opened for read
6646** and write access. ^If the flags parameter is zero, the BLOB is opened for
6647** read-only access.
6648**
6649** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
6650** in *ppBlob. Otherwise an [error code] is returned and, unless the error
6651** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
6652** the API is not misused, it is always safe to call [sqlite3_blob_close()]
6653** on *ppBlob after this function it returns.
6654**
6655** This function fails with SQLITE_ERROR if any of the following are true:
6656** <ul>
6657** <li> ^(Database zDb does not exist)^,
6658** <li> ^(Table zTable does not exist within database zDb)^,
6659** <li> ^(Table zTable is a WITHOUT ROWID table)^,
6660** <li> ^(Column zColumn does not exist)^,
6661** <li> ^(Row iRow is not present in the table)^,
6662** <li> ^(The specified column of row iRow contains a value that is not
6663** a TEXT or BLOB value)^,
6664** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
6665** constraint and the blob is being opened for read/write access)^,
6666** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
6667** column zColumn is part of a [child key] definition and the blob is
6668** being opened for read/write access)^.
6669** </ul>
6670**
6671** ^Unless it returns SQLITE_MISUSE, this function sets the
6672** [database connection] error code and message accessible via
6673** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6674**
6675** A BLOB referenced by sqlite3_blob_open() may be read using the
6676** [sqlite3_blob_read()] interface and modified by using
6677** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
6678** different row of the same table using the [sqlite3_blob_reopen()]
6679** interface. However, the column, table, or database of a [BLOB handle]
6680** cannot be changed after the [BLOB handle] is opened.
6681**
6682** ^(If the row that a BLOB handle points to is modified by an
6683** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6684** then the BLOB handle is marked as "expired".
6685** This is true if any column of the row is changed, even a column
6686** other than the one the BLOB handle is open on.)^
6687** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6688** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6689** ^(Changes written into a BLOB prior to the BLOB expiring are not
6690** rolled back by the expiration of the BLOB. Such changes will eventually
6691** commit if the transaction continues to completion.)^
6692**
6693** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6694** the opened blob. ^The size of a blob may not be changed by this
6695** interface. Use the [UPDATE] SQL command to change the size of a
6696** blob.
6697**
6698** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6699** and the built-in [zeroblob] SQL function may be used to create a
6700** zero-filled blob to read or write using the incremental-blob interface.
6701**
6702** To avoid a resource leak, every open [BLOB handle] should eventually
6703** be released by a call to [sqlite3_blob_close()].
6704**
6705** See also: [sqlite3_blob_close()],
6706** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
6707** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
6708*/
6709SQLITE_API int sqlite3_blob_open(
6710 sqlite3*,
6711 const char *zDb,
6712 const char *zTable,
6713 const char *zColumn,
6714 sqlite3_int64 iRow,
6715 int flags,
6716 sqlite3_blob **ppBlob
6717);
6718
6719/*
6720** CAPI3REF: Move a BLOB Handle to a New Row
6721** METHOD: sqlite3_blob
6722**
6723** ^This function is used to move an existing [BLOB handle] so that it points
6724** to a different row of the same database table. ^The new row is identified
6725** by the rowid value passed as the second argument. Only the row can be
6726** changed. ^The database, table and column on which the blob handle is open
6727** remain the same. Moving an existing [BLOB handle] to a new row is
6728** faster than closing the existing handle and opening a new one.
6729**
6730** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6731** it must exist and there must be either a blob or text value stored in
6732** the nominated column.)^ ^If the new row is not present in the table, or if
6733** it does not contain a blob or text value, or if another error occurs, an
6734** SQLite error code is returned and the blob handle is considered aborted.
6735** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6736** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6737** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6738** always returns zero.
6739**
6740** ^This function sets the database handle error code and message.
6741*/
6742SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6743
6744/*
6745** CAPI3REF: Close A BLOB Handle
6746** DESTRUCTOR: sqlite3_blob
6747**
6748** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6749** unconditionally. Even if this routine returns an error code, the
6750** handle is still closed.)^
6751**
6752** ^If the blob handle being closed was opened for read-write access, and if
6753** the database is in auto-commit mode and there are no other open read-write
6754** blob handles or active write statements, the current transaction is
6755** committed. ^If an error occurs while committing the transaction, an error
6756** code is returned and the transaction rolled back.
6757**
6758** Calling this function with an argument that is not a NULL pointer or an
6759** open blob handle results in undefined behaviour. ^Calling this routine
6760** with a null pointer (such as would be returned by a failed call to
6761** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6762** is passed a valid open blob handle, the values returned by the
6763** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6764*/
6765SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
6766
6767/*
6768** CAPI3REF: Return The Size Of An Open BLOB
6769** METHOD: sqlite3_blob
6770**
6771** ^Returns the size in bytes of the BLOB accessible via the
6772** successfully opened [BLOB handle] in its only argument. ^The
6773** incremental blob I/O routines can only read or overwriting existing
6774** blob content; they cannot change the size of a blob.
6775**
6776** This routine only works on a [BLOB handle] which has been created
6777** by a prior successful call to [sqlite3_blob_open()] and which has not
6778** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6779** to this routine results in undefined and probably undesirable behavior.
6780*/
6781SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
6782
6783/*
6784** CAPI3REF: Read Data From A BLOB Incrementally
6785** METHOD: sqlite3_blob
6786**
6787** ^(This function is used to read data from an open [BLOB handle] into a
6788** caller-supplied buffer. N bytes of data are copied into buffer Z
6789** from the open BLOB, starting at offset iOffset.)^
6790**
6791** ^If offset iOffset is less than N bytes from the end of the BLOB,
6792** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
6793** less than zero, [SQLITE_ERROR] is returned and no data is read.
6794** ^The size of the blob (and hence the maximum value of N+iOffset)
6795** can be determined using the [sqlite3_blob_bytes()] interface.
6796**
6797** ^An attempt to read from an expired [BLOB handle] fails with an
6798** error code of [SQLITE_ABORT].
6799**
6800** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6801** Otherwise, an [error code] or an [extended error code] is returned.)^
6802**
6803** This routine only works on a [BLOB handle] which has been created
6804** by a prior successful call to [sqlite3_blob_open()] and which has not
6805** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6806** to this routine results in undefined and probably undesirable behavior.
6807**
6808** See also: [sqlite3_blob_write()].
6809*/
6810SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6811
6812/*
6813** CAPI3REF: Write Data Into A BLOB Incrementally
6814** METHOD: sqlite3_blob
6815**
6816** ^(This function is used to write data into an open [BLOB handle] from a
6817** caller-supplied buffer. N bytes of data are copied from the buffer Z
6818** into the open BLOB, starting at offset iOffset.)^
6819**
6820** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6821** Otherwise, an [error code] or an [extended error code] is returned.)^
6822** ^Unless SQLITE_MISUSE is returned, this function sets the
6823** [database connection] error code and message accessible via
6824** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6825**
6826** ^If the [BLOB handle] passed as the first argument was not opened for
6827** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6828** this function returns [SQLITE_READONLY].
6829**
6830** This function may only modify the contents of the BLOB; it is
6831** not possible to increase the size of a BLOB using this API.
6832** ^If offset iOffset is less than N bytes from the end of the BLOB,
6833** [SQLITE_ERROR] is returned and no data is written. The size of the
6834** BLOB (and hence the maximum value of N+iOffset) can be determined
6835** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6836** than zero [SQLITE_ERROR] is returned and no data is written.
6837**
6838** ^An attempt to write to an expired [BLOB handle] fails with an
6839** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
6840** before the [BLOB handle] expired are not rolled back by the
6841** expiration of the handle, though of course those changes might
6842** have been overwritten by the statement that expired the BLOB handle
6843** or by other independent statements.
6844**
6845** This routine only works on a [BLOB handle] which has been created
6846** by a prior successful call to [sqlite3_blob_open()] and which has not
6847** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6848** to this routine results in undefined and probably undesirable behavior.
6849**
6850** See also: [sqlite3_blob_read()].
6851*/
6852SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6853
6854/*
6855** CAPI3REF: Virtual File System Objects
6856**
6857** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6858** that SQLite uses to interact
6859** with the underlying operating system. Most SQLite builds come with a
6860** single default VFS that is appropriate for the host computer.
6861** New VFSes can be registered and existing VFSes can be unregistered.
6862** The following interfaces are provided.
6863**
6864** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6865** ^Names are case sensitive.
6866** ^Names are zero-terminated UTF-8 strings.
6867** ^If there is no match, a NULL pointer is returned.
6868** ^If zVfsName is NULL then the default VFS is returned.
6869**
6870** ^New VFSes are registered with sqlite3_vfs_register().
6871** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6872** ^The same VFS can be registered multiple times without injury.
6873** ^To make an existing VFS into the default VFS, register it again
6874** with the makeDflt flag set. If two different VFSes with the
6875** same name are registered, the behavior is undefined. If a
6876** VFS is registered with a name that is NULL or an empty string,
6877** then the behavior is undefined.
6878**
6879** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6880** ^(If the default VFS is unregistered, another VFS is chosen as
6881** the default. The choice for the new VFS is arbitrary.)^
6882*/
6883SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
6884SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6885SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
6886
6887/*
6888** CAPI3REF: Mutexes
6889**
6890** The SQLite core uses these routines for thread
6891** synchronization. Though they are intended for internal
6892** use by SQLite, code that links against SQLite is
6893** permitted to use any of these routines.
6894**
6895** The SQLite source code contains multiple implementations
6896** of these mutex routines. An appropriate implementation
6897** is selected automatically at compile-time. The following
6898** implementations are available in the SQLite core:
6899**
6900** <ul>
6901** <li> SQLITE_MUTEX_PTHREADS
6902** <li> SQLITE_MUTEX_W32
6903** <li> SQLITE_MUTEX_NOOP
6904** </ul>
6905**
6906** The SQLITE_MUTEX_NOOP implementation is a set of routines
6907** that does no real locking and is appropriate for use in
6908** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
6909** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6910** and Windows.
6911**
6912** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6913** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6914** implementation is included with the library. In this case the
6915** application must supply a custom mutex implementation using the
6916** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6917** before calling sqlite3_initialize() or any other public sqlite3_
6918** function that calls sqlite3_initialize().
6919**
6920** ^The sqlite3_mutex_alloc() routine allocates a new
6921** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6922** routine returns NULL if it is unable to allocate the requested
6923** mutex. The argument to sqlite3_mutex_alloc() must one of these
6924** integer constants:
6925**
6926** <ul>
6927** <li> SQLITE_MUTEX_FAST
6928** <li> SQLITE_MUTEX_RECURSIVE
6929** <li> SQLITE_MUTEX_STATIC_MASTER
6930** <li> SQLITE_MUTEX_STATIC_MEM
6931** <li> SQLITE_MUTEX_STATIC_OPEN
6932** <li> SQLITE_MUTEX_STATIC_PRNG
6933** <li> SQLITE_MUTEX_STATIC_LRU
6934** <li> SQLITE_MUTEX_STATIC_PMEM
6935** <li> SQLITE_MUTEX_STATIC_APP1
6936** <li> SQLITE_MUTEX_STATIC_APP2
6937** <li> SQLITE_MUTEX_STATIC_APP3
6938** <li> SQLITE_MUTEX_STATIC_VFS1
6939** <li> SQLITE_MUTEX_STATIC_VFS2
6940** <li> SQLITE_MUTEX_STATIC_VFS3
6941** </ul>
6942**
6943** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
6944** cause sqlite3_mutex_alloc() to create
6945** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
6946** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
6947** The mutex implementation does not need to make a distinction
6948** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
6949** not want to. SQLite will only request a recursive mutex in
6950** cases where it really needs one. If a faster non-recursive mutex
6951** implementation is available on the host platform, the mutex subsystem
6952** might return such a mutex in response to SQLITE_MUTEX_FAST.
6953**
6954** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
6955** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
6956** a pointer to a static preexisting mutex. ^Nine static mutexes are
6957** used by the current version of SQLite. Future versions of SQLite
6958** may add additional static mutexes. Static mutexes are for internal
6959** use by SQLite only. Applications that use SQLite mutexes should
6960** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
6961** SQLITE_MUTEX_RECURSIVE.
6962**
6963** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
6964** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
6965** returns a different mutex on every call. ^For the static
6966** mutex types, the same mutex is returned on every call that has
6967** the same type number.
6968**
6969** ^The sqlite3_mutex_free() routine deallocates a previously
6970** allocated dynamic mutex. Attempting to deallocate a static
6971** mutex results in undefined behavior.
6972**
6973** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
6974** to enter a mutex. ^If another thread is already within the mutex,
6975** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
6976** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
6977** upon successful entry. ^(Mutexes created using
6978** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
6979** In such cases, the
6980** mutex must be exited an equal number of times before another thread
6981** can enter.)^ If the same thread tries to enter any mutex other
6982** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
6983**
6984** ^(Some systems (for example, Windows 95) do not support the operation
6985** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
6986** will always return SQLITE_BUSY. The SQLite core only ever uses
6987** sqlite3_mutex_try() as an optimization so this is acceptable
6988** behavior.)^
6989**
6990** ^The sqlite3_mutex_leave() routine exits a mutex that was
6991** previously entered by the same thread. The behavior
6992** is undefined if the mutex is not currently entered by the
6993** calling thread or is not currently allocated.
6994**
6995** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
6996** sqlite3_mutex_leave() is a NULL pointer, then all three routines
6997** behave as no-ops.
6998**
6999** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7000*/
7001SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7002SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7003SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7004SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7005SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7006
7007/*
7008** CAPI3REF: Mutex Methods Object
7009**
7010** An instance of this structure defines the low-level routines
7011** used to allocate and use mutexes.
7012**
7013** Usually, the default mutex implementations provided by SQLite are
7014** sufficient, however the application has the option of substituting a custom
7015** implementation for specialized deployments or systems for which SQLite
7016** does not provide a suitable implementation. In this case, the application
7017** creates and populates an instance of this structure to pass
7018** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7019** Additionally, an instance of this structure can be used as an
7020** output variable when querying the system for the current mutex
7021** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7022**
7023** ^The xMutexInit method defined by this structure is invoked as
7024** part of system initialization by the sqlite3_initialize() function.
7025** ^The xMutexInit routine is called by SQLite exactly once for each
7026** effective call to [sqlite3_initialize()].
7027**
7028** ^The xMutexEnd method defined by this structure is invoked as
7029** part of system shutdown by the sqlite3_shutdown() function. The
7030** implementation of this method is expected to release all outstanding
7031** resources obtained by the mutex methods implementation, especially
7032** those obtained by the xMutexInit method. ^The xMutexEnd()
7033** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7034**
7035** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7036** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7037** xMutexNotheld) implement the following interfaces (respectively):
7038**
7039** <ul>
7040** <li> [sqlite3_mutex_alloc()] </li>
7041** <li> [sqlite3_mutex_free()] </li>
7042** <li> [sqlite3_mutex_enter()] </li>
7043** <li> [sqlite3_mutex_try()] </li>
7044** <li> [sqlite3_mutex_leave()] </li>
7045** <li> [sqlite3_mutex_held()] </li>
7046** <li> [sqlite3_mutex_notheld()] </li>
7047** </ul>)^
7048**
7049** The only difference is that the public sqlite3_XXX functions enumerated
7050** above silently ignore any invocations that pass a NULL pointer instead
7051** of a valid mutex handle. The implementations of the methods defined
7052** by this structure are not required to handle this case, the results
7053** of passing a NULL pointer instead of a valid mutex handle are undefined
7054** (i.e. it is acceptable to provide an implementation that segfaults if
7055** it is passed a NULL pointer).
7056**
7057** The xMutexInit() method must be threadsafe. It must be harmless to
7058** invoke xMutexInit() multiple times within the same process and without
7059** intervening calls to xMutexEnd(). Second and subsequent calls to
7060** xMutexInit() must be no-ops.
7061**
7062** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7063** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7064** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7065** memory allocation for a fast or recursive mutex.
7066**
7067** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7068** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7069** If xMutexInit fails in any way, it is expected to clean up after itself
7070** prior to returning.
7071*/
7072typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7073struct sqlite3_mutex_methods {
7074 int (*xMutexInit)(void);
7075 int (*xMutexEnd)(void);
7076 sqlite3_mutex *(*xMutexAlloc)(int);
7077 void (*xMutexFree)(sqlite3_mutex *);
7078 void (*xMutexEnter)(sqlite3_mutex *);
7079 int (*xMutexTry)(sqlite3_mutex *);
7080 void (*xMutexLeave)(sqlite3_mutex *);
7081 int (*xMutexHeld)(sqlite3_mutex *);
7082 int (*xMutexNotheld)(sqlite3_mutex *);
7083};
7084
7085/*
7086** CAPI3REF: Mutex Verification Routines
7087**
7088** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7089** are intended for use inside assert() statements. The SQLite core
7090** never uses these routines except inside an assert() and applications
7091** are advised to follow the lead of the core. The SQLite core only
7092** provides implementations for these routines when it is compiled
7093** with the SQLITE_DEBUG flag. External mutex implementations
7094** are only required to provide these routines if SQLITE_DEBUG is
7095** defined and if NDEBUG is not defined.
7096**
7097** These routines should return true if the mutex in their argument
7098** is held or not held, respectively, by the calling thread.
7099**
7100** The implementation is not required to provide versions of these
7101** routines that actually work. If the implementation does not provide working
7102** versions of these routines, it should at least provide stubs that always
7103** return true so that one does not get spurious assertion failures.
7104**
7105** If the argument to sqlite3_mutex_held() is a NULL pointer then
7106** the routine should return 1. This seems counter-intuitive since
7107** clearly the mutex cannot be held if it does not exist. But
7108** the reason the mutex does not exist is because the build is not
7109** using mutexes. And we do not want the assert() containing the
7110** call to sqlite3_mutex_held() to fail, so a non-zero return is
7111** the appropriate thing to do. The sqlite3_mutex_notheld()
7112** interface should also return 1 when given a NULL pointer.
7113*/
7114#ifndef NDEBUG
7115SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7116SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7117#endif
7118
7119/*
7120** CAPI3REF: Mutex Types
7121**
7122** The [sqlite3_mutex_alloc()] interface takes a single argument
7123** which is one of these integer constants.
7124**
7125** The set of static mutexes may change from one SQLite release to the
7126** next. Applications that override the built-in mutex logic must be
7127** prepared to accommodate additional static mutexes.
7128*/
7129#define SQLITE_MUTEX_FAST 0
7130#define SQLITE_MUTEX_RECURSIVE 1
7131#define SQLITE_MUTEX_STATIC_MASTER 2
7132#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7133#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7134#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7135#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7136#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7137#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7138#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7139#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7140#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7141#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7142#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7143#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7144#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7145
7146/*
7147** CAPI3REF: Retrieve the mutex for a database connection
7148** METHOD: sqlite3
7149**
7150** ^This interface returns a pointer the [sqlite3_mutex] object that
7151** serializes access to the [database connection] given in the argument
7152** when the [threading mode] is Serialized.
7153** ^If the [threading mode] is Single-thread or Multi-thread then this
7154** routine returns a NULL pointer.
7155*/
7156SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7157
7158/*
7159** CAPI3REF: Low-Level Control Of Database Files
7160** METHOD: sqlite3
7161** KEYWORDS: {file control}
7162**
7163** ^The [sqlite3_file_control()] interface makes a direct call to the
7164** xFileControl method for the [sqlite3_io_methods] object associated
7165** with a particular database identified by the second argument. ^The
7166** name of the database is "main" for the main database or "temp" for the
7167** TEMP database, or the name that appears after the AS keyword for
7168** databases that are added using the [ATTACH] SQL command.
7169** ^A NULL pointer can be used in place of "main" to refer to the
7170** main database file.
7171** ^The third and fourth parameters to this routine
7172** are passed directly through to the second and third parameters of
7173** the xFileControl method. ^The return value of the xFileControl
7174** method becomes the return value of this routine.
7175**
7176** A few opcodes for [sqlite3_file_control()] are handled directly
7177** by the SQLite core and never invoke the
7178** sqlite3_io_methods.xFileControl method.
7179** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7180** a pointer to the underlying [sqlite3_file] object to be written into
7181** the space pointed to by the 4th parameter. The
7182** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7183** the [sqlite3_file] object associated with the journal file instead of
7184** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7185** a pointer to the underlying [sqlite3_vfs] object for the file.
7186** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7187** from the pager.
7188**
7189** ^If the second parameter (zDbName) does not match the name of any
7190** open database file, then SQLITE_ERROR is returned. ^This error
7191** code is not remembered and will not be recalled by [sqlite3_errcode()]
7192** or [sqlite3_errmsg()]. The underlying xFileControl method might
7193** also return SQLITE_ERROR. There is no way to distinguish between
7194** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7195** xFileControl method.
7196**
7197** See also: [file control opcodes]
7198*/
7199SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7200
7201/*
7202** CAPI3REF: Testing Interface
7203**
7204** ^The sqlite3_test_control() interface is used to read out internal
7205** state of SQLite and to inject faults into SQLite for testing
7206** purposes. ^The first parameter is an operation code that determines
7207** the number, meaning, and operation of all subsequent parameters.
7208**
7209** This interface is not for use by applications. It exists solely
7210** for verifying the correct operation of the SQLite library. Depending
7211** on how the SQLite library is compiled, this interface might not exist.
7212**
7213** The details of the operation codes, their meanings, the parameters
7214** they take, and what they do are all subject to change without notice.
7215** Unlike most of the SQLite API, this function is not guaranteed to
7216** operate consistently from one release to the next.
7217*/
7218SQLITE_API int sqlite3_test_control(int op, ...);
7219
7220/*
7221** CAPI3REF: Testing Interface Operation Codes
7222**
7223** These constants are the valid operation code parameters used
7224** as the first argument to [sqlite3_test_control()].
7225**
7226** These parameters and their meanings are subject to change
7227** without notice. These values are for testing purposes only.
7228** Applications should not use any of these parameters or the
7229** [sqlite3_test_control()] interface.
7230*/
7231#define SQLITE_TESTCTRL_FIRST 5
7232#define SQLITE_TESTCTRL_PRNG_SAVE 5
7233#define SQLITE_TESTCTRL_PRNG_RESTORE 6
7234#define SQLITE_TESTCTRL_PRNG_RESET 7
7235#define SQLITE_TESTCTRL_BITVEC_TEST 8
7236#define SQLITE_TESTCTRL_FAULT_INSTALL 9
7237#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7238#define SQLITE_TESTCTRL_PENDING_BYTE 11
7239#define SQLITE_TESTCTRL_ASSERT 12
7240#define SQLITE_TESTCTRL_ALWAYS 13
7241#define SQLITE_TESTCTRL_RESERVE 14
7242#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
7243#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
7244#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
7245#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
7246#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
7247#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
7248#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
7249#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
7250#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
7251#define SQLITE_TESTCTRL_BYTEORDER 22
7252#define SQLITE_TESTCTRL_ISINIT 23
7253#define SQLITE_TESTCTRL_SORTER_MMAP 24
7254#define SQLITE_TESTCTRL_IMPOSTER 25
7255#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
7256#define SQLITE_TESTCTRL_LAST 26 /* Largest TESTCTRL */
7257
7258/*
7259** CAPI3REF: SQL Keyword Checking
7260**
7261** These routines provide access to the set of SQL language keywords
7262** recognized by SQLite. Applications can uses these routines to determine
7263** whether or not a specific identifier needs to be escaped (for example,
7264** by enclosing in double-quotes) so as not to confuse the parser.
7265**
7266** The sqlite3_keyword_count() interface returns the number of distinct
7267** keywords understood by SQLite.
7268**
7269** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
7270** makes *Z point to that keyword expressed as UTF8 and writes the number
7271** of bytes in the keyword into *L. The string that *Z points to is not
7272** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
7273** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
7274** or L are NULL or invalid pointers then calls to
7275** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
7276**
7277** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
7278** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
7279** if it is and zero if not.
7280**
7281** The parser used by SQLite is forgiving. It is often possible to use
7282** a keyword as an identifier as long as such use does not result in a
7283** parsing ambiguity. For example, the statement
7284** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
7285** creates a new table named "BEGIN" with three columns named
7286** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
7287** using keywords as identifiers. Common techniques used to avoid keyword
7288** name collisions include:
7289** <ul>
7290** <li> Put all identifier names inside double-quotes. This is the official
7291** SQL way to escape identifier names.
7292** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
7293** but it is what SQL Server does and so lots of programmers use this
7294** technique.
7295** <li> Begin every identifier with the letter "Z" as no SQL keywords start
7296** with "Z".
7297** <li> Include a digit somewhere in every identifier name.
7298** </ul>
7299**
7300** Note that the number of keywords understood by SQLite can depend on
7301** compile-time options. For example, "VACUUM" is not a keyword if
7302** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
7303** new keywords may be added to future releases of SQLite.
7304*/
7305SQLITE_API int sqlite3_keyword_count(void);
7306SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
7307SQLITE_API int sqlite3_keyword_check(const char*,int);
7308
7309/*
7310** CAPI3REF: Dynamic String Object
7311** KEYWORDS: {dynamic string}
7312**
7313** An instance of the sqlite3_str object contains a dynamically-sized
7314** string under construction.
7315**
7316** The lifecycle of an sqlite3_str object is as follows:
7317** <ol>
7318** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
7319** <li> ^Text is appended to the sqlite3_str object using various
7320** methods, such as [sqlite3_str_appendf()].
7321** <li> ^The sqlite3_str object is destroyed and the string it created
7322** is returned using the [sqlite3_str_finish()] interface.
7323** </ol>
7324*/
7325typedef struct sqlite3_str sqlite3_str;
7326
7327/*
7328** CAPI3REF: Create A New Dynamic String Object
7329** CONSTRUCTOR: sqlite3_str
7330**
7331** ^The [sqlite3_str_new(D)] interface allocates and initializes
7332** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
7333** [sqlite3_str_new()] must be freed by a subsequent call to
7334** [sqlite3_str_finish(X)].
7335**
7336** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
7337** valid [sqlite3_str] object, though in the event of an out-of-memory
7338** error the returned object might be a special singleton that will
7339** silently reject new text, always return SQLITE_NOMEM from
7340** [sqlite3_str_errcode()], always return 0 for
7341** [sqlite3_str_length()], and always return NULL from
7342** [sqlite3_str_finish(X)]. It is always safe to use the value
7343** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
7344** to any of the other [sqlite3_str] methods.
7345**
7346** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
7347** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
7348** length of the string contained in the [sqlite3_str] object will be
7349** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
7350** of [SQLITE_MAX_LENGTH].
7351*/
7352SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
7353
7354/*
7355** CAPI3REF: Finalize A Dynamic String
7356** DESTRUCTOR: sqlite3_str
7357**
7358** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
7359** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
7360** that contains the constructed string. The calling application should
7361** pass the returned value to [sqlite3_free()] to avoid a memory leak.
7362** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
7363** errors were encountered during construction of the string. ^The
7364** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
7365** string in [sqlite3_str] object X is zero bytes long.
7366*/
7367SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
7368
7369/*
7370** CAPI3REF: Add Content To A Dynamic String
7371** METHOD: sqlite3_str
7372**
7373** These interfaces add content to an sqlite3_str object previously obtained
7374** from [sqlite3_str_new()].
7375**
7376** ^The [sqlite3_str_appendf(X,F,...)] and
7377** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
7378** functionality of SQLite to append formatted text onto the end of
7379** [sqlite3_str] object X.
7380**
7381** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
7382** onto the end of the [sqlite3_str] object X. N must be non-negative.
7383** S must contain at least N non-zero bytes of content. To append a
7384** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
7385** method instead.
7386**
7387** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
7388** zero-terminated string S onto the end of [sqlite3_str] object X.
7389**
7390** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
7391** single-byte character C onto the end of [sqlite3_str] object X.
7392** ^This method can be used, for example, to add whitespace indentation.
7393**
7394** ^The [sqlite3_str_reset(X)] method resets the string under construction
7395** inside [sqlite3_str] object X back to zero bytes in length.
7396**
7397** These methods do not return a result code. ^If an error occurs, that fact
7398** is recorded in the [sqlite3_str] object and can be recovered by a
7399** subsequent call to [sqlite3_str_errcode(X)].
7400*/
7401SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
7402SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
7403SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
7404SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
7405SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
7406SQLITE_API void sqlite3_str_reset(sqlite3_str*);
7407
7408/*
7409** CAPI3REF: Status Of A Dynamic String
7410** METHOD: sqlite3_str
7411**
7412** These interfaces return the current status of an [sqlite3_str] object.
7413**
7414** ^If any prior errors have occurred while constructing the dynamic string
7415** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
7416** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
7417** [SQLITE_NOMEM] following any out-of-memory error, or
7418** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
7419** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
7420**
7421** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
7422** of the dynamic string under construction in [sqlite3_str] object X.
7423** ^The length returned by [sqlite3_str_length(X)] does not include the
7424** zero-termination byte.
7425**
7426** ^The [sqlite3_str_value(X)] method returns a pointer to the current
7427** content of the dynamic string under construction in X. The value
7428** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
7429** and might be freed or altered by any subsequent method on the same
7430** [sqlite3_str] object. Applications must not used the pointer returned
7431** [sqlite3_str_value(X)] after any subsequent method call on the same
7432** object. ^Applications may change the content of the string returned
7433** by [sqlite3_str_value(X)] as long as they do not write into any bytes
7434** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
7435** write any byte after any subsequent sqlite3_str method call.
7436*/
7437SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
7438SQLITE_API int sqlite3_str_length(sqlite3_str*);
7439SQLITE_API char *sqlite3_str_value(sqlite3_str*);
7440
7441/*
7442** CAPI3REF: SQLite Runtime Status
7443**
7444** ^These interfaces are used to retrieve runtime status information
7445** about the performance of SQLite, and optionally to reset various
7446** highwater marks. ^The first argument is an integer code for
7447** the specific parameter to measure. ^(Recognized integer codes
7448** are of the form [status parameters | SQLITE_STATUS_...].)^
7449** ^The current value of the parameter is returned into *pCurrent.
7450** ^The highest recorded value is returned in *pHighwater. ^If the
7451** resetFlag is true, then the highest record value is reset after
7452** *pHighwater is written. ^(Some parameters do not record the highest
7453** value. For those parameters
7454** nothing is written into *pHighwater and the resetFlag is ignored.)^
7455** ^(Other parameters record only the highwater mark and not the current
7456** value. For these latter parameters nothing is written into *pCurrent.)^
7457**
7458** ^The sqlite3_status() and sqlite3_status64() routines return
7459** SQLITE_OK on success and a non-zero [error code] on failure.
7460**
7461** If either the current value or the highwater mark is too large to
7462** be represented by a 32-bit integer, then the values returned by
7463** sqlite3_status() are undefined.
7464**
7465** See also: [sqlite3_db_status()]
7466*/
7467SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
7468SQLITE_API int sqlite3_status64(
7469 int op,
7470 sqlite3_int64 *pCurrent,
7471 sqlite3_int64 *pHighwater,
7472 int resetFlag
7473);
7474
7475
7476/*
7477** CAPI3REF: Status Parameters
7478** KEYWORDS: {status parameters}
7479**
7480** These integer constants designate various run-time status parameters
7481** that can be returned by [sqlite3_status()].
7482**
7483** <dl>
7484** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
7485** <dd>This parameter is the current amount of memory checked out
7486** using [sqlite3_malloc()], either directly or indirectly. The
7487** figure includes calls made to [sqlite3_malloc()] by the application
7488** and internal memory usage by the SQLite library. Auxiliary page-cache
7489** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
7490** this parameter. The amount returned is the sum of the allocation
7491** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
7492**
7493** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
7494** <dd>This parameter records the largest memory allocation request
7495** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
7496** internal equivalents). Only the value returned in the
7497** *pHighwater parameter to [sqlite3_status()] is of interest.
7498** The value written into the *pCurrent parameter is undefined.</dd>)^
7499**
7500** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
7501** <dd>This parameter records the number of separate memory allocations
7502** currently checked out.</dd>)^
7503**
7504** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
7505** <dd>This parameter returns the number of pages used out of the
7506** [pagecache memory allocator] that was configured using
7507** [SQLITE_CONFIG_PAGECACHE]. The
7508** value returned is in pages, not in bytes.</dd>)^
7509**
7510** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
7511** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
7512** <dd>This parameter returns the number of bytes of page cache
7513** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
7514** buffer and where forced to overflow to [sqlite3_malloc()]. The
7515** returned value includes allocations that overflowed because they
7516** where too large (they were larger than the "sz" parameter to
7517** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
7518** no space was left in the page cache.</dd>)^
7519**
7520** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
7521** <dd>This parameter records the largest memory allocation request
7522** handed to [pagecache memory allocator]. Only the value returned in the
7523** *pHighwater parameter to [sqlite3_status()] is of interest.
7524** The value written into the *pCurrent parameter is undefined.</dd>)^
7525**
7526** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
7527** <dd>No longer used.</dd>
7528**
7529** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
7530** <dd>No longer used.</dd>
7531**
7532** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
7533** <dd>No longer used.</dd>
7534**
7535** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
7536** <dd>The *pHighwater parameter records the deepest parser stack.
7537** The *pCurrent value is undefined. The *pHighwater value is only
7538** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
7539** </dl>
7540**
7541** New status parameters may be added from time to time.
7542*/
7543#define SQLITE_STATUS_MEMORY_USED 0
7544#define SQLITE_STATUS_PAGECACHE_USED 1
7545#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
7546#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
7547#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
7548#define SQLITE_STATUS_MALLOC_SIZE 5
7549#define SQLITE_STATUS_PARSER_STACK 6
7550#define SQLITE_STATUS_PAGECACHE_SIZE 7
7551#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
7552#define SQLITE_STATUS_MALLOC_COUNT 9
7553
7554/*
7555** CAPI3REF: Database Connection Status
7556** METHOD: sqlite3
7557**
7558** ^This interface is used to retrieve runtime status information
7559** about a single [database connection]. ^The first argument is the
7560** database connection object to be interrogated. ^The second argument
7561** is an integer constant, taken from the set of
7562** [SQLITE_DBSTATUS options], that
7563** determines the parameter to interrogate. The set of
7564** [SQLITE_DBSTATUS options] is likely
7565** to grow in future releases of SQLite.
7566**
7567** ^The current value of the requested parameter is written into *pCur
7568** and the highest instantaneous value is written into *pHiwtr. ^If
7569** the resetFlg is true, then the highest instantaneous value is
7570** reset back down to the current value.
7571**
7572** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
7573** non-zero [error code] on failure.
7574**
7575** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
7576*/
7577SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
7578
7579/*
7580** CAPI3REF: Status Parameters for database connections
7581** KEYWORDS: {SQLITE_DBSTATUS options}
7582**
7583** These constants are the available integer "verbs" that can be passed as
7584** the second argument to the [sqlite3_db_status()] interface.
7585**
7586** New verbs may be added in future releases of SQLite. Existing verbs
7587** might be discontinued. Applications should check the return code from
7588** [sqlite3_db_status()] to make sure that the call worked.
7589** The [sqlite3_db_status()] interface will return a non-zero error code
7590** if a discontinued or unsupported verb is invoked.
7591**
7592** <dl>
7593** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
7594** <dd>This parameter returns the number of lookaside memory slots currently
7595** checked out.</dd>)^
7596**
7597** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
7598** <dd>This parameter returns the number malloc attempts that were
7599** satisfied using lookaside memory. Only the high-water value is meaningful;
7600** the current value is always zero.)^
7601**
7602** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
7603** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
7604** <dd>This parameter returns the number malloc attempts that might have
7605** been satisfied using lookaside memory but failed due to the amount of
7606** memory requested being larger than the lookaside slot size.
7607** Only the high-water value is meaningful;
7608** the current value is always zero.)^
7609**
7610** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
7611** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
7612** <dd>This parameter returns the number malloc attempts that might have
7613** been satisfied using lookaside memory but failed due to all lookaside
7614** memory already being in use.
7615** Only the high-water value is meaningful;
7616** the current value is always zero.)^
7617**
7618** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
7619** <dd>This parameter returns the approximate number of bytes of heap
7620** memory used by all pager caches associated with the database connection.)^
7621** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
7622**
7623** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
7624** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
7625** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
7626** pager cache is shared between two or more connections the bytes of heap
7627** memory used by that pager cache is divided evenly between the attached
7628** connections.)^ In other words, if none of the pager caches associated
7629** with the database connection are shared, this request returns the same
7630** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
7631** shared, the value returned by this call will be smaller than that returned
7632** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
7633** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
7634**
7635** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
7636** <dd>This parameter returns the approximate number of bytes of heap
7637** memory used to store the schema for all databases associated
7638** with the connection - main, temp, and any [ATTACH]-ed databases.)^
7639** ^The full amount of memory used by the schemas is reported, even if the
7640** schema memory is shared with other database connections due to
7641** [shared cache mode] being enabled.
7642** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
7643**
7644** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
7645** <dd>This parameter returns the approximate number of bytes of heap
7646** and lookaside memory used by all prepared statements associated with
7647** the database connection.)^
7648** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
7649** </dd>
7650**
7651** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
7652** <dd>This parameter returns the number of pager cache hits that have
7653** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
7654** is always 0.
7655** </dd>
7656**
7657** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
7658** <dd>This parameter returns the number of pager cache misses that have
7659** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
7660** is always 0.
7661** </dd>
7662**
7663** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
7664** <dd>This parameter returns the number of dirty cache entries that have
7665** been written to disk. Specifically, the number of pages written to the
7666** wal file in wal mode databases, or the number of pages written to the
7667** database file in rollback mode databases. Any pages written as part of
7668** transaction rollback or database recovery operations are not included.
7669** If an IO or other error occurs while writing a page to disk, the effect
7670** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
7671** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
7672** </dd>
7673**
7674** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
7675** <dd>This parameter returns the number of dirty cache entries that have
7676** been written to disk in the middle of a transaction due to the page
7677** cache overflowing. Transactions are more efficient if they are written
7678** to disk all at once. When pages spill mid-transaction, that introduces
7679** additional overhead. This parameter can be used help identify
7680** inefficiencies that can be resolve by increasing the cache size.
7681** </dd>
7682**
7683** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
7684** <dd>This parameter returns zero for the current value if and only if
7685** all foreign key constraints (deferred or immediate) have been
7686** resolved.)^ ^The highwater mark is always 0.
7687** </dd>
7688** </dl>
7689*/
7690#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
7691#define SQLITE_DBSTATUS_CACHE_USED 1
7692#define SQLITE_DBSTATUS_SCHEMA_USED 2
7693#define SQLITE_DBSTATUS_STMT_USED 3
7694#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
7695#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
7696#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
7697#define SQLITE_DBSTATUS_CACHE_HIT 7
7698#define SQLITE_DBSTATUS_CACHE_MISS 8
7699#define SQLITE_DBSTATUS_CACHE_WRITE 9
7700#define SQLITE_DBSTATUS_DEFERRED_FKS 10
7701#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
7702#define SQLITE_DBSTATUS_CACHE_SPILL 12
7703#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
7704
7705
7706/*
7707** CAPI3REF: Prepared Statement Status
7708** METHOD: sqlite3_stmt
7709**
7710** ^(Each prepared statement maintains various
7711** [SQLITE_STMTSTATUS counters] that measure the number
7712** of times it has performed specific operations.)^ These counters can
7713** be used to monitor the performance characteristics of the prepared
7714** statements. For example, if the number of table steps greatly exceeds
7715** the number of table searches or result rows, that would tend to indicate
7716** that the prepared statement is using a full table scan rather than
7717** an index.
7718**
7719** ^(This interface is used to retrieve and reset counter values from
7720** a [prepared statement]. The first argument is the prepared statement
7721** object to be interrogated. The second argument
7722** is an integer code for a specific [SQLITE_STMTSTATUS counter]
7723** to be interrogated.)^
7724** ^The current value of the requested counter is returned.
7725** ^If the resetFlg is true, then the counter is reset to zero after this
7726** interface call returns.
7727**
7728** See also: [sqlite3_status()] and [sqlite3_db_status()].
7729*/
7730SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
7731
7732/*
7733** CAPI3REF: Status Parameters for prepared statements
7734** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
7735**
7736** These preprocessor macros define integer codes that name counter
7737** values associated with the [sqlite3_stmt_status()] interface.
7738** The meanings of the various counters are as follows:
7739**
7740** <dl>
7741** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
7742** <dd>^This is the number of times that SQLite has stepped forward in
7743** a table as part of a full table scan. Large numbers for this counter
7744** may indicate opportunities for performance improvement through
7745** careful use of indices.</dd>
7746**
7747** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
7748** <dd>^This is the number of sort operations that have occurred.
7749** A non-zero value in this counter may indicate an opportunity to
7750** improvement performance through careful use of indices.</dd>
7751**
7752** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
7753** <dd>^This is the number of rows inserted into transient indices that
7754** were created automatically in order to help joins run faster.
7755** A non-zero value in this counter may indicate an opportunity to
7756** improvement performance by adding permanent indices that do not
7757** need to be reinitialized each time the statement is run.</dd>
7758**
7759** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
7760** <dd>^This is the number of virtual machine operations executed
7761** by the prepared statement if that number is less than or equal
7762** to 2147483647. The number of virtual machine operations can be
7763** used as a proxy for the total work done by the prepared statement.
7764** If the number of virtual machine operations exceeds 2147483647
7765** then the value returned by this statement status code is undefined.
7766**
7767** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
7768** <dd>^This is the number of times that the prepare statement has been
7769** automatically regenerated due to schema changes or change to
7770** [bound parameters] that might affect the query plan.
7771**
7772** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
7773** <dd>^This is the number of times that the prepared statement has
7774** been run. A single "run" for the purposes of this counter is one
7775** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
7776** The counter is incremented on the first [sqlite3_step()] call of each
7777** cycle.
7778**
7779** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
7780** <dd>^This is the approximate number of bytes of heap memory
7781** used to store the prepared statement. ^This value is not actually
7782** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
7783** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
7784** </dd>
7785** </dl>
7786*/
7787#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
7788#define SQLITE_STMTSTATUS_SORT 2
7789#define SQLITE_STMTSTATUS_AUTOINDEX 3
7790#define SQLITE_STMTSTATUS_VM_STEP 4
7791#define SQLITE_STMTSTATUS_REPREPARE 5
7792#define SQLITE_STMTSTATUS_RUN 6
7793#define SQLITE_STMTSTATUS_MEMUSED 99
7794
7795/*
7796** CAPI3REF: Custom Page Cache Object
7797**
7798** The sqlite3_pcache type is opaque. It is implemented by
7799** the pluggable module. The SQLite core has no knowledge of
7800** its size or internal structure and never deals with the
7801** sqlite3_pcache object except by holding and passing pointers
7802** to the object.
7803**
7804** See [sqlite3_pcache_methods2] for additional information.
7805*/
7806typedef struct sqlite3_pcache sqlite3_pcache;
7807
7808/*
7809** CAPI3REF: Custom Page Cache Object
7810**
7811** The sqlite3_pcache_page object represents a single page in the
7812** page cache. The page cache will allocate instances of this
7813** object. Various methods of the page cache use pointers to instances
7814** of this object as parameters or as their return value.
7815**
7816** See [sqlite3_pcache_methods2] for additional information.
7817*/
7818typedef struct sqlite3_pcache_page sqlite3_pcache_page;
7819struct sqlite3_pcache_page {
7820 void *pBuf; /* The content of the page */
7821 void *pExtra; /* Extra information associated with the page */
7822};
7823
7824/*
7825** CAPI3REF: Application Defined Page Cache.
7826** KEYWORDS: {page cache}
7827**
7828** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
7829** register an alternative page cache implementation by passing in an
7830** instance of the sqlite3_pcache_methods2 structure.)^
7831** In many applications, most of the heap memory allocated by
7832** SQLite is used for the page cache.
7833** By implementing a
7834** custom page cache using this API, an application can better control
7835** the amount of memory consumed by SQLite, the way in which
7836** that memory is allocated and released, and the policies used to
7837** determine exactly which parts of a database file are cached and for
7838** how long.
7839**
7840** The alternative page cache mechanism is an
7841** extreme measure that is only needed by the most demanding applications.
7842** The built-in page cache is recommended for most uses.
7843**
7844** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
7845** internal buffer by SQLite within the call to [sqlite3_config]. Hence
7846** the application may discard the parameter after the call to
7847** [sqlite3_config()] returns.)^
7848**
7849** [[the xInit() page cache method]]
7850** ^(The xInit() method is called once for each effective
7851** call to [sqlite3_initialize()])^
7852** (usually only once during the lifetime of the process). ^(The xInit()
7853** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
7854** The intent of the xInit() method is to set up global data structures
7855** required by the custom page cache implementation.
7856** ^(If the xInit() method is NULL, then the
7857** built-in default page cache is used instead of the application defined
7858** page cache.)^
7859**
7860** [[the xShutdown() page cache method]]
7861** ^The xShutdown() method is called by [sqlite3_shutdown()].
7862** It can be used to clean up
7863** any outstanding resources before process shutdown, if required.
7864** ^The xShutdown() method may be NULL.
7865**
7866** ^SQLite automatically serializes calls to the xInit method,
7867** so the xInit method need not be threadsafe. ^The
7868** xShutdown method is only called from [sqlite3_shutdown()] so it does
7869** not need to be threadsafe either. All other methods must be threadsafe
7870** in multithreaded applications.
7871**
7872** ^SQLite will never invoke xInit() more than once without an intervening
7873** call to xShutdown().
7874**
7875** [[the xCreate() page cache methods]]
7876** ^SQLite invokes the xCreate() method to construct a new cache instance.
7877** SQLite will typically create one cache instance for each open database file,
7878** though this is not guaranteed. ^The
7879** first parameter, szPage, is the size in bytes of the pages that must
7880** be allocated by the cache. ^szPage will always a power of two. ^The
7881** second parameter szExtra is a number of bytes of extra storage
7882** associated with each page cache entry. ^The szExtra parameter will
7883** a number less than 250. SQLite will use the
7884** extra szExtra bytes on each page to store metadata about the underlying
7885** database page on disk. The value passed into szExtra depends
7886** on the SQLite version, the target platform, and how SQLite was compiled.
7887** ^The third argument to xCreate(), bPurgeable, is true if the cache being
7888** created will be used to cache database pages of a file stored on disk, or
7889** false if it is used for an in-memory database. The cache implementation
7890** does not have to do anything special based with the value of bPurgeable;
7891** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
7892** never invoke xUnpin() except to deliberately delete a page.
7893** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
7894** false will always have the "discard" flag set to true.
7895** ^Hence, a cache created with bPurgeable false will
7896** never contain any unpinned pages.
7897**
7898** [[the xCachesize() page cache method]]
7899** ^(The xCachesize() method may be called at any time by SQLite to set the
7900** suggested maximum cache-size (number of pages stored by) the cache
7901** instance passed as the first argument. This is the value configured using
7902** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
7903** parameter, the implementation is not required to do anything with this
7904** value; it is advisory only.
7905**
7906** [[the xPagecount() page cache methods]]
7907** The xPagecount() method must return the number of pages currently
7908** stored in the cache, both pinned and unpinned.
7909**
7910** [[the xFetch() page cache methods]]
7911** The xFetch() method locates a page in the cache and returns a pointer to
7912** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7913** The pBuf element of the returned sqlite3_pcache_page object will be a
7914** pointer to a buffer of szPage bytes used to store the content of a
7915** single database page. The pExtra element of sqlite3_pcache_page will be
7916** a pointer to the szExtra bytes of extra storage that SQLite has requested
7917** for each entry in the page cache.
7918**
7919** The page to be fetched is determined by the key. ^The minimum key value
7920** is 1. After it has been retrieved using xFetch, the page is considered
7921** to be "pinned".
7922**
7923** If the requested page is already in the page cache, then the page cache
7924** implementation must return a pointer to the page buffer with its content
7925** intact. If the requested page is not already in the cache, then the
7926** cache implementation should use the value of the createFlag
7927** parameter to help it determined what action to take:
7928**
7929** <table border=1 width=85% align=center>
7930** <tr><th> createFlag <th> Behavior when page is not already in cache
7931** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
7932** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7933** Otherwise return NULL.
7934** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
7935** NULL if allocating a new page is effectively impossible.
7936** </table>
7937**
7938** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
7939** will only use a createFlag of 2 after a prior call with a createFlag of 1
7940** failed.)^ In between the to xFetch() calls, SQLite may
7941** attempt to unpin one or more cache pages by spilling the content of
7942** pinned pages to disk and synching the operating system disk cache.
7943**
7944** [[the xUnpin() page cache method]]
7945** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
7946** as its second argument. If the third parameter, discard, is non-zero,
7947** then the page must be evicted from the cache.
7948** ^If the discard parameter is
7949** zero, then the page may be discarded or retained at the discretion of
7950** page cache implementation. ^The page cache implementation
7951** may choose to evict unpinned pages at any time.
7952**
7953** The cache must not perform any reference counting. A single
7954** call to xUnpin() unpins the page regardless of the number of prior calls
7955** to xFetch().
7956**
7957** [[the xRekey() page cache methods]]
7958** The xRekey() method is used to change the key value associated with the
7959** page passed as the second argument. If the cache
7960** previously contains an entry associated with newKey, it must be
7961** discarded. ^Any prior cache entry associated with newKey is guaranteed not
7962** to be pinned.
7963**
7964** When SQLite calls the xTruncate() method, the cache must discard all
7965** existing cache entries with page numbers (keys) greater than or equal
7966** to the value of the iLimit parameter passed to xTruncate(). If any
7967** of these pages are pinned, they are implicitly unpinned, meaning that
7968** they can be safely discarded.
7969**
7970** [[the xDestroy() page cache method]]
7971** ^The xDestroy() method is used to delete a cache allocated by xCreate().
7972** All resources associated with the specified cache should be freed. ^After
7973** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
7974** handle invalid, and will not use it with any other sqlite3_pcache_methods2
7975** functions.
7976**
7977** [[the xShrink() page cache method]]
7978** ^SQLite invokes the xShrink() method when it wants the page cache to
7979** free up as much of heap memory as possible. The page cache implementation
7980** is not obligated to free any memory, but well-behaved implementations should
7981** do their best.
7982*/
7983typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
7984struct sqlite3_pcache_methods2 {
7985 int iVersion;
7986 void *pArg;
7987 int (*xInit)(void*);
7988 void (*xShutdown)(void*);
7989 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
7990 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7991 int (*xPagecount)(sqlite3_pcache*);
7992 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7993 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
7994 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
7995 unsigned oldKey, unsigned newKey);
7996 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7997 void (*xDestroy)(sqlite3_pcache*);
7998 void (*xShrink)(sqlite3_pcache*);
7999};
8000
8001/*
8002** This is the obsolete pcache_methods object that has now been replaced
8003** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8004** retained in the header file for backwards compatibility only.
8005*/
8006typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8007struct sqlite3_pcache_methods {
8008 void *pArg;
8009 int (*xInit)(void*);
8010 void (*xShutdown)(void*);
8011 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8012 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8013 int (*xPagecount)(sqlite3_pcache*);
8014 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8015 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8016 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8017 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8018 void (*xDestroy)(sqlite3_pcache*);
8019};
8020
8021
8022/*
8023** CAPI3REF: Online Backup Object
8024**
8025** The sqlite3_backup object records state information about an ongoing
8026** online backup operation. ^The sqlite3_backup object is created by
8027** a call to [sqlite3_backup_init()] and is destroyed by a call to
8028** [sqlite3_backup_finish()].
8029**
8030** See Also: [Using the SQLite Online Backup API]
8031*/
8032typedef struct sqlite3_backup sqlite3_backup;
8033
8034/*
8035** CAPI3REF: Online Backup API.
8036**
8037** The backup API copies the content of one database into another.
8038** It is useful either for creating backups of databases or
8039** for copying in-memory databases to or from persistent files.
8040**
8041** See Also: [Using the SQLite Online Backup API]
8042**
8043** ^SQLite holds a write transaction open on the destination database file
8044** for the duration of the backup operation.
8045** ^The source database is read-locked only while it is being read;
8046** it is not locked continuously for the entire backup operation.
8047** ^Thus, the backup may be performed on a live source database without
8048** preventing other database connections from
8049** reading or writing to the source database while the backup is underway.
8050**
8051** ^(To perform a backup operation:
8052** <ol>
8053** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8054** backup,
8055** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8056** the data between the two databases, and finally
8057** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8058** associated with the backup operation.
8059** </ol>)^
8060** There should be exactly one call to sqlite3_backup_finish() for each
8061** successful call to sqlite3_backup_init().
8062**
8063** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8064**
8065** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8066** [database connection] associated with the destination database
8067** and the database name, respectively.
8068** ^The database name is "main" for the main database, "temp" for the
8069** temporary database, or the name specified after the AS keyword in
8070** an [ATTACH] statement for an attached database.
8071** ^The S and M arguments passed to
8072** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8073** and database name of the source database, respectively.
8074** ^The source and destination [database connections] (parameters S and D)
8075** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8076** an error.
8077**
8078** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8079** there is already a read or read-write transaction open on the
8080** destination database.
8081**
8082** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8083** returned and an error code and error message are stored in the
8084** destination [database connection] D.
8085** ^The error code and message for the failed call to sqlite3_backup_init()
8086** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8087** [sqlite3_errmsg16()] functions.
8088** ^A successful call to sqlite3_backup_init() returns a pointer to an
8089** [sqlite3_backup] object.
8090** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8091** sqlite3_backup_finish() functions to perform the specified backup
8092** operation.
8093**
8094** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8095**
8096** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8097** the source and destination databases specified by [sqlite3_backup] object B.
8098** ^If N is negative, all remaining source pages are copied.
8099** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8100** are still more pages to be copied, then the function returns [SQLITE_OK].
8101** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8102** from source to destination, then it returns [SQLITE_DONE].
8103** ^If an error occurs while running sqlite3_backup_step(B,N),
8104** then an [error code] is returned. ^As well as [SQLITE_OK] and
8105** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8106** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8107** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8108**
8109** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8110** <ol>
8111** <li> the destination database was opened read-only, or
8112** <li> the destination database is using write-ahead-log journaling
8113** and the destination and source page sizes differ, or
8114** <li> the destination database is an in-memory database and the
8115** destination and source page sizes differ.
8116** </ol>)^
8117**
8118** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8119** the [sqlite3_busy_handler | busy-handler function]
8120** is invoked (if one is specified). ^If the
8121** busy-handler returns non-zero before the lock is available, then
8122** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8123** sqlite3_backup_step() can be retried later. ^If the source
8124** [database connection]
8125** is being used to write to the source database when sqlite3_backup_step()
8126** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8127** case the call to sqlite3_backup_step() can be retried later on. ^(If
8128** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8129** [SQLITE_READONLY] is returned, then
8130** there is no point in retrying the call to sqlite3_backup_step(). These
8131** errors are considered fatal.)^ The application must accept
8132** that the backup operation has failed and pass the backup operation handle
8133** to the sqlite3_backup_finish() to release associated resources.
8134**
8135** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8136** on the destination file. ^The exclusive lock is not released until either
8137** sqlite3_backup_finish() is called or the backup operation is complete
8138** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8139** sqlite3_backup_step() obtains a [shared lock] on the source database that
8140** lasts for the duration of the sqlite3_backup_step() call.
8141** ^Because the source database is not locked between calls to
8142** sqlite3_backup_step(), the source database may be modified mid-way
8143** through the backup process. ^If the source database is modified by an
8144** external process or via a database connection other than the one being
8145** used by the backup operation, then the backup will be automatically
8146** restarted by the next call to sqlite3_backup_step(). ^If the source
8147** database is modified by the using the same database connection as is used
8148** by the backup operation, then the backup database is automatically
8149** updated at the same time.
8150**
8151** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8152**
8153** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8154** application wishes to abandon the backup operation, the application
8155** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8156** ^The sqlite3_backup_finish() interfaces releases all
8157** resources associated with the [sqlite3_backup] object.
8158** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8159** active write-transaction on the destination database is rolled back.
8160** The [sqlite3_backup] object is invalid
8161** and may not be used following a call to sqlite3_backup_finish().
8162**
8163** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8164** sqlite3_backup_step() errors occurred, regardless or whether or not
8165** sqlite3_backup_step() completed.
8166** ^If an out-of-memory condition or IO error occurred during any prior
8167** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8168** sqlite3_backup_finish() returns the corresponding [error code].
8169**
8170** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8171** is not a permanent error and does not affect the return value of
8172** sqlite3_backup_finish().
8173**
8174** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8175** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8176**
8177** ^The sqlite3_backup_remaining() routine returns the number of pages still
8178** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8179** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8180** in the source database at the conclusion of the most recent
8181** sqlite3_backup_step().
8182** ^(The values returned by these functions are only updated by
8183** sqlite3_backup_step(). If the source database is modified in a way that
8184** changes the size of the source database or the number of pages remaining,
8185** those changes are not reflected in the output of sqlite3_backup_pagecount()
8186** and sqlite3_backup_remaining() until after the next
8187** sqlite3_backup_step().)^
8188**
8189** <b>Concurrent Usage of Database Handles</b>
8190**
8191** ^The source [database connection] may be used by the application for other
8192** purposes while a backup operation is underway or being initialized.
8193** ^If SQLite is compiled and configured to support threadsafe database
8194** connections, then the source database connection may be used concurrently
8195** from within other threads.
8196**
8197** However, the application must guarantee that the destination
8198** [database connection] is not passed to any other API (by any thread) after
8199** sqlite3_backup_init() is called and before the corresponding call to
8200** sqlite3_backup_finish(). SQLite does not currently check to see
8201** if the application incorrectly accesses the destination [database connection]
8202** and so no error code is reported, but the operations may malfunction
8203** nevertheless. Use of the destination database connection while a
8204** backup is in progress might also also cause a mutex deadlock.
8205**
8206** If running in [shared cache mode], the application must
8207** guarantee that the shared cache used by the destination database
8208** is not accessed while the backup is running. In practice this means
8209** that the application must guarantee that the disk file being
8210** backed up to is not accessed by any connection within the process,
8211** not just the specific connection that was passed to sqlite3_backup_init().
8212**
8213** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8214** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8215** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8216** APIs are not strictly speaking threadsafe. If they are invoked at the
8217** same time as another thread is invoking sqlite3_backup_step() it is
8218** possible that they return invalid values.
8219*/
8220SQLITE_API sqlite3_backup *sqlite3_backup_init(
8221 sqlite3 *pDest, /* Destination database handle */
8222 const char *zDestName, /* Destination database name */
8223 sqlite3 *pSource, /* Source database handle */
8224 const char *zSourceName /* Source database name */
8225);
8226SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
8227SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
8228SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
8229SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
8230
8231/*
8232** CAPI3REF: Unlock Notification
8233** METHOD: sqlite3
8234**
8235** ^When running in shared-cache mode, a database operation may fail with
8236** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
8237** individual tables within the shared-cache cannot be obtained. See
8238** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
8239** ^This API may be used to register a callback that SQLite will invoke
8240** when the connection currently holding the required lock relinquishes it.
8241** ^This API is only available if the library was compiled with the
8242** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
8243**
8244** See Also: [Using the SQLite Unlock Notification Feature].
8245**
8246** ^Shared-cache locks are released when a database connection concludes
8247** its current transaction, either by committing it or rolling it back.
8248**
8249** ^When a connection (known as the blocked connection) fails to obtain a
8250** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
8251** identity of the database connection (the blocking connection) that
8252** has locked the required resource is stored internally. ^After an
8253** application receives an SQLITE_LOCKED error, it may call the
8254** sqlite3_unlock_notify() method with the blocked connection handle as
8255** the first argument to register for a callback that will be invoked
8256** when the blocking connections current transaction is concluded. ^The
8257** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
8258** call that concludes the blocking connections transaction.
8259**
8260** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
8261** there is a chance that the blocking connection will have already
8262** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
8263** If this happens, then the specified callback is invoked immediately,
8264** from within the call to sqlite3_unlock_notify().)^
8265**
8266** ^If the blocked connection is attempting to obtain a write-lock on a
8267** shared-cache table, and more than one other connection currently holds
8268** a read-lock on the same table, then SQLite arbitrarily selects one of
8269** the other connections to use as the blocking connection.
8270**
8271** ^(There may be at most one unlock-notify callback registered by a
8272** blocked connection. If sqlite3_unlock_notify() is called when the
8273** blocked connection already has a registered unlock-notify callback,
8274** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
8275** called with a NULL pointer as its second argument, then any existing
8276** unlock-notify callback is canceled. ^The blocked connections
8277** unlock-notify callback may also be canceled by closing the blocked
8278** connection using [sqlite3_close()].
8279**
8280** The unlock-notify callback is not reentrant. If an application invokes
8281** any sqlite3_xxx API functions from within an unlock-notify callback, a
8282** crash or deadlock may be the result.
8283**
8284** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
8285** returns SQLITE_OK.
8286**
8287** <b>Callback Invocation Details</b>
8288**
8289** When an unlock-notify callback is registered, the application provides a
8290** single void* pointer that is passed to the callback when it is invoked.
8291** However, the signature of the callback function allows SQLite to pass
8292** it an array of void* context pointers. The first argument passed to
8293** an unlock-notify callback is a pointer to an array of void* pointers,
8294** and the second is the number of entries in the array.
8295**
8296** When a blocking connections transaction is concluded, there may be
8297** more than one blocked connection that has registered for an unlock-notify
8298** callback. ^If two or more such blocked connections have specified the
8299** same callback function, then instead of invoking the callback function
8300** multiple times, it is invoked once with the set of void* context pointers
8301** specified by the blocked connections bundled together into an array.
8302** This gives the application an opportunity to prioritize any actions
8303** related to the set of unblocked database connections.
8304**
8305** <b>Deadlock Detection</b>
8306**
8307** Assuming that after registering for an unlock-notify callback a
8308** database waits for the callback to be issued before taking any further
8309** action (a reasonable assumption), then using this API may cause the
8310** application to deadlock. For example, if connection X is waiting for
8311** connection Y's transaction to be concluded, and similarly connection
8312** Y is waiting on connection X's transaction, then neither connection
8313** will proceed and the system may remain deadlocked indefinitely.
8314**
8315** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
8316** detection. ^If a given call to sqlite3_unlock_notify() would put the
8317** system in a deadlocked state, then SQLITE_LOCKED is returned and no
8318** unlock-notify callback is registered. The system is said to be in
8319** a deadlocked state if connection A has registered for an unlock-notify
8320** callback on the conclusion of connection B's transaction, and connection
8321** B has itself registered for an unlock-notify callback when connection
8322** A's transaction is concluded. ^Indirect deadlock is also detected, so
8323** the system is also considered to be deadlocked if connection B has
8324** registered for an unlock-notify callback on the conclusion of connection
8325** C's transaction, where connection C is waiting on connection A. ^Any
8326** number of levels of indirection are allowed.
8327**
8328** <b>The "DROP TABLE" Exception</b>
8329**
8330** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
8331** always appropriate to call sqlite3_unlock_notify(). There is however,
8332** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
8333** SQLite checks if there are any currently executing SELECT statements
8334** that belong to the same connection. If there are, SQLITE_LOCKED is
8335** returned. In this case there is no "blocking connection", so invoking
8336** sqlite3_unlock_notify() results in the unlock-notify callback being
8337** invoked immediately. If the application then re-attempts the "DROP TABLE"
8338** or "DROP INDEX" query, an infinite loop might be the result.
8339**
8340** One way around this problem is to check the extended error code returned
8341** by an sqlite3_step() call. ^(If there is a blocking connection, then the
8342** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
8343** the special "DROP TABLE/INDEX" case, the extended error code is just
8344** SQLITE_LOCKED.)^
8345*/
8346SQLITE_API int sqlite3_unlock_notify(
8347 sqlite3 *pBlocked, /* Waiting connection */
8348 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
8349 void *pNotifyArg /* Argument to pass to xNotify */
8350);
8351
8352
8353/*
8354** CAPI3REF: String Comparison
8355**
8356** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
8357** and extensions to compare the contents of two buffers containing UTF-8
8358** strings in a case-independent fashion, using the same definition of "case
8359** independence" that SQLite uses internally when comparing identifiers.
8360*/
8361SQLITE_API int sqlite3_stricmp(const char *, const char *);
8362SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
8363
8364/*
8365** CAPI3REF: String Globbing
8366*
8367** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
8368** string X matches the [GLOB] pattern P.
8369** ^The definition of [GLOB] pattern matching used in
8370** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
8371** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
8372** is case sensitive.
8373**
8374** Note that this routine returns zero on a match and non-zero if the strings
8375** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8376**
8377** See also: [sqlite3_strlike()].
8378*/
8379SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
8380
8381/*
8382** CAPI3REF: String LIKE Matching
8383*
8384** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
8385** string X matches the [LIKE] pattern P with escape character E.
8386** ^The definition of [LIKE] pattern matching used in
8387** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
8388** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
8389** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
8390** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
8391** insensitive - equivalent upper and lower case ASCII characters match
8392** one another.
8393**
8394** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
8395** only ASCII characters are case folded.
8396**
8397** Note that this routine returns zero on a match and non-zero if the strings
8398** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
8399**
8400** See also: [sqlite3_strglob()].
8401*/
8402SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
8403
8404/*
8405** CAPI3REF: Error Logging Interface
8406**
8407** ^The [sqlite3_log()] interface writes a message into the [error log]
8408** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
8409** ^If logging is enabled, the zFormat string and subsequent arguments are
8410** used with [sqlite3_snprintf()] to generate the final output string.
8411**
8412** The sqlite3_log() interface is intended for use by extensions such as
8413** virtual tables, collating functions, and SQL functions. While there is
8414** nothing to prevent an application from calling sqlite3_log(), doing so
8415** is considered bad form.
8416**
8417** The zFormat string must not be NULL.
8418**
8419** To avoid deadlocks and other threading problems, the sqlite3_log() routine
8420** will not use dynamically allocated memory. The log message is stored in
8421** a fixed-length buffer on the stack. If the log message is longer than
8422** a few hundred characters, it will be truncated to the length of the
8423** buffer.
8424*/
8425SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
8426
8427/*
8428** CAPI3REF: Write-Ahead Log Commit Hook
8429** METHOD: sqlite3
8430**
8431** ^The [sqlite3_wal_hook()] function is used to register a callback that
8432** is invoked each time data is committed to a database in wal mode.
8433**
8434** ^(The callback is invoked by SQLite after the commit has taken place and
8435** the associated write-lock on the database released)^, so the implementation
8436** may read, write or [checkpoint] the database as required.
8437**
8438** ^The first parameter passed to the callback function when it is invoked
8439** is a copy of the third parameter passed to sqlite3_wal_hook() when
8440** registering the callback. ^The second is a copy of the database handle.
8441** ^The third parameter is the name of the database that was written to -
8442** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
8443** is the number of pages currently in the write-ahead log file,
8444** including those that were just committed.
8445**
8446** The callback function should normally return [SQLITE_OK]. ^If an error
8447** code is returned, that error will propagate back up through the
8448** SQLite code base to cause the statement that provoked the callback
8449** to report an error, though the commit will have still occurred. If the
8450** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
8451** that does not correspond to any valid SQLite error code, the results
8452** are undefined.
8453**
8454** A single database handle may have at most a single write-ahead log callback
8455** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
8456** previously registered write-ahead log callback. ^Note that the
8457** [sqlite3_wal_autocheckpoint()] interface and the
8458** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
8459** overwrite any prior [sqlite3_wal_hook()] settings.
8460*/
8461SQLITE_API void *sqlite3_wal_hook(
8462 sqlite3*,
8463 int(*)(void *,sqlite3*,const char*,int),
8464 void*
8465);
8466
8467/*
8468** CAPI3REF: Configure an auto-checkpoint
8469** METHOD: sqlite3
8470**
8471** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
8472** [sqlite3_wal_hook()] that causes any database on [database connection] D
8473** to automatically [checkpoint]
8474** after committing a transaction if there are N or
8475** more frames in the [write-ahead log] file. ^Passing zero or
8476** a negative value as the nFrame parameter disables automatic
8477** checkpoints entirely.
8478**
8479** ^The callback registered by this function replaces any existing callback
8480** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
8481** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
8482** configured by this function.
8483**
8484** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
8485** from SQL.
8486**
8487** ^Checkpoints initiated by this mechanism are
8488** [sqlite3_wal_checkpoint_v2|PASSIVE].
8489**
8490** ^Every new [database connection] defaults to having the auto-checkpoint
8491** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
8492** pages. The use of this interface
8493** is only necessary if the default setting is found to be suboptimal
8494** for a particular application.
8495*/
8496SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
8497
8498/*
8499** CAPI3REF: Checkpoint a database
8500** METHOD: sqlite3
8501**
8502** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
8503** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
8504**
8505** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
8506** [write-ahead log] for database X on [database connection] D to be
8507** transferred into the database file and for the write-ahead log to
8508** be reset. See the [checkpointing] documentation for addition
8509** information.
8510**
8511** This interface used to be the only way to cause a checkpoint to
8512** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
8513** interface was added. This interface is retained for backwards
8514** compatibility and as a convenience for applications that need to manually
8515** start a callback but which do not need the full power (and corresponding
8516** complication) of [sqlite3_wal_checkpoint_v2()].
8517*/
8518SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
8519
8520/*
8521** CAPI3REF: Checkpoint a database
8522** METHOD: sqlite3
8523**
8524** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
8525** operation on database X of [database connection] D in mode M. Status
8526** information is written back into integers pointed to by L and C.)^
8527** ^(The M parameter must be a valid [checkpoint mode]:)^
8528**
8529** <dl>
8530** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
8531** ^Checkpoint as many frames as possible without waiting for any database
8532** readers or writers to finish, then sync the database file if all frames
8533** in the log were checkpointed. ^The [busy-handler callback]
8534** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
8535** ^On the other hand, passive mode might leave the checkpoint unfinished
8536** if there are concurrent readers or writers.
8537**
8538** <dt>SQLITE_CHECKPOINT_FULL<dd>
8539** ^This mode blocks (it invokes the
8540** [sqlite3_busy_handler|busy-handler callback]) until there is no
8541** database writer and all readers are reading from the most recent database
8542** snapshot. ^It then checkpoints all frames in the log file and syncs the
8543** database file. ^This mode blocks new database writers while it is pending,
8544** but new database readers are allowed to continue unimpeded.
8545**
8546** <dt>SQLITE_CHECKPOINT_RESTART<dd>
8547** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
8548** that after checkpointing the log file it blocks (calls the
8549** [busy-handler callback])
8550** until all readers are reading from the database file only. ^This ensures
8551** that the next writer will restart the log file from the beginning.
8552** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
8553** database writer attempts while it is pending, but does not impede readers.
8554**
8555** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
8556** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
8557** addition that it also truncates the log file to zero bytes just prior
8558** to a successful return.
8559** </dl>
8560**
8561** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
8562** the log file or to -1 if the checkpoint could not run because
8563** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
8564** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
8565** log file (including any that were already checkpointed before the function
8566** was called) or to -1 if the checkpoint could not run due to an error or
8567** because the database is not in WAL mode. ^Note that upon successful
8568** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
8569** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
8570**
8571** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
8572** any other process is running a checkpoint operation at the same time, the
8573** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
8574** busy-handler configured, it will not be invoked in this case.
8575**
8576** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
8577** exclusive "writer" lock on the database file. ^If the writer lock cannot be
8578** obtained immediately, and a busy-handler is configured, it is invoked and
8579** the writer lock retried until either the busy-handler returns 0 or the lock
8580** is successfully obtained. ^The busy-handler is also invoked while waiting for
8581** database readers as described above. ^If the busy-handler returns 0 before
8582** the writer lock is obtained or while waiting for database readers, the
8583** checkpoint operation proceeds from that point in the same way as
8584** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
8585** without blocking any further. ^SQLITE_BUSY is returned in this case.
8586**
8587** ^If parameter zDb is NULL or points to a zero length string, then the
8588** specified operation is attempted on all WAL databases [attached] to
8589** [database connection] db. In this case the
8590** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
8591** an SQLITE_BUSY error is encountered when processing one or more of the
8592** attached WAL databases, the operation is still attempted on any remaining
8593** attached databases and SQLITE_BUSY is returned at the end. ^If any other
8594** error occurs while processing an attached database, processing is abandoned
8595** and the error code is returned to the caller immediately. ^If no error
8596** (SQLITE_BUSY or otherwise) is encountered while processing the attached
8597** databases, SQLITE_OK is returned.
8598**
8599** ^If database zDb is the name of an attached database that is not in WAL
8600** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
8601** zDb is not NULL (or a zero length string) and is not the name of any
8602** attached database, SQLITE_ERROR is returned to the caller.
8603**
8604** ^Unless it returns SQLITE_MISUSE,
8605** the sqlite3_wal_checkpoint_v2() interface
8606** sets the error information that is queried by
8607** [sqlite3_errcode()] and [sqlite3_errmsg()].
8608**
8609** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
8610** from SQL.
8611*/
8612SQLITE_API int sqlite3_wal_checkpoint_v2(
8613 sqlite3 *db, /* Database handle */
8614 const char *zDb, /* Name of attached database (or NULL) */
8615 int eMode, /* SQLITE_CHECKPOINT_* value */
8616 int *pnLog, /* OUT: Size of WAL log in frames */
8617 int *pnCkpt /* OUT: Total number of frames checkpointed */
8618);
8619
8620/*
8621** CAPI3REF: Checkpoint Mode Values
8622** KEYWORDS: {checkpoint mode}
8623**
8624** These constants define all valid values for the "checkpoint mode" passed
8625** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
8626** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
8627** meaning of each of these checkpoint modes.
8628*/
8629#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
8630#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
8631#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
8632#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
8633
8634/*
8635** CAPI3REF: Virtual Table Interface Configuration
8636**
8637** This function may be called by either the [xConnect] or [xCreate] method
8638** of a [virtual table] implementation to configure
8639** various facets of the virtual table interface.
8640**
8641** If this interface is invoked outside the context of an xConnect or
8642** xCreate virtual table method then the behavior is undefined.
8643**
8644** At present, there is only one option that may be configured using
8645** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
8646** may be added in the future.
8647*/
8648SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
8649
8650/*
8651** CAPI3REF: Virtual Table Configuration Options
8652**
8653** These macros define the various options to the
8654** [sqlite3_vtab_config()] interface that [virtual table] implementations
8655** can use to customize and optimize their behavior.
8656**
8657** <dl>
8658** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
8659** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
8660** <dd>Calls of the form
8661** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
8662** where X is an integer. If X is zero, then the [virtual table] whose
8663** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
8664** support constraints. In this configuration (which is the default) if
8665** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
8666** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
8667** specified as part of the users SQL statement, regardless of the actual
8668** ON CONFLICT mode specified.
8669**
8670** If X is non-zero, then the virtual table implementation guarantees
8671** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
8672** any modifications to internal or persistent data structures have been made.
8673** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
8674** is able to roll back a statement or database transaction, and abandon
8675** or continue processing the current SQL statement as appropriate.
8676** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
8677** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
8678** had been ABORT.
8679**
8680** Virtual table implementations that are required to handle OR REPLACE
8681** must do so within the [xUpdate] method. If a call to the
8682** [sqlite3_vtab_on_conflict()] function indicates that the current ON
8683** CONFLICT policy is REPLACE, the virtual table implementation should
8684** silently replace the appropriate rows within the xUpdate callback and
8685** return SQLITE_OK. Or, if this is not possible, it may return
8686** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
8687** constraint handling.
8688** </dl>
8689*/
8690#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
8691
8692/*
8693** CAPI3REF: Determine The Virtual Table Conflict Policy
8694**
8695** This function may only be called from within a call to the [xUpdate] method
8696** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
8697** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
8698** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
8699** of the SQL statement that triggered the call to the [xUpdate] method of the
8700** [virtual table].
8701*/
8702SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
8703
8704/*
8705** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
8706**
8707** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
8708** method of a [virtual table], then it returns true if and only if the
8709** column is being fetched as part of an UPDATE operation during which the
8710** column value will not change. Applications might use this to substitute
8711** a return value that is less expensive to compute and that the corresponding
8712** [xUpdate] method understands as a "no-change" value.
8713**
8714** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
8715** the column is not changed by the UPDATE statement, then the xColumn
8716** method can optionally return without setting a result, without calling
8717** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
8718** In that case, [sqlite3_value_nochange(X)] will return true for the
8719** same column in the [xUpdate] method.
8720*/
8721SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
8722
8723/*
8724** CAPI3REF: Determine The Collation For a Virtual Table Constraint
8725**
8726** This function may only be called from within a call to the [xBestIndex]
8727** method of a [virtual table].
8728**
8729** The first argument must be the sqlite3_index_info object that is the
8730** first parameter to the xBestIndex() method. The second argument must be
8731** an index into the aConstraint[] array belonging to the sqlite3_index_info
8732** structure passed to xBestIndex. This function returns a pointer to a buffer
8733** containing the name of the collation sequence for the corresponding
8734** constraint.
8735*/
8736SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
8737
8738/*
8739** CAPI3REF: Conflict resolution modes
8740** KEYWORDS: {conflict resolution mode}
8741**
8742** These constants are returned by [sqlite3_vtab_on_conflict()] to
8743** inform a [virtual table] implementation what the [ON CONFLICT] mode
8744** is for the SQL statement being evaluated.
8745**
8746** Note that the [SQLITE_IGNORE] constant is also used as a potential
8747** return value from the [sqlite3_set_authorizer()] callback and that
8748** [SQLITE_ABORT] is also a [result code].
8749*/
8750#define SQLITE_ROLLBACK 1
8751/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
8752#define SQLITE_FAIL 3
8753/* #define SQLITE_ABORT 4 // Also an error code */
8754#define SQLITE_REPLACE 5
8755
8756/*
8757** CAPI3REF: Prepared Statement Scan Status Opcodes
8758** KEYWORDS: {scanstatus options}
8759**
8760** The following constants can be used for the T parameter to the
8761** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
8762** different metric for sqlite3_stmt_scanstatus() to return.
8763**
8764** When the value returned to V is a string, space to hold that string is
8765** managed by the prepared statement S and will be automatically freed when
8766** S is finalized.
8767**
8768** <dl>
8769** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
8770** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
8771** set to the total number of times that the X-th loop has run.</dd>
8772**
8773** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
8774** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
8775** to the total number of rows examined by all iterations of the X-th loop.</dd>
8776**
8777** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
8778** <dd>^The "double" variable pointed to by the T parameter will be set to the
8779** query planner's estimate for the average number of rows output from each
8780** iteration of the X-th loop. If the query planner's estimates was accurate,
8781** then this value will approximate the quotient NVISIT/NLOOP and the
8782** product of this value for all prior loops with the same SELECTID will
8783** be the NLOOP value for the current loop.
8784**
8785** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
8786** <dd>^The "const char *" variable pointed to by the T parameter will be set
8787** to a zero-terminated UTF-8 string containing the name of the index or table
8788** used for the X-th loop.
8789**
8790** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
8791** <dd>^The "const char *" variable pointed to by the T parameter will be set
8792** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
8793** description for the X-th loop.
8794**
8795** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
8796** <dd>^The "int" variable pointed to by the T parameter will be set to the
8797** "select-id" for the X-th loop. The select-id identifies which query or
8798** subquery the loop is part of. The main query has a select-id of zero.
8799** The select-id is the same value as is output in the first column
8800** of an [EXPLAIN QUERY PLAN] query.
8801** </dl>
8802*/
8803#define SQLITE_SCANSTAT_NLOOP 0
8804#define SQLITE_SCANSTAT_NVISIT 1
8805#define SQLITE_SCANSTAT_EST 2
8806#define SQLITE_SCANSTAT_NAME 3
8807#define SQLITE_SCANSTAT_EXPLAIN 4
8808#define SQLITE_SCANSTAT_SELECTID 5
8809
8810/*
8811** CAPI3REF: Prepared Statement Scan Status
8812** METHOD: sqlite3_stmt
8813**
8814** This interface returns information about the predicted and measured
8815** performance for pStmt. Advanced applications can use this
8816** interface to compare the predicted and the measured performance and
8817** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
8818**
8819** Since this interface is expected to be rarely used, it is only
8820** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
8821** compile-time option.
8822**
8823** The "iScanStatusOp" parameter determines which status information to return.
8824** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
8825** of this interface is undefined.
8826** ^The requested measurement is written into a variable pointed to by
8827** the "pOut" parameter.
8828** Parameter "idx" identifies the specific loop to retrieve statistics for.
8829** Loops are numbered starting from zero. ^If idx is out of range - less than
8830** zero or greater than or equal to the total number of loops used to implement
8831** the statement - a non-zero value is returned and the variable that pOut
8832** points to is unchanged.
8833**
8834** ^Statistics might not be available for all loops in all statements. ^In cases
8835** where there exist loops with no available statistics, this function behaves
8836** as if the loop did not exist - it returns non-zero and leave the variable
8837** that pOut points to unchanged.
8838**
8839** See also: [sqlite3_stmt_scanstatus_reset()]
8840*/
8841SQLITE_API int sqlite3_stmt_scanstatus(
8842 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
8843 int idx, /* Index of loop to report on */
8844 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
8845 void *pOut /* Result written here */
8846);
8847
8848/*
8849** CAPI3REF: Zero Scan-Status Counters
8850** METHOD: sqlite3_stmt
8851**
8852** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
8853**
8854** This API is only available if the library is built with pre-processor
8855** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
8856*/
8857SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
8858
8859/*
8860** CAPI3REF: Flush caches to disk mid-transaction
8861**
8862** ^If a write-transaction is open on [database connection] D when the
8863** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
8864** pages in the pager-cache that are not currently in use are written out
8865** to disk. A dirty page may be in use if a database cursor created by an
8866** active SQL statement is reading from it, or if it is page 1 of a database
8867** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
8868** interface flushes caches for all schemas - "main", "temp", and
8869** any [attached] databases.
8870**
8871** ^If this function needs to obtain extra database locks before dirty pages
8872** can be flushed to disk, it does so. ^If those locks cannot be obtained
8873** immediately and there is a busy-handler callback configured, it is invoked
8874** in the usual manner. ^If the required lock still cannot be obtained, then
8875** the database is skipped and an attempt made to flush any dirty pages
8876** belonging to the next (if any) database. ^If any databases are skipped
8877** because locks cannot be obtained, but no other error occurs, this
8878** function returns SQLITE_BUSY.
8879**
8880** ^If any other error occurs while flushing dirty pages to disk (for
8881** example an IO error or out-of-memory condition), then processing is
8882** abandoned and an SQLite [error code] is returned to the caller immediately.
8883**
8884** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
8885**
8886** ^This function does not set the database handle error code or message
8887** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
8888*/
8889SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
8890
8891/*
8892** CAPI3REF: The pre-update hook.
8893**
8894** ^These interfaces are only available if SQLite is compiled using the
8895** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
8896**
8897** ^The [sqlite3_preupdate_hook()] interface registers a callback function
8898** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
8899** on a database table.
8900** ^At most one preupdate hook may be registered at a time on a single
8901** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
8902** the previous setting.
8903** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
8904** with a NULL pointer as the second parameter.
8905** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
8906** the first parameter to callbacks.
8907**
8908** ^The preupdate hook only fires for changes to real database tables; the
8909** preupdate hook is not invoked for changes to [virtual tables] or to
8910** system tables like sqlite_master or sqlite_stat1.
8911**
8912** ^The second parameter to the preupdate callback is a pointer to
8913** the [database connection] that registered the preupdate hook.
8914** ^The third parameter to the preupdate callback is one of the constants
8915** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
8916** kind of update operation that is about to occur.
8917** ^(The fourth parameter to the preupdate callback is the name of the
8918** database within the database connection that is being modified. This
8919** will be "main" for the main database or "temp" for TEMP tables or
8920** the name given after the AS keyword in the [ATTACH] statement for attached
8921** databases.)^
8922** ^The fifth parameter to the preupdate callback is the name of the
8923** table that is being modified.
8924**
8925** For an UPDATE or DELETE operation on a [rowid table], the sixth
8926** parameter passed to the preupdate callback is the initial [rowid] of the
8927** row being modified or deleted. For an INSERT operation on a rowid table,
8928** or any operation on a WITHOUT ROWID table, the value of the sixth
8929** parameter is undefined. For an INSERT or UPDATE on a rowid table the
8930** seventh parameter is the final rowid value of the row being inserted
8931** or updated. The value of the seventh parameter passed to the callback
8932** function is not defined for operations on WITHOUT ROWID tables, or for
8933** INSERT operations on rowid tables.
8934**
8935** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
8936** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
8937** provide additional information about a preupdate event. These routines
8938** may only be called from within a preupdate callback. Invoking any of
8939** these routines from outside of a preupdate callback or with a
8940** [database connection] pointer that is different from the one supplied
8941** to the preupdate callback results in undefined and probably undesirable
8942** behavior.
8943**
8944** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
8945** in the row that is being inserted, updated, or deleted.
8946**
8947** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
8948** a [protected sqlite3_value] that contains the value of the Nth column of
8949** the table row before it is updated. The N parameter must be between 0
8950** and one less than the number of columns or the behavior will be
8951** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
8952** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
8953** behavior is undefined. The [sqlite3_value] that P points to
8954** will be destroyed when the preupdate callback returns.
8955**
8956** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
8957** a [protected sqlite3_value] that contains the value of the Nth column of
8958** the table row after it is updated. The N parameter must be between 0
8959** and one less than the number of columns or the behavior will be
8960** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
8961** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
8962** behavior is undefined. The [sqlite3_value] that P points to
8963** will be destroyed when the preupdate callback returns.
8964**
8965** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
8966** callback was invoked as a result of a direct insert, update, or delete
8967** operation; or 1 for inserts, updates, or deletes invoked by top-level
8968** triggers; or 2 for changes resulting from triggers called by top-level
8969** triggers; and so forth.
8970**
8971** See also: [sqlite3_update_hook()]
8972*/
8973#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
8974SQLITE_API void *sqlite3_preupdate_hook(
8975 sqlite3 *db,
8976 void(*xPreUpdate)(
8977 void *pCtx, /* Copy of third arg to preupdate_hook() */
8978 sqlite3 *db, /* Database handle */
8979 int op, /* SQLITE_UPDATE, DELETE or INSERT */
8980 char const *zDb, /* Database name */
8981 char const *zName, /* Table name */
8982 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
8983 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
8984 ),
8985 void*
8986);
8987SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
8988SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
8989SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
8990SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
8991#endif
8992
8993/*
8994** CAPI3REF: Low-level system error code
8995**
8996** ^Attempt to return the underlying operating system error code or error
8997** number that caused the most recent I/O error or failure to open a file.
8998** The return value is OS-dependent. For example, on unix systems, after
8999** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
9000** called to get back the underlying "errno" that caused the problem, such
9001** as ENOSPC, EAUTH, EISDIR, and so forth.
9002*/
9003SQLITE_API int sqlite3_system_errno(sqlite3*);
9004
9005/*
9006** CAPI3REF: Database Snapshot
9007** KEYWORDS: {snapshot} {sqlite3_snapshot}
9008**
9009** An instance of the snapshot object records the state of a [WAL mode]
9010** database for some specific point in history.
9011**
9012** In [WAL mode], multiple [database connections] that are open on the
9013** same database file can each be reading a different historical version
9014** of the database file. When a [database connection] begins a read
9015** transaction, that connection sees an unchanging copy of the database
9016** as it existed for the point in time when the transaction first started.
9017** Subsequent changes to the database from other connections are not seen
9018** by the reader until a new read transaction is started.
9019**
9020** The sqlite3_snapshot object records state information about an historical
9021** version of the database file so that it is possible to later open a new read
9022** transaction that sees that historical version of the database rather than
9023** the most recent version.
9024*/
9025typedef struct sqlite3_snapshot {
9026 unsigned char hidden[48];
9027} sqlite3_snapshot;
9028
9029/*
9030** CAPI3REF: Record A Database Snapshot
9031** CONSTRUCTOR: sqlite3_snapshot
9032**
9033** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
9034** new [sqlite3_snapshot] object that records the current state of
9035** schema S in database connection D. ^On success, the
9036** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
9037** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
9038** If there is not already a read-transaction open on schema S when
9039** this function is called, one is opened automatically.
9040**
9041** The following must be true for this function to succeed. If any of
9042** the following statements are false when sqlite3_snapshot_get() is
9043** called, SQLITE_ERROR is returned. The final value of *P is undefined
9044** in this case.
9045**
9046** <ul>
9047** <li> The database handle must not be in [autocommit mode].
9048**
9049** <li> Schema S of [database connection] D must be a [WAL mode] database.
9050**
9051** <li> There must not be a write transaction open on schema S of database
9052** connection D.
9053**
9054** <li> One or more transactions must have been written to the current wal
9055** file since it was created on disk (by any connection). This means
9056** that a snapshot cannot be taken on a wal mode database with no wal
9057** file immediately after it is first opened. At least one transaction
9058** must be written to it first.
9059** </ul>
9060**
9061** This function may also return SQLITE_NOMEM. If it is called with the
9062** database handle in autocommit mode but fails for some other reason,
9063** whether or not a read transaction is opened on schema S is undefined.
9064**
9065** The [sqlite3_snapshot] object returned from a successful call to
9066** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
9067** to avoid a memory leak.
9068**
9069** The [sqlite3_snapshot_get()] interface is only available when the
9070** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9071*/
9072SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
9073 sqlite3 *db,
9074 const char *zSchema,
9075 sqlite3_snapshot **ppSnapshot
9076);
9077
9078/*
9079** CAPI3REF: Start a read transaction on an historical snapshot
9080** METHOD: sqlite3_snapshot
9081**
9082** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
9083** transaction or upgrades an existing one for schema S of
9084** [database connection] D such that the read transaction refers to
9085** historical [snapshot] P, rather than the most recent change to the
9086** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
9087** on success or an appropriate [error code] if it fails.
9088**
9089** ^In order to succeed, the database connection must not be in
9090** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
9091** is already a read transaction open on schema S, then the database handle
9092** must have no active statements (SELECT statements that have been passed
9093** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
9094** SQLITE_ERROR is returned if either of these conditions is violated, or
9095** if schema S does not exist, or if the snapshot object is invalid.
9096**
9097** ^A call to sqlite3_snapshot_open() will fail to open if the specified
9098** snapshot has been overwritten by a [checkpoint]. In this case
9099** SQLITE_ERROR_SNAPSHOT is returned.
9100**
9101** If there is already a read transaction open when this function is
9102** invoked, then the same read transaction remains open (on the same
9103** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
9104** is returned. If another error code - for example SQLITE_PROTOCOL or an
9105** SQLITE_IOERR error code - is returned, then the final state of the
9106** read transaction is undefined. If SQLITE_OK is returned, then the
9107** read transaction is now open on database snapshot P.
9108**
9109** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
9110** database connection D does not know that the database file for
9111** schema S is in [WAL mode]. A database connection might not know
9112** that the database file is in [WAL mode] if there has been no prior
9113** I/O on that database connection, or if the database entered [WAL mode]
9114** after the most recent I/O on the database connection.)^
9115** (Hint: Run "[PRAGMA application_id]" against a newly opened
9116** database connection in order to make it ready to use snapshots.)
9117**
9118** The [sqlite3_snapshot_open()] interface is only available when the
9119** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9120*/
9121SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
9122 sqlite3 *db,
9123 const char *zSchema,
9124 sqlite3_snapshot *pSnapshot
9125);
9126
9127/*
9128** CAPI3REF: Destroy a snapshot
9129** DESTRUCTOR: sqlite3_snapshot
9130**
9131** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
9132** The application must eventually free every [sqlite3_snapshot] object
9133** using this routine to avoid a memory leak.
9134**
9135** The [sqlite3_snapshot_free()] interface is only available when the
9136** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
9137*/
9138SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
9139
9140/*
9141** CAPI3REF: Compare the ages of two snapshot handles.
9142** METHOD: sqlite3_snapshot
9143**
9144** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
9145** of two valid snapshot handles.
9146**
9147** If the two snapshot handles are not associated with the same database
9148** file, the result of the comparison is undefined.
9149**
9150** Additionally, the result of the comparison is only valid if both of the
9151** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
9152** last time the wal file was deleted. The wal file is deleted when the
9153** database is changed back to rollback mode or when the number of database
9154** clients drops to zero. If either snapshot handle was obtained before the
9155** wal file was last deleted, the value returned by this function
9156** is undefined.
9157**
9158** Otherwise, this API returns a negative value if P1 refers to an older
9159** snapshot than P2, zero if the two handles refer to the same database
9160** snapshot, and a positive value if P1 is a newer snapshot than P2.
9161**
9162** This interface is only available if SQLite is compiled with the
9163** [SQLITE_ENABLE_SNAPSHOT] option.
9164*/
9165SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
9166 sqlite3_snapshot *p1,
9167 sqlite3_snapshot *p2
9168);
9169
9170/*
9171** CAPI3REF: Recover snapshots from a wal file
9172** METHOD: sqlite3_snapshot
9173**
9174** If a [WAL file] remains on disk after all database connections close
9175** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
9176** or because the last process to have the database opened exited without
9177** calling [sqlite3_close()]) and a new connection is subsequently opened
9178** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
9179** will only be able to open the last transaction added to the WAL file
9180** even though the WAL file contains other valid transactions.
9181**
9182** This function attempts to scan the WAL file associated with database zDb
9183** of database handle db and make all valid snapshots available to
9184** sqlite3_snapshot_open(). It is an error if there is already a read
9185** transaction open on the database, or if the database is not a WAL mode
9186** database.
9187**
9188** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
9189**
9190** This interface is only available if SQLite is compiled with the
9191** [SQLITE_ENABLE_SNAPSHOT] option.
9192*/
9193SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
9194
9195/*
9196** CAPI3REF: Serialize a database
9197**
9198** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
9199** that is a serialization of the S database on [database connection] D.
9200** If P is not a NULL pointer, then the size of the database in bytes
9201** is written into *P.
9202**
9203** For an ordinary on-disk database file, the serialization is just a
9204** copy of the disk file. For an in-memory database or a "TEMP" database,
9205** the serialization is the same sequence of bytes which would be written
9206** to disk if that database where backed up to disk.
9207**
9208** The usual case is that sqlite3_serialize() copies the serialization of
9209** the database into memory obtained from [sqlite3_malloc64()] and returns
9210** a pointer to that memory. The caller is responsible for freeing the
9211** returned value to avoid a memory leak. However, if the F argument
9212** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
9213** are made, and the sqlite3_serialize() function will return a pointer
9214** to the contiguous memory representation of the database that SQLite
9215** is currently using for that database, or NULL if the no such contiguous
9216** memory representation of the database exists. A contiguous memory
9217** representation of the database will usually only exist if there has
9218** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
9219** values of D and S.
9220** The size of the database is written into *P even if the
9221** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
9222** of the database exists.
9223**
9224** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
9225** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
9226** allocation error occurs.
9227**
9228** This interface is only available if SQLite is compiled with the
9229** [SQLITE_ENABLE_DESERIALIZE] option.
9230*/
9231SQLITE_API unsigned char *sqlite3_serialize(
9232 sqlite3 *db, /* The database connection */
9233 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
9234 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
9235 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
9236);
9237
9238/*
9239** CAPI3REF: Flags for sqlite3_serialize
9240**
9241** Zero or more of the following constants can be OR-ed together for
9242** the F argument to [sqlite3_serialize(D,S,P,F)].
9243**
9244** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
9245** a pointer to contiguous in-memory database that it is currently using,
9246** without making a copy of the database. If SQLite is not currently using
9247** a contiguous in-memory database, then this option causes
9248** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
9249** using a contiguous in-memory database if it has been initialized by a
9250** prior call to [sqlite3_deserialize()].
9251*/
9252#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
9253
9254/*
9255** CAPI3REF: Deserialize a database
9256**
9257** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
9258** [database connection] D to disconnect from database S and then
9259** reopen S as an in-memory database based on the serialization contained
9260** in P. The serialized database P is N bytes in size. M is the size of
9261** the buffer P, which might be larger than N. If M is larger than N, and
9262** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
9263** permitted to add content to the in-memory database as long as the total
9264** size does not exceed M bytes.
9265**
9266** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
9267** invoke sqlite3_free() on the serialization buffer when the database
9268** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
9269** SQLite will try to increase the buffer size using sqlite3_realloc64()
9270** if writes on the database cause it to grow larger than M bytes.
9271**
9272** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
9273** database is currently in a read transaction or is involved in a backup
9274** operation.
9275**
9276** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
9277** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
9278** [sqlite3_free()] is invoked on argument P prior to returning.
9279**
9280** This interface is only available if SQLite is compiled with the
9281** [SQLITE_ENABLE_DESERIALIZE] option.
9282*/
9283SQLITE_API int sqlite3_deserialize(
9284 sqlite3 *db, /* The database connection */
9285 const char *zSchema, /* Which DB to reopen with the deserialization */
9286 unsigned char *pData, /* The serialized database content */
9287 sqlite3_int64 szDb, /* Number bytes in the deserialization */
9288 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
9289 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
9290);
9291
9292/*
9293** CAPI3REF: Flags for sqlite3_deserialize()
9294**
9295** The following are allowed values for 6th argument (the F argument) to
9296** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
9297**
9298** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
9299** in the P argument is held in memory obtained from [sqlite3_malloc64()]
9300** and that SQLite should take ownership of this memory and automatically
9301** free it when it has finished using it. Without this flag, the caller
9302** is responsible for freeing any dynamically allocated memory.
9303**
9304** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
9305** grow the size of the database using calls to [sqlite3_realloc64()]. This
9306** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
9307** Without this flag, the deserialized database cannot increase in size beyond
9308** the number of bytes specified by the M parameter.
9309**
9310** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
9311** should be treated as read-only.
9312*/
9313#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
9314#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
9315#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
9316
9317/*
9318** Undo the hack that converts floating point types to integer for
9319** builds on processors without floating point support.
9320*/
9321#ifdef SQLITE_OMIT_FLOATING_POINT
9322# undef double
9323#endif
9324
9325#ifdef __cplusplus
9326} /* End of the 'extern "C"' block */
9327#endif
9328#endif /* SQLITE3_H */
9329
9330/******** Begin file sqlite3rtree.h *********/
9331/*
9332** 2010 August 30
9333**
9334** The author disclaims copyright to this source code. In place of
9335** a legal notice, here is a blessing:
9336**
9337** May you do good and not evil.
9338** May you find forgiveness for yourself and forgive others.
9339** May you share freely, never taking more than you give.
9340**
9341*************************************************************************
9342*/
9343
9344#ifndef _SQLITE3RTREE_H_
9345#define _SQLITE3RTREE_H_
9346
9347
9348#ifdef __cplusplus
9349extern "C" {
9350#endif
9351
9352typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
9353typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
9354
9355/* The double-precision datatype used by RTree depends on the
9356** SQLITE_RTREE_INT_ONLY compile-time option.
9357*/
9358#ifdef SQLITE_RTREE_INT_ONLY
9359 typedef sqlite3_int64 sqlite3_rtree_dbl;
9360#else
9361 typedef double sqlite3_rtree_dbl;
9362#endif
9363
9364/*
9365** Register a geometry callback named zGeom that can be used as part of an
9366** R-Tree geometry query as follows:
9367**
9368** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
9369*/
9370SQLITE_API int sqlite3_rtree_geometry_callback(
9371 sqlite3 *db,
9372 const char *zGeom,
9373 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
9374 void *pContext
9375);
9376
9377
9378/*
9379** A pointer to a structure of the following type is passed as the first
9380** argument to callbacks registered using rtree_geometry_callback().
9381*/
9382struct sqlite3_rtree_geometry {
9383 void *pContext; /* Copy of pContext passed to s_r_g_c() */
9384 int nParam; /* Size of array aParam[] */
9385 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
9386 void *pUser; /* Callback implementation user data */
9387 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
9388};
9389
9390/*
9391** Register a 2nd-generation geometry callback named zScore that can be
9392** used as part of an R-Tree geometry query as follows:
9393**
9394** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
9395*/
9396SQLITE_API int sqlite3_rtree_query_callback(
9397 sqlite3 *db,
9398 const char *zQueryFunc,
9399 int (*xQueryFunc)(sqlite3_rtree_query_info*),
9400 void *pContext,
9401 void (*xDestructor)(void*)
9402);
9403
9404
9405/*
9406** A pointer to a structure of the following type is passed as the
9407** argument to scored geometry callback registered using
9408** sqlite3_rtree_query_callback().
9409**
9410** Note that the first 5 fields of this structure are identical to
9411** sqlite3_rtree_geometry. This structure is a subclass of
9412** sqlite3_rtree_geometry.
9413*/
9414struct sqlite3_rtree_query_info {
9415 void *pContext; /* pContext from when function registered */
9416 int nParam; /* Number of function parameters */
9417 sqlite3_rtree_dbl *aParam; /* value of function parameters */
9418 void *pUser; /* callback can use this, if desired */
9419 void (*xDelUser)(void*); /* function to free pUser */
9420 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
9421 unsigned int *anQueue; /* Number of pending entries in the queue */
9422 int nCoord; /* Number of coordinates */
9423 int iLevel; /* Level of current node or entry */
9424 int mxLevel; /* The largest iLevel value in the tree */
9425 sqlite3_int64 iRowid; /* Rowid for current entry */
9426 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
9427 int eParentWithin; /* Visibility of parent node */
9428 int eWithin; /* OUT: Visibility */
9429 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
9430 /* The following fields are only available in 3.8.11 and later */
9431 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
9432};
9433
9434/*
9435** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
9436*/
9437#define NOT_WITHIN 0 /* Object completely outside of query region */
9438#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
9439#define FULLY_WITHIN 2 /* Object fully contained within query region */
9440
9441
9442#ifdef __cplusplus
9443} /* end of the 'extern "C"' block */
9444#endif
9445
9446#endif /* ifndef _SQLITE3RTREE_H_ */
9447
9448/******** End of sqlite3rtree.h *********/
9449/******** Begin file sqlite3session.h *********/
9450
9451#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
9452#define __SQLITESESSION_H_ 1
9453
9454/*
9455** Make sure we can call this stuff from C++.
9456*/
9457#ifdef __cplusplus
9458extern "C" {
9459#endif
9460
9461
9462/*
9463** CAPI3REF: Session Object Handle
9464**
9465** An instance of this object is a [session] that can be used to
9466** record changes to a database.
9467*/
9468typedef struct sqlite3_session sqlite3_session;
9469
9470/*
9471** CAPI3REF: Changeset Iterator Handle
9472**
9473** An instance of this object acts as a cursor for iterating
9474** over the elements of a [changeset] or [patchset].
9475*/
9476typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
9477
9478/*
9479** CAPI3REF: Create A New Session Object
9480** CONSTRUCTOR: sqlite3_session
9481**
9482** Create a new session object attached to database handle db. If successful,
9483** a pointer to the new object is written to *ppSession and SQLITE_OK is
9484** returned. If an error occurs, *ppSession is set to NULL and an SQLite
9485** error code (e.g. SQLITE_NOMEM) is returned.
9486**
9487** It is possible to create multiple session objects attached to a single
9488** database handle.
9489**
9490** Session objects created using this function should be deleted using the
9491** [sqlite3session_delete()] function before the database handle that they
9492** are attached to is itself closed. If the database handle is closed before
9493** the session object is deleted, then the results of calling any session
9494** module function, including [sqlite3session_delete()] on the session object
9495** are undefined.
9496**
9497** Because the session module uses the [sqlite3_preupdate_hook()] API, it
9498** is not possible for an application to register a pre-update hook on a
9499** database handle that has one or more session objects attached. Nor is
9500** it possible to create a session object attached to a database handle for
9501** which a pre-update hook is already defined. The results of attempting
9502** either of these things are undefined.
9503**
9504** The session object will be used to create changesets for tables in
9505** database zDb, where zDb is either "main", or "temp", or the name of an
9506** attached database. It is not an error if database zDb is not attached
9507** to the database when the session object is created.
9508*/
9509SQLITE_API int sqlite3session_create(
9510 sqlite3 *db, /* Database handle */
9511 const char *zDb, /* Name of db (e.g. "main") */
9512 sqlite3_session **ppSession /* OUT: New session object */
9513);
9514
9515/*
9516** CAPI3REF: Delete A Session Object
9517** DESTRUCTOR: sqlite3_session
9518**
9519** Delete a session object previously allocated using
9520** [sqlite3session_create()]. Once a session object has been deleted, the
9521** results of attempting to use pSession with any other session module
9522** function are undefined.
9523**
9524** Session objects must be deleted before the database handle to which they
9525** are attached is closed. Refer to the documentation for
9526** [sqlite3session_create()] for details.
9527*/
9528SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
9529
9530
9531/*
9532** CAPI3REF: Enable Or Disable A Session Object
9533** METHOD: sqlite3_session
9534**
9535** Enable or disable the recording of changes by a session object. When
9536** enabled, a session object records changes made to the database. When
9537** disabled - it does not. A newly created session object is enabled.
9538** Refer to the documentation for [sqlite3session_changeset()] for further
9539** details regarding how enabling and disabling a session object affects
9540** the eventual changesets.
9541**
9542** Passing zero to this function disables the session. Passing a value
9543** greater than zero enables it. Passing a value less than zero is a
9544** no-op, and may be used to query the current state of the session.
9545**
9546** The return value indicates the final state of the session object: 0 if
9547** the session is disabled, or 1 if it is enabled.
9548*/
9549SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
9550
9551/*
9552** CAPI3REF: Set Or Clear the Indirect Change Flag
9553** METHOD: sqlite3_session
9554**
9555** Each change recorded by a session object is marked as either direct or
9556** indirect. A change is marked as indirect if either:
9557**
9558** <ul>
9559** <li> The session object "indirect" flag is set when the change is
9560** made, or
9561** <li> The change is made by an SQL trigger or foreign key action
9562** instead of directly as a result of a users SQL statement.
9563** </ul>
9564**
9565** If a single row is affected by more than one operation within a session,
9566** then the change is considered indirect if all operations meet the criteria
9567** for an indirect change above, or direct otherwise.
9568**
9569** This function is used to set, clear or query the session object indirect
9570** flag. If the second argument passed to this function is zero, then the
9571** indirect flag is cleared. If it is greater than zero, the indirect flag
9572** is set. Passing a value less than zero does not modify the current value
9573** of the indirect flag, and may be used to query the current state of the
9574** indirect flag for the specified session object.
9575**
9576** The return value indicates the final state of the indirect flag: 0 if
9577** it is clear, or 1 if it is set.
9578*/
9579SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
9580
9581/*
9582** CAPI3REF: Attach A Table To A Session Object
9583** METHOD: sqlite3_session
9584**
9585** If argument zTab is not NULL, then it is the name of a table to attach
9586** to the session object passed as the first argument. All subsequent changes
9587** made to the table while the session object is enabled will be recorded. See
9588** documentation for [sqlite3session_changeset()] for further details.
9589**
9590** Or, if argument zTab is NULL, then changes are recorded for all tables
9591** in the database. If additional tables are added to the database (by
9592** executing "CREATE TABLE" statements) after this call is made, changes for
9593** the new tables are also recorded.
9594**
9595** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
9596** defined as part of their CREATE TABLE statement. It does not matter if the
9597** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
9598** KEY may consist of a single column, or may be a composite key.
9599**
9600** It is not an error if the named table does not exist in the database. Nor
9601** is it an error if the named table does not have a PRIMARY KEY. However,
9602** no changes will be recorded in either of these scenarios.
9603**
9604** Changes are not recorded for individual rows that have NULL values stored
9605** in one or more of their PRIMARY KEY columns.
9606**
9607** SQLITE_OK is returned if the call completes without error. Or, if an error
9608** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
9609**
9610** <h3>Special sqlite_stat1 Handling</h3>
9611**
9612** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
9613** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
9614** <pre>
9615** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
9616** </pre>
9617**
9618** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
9619** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
9620** are recorded for rows for which (idx IS NULL) is true. However, for such
9621** rows a zero-length blob (SQL value X'') is stored in the changeset or
9622** patchset instead of a NULL value. This allows such changesets to be
9623** manipulated by legacy implementations of sqlite3changeset_invert(),
9624** concat() and similar.
9625**
9626** The sqlite3changeset_apply() function automatically converts the
9627** zero-length blob back to a NULL value when updating the sqlite_stat1
9628** table. However, if the application calls sqlite3changeset_new(),
9629** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
9630** iterator directly (including on a changeset iterator passed to a
9631** conflict-handler callback) then the X'' value is returned. The application
9632** must translate X'' to NULL itself if required.
9633**
9634** Legacy (older than 3.22.0) versions of the sessions module cannot capture
9635** changes made to the sqlite_stat1 table. Legacy versions of the
9636** sqlite3changeset_apply() function silently ignore any modifications to the
9637** sqlite_stat1 table that are part of a changeset or patchset.
9638*/
9639SQLITE_API int sqlite3session_attach(
9640 sqlite3_session *pSession, /* Session object */
9641 const char *zTab /* Table name */
9642);
9643
9644/*
9645** CAPI3REF: Set a table filter on a Session Object.
9646** METHOD: sqlite3_session
9647**
9648** The second argument (xFilter) is the "filter callback". For changes to rows
9649** in tables that are not attached to the Session object, the filter is called
9650** to determine whether changes to the table's rows should be tracked or not.
9651** If xFilter returns 0, changes is not tracked. Note that once a table is
9652** attached, xFilter will not be called again.
9653*/
9654SQLITE_API void sqlite3session_table_filter(
9655 sqlite3_session *pSession, /* Session object */
9656 int(*xFilter)(
9657 void *pCtx, /* Copy of third arg to _filter_table() */
9658 const char *zTab /* Table name */
9659 ),
9660 void *pCtx /* First argument passed to xFilter */
9661);
9662
9663/*
9664** CAPI3REF: Generate A Changeset From A Session Object
9665** METHOD: sqlite3_session
9666**
9667** Obtain a changeset containing changes to the tables attached to the
9668** session object passed as the first argument. If successful,
9669** set *ppChangeset to point to a buffer containing the changeset
9670** and *pnChangeset to the size of the changeset in bytes before returning
9671** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
9672** zero and return an SQLite error code.
9673**
9674** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
9675** each representing a change to a single row of an attached table. An INSERT
9676** change contains the values of each field of a new database row. A DELETE
9677** contains the original values of each field of a deleted database row. An
9678** UPDATE change contains the original values of each field of an updated
9679** database row along with the updated values for each updated non-primary-key
9680** column. It is not possible for an UPDATE change to represent a change that
9681** modifies the values of primary key columns. If such a change is made, it
9682** is represented in a changeset as a DELETE followed by an INSERT.
9683**
9684** Changes are not recorded for rows that have NULL values stored in one or
9685** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
9686** no corresponding change is present in the changesets returned by this
9687** function. If an existing row with one or more NULL values stored in
9688** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
9689** only an INSERT is appears in the changeset. Similarly, if an existing row
9690** with non-NULL PRIMARY KEY values is updated so that one or more of its
9691** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
9692** DELETE change only.
9693**
9694** The contents of a changeset may be traversed using an iterator created
9695** using the [sqlite3changeset_start()] API. A changeset may be applied to
9696** a database with a compatible schema using the [sqlite3changeset_apply()]
9697** API.
9698**
9699** Within a changeset generated by this function, all changes related to a
9700** single table are grouped together. In other words, when iterating through
9701** a changeset or when applying a changeset to a database, all changes related
9702** to a single table are processed before moving on to the next table. Tables
9703** are sorted in the same order in which they were attached (or auto-attached)
9704** to the sqlite3_session object. The order in which the changes related to
9705** a single table are stored is undefined.
9706**
9707** Following a successful call to this function, it is the responsibility of
9708** the caller to eventually free the buffer that *ppChangeset points to using
9709** [sqlite3_free()].
9710**
9711** <h3>Changeset Generation</h3>
9712**
9713** Once a table has been attached to a session object, the session object
9714** records the primary key values of all new rows inserted into the table.
9715** It also records the original primary key and other column values of any
9716** deleted or updated rows. For each unique primary key value, data is only
9717** recorded once - the first time a row with said primary key is inserted,
9718** updated or deleted in the lifetime of the session.
9719**
9720** There is one exception to the previous paragraph: when a row is inserted,
9721** updated or deleted, if one or more of its primary key columns contain a
9722** NULL value, no record of the change is made.
9723**
9724** The session object therefore accumulates two types of records - those
9725** that consist of primary key values only (created when the user inserts
9726** a new record) and those that consist of the primary key values and the
9727** original values of other table columns (created when the users deletes
9728** or updates a record).
9729**
9730** When this function is called, the requested changeset is created using
9731** both the accumulated records and the current contents of the database
9732** file. Specifically:
9733**
9734** <ul>
9735** <li> For each record generated by an insert, the database is queried
9736** for a row with a matching primary key. If one is found, an INSERT
9737** change is added to the changeset. If no such row is found, no change
9738** is added to the changeset.
9739**
9740** <li> For each record generated by an update or delete, the database is
9741** queried for a row with a matching primary key. If such a row is
9742** found and one or more of the non-primary key fields have been
9743** modified from their original values, an UPDATE change is added to
9744** the changeset. Or, if no such row is found in the table, a DELETE
9745** change is added to the changeset. If there is a row with a matching
9746** primary key in the database, but all fields contain their original
9747** values, no change is added to the changeset.
9748** </ul>
9749**
9750** This means, amongst other things, that if a row is inserted and then later
9751** deleted while a session object is active, neither the insert nor the delete
9752** will be present in the changeset. Or if a row is deleted and then later a
9753** row with the same primary key values inserted while a session object is
9754** active, the resulting changeset will contain an UPDATE change instead of
9755** a DELETE and an INSERT.
9756**
9757** When a session object is disabled (see the [sqlite3session_enable()] API),
9758** it does not accumulate records when rows are inserted, updated or deleted.
9759** This may appear to have some counter-intuitive effects if a single row
9760** is written to more than once during a session. For example, if a row
9761** is inserted while a session object is enabled, then later deleted while
9762** the same session object is disabled, no INSERT record will appear in the
9763** changeset, even though the delete took place while the session was disabled.
9764** Or, if one field of a row is updated while a session is disabled, and
9765** another field of the same row is updated while the session is enabled, the
9766** resulting changeset will contain an UPDATE change that updates both fields.
9767*/
9768SQLITE_API int sqlite3session_changeset(
9769 sqlite3_session *pSession, /* Session object */
9770 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
9771 void **ppChangeset /* OUT: Buffer containing changeset */
9772);
9773
9774/*
9775** CAPI3REF: Load The Difference Between Tables Into A Session
9776** METHOD: sqlite3_session
9777**
9778** If it is not already attached to the session object passed as the first
9779** argument, this function attaches table zTbl in the same manner as the
9780** [sqlite3session_attach()] function. If zTbl does not exist, or if it
9781** does not have a primary key, this function is a no-op (but does not return
9782** an error).
9783**
9784** Argument zFromDb must be the name of a database ("main", "temp" etc.)
9785** attached to the same database handle as the session object that contains
9786** a table compatible with the table attached to the session by this function.
9787** A table is considered compatible if it:
9788**
9789** <ul>
9790** <li> Has the same name,
9791** <li> Has the same set of columns declared in the same order, and
9792** <li> Has the same PRIMARY KEY definition.
9793** </ul>
9794**
9795** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
9796** are compatible but do not have any PRIMARY KEY columns, it is not an error
9797** but no changes are added to the session object. As with other session
9798** APIs, tables without PRIMARY KEYs are simply ignored.
9799**
9800** This function adds a set of changes to the session object that could be
9801** used to update the table in database zFrom (call this the "from-table")
9802** so that its content is the same as the table attached to the session
9803** object (call this the "to-table"). Specifically:
9804**
9805** <ul>
9806** <li> For each row (primary key) that exists in the to-table but not in
9807** the from-table, an INSERT record is added to the session object.
9808**
9809** <li> For each row (primary key) that exists in the to-table but not in
9810** the from-table, a DELETE record is added to the session object.
9811**
9812** <li> For each row (primary key) that exists in both tables, but features
9813** different non-PK values in each, an UPDATE record is added to the
9814** session.
9815** </ul>
9816**
9817** To clarify, if this function is called and then a changeset constructed
9818** using [sqlite3session_changeset()], then after applying that changeset to
9819** database zFrom the contents of the two compatible tables would be
9820** identical.
9821**
9822** It an error if database zFrom does not exist or does not contain the
9823** required compatible table.
9824**
9825** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
9826** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
9827** may be set to point to a buffer containing an English language error
9828** message. It is the responsibility of the caller to free this buffer using
9829** sqlite3_free().
9830*/
9831SQLITE_API int sqlite3session_diff(
9832 sqlite3_session *pSession,
9833 const char *zFromDb,
9834 const char *zTbl,
9835 char **pzErrMsg
9836);
9837
9838
9839/*
9840** CAPI3REF: Generate A Patchset From A Session Object
9841** METHOD: sqlite3_session
9842**
9843** The differences between a patchset and a changeset are that:
9844**
9845** <ul>
9846** <li> DELETE records consist of the primary key fields only. The
9847** original values of other fields are omitted.
9848** <li> The original values of any modified fields are omitted from
9849** UPDATE records.
9850** </ul>
9851**
9852** A patchset blob may be used with up to date versions of all
9853** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
9854** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
9855** attempting to use a patchset blob with old versions of the
9856** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
9857**
9858** Because the non-primary key "old.*" fields are omitted, no
9859** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
9860** is passed to the sqlite3changeset_apply() API. Other conflict types work
9861** in the same way as for changesets.
9862**
9863** Changes within a patchset are ordered in the same way as for changesets
9864** generated by the sqlite3session_changeset() function (i.e. all changes for
9865** a single table are grouped together, tables appear in the order in which
9866** they were attached to the session object).
9867*/
9868SQLITE_API int sqlite3session_patchset(
9869 sqlite3_session *pSession, /* Session object */
9870 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
9871 void **ppPatchset /* OUT: Buffer containing patchset */
9872);
9873
9874/*
9875** CAPI3REF: Test if a changeset has recorded any changes.
9876**
9877** Return non-zero if no changes to attached tables have been recorded by
9878** the session object passed as the first argument. Otherwise, if one or
9879** more changes have been recorded, return zero.
9880**
9881** Even if this function returns zero, it is possible that calling
9882** [sqlite3session_changeset()] on the session handle may still return a
9883** changeset that contains no changes. This can happen when a row in
9884** an attached table is modified and then later on the original values
9885** are restored. However, if this function returns non-zero, then it is
9886** guaranteed that a call to sqlite3session_changeset() will return a
9887** changeset containing zero changes.
9888*/
9889SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
9890
9891/*
9892** CAPI3REF: Create An Iterator To Traverse A Changeset
9893** CONSTRUCTOR: sqlite3_changeset_iter
9894**
9895** Create an iterator used to iterate through the contents of a changeset.
9896** If successful, *pp is set to point to the iterator handle and SQLITE_OK
9897** is returned. Otherwise, if an error occurs, *pp is set to zero and an
9898** SQLite error code is returned.
9899**
9900** The following functions can be used to advance and query a changeset
9901** iterator created by this function:
9902**
9903** <ul>
9904** <li> [sqlite3changeset_next()]
9905** <li> [sqlite3changeset_op()]
9906** <li> [sqlite3changeset_new()]
9907** <li> [sqlite3changeset_old()]
9908** </ul>
9909**
9910** It is the responsibility of the caller to eventually destroy the iterator
9911** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
9912** changeset (pChangeset) must remain valid until after the iterator is
9913** destroyed.
9914**
9915** Assuming the changeset blob was created by one of the
9916** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
9917** [sqlite3changeset_invert()] functions, all changes within the changeset
9918** that apply to a single table are grouped together. This means that when
9919** an application iterates through a changeset using an iterator created by
9920** this function, all changes that relate to a single table are visited
9921** consecutively. There is no chance that the iterator will visit a change
9922** the applies to table X, then one for table Y, and then later on visit
9923** another change for table X.
9924**
9925** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
9926** may be modified by passing a combination of
9927** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
9928**
9929** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
9930** and therefore subject to change.
9931*/
9932SQLITE_API int sqlite3changeset_start(
9933 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
9934 int nChangeset, /* Size of changeset blob in bytes */
9935 void *pChangeset /* Pointer to blob containing changeset */
9936);
9937SQLITE_API int sqlite3changeset_start_v2(
9938 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
9939 int nChangeset, /* Size of changeset blob in bytes */
9940 void *pChangeset, /* Pointer to blob containing changeset */
9941 int flags /* SESSION_CHANGESETSTART_* flags */
9942);
9943
9944/*
9945** CAPI3REF: Flags for sqlite3changeset_start_v2
9946**
9947** The following flags may passed via the 4th parameter to
9948** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
9949**
9950** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
9951** Invert the changeset while iterating through it. This is equivalent to
9952** inverting a changeset using sqlite3changeset_invert() before applying it.
9953** It is an error to specify this flag with a patchset.
9954*/
9955#define SQLITE_CHANGESETSTART_INVERT 0x0002
9956
9957
9958/*
9959** CAPI3REF: Advance A Changeset Iterator
9960** METHOD: sqlite3_changeset_iter
9961**
9962** This function may only be used with iterators created by function
9963** [sqlite3changeset_start()]. If it is called on an iterator passed to
9964** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
9965** is returned and the call has no effect.
9966**
9967** Immediately after an iterator is created by sqlite3changeset_start(), it
9968** does not point to any change in the changeset. Assuming the changeset
9969** is not empty, the first call to this function advances the iterator to
9970** point to the first change in the changeset. Each subsequent call advances
9971** the iterator to point to the next change in the changeset (if any). If
9972** no error occurs and the iterator points to a valid change after a call
9973** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
9974** Otherwise, if all changes in the changeset have already been visited,
9975** SQLITE_DONE is returned.
9976**
9977** If an error occurs, an SQLite error code is returned. Possible error
9978** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
9979** SQLITE_NOMEM.
9980*/
9981SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
9982
9983/*
9984** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
9985** METHOD: sqlite3_changeset_iter
9986**
9987** The pIter argument passed to this function may either be an iterator
9988** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
9989** created by [sqlite3changeset_start()]. In the latter case, the most recent
9990** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
9991** is not the case, this function returns [SQLITE_MISUSE].
9992**
9993** If argument pzTab is not NULL, then *pzTab is set to point to a
9994** nul-terminated utf-8 encoded string containing the name of the table
9995** affected by the current change. The buffer remains valid until either
9996** sqlite3changeset_next() is called on the iterator or until the
9997** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
9998** set to the number of columns in the table affected by the change. If
9999** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
10000** is an indirect change, or false (0) otherwise. See the documentation for
10001** [sqlite3session_indirect()] for a description of direct and indirect
10002** changes. Finally, if pOp is not NULL, then *pOp is set to one of
10003** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
10004** type of change that the iterator currently points to.
10005**
10006** If no error occurs, SQLITE_OK is returned. If an error does occur, an
10007** SQLite error code is returned. The values of the output variables may not
10008** be trusted in this case.
10009*/
10010SQLITE_API int sqlite3changeset_op(
10011 sqlite3_changeset_iter *pIter, /* Iterator object */
10012 const char **pzTab, /* OUT: Pointer to table name */
10013 int *pnCol, /* OUT: Number of columns in table */
10014 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
10015 int *pbIndirect /* OUT: True for an 'indirect' change */
10016);
10017
10018/*
10019** CAPI3REF: Obtain The Primary Key Definition Of A Table
10020** METHOD: sqlite3_changeset_iter
10021**
10022** For each modified table, a changeset includes the following:
10023**
10024** <ul>
10025** <li> The number of columns in the table, and
10026** <li> Which of those columns make up the tables PRIMARY KEY.
10027** </ul>
10028**
10029** This function is used to find which columns comprise the PRIMARY KEY of
10030** the table modified by the change that iterator pIter currently points to.
10031** If successful, *pabPK is set to point to an array of nCol entries, where
10032** nCol is the number of columns in the table. Elements of *pabPK are set to
10033** 0x01 if the corresponding column is part of the tables primary key, or
10034** 0x00 if it is not.
10035**
10036** If argument pnCol is not NULL, then *pnCol is set to the number of columns
10037** in the table.
10038**
10039** If this function is called when the iterator does not point to a valid
10040** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
10041** SQLITE_OK is returned and the output variables populated as described
10042** above.
10043*/
10044SQLITE_API int sqlite3changeset_pk(
10045 sqlite3_changeset_iter *pIter, /* Iterator object */
10046 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
10047 int *pnCol /* OUT: Number of entries in output array */
10048);
10049
10050/*
10051** CAPI3REF: Obtain old.* Values From A Changeset Iterator
10052** METHOD: sqlite3_changeset_iter
10053**
10054** The pIter argument passed to this function may either be an iterator
10055** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10056** created by [sqlite3changeset_start()]. In the latter case, the most recent
10057** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10058** Furthermore, it may only be called if the type of change that the iterator
10059** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
10060** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10061**
10062** Argument iVal must be greater than or equal to 0, and less than the number
10063** of columns in the table affected by the current change. Otherwise,
10064** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10065**
10066** If successful, this function sets *ppValue to point to a protected
10067** sqlite3_value object containing the iVal'th value from the vector of
10068** original row values stored as part of the UPDATE or DELETE change and
10069** returns SQLITE_OK. The name of the function comes from the fact that this
10070** is similar to the "old.*" columns available to update or delete triggers.
10071**
10072** If some other error occurs (e.g. an OOM condition), an SQLite error code
10073** is returned and *ppValue is set to NULL.
10074*/
10075SQLITE_API int sqlite3changeset_old(
10076 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10077 int iVal, /* Column number */
10078 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
10079);
10080
10081/*
10082** CAPI3REF: Obtain new.* Values From A Changeset Iterator
10083** METHOD: sqlite3_changeset_iter
10084**
10085** The pIter argument passed to this function may either be an iterator
10086** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
10087** created by [sqlite3changeset_start()]. In the latter case, the most recent
10088** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
10089** Furthermore, it may only be called if the type of change that the iterator
10090** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
10091** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
10092**
10093** Argument iVal must be greater than or equal to 0, and less than the number
10094** of columns in the table affected by the current change. Otherwise,
10095** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10096**
10097** If successful, this function sets *ppValue to point to a protected
10098** sqlite3_value object containing the iVal'th value from the vector of
10099** new row values stored as part of the UPDATE or INSERT change and
10100** returns SQLITE_OK. If the change is an UPDATE and does not include
10101** a new value for the requested column, *ppValue is set to NULL and
10102** SQLITE_OK returned. The name of the function comes from the fact that
10103** this is similar to the "new.*" columns available to update or delete
10104** triggers.
10105**
10106** If some other error occurs (e.g. an OOM condition), an SQLite error code
10107** is returned and *ppValue is set to NULL.
10108*/
10109SQLITE_API int sqlite3changeset_new(
10110 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10111 int iVal, /* Column number */
10112 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
10113);
10114
10115/*
10116** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
10117** METHOD: sqlite3_changeset_iter
10118**
10119** This function should only be used with iterator objects passed to a
10120** conflict-handler callback by [sqlite3changeset_apply()] with either
10121** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
10122** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
10123** is set to NULL.
10124**
10125** Argument iVal must be greater than or equal to 0, and less than the number
10126** of columns in the table affected by the current change. Otherwise,
10127** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
10128**
10129** If successful, this function sets *ppValue to point to a protected
10130** sqlite3_value object containing the iVal'th value from the
10131** "conflicting row" associated with the current conflict-handler callback
10132** and returns SQLITE_OK.
10133**
10134** If some other error occurs (e.g. an OOM condition), an SQLite error code
10135** is returned and *ppValue is set to NULL.
10136*/
10137SQLITE_API int sqlite3changeset_conflict(
10138 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10139 int iVal, /* Column number */
10140 sqlite3_value **ppValue /* OUT: Value from conflicting row */
10141);
10142
10143/*
10144** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
10145** METHOD: sqlite3_changeset_iter
10146**
10147** This function may only be called with an iterator passed to an
10148** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
10149** it sets the output variable to the total number of known foreign key
10150** violations in the destination database and returns SQLITE_OK.
10151**
10152** In all other cases this function returns SQLITE_MISUSE.
10153*/
10154SQLITE_API int sqlite3changeset_fk_conflicts(
10155 sqlite3_changeset_iter *pIter, /* Changeset iterator */
10156 int *pnOut /* OUT: Number of FK violations */
10157);
10158
10159
10160/*
10161** CAPI3REF: Finalize A Changeset Iterator
10162** METHOD: sqlite3_changeset_iter
10163**
10164** This function is used to finalize an iterator allocated with
10165** [sqlite3changeset_start()].
10166**
10167** This function should only be called on iterators created using the
10168** [sqlite3changeset_start()] function. If an application calls this
10169** function with an iterator passed to a conflict-handler by
10170** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
10171** call has no effect.
10172**
10173** If an error was encountered within a call to an sqlite3changeset_xxx()
10174** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
10175** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
10176** to that error is returned by this function. Otherwise, SQLITE_OK is
10177** returned. This is to allow the following pattern (pseudo-code):
10178**
10179** <pre>
10180** sqlite3changeset_start();
10181** while( SQLITE_ROW==sqlite3changeset_next() ){
10182** // Do something with change.
10183** }
10184** rc = sqlite3changeset_finalize();
10185** if( rc!=SQLITE_OK ){
10186** // An error has occurred
10187** }
10188** </pre>
10189*/
10190SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
10191
10192/*
10193** CAPI3REF: Invert A Changeset
10194**
10195** This function is used to "invert" a changeset object. Applying an inverted
10196** changeset to a database reverses the effects of applying the uninverted
10197** changeset. Specifically:
10198**
10199** <ul>
10200** <li> Each DELETE change is changed to an INSERT, and
10201** <li> Each INSERT change is changed to a DELETE, and
10202** <li> For each UPDATE change, the old.* and new.* values are exchanged.
10203** </ul>
10204**
10205** This function does not change the order in which changes appear within
10206** the changeset. It merely reverses the sense of each individual change.
10207**
10208** If successful, a pointer to a buffer containing the inverted changeset
10209** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
10210** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
10211** zeroed and an SQLite error code returned.
10212**
10213** It is the responsibility of the caller to eventually call sqlite3_free()
10214** on the *ppOut pointer to free the buffer allocation following a successful
10215** call to this function.
10216**
10217** WARNING/TODO: This function currently assumes that the input is a valid
10218** changeset. If it is not, the results are undefined.
10219*/
10220SQLITE_API int sqlite3changeset_invert(
10221 int nIn, const void *pIn, /* Input changeset */
10222 int *pnOut, void **ppOut /* OUT: Inverse of input */
10223);
10224
10225/*
10226** CAPI3REF: Concatenate Two Changeset Objects
10227**
10228** This function is used to concatenate two changesets, A and B, into a
10229** single changeset. The result is a changeset equivalent to applying
10230** changeset A followed by changeset B.
10231**
10232** This function combines the two input changesets using an
10233** sqlite3_changegroup object. Calling it produces similar results as the
10234** following code fragment:
10235**
10236** <pre>
10237** sqlite3_changegroup *pGrp;
10238** rc = sqlite3_changegroup_new(&pGrp);
10239** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
10240** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
10241** if( rc==SQLITE_OK ){
10242** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
10243** }else{
10244** *ppOut = 0;
10245** *pnOut = 0;
10246** }
10247** </pre>
10248**
10249** Refer to the sqlite3_changegroup documentation below for details.
10250*/
10251SQLITE_API int sqlite3changeset_concat(
10252 int nA, /* Number of bytes in buffer pA */
10253 void *pA, /* Pointer to buffer containing changeset A */
10254 int nB, /* Number of bytes in buffer pB */
10255 void *pB, /* Pointer to buffer containing changeset B */
10256 int *pnOut, /* OUT: Number of bytes in output changeset */
10257 void **ppOut /* OUT: Buffer containing output changeset */
10258);
10259
10260
10261/*
10262** CAPI3REF: Changegroup Handle
10263**
10264** A changegroup is an object used to combine two or more
10265** [changesets] or [patchsets]
10266*/
10267typedef struct sqlite3_changegroup sqlite3_changegroup;
10268
10269/*
10270** CAPI3REF: Create A New Changegroup Object
10271** CONSTRUCTOR: sqlite3_changegroup
10272**
10273** An sqlite3_changegroup object is used to combine two or more changesets
10274** (or patchsets) into a single changeset (or patchset). A single changegroup
10275** object may combine changesets or patchsets, but not both. The output is
10276** always in the same format as the input.
10277**
10278** If successful, this function returns SQLITE_OK and populates (*pp) with
10279** a pointer to a new sqlite3_changegroup object before returning. The caller
10280** should eventually free the returned object using a call to
10281** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
10282** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
10283**
10284** The usual usage pattern for an sqlite3_changegroup object is as follows:
10285**
10286** <ul>
10287** <li> It is created using a call to sqlite3changegroup_new().
10288**
10289** <li> Zero or more changesets (or patchsets) are added to the object
10290** by calling sqlite3changegroup_add().
10291**
10292** <li> The result of combining all input changesets together is obtained
10293** by the application via a call to sqlite3changegroup_output().
10294**
10295** <li> The object is deleted using a call to sqlite3changegroup_delete().
10296** </ul>
10297**
10298** Any number of calls to add() and output() may be made between the calls to
10299** new() and delete(), and in any order.
10300**
10301** As well as the regular sqlite3changegroup_add() and
10302** sqlite3changegroup_output() functions, also available are the streaming
10303** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
10304*/
10305SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
10306
10307/*
10308** CAPI3REF: Add A Changeset To A Changegroup
10309** METHOD: sqlite3_changegroup
10310**
10311** Add all changes within the changeset (or patchset) in buffer pData (size
10312** nData bytes) to the changegroup.
10313**
10314** If the buffer contains a patchset, then all prior calls to this function
10315** on the same changegroup object must also have specified patchsets. Or, if
10316** the buffer contains a changeset, so must have the earlier calls to this
10317** function. Otherwise, SQLITE_ERROR is returned and no changes are added
10318** to the changegroup.
10319**
10320** Rows within the changeset and changegroup are identified by the values in
10321** their PRIMARY KEY columns. A change in the changeset is considered to
10322** apply to the same row as a change already present in the changegroup if
10323** the two rows have the same primary key.
10324**
10325** Changes to rows that do not already appear in the changegroup are
10326** simply copied into it. Or, if both the new changeset and the changegroup
10327** contain changes that apply to a single row, the final contents of the
10328** changegroup depends on the type of each change, as follows:
10329**
10330** <table border=1 style="margin-left:8ex;margin-right:8ex">
10331** <tr><th style="white-space:pre">Existing Change </th>
10332** <th style="white-space:pre">New Change </th>
10333** <th>Output Change
10334** <tr><td>INSERT <td>INSERT <td>
10335** The new change is ignored. This case does not occur if the new
10336** changeset was recorded immediately after the changesets already
10337** added to the changegroup.
10338** <tr><td>INSERT <td>UPDATE <td>
10339** The INSERT change remains in the changegroup. The values in the
10340** INSERT change are modified as if the row was inserted by the
10341** existing change and then updated according to the new change.
10342** <tr><td>INSERT <td>DELETE <td>
10343** The existing INSERT is removed from the changegroup. The DELETE is
10344** not added.
10345** <tr><td>UPDATE <td>INSERT <td>
10346** The new change is ignored. This case does not occur if the new
10347** changeset was recorded immediately after the changesets already
10348** added to the changegroup.
10349** <tr><td>UPDATE <td>UPDATE <td>
10350** The existing UPDATE remains within the changegroup. It is amended
10351** so that the accompanying values are as if the row was updated once
10352** by the existing change and then again by the new change.
10353** <tr><td>UPDATE <td>DELETE <td>
10354** The existing UPDATE is replaced by the new DELETE within the
10355** changegroup.
10356** <tr><td>DELETE <td>INSERT <td>
10357** If one or more of the column values in the row inserted by the
10358** new change differ from those in the row deleted by the existing
10359** change, the existing DELETE is replaced by an UPDATE within the
10360** changegroup. Otherwise, if the inserted row is exactly the same
10361** as the deleted row, the existing DELETE is simply discarded.
10362** <tr><td>DELETE <td>UPDATE <td>
10363** The new change is ignored. This case does not occur if the new
10364** changeset was recorded immediately after the changesets already
10365** added to the changegroup.
10366** <tr><td>DELETE <td>DELETE <td>
10367** The new change is ignored. This case does not occur if the new
10368** changeset was recorded immediately after the changesets already
10369** added to the changegroup.
10370** </table>
10371**
10372** If the new changeset contains changes to a table that is already present
10373** in the changegroup, then the number of columns and the position of the
10374** primary key columns for the table must be consistent. If this is not the
10375** case, this function fails with SQLITE_SCHEMA. If the input changeset
10376** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
10377** returned. Or, if an out-of-memory condition occurs during processing, this
10378** function returns SQLITE_NOMEM. In all cases, if an error occurs the
10379** final contents of the changegroup is undefined.
10380**
10381** If no error occurs, SQLITE_OK is returned.
10382*/
10383SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
10384
10385/*
10386** CAPI3REF: Obtain A Composite Changeset From A Changegroup
10387** METHOD: sqlite3_changegroup
10388**
10389** Obtain a buffer containing a changeset (or patchset) representing the
10390** current contents of the changegroup. If the inputs to the changegroup
10391** were themselves changesets, the output is a changeset. Or, if the
10392** inputs were patchsets, the output is also a patchset.
10393**
10394** As with the output of the sqlite3session_changeset() and
10395** sqlite3session_patchset() functions, all changes related to a single
10396** table are grouped together in the output of this function. Tables appear
10397** in the same order as for the very first changeset added to the changegroup.
10398** If the second or subsequent changesets added to the changegroup contain
10399** changes for tables that do not appear in the first changeset, they are
10400** appended onto the end of the output changeset, again in the order in
10401** which they are first encountered.
10402**
10403** If an error occurs, an SQLite error code is returned and the output
10404** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
10405** is returned and the output variables are set to the size of and a
10406** pointer to the output buffer, respectively. In this case it is the
10407** responsibility of the caller to eventually free the buffer using a
10408** call to sqlite3_free().
10409*/
10410SQLITE_API int sqlite3changegroup_output(
10411 sqlite3_changegroup*,
10412 int *pnData, /* OUT: Size of output buffer in bytes */
10413 void **ppData /* OUT: Pointer to output buffer */
10414);
10415
10416/*
10417** CAPI3REF: Delete A Changegroup Object
10418** DESTRUCTOR: sqlite3_changegroup
10419*/
10420SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
10421
10422/*
10423** CAPI3REF: Apply A Changeset To A Database
10424**
10425** Apply a changeset or patchset to a database. These functions attempt to
10426** update the "main" database attached to handle db with the changes found in
10427** the changeset passed via the second and third arguments.
10428**
10429** The fourth argument (xFilter) passed to these functions is the "filter
10430** callback". If it is not NULL, then for each table affected by at least one
10431** change in the changeset, the filter callback is invoked with
10432** the table name as the second argument, and a copy of the context pointer
10433** passed as the sixth argument as the first. If the "filter callback"
10434** returns zero, then no attempt is made to apply any changes to the table.
10435** Otherwise, if the return value is non-zero or the xFilter argument to
10436** is NULL, all changes related to the table are attempted.
10437**
10438** For each table that is not excluded by the filter callback, this function
10439** tests that the target database contains a compatible table. A table is
10440** considered compatible if all of the following are true:
10441**
10442** <ul>
10443** <li> The table has the same name as the name recorded in the
10444** changeset, and
10445** <li> The table has at least as many columns as recorded in the
10446** changeset, and
10447** <li> The table has primary key columns in the same position as
10448** recorded in the changeset.
10449** </ul>
10450**
10451** If there is no compatible table, it is not an error, but none of the
10452** changes associated with the table are applied. A warning message is issued
10453** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
10454** one such warning is issued for each table in the changeset.
10455**
10456** For each change for which there is a compatible table, an attempt is made
10457** to modify the table contents according to the UPDATE, INSERT or DELETE
10458** change. If a change cannot be applied cleanly, the conflict handler
10459** function passed as the fifth argument to sqlite3changeset_apply() may be
10460** invoked. A description of exactly when the conflict handler is invoked for
10461** each type of change is below.
10462**
10463** Unlike the xFilter argument, xConflict may not be passed NULL. The results
10464** of passing anything other than a valid function pointer as the xConflict
10465** argument are undefined.
10466**
10467** Each time the conflict handler function is invoked, it must return one
10468** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
10469** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
10470** if the second argument passed to the conflict handler is either
10471** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
10472** returns an illegal value, any changes already made are rolled back and
10473** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
10474** actions are taken by sqlite3changeset_apply() depending on the value
10475** returned by each invocation of the conflict-handler function. Refer to
10476** the documentation for the three
10477** [SQLITE_CHANGESET_OMIT|available return values] for details.
10478**
10479** <dl>
10480** <dt>DELETE Changes<dd>
10481** For each DELETE change, the function checks if the target database
10482** contains a row with the same primary key value (or values) as the
10483** original row values stored in the changeset. If it does, and the values
10484** stored in all non-primary key columns also match the values stored in
10485** the changeset the row is deleted from the target database.
10486**
10487** If a row with matching primary key values is found, but one or more of
10488** the non-primary key fields contains a value different from the original
10489** row value stored in the changeset, the conflict-handler function is
10490** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
10491** database table has more columns than are recorded in the changeset,
10492** only the values of those non-primary key fields are compared against
10493** the current database contents - any trailing database table columns
10494** are ignored.
10495**
10496** If no row with matching primary key values is found in the database,
10497** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10498** passed as the second argument.
10499**
10500** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
10501** (which can only happen if a foreign key constraint is violated), the
10502** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
10503** passed as the second argument. This includes the case where the DELETE
10504** operation is attempted because an earlier call to the conflict handler
10505** function returned [SQLITE_CHANGESET_REPLACE].
10506**
10507** <dt>INSERT Changes<dd>
10508** For each INSERT change, an attempt is made to insert the new row into
10509** the database. If the changeset row contains fewer fields than the
10510** database table, the trailing fields are populated with their default
10511** values.
10512**
10513** If the attempt to insert the row fails because the database already
10514** contains a row with the same primary key values, the conflict handler
10515** function is invoked with the second argument set to
10516** [SQLITE_CHANGESET_CONFLICT].
10517**
10518** If the attempt to insert the row fails because of some other constraint
10519** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
10520** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
10521** This includes the case where the INSERT operation is re-attempted because
10522** an earlier call to the conflict handler function returned
10523** [SQLITE_CHANGESET_REPLACE].
10524**
10525** <dt>UPDATE Changes<dd>
10526** For each UPDATE change, the function checks if the target database
10527** contains a row with the same primary key value (or values) as the
10528** original row values stored in the changeset. If it does, and the values
10529** stored in all modified non-primary key columns also match the values
10530** stored in the changeset the row is updated within the target database.
10531**
10532** If a row with matching primary key values is found, but one or more of
10533** the modified non-primary key fields contains a value different from an
10534** original row value stored in the changeset, the conflict-handler function
10535** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
10536** UPDATE changes only contain values for non-primary key fields that are
10537** to be modified, only those fields need to match the original values to
10538** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
10539**
10540** If no row with matching primary key values is found in the database,
10541** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
10542** passed as the second argument.
10543**
10544** If the UPDATE operation is attempted, but SQLite returns
10545** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
10546** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
10547** This includes the case where the UPDATE operation is attempted after
10548** an earlier call to the conflict handler function returned
10549** [SQLITE_CHANGESET_REPLACE].
10550** </dl>
10551**
10552** It is safe to execute SQL statements, including those that write to the
10553** table that the callback related to, from within the xConflict callback.
10554** This can be used to further customize the applications conflict
10555** resolution strategy.
10556**
10557** All changes made by these functions are enclosed in a savepoint transaction.
10558** If any other error (aside from a constraint failure when attempting to
10559** write to the target database) occurs, then the savepoint transaction is
10560** rolled back, restoring the target database to its original state, and an
10561** SQLite error code returned.
10562**
10563** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
10564** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
10565** may set (*ppRebase) to point to a "rebase" that may be used with the
10566** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
10567** is set to the size of the buffer in bytes. It is the responsibility of the
10568** caller to eventually free any such buffer using sqlite3_free(). The buffer
10569** is only allocated and populated if one or more conflicts were encountered
10570** while applying the patchset. See comments surrounding the sqlite3_rebaser
10571** APIs for further details.
10572**
10573** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
10574** may be modified by passing a combination of
10575** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
10576**
10577** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
10578** and therefore subject to change.
10579*/
10580SQLITE_API int sqlite3changeset_apply(
10581 sqlite3 *db, /* Apply change to "main" db of this handle */
10582 int nChangeset, /* Size of changeset in bytes */
10583 void *pChangeset, /* Changeset blob */
10584 int(*xFilter)(
10585 void *pCtx, /* Copy of sixth arg to _apply() */
10586 const char *zTab /* Table name */
10587 ),
10588 int(*xConflict)(
10589 void *pCtx, /* Copy of sixth arg to _apply() */
10590 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10591 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10592 ),
10593 void *pCtx /* First argument passed to xConflict */
10594);
10595SQLITE_API int sqlite3changeset_apply_v2(
10596 sqlite3 *db, /* Apply change to "main" db of this handle */
10597 int nChangeset, /* Size of changeset in bytes */
10598 void *pChangeset, /* Changeset blob */
10599 int(*xFilter)(
10600 void *pCtx, /* Copy of sixth arg to _apply() */
10601 const char *zTab /* Table name */
10602 ),
10603 int(*xConflict)(
10604 void *pCtx, /* Copy of sixth arg to _apply() */
10605 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10606 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10607 ),
10608 void *pCtx, /* First argument passed to xConflict */
10609 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
10610 int flags /* SESSION_CHANGESETAPPLY_* flags */
10611);
10612
10613/*
10614** CAPI3REF: Flags for sqlite3changeset_apply_v2
10615**
10616** The following flags may passed via the 9th parameter to
10617** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
10618**
10619** <dl>
10620** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
10621** Usually, the sessions module encloses all operations performed by
10622** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
10623** SAVEPOINT is committed if the changeset or patchset is successfully
10624** applied, or rolled back if an error occurs. Specifying this flag
10625** causes the sessions module to omit this savepoint. In this case, if the
10626** caller has an open transaction or savepoint when apply_v2() is called,
10627** it may revert the partially applied changeset by rolling it back.
10628**
10629** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
10630** Invert the changeset before applying it. This is equivalent to inverting
10631** a changeset using sqlite3changeset_invert() before applying it. It is
10632** an error to specify this flag with a patchset.
10633*/
10634#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
10635#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
10636
10637/*
10638** CAPI3REF: Constants Passed To The Conflict Handler
10639**
10640** Values that may be passed as the second argument to a conflict-handler.
10641**
10642** <dl>
10643** <dt>SQLITE_CHANGESET_DATA<dd>
10644** The conflict handler is invoked with CHANGESET_DATA as the second argument
10645** when processing a DELETE or UPDATE change if a row with the required
10646** PRIMARY KEY fields is present in the database, but one or more other
10647** (non primary-key) fields modified by the update do not contain the
10648** expected "before" values.
10649**
10650** The conflicting row, in this case, is the database row with the matching
10651** primary key.
10652**
10653** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
10654** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
10655** argument when processing a DELETE or UPDATE change if a row with the
10656** required PRIMARY KEY fields is not present in the database.
10657**
10658** There is no conflicting row in this case. The results of invoking the
10659** sqlite3changeset_conflict() API are undefined.
10660**
10661** <dt>SQLITE_CHANGESET_CONFLICT<dd>
10662** CHANGESET_CONFLICT is passed as the second argument to the conflict
10663** handler while processing an INSERT change if the operation would result
10664** in duplicate primary key values.
10665**
10666** The conflicting row in this case is the database row with the matching
10667** primary key.
10668**
10669** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
10670** If foreign key handling is enabled, and applying a changeset leaves the
10671** database in a state containing foreign key violations, the conflict
10672** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
10673** exactly once before the changeset is committed. If the conflict handler
10674** returns CHANGESET_OMIT, the changes, including those that caused the
10675** foreign key constraint violation, are committed. Or, if it returns
10676** CHANGESET_ABORT, the changeset is rolled back.
10677**
10678** No current or conflicting row information is provided. The only function
10679** it is possible to call on the supplied sqlite3_changeset_iter handle
10680** is sqlite3changeset_fk_conflicts().
10681**
10682** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
10683** If any other constraint violation occurs while applying a change (i.e.
10684** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
10685** invoked with CHANGESET_CONSTRAINT as the second argument.
10686**
10687** There is no conflicting row in this case. The results of invoking the
10688** sqlite3changeset_conflict() API are undefined.
10689**
10690** </dl>
10691*/
10692#define SQLITE_CHANGESET_DATA 1
10693#define SQLITE_CHANGESET_NOTFOUND 2
10694#define SQLITE_CHANGESET_CONFLICT 3
10695#define SQLITE_CHANGESET_CONSTRAINT 4
10696#define SQLITE_CHANGESET_FOREIGN_KEY 5
10697
10698/*
10699** CAPI3REF: Constants Returned By The Conflict Handler
10700**
10701** A conflict handler callback must return one of the following three values.
10702**
10703** <dl>
10704** <dt>SQLITE_CHANGESET_OMIT<dd>
10705** If a conflict handler returns this value no special action is taken. The
10706** change that caused the conflict is not applied. The session module
10707** continues to the next change in the changeset.
10708**
10709** <dt>SQLITE_CHANGESET_REPLACE<dd>
10710** This value may only be returned if the second argument to the conflict
10711** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
10712** is not the case, any changes applied so far are rolled back and the
10713** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
10714**
10715** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
10716** handler, then the conflicting row is either updated or deleted, depending
10717** on the type of change.
10718**
10719** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
10720** handler, then the conflicting row is removed from the database and a
10721** second attempt to apply the change is made. If this second attempt fails,
10722** the original row is restored to the database before continuing.
10723**
10724** <dt>SQLITE_CHANGESET_ABORT<dd>
10725** If this value is returned, any changes applied so far are rolled back
10726** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
10727** </dl>
10728*/
10729#define SQLITE_CHANGESET_OMIT 0
10730#define SQLITE_CHANGESET_REPLACE 1
10731#define SQLITE_CHANGESET_ABORT 2
10732
10733/*
10734** CAPI3REF: Rebasing changesets
10735** EXPERIMENTAL
10736**
10737** Suppose there is a site hosting a database in state S0. And that
10738** modifications are made that move that database to state S1 and a
10739** changeset recorded (the "local" changeset). Then, a changeset based
10740** on S0 is received from another site (the "remote" changeset) and
10741** applied to the database. The database is then in state
10742** (S1+"remote"), where the exact state depends on any conflict
10743** resolution decisions (OMIT or REPLACE) made while applying "remote".
10744** Rebasing a changeset is to update it to take those conflict
10745** resolution decisions into account, so that the same conflicts
10746** do not have to be resolved elsewhere in the network.
10747**
10748** For example, if both the local and remote changesets contain an
10749** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
10750**
10751** local: INSERT INTO t1 VALUES(1, 'v1');
10752** remote: INSERT INTO t1 VALUES(1, 'v2');
10753**
10754** and the conflict resolution is REPLACE, then the INSERT change is
10755** removed from the local changeset (it was overridden). Or, if the
10756** conflict resolution was "OMIT", then the local changeset is modified
10757** to instead contain:
10758**
10759** UPDATE t1 SET b = 'v2' WHERE a=1;
10760**
10761** Changes within the local changeset are rebased as follows:
10762**
10763** <dl>
10764** <dt>Local INSERT<dd>
10765** This may only conflict with a remote INSERT. If the conflict
10766** resolution was OMIT, then add an UPDATE change to the rebased
10767** changeset. Or, if the conflict resolution was REPLACE, add
10768** nothing to the rebased changeset.
10769**
10770** <dt>Local DELETE<dd>
10771** This may conflict with a remote UPDATE or DELETE. In both cases the
10772** only possible resolution is OMIT. If the remote operation was a
10773** DELETE, then add no change to the rebased changeset. If the remote
10774** operation was an UPDATE, then the old.* fields of change are updated
10775** to reflect the new.* values in the UPDATE.
10776**
10777** <dt>Local UPDATE<dd>
10778** This may conflict with a remote UPDATE or DELETE. If it conflicts
10779** with a DELETE, and the conflict resolution was OMIT, then the update
10780** is changed into an INSERT. Any undefined values in the new.* record
10781** from the update change are filled in using the old.* values from
10782** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
10783** the UPDATE change is simply omitted from the rebased changeset.
10784**
10785** If conflict is with a remote UPDATE and the resolution is OMIT, then
10786** the old.* values are rebased using the new.* values in the remote
10787** change. Or, if the resolution is REPLACE, then the change is copied
10788** into the rebased changeset with updates to columns also updated by
10789** the conflicting remote UPDATE removed. If this means no columns would
10790** be updated, the change is omitted.
10791** </dl>
10792**
10793** A local change may be rebased against multiple remote changes
10794** simultaneously. If a single key is modified by multiple remote
10795** changesets, they are combined as follows before the local changeset
10796** is rebased:
10797**
10798** <ul>
10799** <li> If there has been one or more REPLACE resolutions on a
10800** key, it is rebased according to a REPLACE.
10801**
10802** <li> If there have been no REPLACE resolutions on a key, then
10803** the local changeset is rebased according to the most recent
10804** of the OMIT resolutions.
10805** </ul>
10806**
10807** Note that conflict resolutions from multiple remote changesets are
10808** combined on a per-field basis, not per-row. This means that in the
10809** case of multiple remote UPDATE operations, some fields of a single
10810** local change may be rebased for REPLACE while others are rebased for
10811** OMIT.
10812**
10813** In order to rebase a local changeset, the remote changeset must first
10814** be applied to the local database using sqlite3changeset_apply_v2() and
10815** the buffer of rebase information captured. Then:
10816**
10817** <ol>
10818** <li> An sqlite3_rebaser object is created by calling
10819** sqlite3rebaser_create().
10820** <li> The new object is configured with the rebase buffer obtained from
10821** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
10822** If the local changeset is to be rebased against multiple remote
10823** changesets, then sqlite3rebaser_configure() should be called
10824** multiple times, in the same order that the multiple
10825** sqlite3changeset_apply_v2() calls were made.
10826** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
10827** <li> The sqlite3_rebaser object is deleted by calling
10828** sqlite3rebaser_delete().
10829** </ol>
10830*/
10831typedef struct sqlite3_rebaser sqlite3_rebaser;
10832
10833/*
10834** CAPI3REF: Create a changeset rebaser object.
10835** EXPERIMENTAL
10836**
10837** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
10838** point to the new object and return SQLITE_OK. Otherwise, if an error
10839** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
10840** to NULL.
10841*/
10842SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
10843
10844/*
10845** CAPI3REF: Configure a changeset rebaser object.
10846** EXPERIMENTAL
10847**
10848** Configure the changeset rebaser object to rebase changesets according
10849** to the conflict resolutions described by buffer pRebase (size nRebase
10850** bytes), which must have been obtained from a previous call to
10851** sqlite3changeset_apply_v2().
10852*/
10853SQLITE_API int sqlite3rebaser_configure(
10854 sqlite3_rebaser*,
10855 int nRebase, const void *pRebase
10856);
10857
10858/*
10859** CAPI3REF: Rebase a changeset
10860** EXPERIMENTAL
10861**
10862** Argument pIn must point to a buffer containing a changeset nIn bytes
10863** in size. This function allocates and populates a buffer with a copy
10864** of the changeset rebased rebased according to the configuration of the
10865** rebaser object passed as the first argument. If successful, (*ppOut)
10866** is set to point to the new buffer containing the rebased changset and
10867** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
10868** responsibility of the caller to eventually free the new buffer using
10869** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
10870** are set to zero and an SQLite error code returned.
10871*/
10872SQLITE_API int sqlite3rebaser_rebase(
10873 sqlite3_rebaser*,
10874 int nIn, const void *pIn,
10875 int *pnOut, void **ppOut
10876);
10877
10878/*
10879** CAPI3REF: Delete a changeset rebaser object.
10880** EXPERIMENTAL
10881**
10882** Delete the changeset rebaser object and all associated resources. There
10883** should be one call to this function for each successful invocation
10884** of sqlite3rebaser_create().
10885*/
10886SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
10887
10888/*
10889** CAPI3REF: Streaming Versions of API functions.
10890**
10891** The six streaming API xxx_strm() functions serve similar purposes to the
10892** corresponding non-streaming API functions:
10893**
10894** <table border=1 style="margin-left:8ex;margin-right:8ex">
10895** <tr><th>Streaming function<th>Non-streaming equivalent</th>
10896** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
10897** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
10898** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
10899** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
10900** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
10901** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
10902** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
10903** </table>
10904**
10905** Non-streaming functions that accept changesets (or patchsets) as input
10906** require that the entire changeset be stored in a single buffer in memory.
10907** Similarly, those that return a changeset or patchset do so by returning
10908** a pointer to a single large buffer allocated using sqlite3_malloc().
10909** Normally this is convenient. However, if an application running in a
10910** low-memory environment is required to handle very large changesets, the
10911** large contiguous memory allocations required can become onerous.
10912**
10913** In order to avoid this problem, instead of a single large buffer, input
10914** is passed to a streaming API functions by way of a callback function that
10915** the sessions module invokes to incrementally request input data as it is
10916** required. In all cases, a pair of API function parameters such as
10917**
10918** <pre>
10919** &nbsp; int nChangeset,
10920** &nbsp; void *pChangeset,
10921** </pre>
10922**
10923** Is replaced by:
10924**
10925** <pre>
10926** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
10927** &nbsp; void *pIn,
10928** </pre>
10929**
10930** Each time the xInput callback is invoked by the sessions module, the first
10931** argument passed is a copy of the supplied pIn context pointer. The second
10932** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
10933** error occurs the xInput method should copy up to (*pnData) bytes of data
10934** into the buffer and set (*pnData) to the actual number of bytes copied
10935** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
10936** should be set to zero to indicate this. Or, if an error occurs, an SQLite
10937** error code should be returned. In all cases, if an xInput callback returns
10938** an error, all processing is abandoned and the streaming API function
10939** returns a copy of the error code to the caller.
10940**
10941** In the case of sqlite3changeset_start_strm(), the xInput callback may be
10942** invoked by the sessions module at any point during the lifetime of the
10943** iterator. If such an xInput callback returns an error, the iterator enters
10944** an error state, whereby all subsequent calls to iterator functions
10945** immediately fail with the same error code as returned by xInput.
10946**
10947** Similarly, streaming API functions that return changesets (or patchsets)
10948** return them in chunks by way of a callback function instead of via a
10949** pointer to a single large buffer. In this case, a pair of parameters such
10950** as:
10951**
10952** <pre>
10953** &nbsp; int *pnChangeset,
10954** &nbsp; void **ppChangeset,
10955** </pre>
10956**
10957** Is replaced by:
10958**
10959** <pre>
10960** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
10961** &nbsp; void *pOut
10962** </pre>
10963**
10964** The xOutput callback is invoked zero or more times to return data to
10965** the application. The first parameter passed to each call is a copy of the
10966** pOut pointer supplied by the application. The second parameter, pData,
10967** points to a buffer nData bytes in size containing the chunk of output
10968** data being returned. If the xOutput callback successfully processes the
10969** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
10970** it should return some other SQLite error code. In this case processing
10971** is immediately abandoned and the streaming API function returns a copy
10972** of the xOutput error code to the application.
10973**
10974** The sessions module never invokes an xOutput callback with the third
10975** parameter set to a value less than or equal to zero. Other than this,
10976** no guarantees are made as to the size of the chunks of data returned.
10977*/
10978SQLITE_API int sqlite3changeset_apply_strm(
10979 sqlite3 *db, /* Apply change to "main" db of this handle */
10980 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
10981 void *pIn, /* First arg for xInput */
10982 int(*xFilter)(
10983 void *pCtx, /* Copy of sixth arg to _apply() */
10984 const char *zTab /* Table name */
10985 ),
10986 int(*xConflict)(
10987 void *pCtx, /* Copy of sixth arg to _apply() */
10988 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
10989 sqlite3_changeset_iter *p /* Handle describing change and conflict */
10990 ),
10991 void *pCtx /* First argument passed to xConflict */
10992);
10993SQLITE_API int sqlite3changeset_apply_v2_strm(
10994 sqlite3 *db, /* Apply change to "main" db of this handle */
10995 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
10996 void *pIn, /* First arg for xInput */
10997 int(*xFilter)(
10998 void *pCtx, /* Copy of sixth arg to _apply() */
10999 const char *zTab /* Table name */
11000 ),
11001 int(*xConflict)(
11002 void *pCtx, /* Copy of sixth arg to _apply() */
11003 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11004 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11005 ),
11006 void *pCtx, /* First argument passed to xConflict */
11007 void **ppRebase, int *pnRebase,
11008 int flags
11009);
11010SQLITE_API int sqlite3changeset_concat_strm(
11011 int (*xInputA)(void *pIn, void *pData, int *pnData),
11012 void *pInA,
11013 int (*xInputB)(void *pIn, void *pData, int *pnData),
11014 void *pInB,
11015 int (*xOutput)(void *pOut, const void *pData, int nData),
11016 void *pOut
11017);
11018SQLITE_API int sqlite3changeset_invert_strm(
11019 int (*xInput)(void *pIn, void *pData, int *pnData),
11020 void *pIn,
11021 int (*xOutput)(void *pOut, const void *pData, int nData),
11022 void *pOut
11023);
11024SQLITE_API int sqlite3changeset_start_strm(
11025 sqlite3_changeset_iter **pp,
11026 int (*xInput)(void *pIn, void *pData, int *pnData),
11027 void *pIn
11028);
11029SQLITE_API int sqlite3changeset_start_v2_strm(
11030 sqlite3_changeset_iter **pp,
11031 int (*xInput)(void *pIn, void *pData, int *pnData),
11032 void *pIn,
11033 int flags
11034);
11035SQLITE_API int sqlite3session_changeset_strm(
11036 sqlite3_session *pSession,
11037 int (*xOutput)(void *pOut, const void *pData, int nData),
11038 void *pOut
11039);
11040SQLITE_API int sqlite3session_patchset_strm(
11041 sqlite3_session *pSession,
11042 int (*xOutput)(void *pOut, const void *pData, int nData),
11043 void *pOut
11044);
11045SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
11046 int (*xInput)(void *pIn, void *pData, int *pnData),
11047 void *pIn
11048);
11049SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
11050 int (*xOutput)(void *pOut, const void *pData, int nData),
11051 void *pOut
11052);
11053SQLITE_API int sqlite3rebaser_rebase_strm(
11054 sqlite3_rebaser *pRebaser,
11055 int (*xInput)(void *pIn, void *pData, int *pnData),
11056 void *pIn,
11057 int (*xOutput)(void *pOut, const void *pData, int nData),
11058 void *pOut
11059);
11060
11061/*
11062** CAPI3REF: Configure global parameters
11063**
11064** The sqlite3session_config() interface is used to make global configuration
11065** changes to the sessions module in order to tune it to the specific needs
11066** of the application.
11067**
11068** The sqlite3session_config() interface is not threadsafe. If it is invoked
11069** while any other thread is inside any other sessions method then the
11070** results are undefined. Furthermore, if it is invoked after any sessions
11071** related objects have been created, the results are also undefined.
11072**
11073** The first argument to the sqlite3session_config() function must be one
11074** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
11075** interpretation of the (void*) value passed as the second parameter and
11076** the effect of calling this function depends on the value of the first
11077** parameter.
11078**
11079** <dl>
11080** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
11081** By default, the sessions module streaming interfaces attempt to input
11082** and output data in approximately 1 KiB chunks. This operand may be used
11083** to set and query the value of this configuration setting. The pointer
11084** passed as the second argument must point to a value of type (int).
11085** If this value is greater than 0, it is used as the new streaming data
11086** chunk size for both input and output. Before returning, the (int) value
11087** pointed to by pArg is set to the final value of the streaming interface
11088** chunk size.
11089** </dl>
11090**
11091** This function returns SQLITE_OK if successful, or an SQLite error code
11092** otherwise.
11093*/
11094SQLITE_API int sqlite3session_config(int op, void *pArg);
11095
11096/*
11097** CAPI3REF: Values for sqlite3session_config().
11098*/
11099#define SQLITE_SESSION_CONFIG_STRMSIZE 1
11100
11101/*
11102** Make sure we can call this stuff from C++.
11103*/
11104#ifdef __cplusplus
11105}
11106#endif
11107
11108#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
11109
11110/******** End of sqlite3session.h *********/
11111/******** Begin file fts5.h *********/
11112/*
11113** 2014 May 31
11114**
11115** The author disclaims copyright to this source code. In place of
11116** a legal notice, here is a blessing:
11117**
11118** May you do good and not evil.
11119** May you find forgiveness for yourself and forgive others.
11120** May you share freely, never taking more than you give.
11121**
11122******************************************************************************
11123**
11124** Interfaces to extend FTS5. Using the interfaces defined in this file,
11125** FTS5 may be extended with:
11126**
11127** * custom tokenizers, and
11128** * custom auxiliary functions.
11129*/
11130
11131
11132#ifndef _FTS5_H
11133#define _FTS5_H
11134
11135
11136#ifdef __cplusplus
11137extern "C" {
11138#endif
11139
11140/*************************************************************************
11141** CUSTOM AUXILIARY FUNCTIONS
11142**
11143** Virtual table implementations may overload SQL functions by implementing
11144** the sqlite3_module.xFindFunction() method.
11145*/
11146
11147typedef struct Fts5ExtensionApi Fts5ExtensionApi;
11148typedef struct Fts5Context Fts5Context;
11149typedef struct Fts5PhraseIter Fts5PhraseIter;
11150
11151typedef void (*fts5_extension_function)(
11152 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
11153 Fts5Context *pFts, /* First arg to pass to pApi functions */
11154 sqlite3_context *pCtx, /* Context for returning result/error */
11155 int nVal, /* Number of values in apVal[] array */
11156 sqlite3_value **apVal /* Array of trailing arguments */
11157);
11158
11159struct Fts5PhraseIter {
11160 const unsigned char *a;
11161 const unsigned char *b;
11162};
11163
11164/*
11165** EXTENSION API FUNCTIONS
11166**
11167** xUserData(pFts):
11168** Return a copy of the context pointer the extension function was
11169** registered with.
11170**
11171** xColumnTotalSize(pFts, iCol, pnToken):
11172** If parameter iCol is less than zero, set output variable *pnToken
11173** to the total number of tokens in the FTS5 table. Or, if iCol is
11174** non-negative but less than the number of columns in the table, return
11175** the total number of tokens in column iCol, considering all rows in
11176** the FTS5 table.
11177**
11178** If parameter iCol is greater than or equal to the number of columns
11179** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11180** an OOM condition or IO error), an appropriate SQLite error code is
11181** returned.
11182**
11183** xColumnCount(pFts):
11184** Return the number of columns in the table.
11185**
11186** xColumnSize(pFts, iCol, pnToken):
11187** If parameter iCol is less than zero, set output variable *pnToken
11188** to the total number of tokens in the current row. Or, if iCol is
11189** non-negative but less than the number of columns in the table, set
11190** *pnToken to the number of tokens in column iCol of the current row.
11191**
11192** If parameter iCol is greater than or equal to the number of columns
11193** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
11194** an OOM condition or IO error), an appropriate SQLite error code is
11195** returned.
11196**
11197** This function may be quite inefficient if used with an FTS5 table
11198** created with the "columnsize=0" option.
11199**
11200** xColumnText:
11201** This function attempts to retrieve the text of column iCol of the
11202** current document. If successful, (*pz) is set to point to a buffer
11203** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
11204** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
11205** if an error occurs, an SQLite error code is returned and the final values
11206** of (*pz) and (*pn) are undefined.
11207**
11208** xPhraseCount:
11209** Returns the number of phrases in the current query expression.
11210**
11211** xPhraseSize:
11212** Returns the number of tokens in phrase iPhrase of the query. Phrases
11213** are numbered starting from zero.
11214**
11215** xInstCount:
11216** Set *pnInst to the total number of occurrences of all phrases within
11217** the query within the current row. Return SQLITE_OK if successful, or
11218** an error code (i.e. SQLITE_NOMEM) if an error occurs.
11219**
11220** This API can be quite slow if used with an FTS5 table created with the
11221** "detail=none" or "detail=column" option. If the FTS5 table is created
11222** with either "detail=none" or "detail=column" and "content=" option
11223** (i.e. if it is a contentless table), then this API always returns 0.
11224**
11225** xInst:
11226** Query for the details of phrase match iIdx within the current row.
11227** Phrase matches are numbered starting from zero, so the iIdx argument
11228** should be greater than or equal to zero and smaller than the value
11229** output by xInstCount().
11230**
11231** Usually, output parameter *piPhrase is set to the phrase number, *piCol
11232** to the column in which it occurs and *piOff the token offset of the
11233** first token of the phrase. The exception is if the table was created
11234** with the offsets=0 option specified. In this case *piOff is always
11235** set to -1.
11236**
11237** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM)
11238** if an error occurs.
11239**
11240** This API can be quite slow if used with an FTS5 table created with the
11241** "detail=none" or "detail=column" option.
11242**
11243** xRowid:
11244** Returns the rowid of the current row.
11245**
11246** xTokenize:
11247** Tokenize text using the tokenizer belonging to the FTS5 table.
11248**
11249** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
11250** This API function is used to query the FTS table for phrase iPhrase
11251** of the current query. Specifically, a query equivalent to:
11252**
11253** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
11254**
11255** with $p set to a phrase equivalent to the phrase iPhrase of the
11256** current query is executed. Any column filter that applies to
11257** phrase iPhrase of the current query is included in $p. For each
11258** row visited, the callback function passed as the fourth argument
11259** is invoked. The context and API objects passed to the callback
11260** function may be used to access the properties of each matched row.
11261** Invoking Api.xUserData() returns a copy of the pointer passed as
11262** the third argument to pUserData.
11263**
11264** If the callback function returns any value other than SQLITE_OK, the
11265** query is abandoned and the xQueryPhrase function returns immediately.
11266** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
11267** Otherwise, the error code is propagated upwards.
11268**
11269** If the query runs to completion without incident, SQLITE_OK is returned.
11270** Or, if some error occurs before the query completes or is aborted by
11271** the callback, an SQLite error code is returned.
11272**
11273**
11274** xSetAuxdata(pFts5, pAux, xDelete)
11275**
11276** Save the pointer passed as the second argument as the extension functions
11277** "auxiliary data". The pointer may then be retrieved by the current or any
11278** future invocation of the same fts5 extension function made as part of
11279** of the same MATCH query using the xGetAuxdata() API.
11280**
11281** Each extension function is allocated a single auxiliary data slot for
11282** each FTS query (MATCH expression). If the extension function is invoked
11283** more than once for a single FTS query, then all invocations share a
11284** single auxiliary data context.
11285**
11286** If there is already an auxiliary data pointer when this function is
11287** invoked, then it is replaced by the new pointer. If an xDelete callback
11288** was specified along with the original pointer, it is invoked at this
11289** point.
11290**
11291** The xDelete callback, if one is specified, is also invoked on the
11292** auxiliary data pointer after the FTS5 query has finished.
11293**
11294** If an error (e.g. an OOM condition) occurs within this function, an
11295** the auxiliary data is set to NULL and an error code returned. If the
11296** xDelete parameter was not NULL, it is invoked on the auxiliary data
11297** pointer before returning.
11298**
11299**
11300** xGetAuxdata(pFts5, bClear)
11301**
11302** Returns the current auxiliary data pointer for the fts5 extension
11303** function. See the xSetAuxdata() method for details.
11304**
11305** If the bClear argument is non-zero, then the auxiliary data is cleared
11306** (set to NULL) before this function returns. In this case the xDelete,
11307** if any, is not invoked.
11308**
11309**
11310** xRowCount(pFts5, pnRow)
11311**
11312** This function is used to retrieve the total number of rows in the table.
11313** In other words, the same value that would be returned by:
11314**
11315** SELECT count(*) FROM ftstable;
11316**
11317** xPhraseFirst()
11318** This function is used, along with type Fts5PhraseIter and the xPhraseNext
11319** method, to iterate through all instances of a single query phrase within
11320** the current row. This is the same information as is accessible via the
11321** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
11322** to use, this API may be faster under some circumstances. To iterate
11323** through instances of phrase iPhrase, use the following code:
11324**
11325** Fts5PhraseIter iter;
11326** int iCol, iOff;
11327** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
11328** iCol>=0;
11329** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
11330** ){
11331** // An instance of phrase iPhrase at offset iOff of column iCol
11332** }
11333**
11334** The Fts5PhraseIter structure is defined above. Applications should not
11335** modify this structure directly - it should only be used as shown above
11336** with the xPhraseFirst() and xPhraseNext() API methods (and by
11337** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
11338**
11339** This API can be quite slow if used with an FTS5 table created with the
11340** "detail=none" or "detail=column" option. If the FTS5 table is created
11341** with either "detail=none" or "detail=column" and "content=" option
11342** (i.e. if it is a contentless table), then this API always iterates
11343** through an empty set (all calls to xPhraseFirst() set iCol to -1).
11344**
11345** xPhraseNext()
11346** See xPhraseFirst above.
11347**
11348** xPhraseFirstColumn()
11349** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
11350** and xPhraseNext() APIs described above. The difference is that instead
11351** of iterating through all instances of a phrase in the current row, these
11352** APIs are used to iterate through the set of columns in the current row
11353** that contain one or more instances of a specified phrase. For example:
11354**
11355** Fts5PhraseIter iter;
11356** int iCol;
11357** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
11358** iCol>=0;
11359** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
11360** ){
11361** // Column iCol contains at least one instance of phrase iPhrase
11362** }
11363**
11364** This API can be quite slow if used with an FTS5 table created with the
11365** "detail=none" option. If the FTS5 table is created with either
11366** "detail=none" "content=" option (i.e. if it is a contentless table),
11367** then this API always iterates through an empty set (all calls to
11368** xPhraseFirstColumn() set iCol to -1).
11369**
11370** The information accessed using this API and its companion
11371** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
11372** (or xInst/xInstCount). The chief advantage of this API is that it is
11373** significantly more efficient than those alternatives when used with
11374** "detail=column" tables.
11375**
11376** xPhraseNextColumn()
11377** See xPhraseFirstColumn above.
11378*/
11379struct Fts5ExtensionApi {
11380 int iVersion; /* Currently always set to 3 */
11381
11382 void *(*xUserData)(Fts5Context*);
11383
11384 int (*xColumnCount)(Fts5Context*);
11385 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
11386 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
11387
11388 int (*xTokenize)(Fts5Context*,
11389 const char *pText, int nText, /* Text to tokenize */
11390 void *pCtx, /* Context passed to xToken() */
11391 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
11392 );
11393
11394 int (*xPhraseCount)(Fts5Context*);
11395 int (*xPhraseSize)(Fts5Context*, int iPhrase);
11396
11397 int (*xInstCount)(Fts5Context*, int *pnInst);
11398 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
11399
11400 sqlite3_int64 (*xRowid)(Fts5Context*);
11401 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
11402 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
11403
11404 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
11405 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
11406 );
11407 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
11408 void *(*xGetAuxdata)(Fts5Context*, int bClear);
11409
11410 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
11411 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
11412
11413 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
11414 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
11415};
11416
11417/*
11418** CUSTOM AUXILIARY FUNCTIONS
11419*************************************************************************/
11420
11421/*************************************************************************
11422** CUSTOM TOKENIZERS
11423**
11424** Applications may also register custom tokenizer types. A tokenizer
11425** is registered by providing fts5 with a populated instance of the
11426** following structure. All structure methods must be defined, setting
11427** any member of the fts5_tokenizer struct to NULL leads to undefined
11428** behaviour. The structure methods are expected to function as follows:
11429**
11430** xCreate:
11431** This function is used to allocate and initialize a tokenizer instance.
11432** A tokenizer instance is required to actually tokenize text.
11433**
11434** The first argument passed to this function is a copy of the (void*)
11435** pointer provided by the application when the fts5_tokenizer object
11436** was registered with FTS5 (the third argument to xCreateTokenizer()).
11437** The second and third arguments are an array of nul-terminated strings
11438** containing the tokenizer arguments, if any, specified following the
11439** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
11440** to create the FTS5 table.
11441**
11442** The final argument is an output variable. If successful, (*ppOut)
11443** should be set to point to the new tokenizer handle and SQLITE_OK
11444** returned. If an error occurs, some value other than SQLITE_OK should
11445** be returned. In this case, fts5 assumes that the final value of *ppOut
11446** is undefined.
11447**
11448** xDelete:
11449** This function is invoked to delete a tokenizer handle previously
11450** allocated using xCreate(). Fts5 guarantees that this function will
11451** be invoked exactly once for each successful call to xCreate().
11452**
11453** xTokenize:
11454** This function is expected to tokenize the nText byte string indicated
11455** by argument pText. pText may or may not be nul-terminated. The first
11456** argument passed to this function is a pointer to an Fts5Tokenizer object
11457** returned by an earlier call to xCreate().
11458**
11459** The second argument indicates the reason that FTS5 is requesting
11460** tokenization of the supplied text. This is always one of the following
11461** four values:
11462**
11463** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
11464** or removed from the FTS table. The tokenizer is being invoked to
11465** determine the set of tokens to add to (or delete from) the
11466** FTS index.
11467**
11468** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
11469** against the FTS index. The tokenizer is being called to tokenize
11470** a bareword or quoted string specified as part of the query.
11471**
11472** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
11473** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
11474** followed by a "*" character, indicating that the last token
11475** returned by the tokenizer will be treated as a token prefix.
11476**
11477** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
11478** satisfy an fts5_api.xTokenize() request made by an auxiliary
11479** function. Or an fts5_api.xColumnSize() request made by the same
11480** on a columnsize=0 database.
11481** </ul>
11482**
11483** For each token in the input string, the supplied callback xToken() must
11484** be invoked. The first argument to it should be a copy of the pointer
11485** passed as the second argument to xTokenize(). The third and fourth
11486** arguments are a pointer to a buffer containing the token text, and the
11487** size of the token in bytes. The 4th and 5th arguments are the byte offsets
11488** of the first byte of and first byte immediately following the text from
11489** which the token is derived within the input.
11490**
11491** The second argument passed to the xToken() callback ("tflags") should
11492** normally be set to 0. The exception is if the tokenizer supports
11493** synonyms. In this case see the discussion below for details.
11494**
11495** FTS5 assumes the xToken() callback is invoked for each token in the
11496** order that they occur within the input text.
11497**
11498** If an xToken() callback returns any value other than SQLITE_OK, then
11499** the tokenization should be abandoned and the xTokenize() method should
11500** immediately return a copy of the xToken() return value. Or, if the
11501** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
11502** if an error occurs with the xTokenize() implementation itself, it
11503** may abandon the tokenization and return any error code other than
11504** SQLITE_OK or SQLITE_DONE.
11505**
11506** SYNONYM SUPPORT
11507**
11508** Custom tokenizers may also support synonyms. Consider a case in which a
11509** user wishes to query for a phrase such as "first place". Using the
11510** built-in tokenizers, the FTS5 query 'first + place' will match instances
11511** of "first place" within the document set, but not alternative forms
11512** such as "1st place". In some applications, it would be better to match
11513** all instances of "first place" or "1st place" regardless of which form
11514** the user specified in the MATCH query text.
11515**
11516** There are several ways to approach this in FTS5:
11517**
11518** <ol><li> By mapping all synonyms to a single token. In this case, the
11519** In the above example, this means that the tokenizer returns the
11520** same token for inputs "first" and "1st". Say that token is in
11521** fact "first", so that when the user inserts the document "I won
11522** 1st place" entries are added to the index for tokens "i", "won",
11523** "first" and "place". If the user then queries for '1st + place',
11524** the tokenizer substitutes "first" for "1st" and the query works
11525** as expected.
11526**
11527** <li> By adding multiple synonyms for a single term to the FTS index.
11528** In this case, when tokenizing query text, the tokenizer may
11529** provide multiple synonyms for a single term within the document.
11530** FTS5 then queries the index for each synonym individually. For
11531** example, faced with the query:
11532**
11533** <codeblock>
11534** ... MATCH 'first place'</codeblock>
11535**
11536** the tokenizer offers both "1st" and "first" as synonyms for the
11537** first token in the MATCH query and FTS5 effectively runs a query
11538** similar to:
11539**
11540** <codeblock>
11541** ... MATCH '(first OR 1st) place'</codeblock>
11542**
11543** except that, for the purposes of auxiliary functions, the query
11544** still appears to contain just two phrases - "(first OR 1st)"
11545** being treated as a single phrase.
11546**
11547** <li> By adding multiple synonyms for a single term to the FTS index.
11548** Using this method, when tokenizing document text, the tokenizer
11549** provides multiple synonyms for each token. So that when a
11550** document such as "I won first place" is tokenized, entries are
11551** added to the FTS index for "i", "won", "first", "1st" and
11552** "place".
11553**
11554** This way, even if the tokenizer does not provide synonyms
11555** when tokenizing query text (it should not - to do would be
11556** inefficient), it doesn't matter if the user queries for
11557** 'first + place' or '1st + place', as there are entries in the
11558** FTS index corresponding to both forms of the first token.
11559** </ol>
11560**
11561** Whether it is parsing document or query text, any call to xToken that
11562** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
11563** is considered to supply a synonym for the previous token. For example,
11564** when parsing the document "I won first place", a tokenizer that supports
11565** synonyms would call xToken() 5 times, as follows:
11566**
11567** <codeblock>
11568** xToken(pCtx, 0, "i", 1, 0, 1);
11569** xToken(pCtx, 0, "won", 3, 2, 5);
11570** xToken(pCtx, 0, "first", 5, 6, 11);
11571** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
11572** xToken(pCtx, 0, "place", 5, 12, 17);
11573**</codeblock>
11574**
11575** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
11576** xToken() is called. Multiple synonyms may be specified for a single token
11577** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
11578** There is no limit to the number of synonyms that may be provided for a
11579** single token.
11580**
11581** In many cases, method (1) above is the best approach. It does not add
11582** extra data to the FTS index or require FTS5 to query for multiple terms,
11583** so it is efficient in terms of disk space and query speed. However, it
11584** does not support prefix queries very well. If, as suggested above, the
11585** token "first" is substituted for "1st" by the tokenizer, then the query:
11586**
11587** <codeblock>
11588** ... MATCH '1s*'</codeblock>
11589**
11590** will not match documents that contain the token "1st" (as the tokenizer
11591** will probably not map "1s" to any prefix of "first").
11592**
11593** For full prefix support, method (3) may be preferred. In this case,
11594** because the index contains entries for both "first" and "1st", prefix
11595** queries such as 'fi*' or '1s*' will match correctly. However, because
11596** extra entries are added to the FTS index, this method uses more space
11597** within the database.
11598**
11599** Method (2) offers a midpoint between (1) and (3). Using this method,
11600** a query such as '1s*' will match documents that contain the literal
11601** token "1st", but not "first" (assuming the tokenizer is not able to
11602** provide synonyms for prefixes). However, a non-prefix query like '1st'
11603** will match against "1st" and "first". This method does not require
11604** extra disk space, as no extra entries are added to the FTS index.
11605** On the other hand, it may require more CPU cycles to run MATCH queries,
11606** as separate queries of the FTS index are required for each synonym.
11607**
11608** When using methods (2) or (3), it is important that the tokenizer only
11609** provide synonyms when tokenizing document text (method (2)) or query
11610** text (method (3)), not both. Doing so will not cause any errors, but is
11611** inefficient.
11612*/
11613typedef struct Fts5Tokenizer Fts5Tokenizer;
11614typedef struct fts5_tokenizer fts5_tokenizer;
11615struct fts5_tokenizer {
11616 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
11617 void (*xDelete)(Fts5Tokenizer*);
11618 int (*xTokenize)(Fts5Tokenizer*,
11619 void *pCtx,
11620 int flags, /* Mask of FTS5_TOKENIZE_* flags */
11621 const char *pText, int nText,
11622 int (*xToken)(
11623 void *pCtx, /* Copy of 2nd argument to xTokenize() */
11624 int tflags, /* Mask of FTS5_TOKEN_* flags */
11625 const char *pToken, /* Pointer to buffer containing token */
11626 int nToken, /* Size of token in bytes */
11627 int iStart, /* Byte offset of token within input text */
11628 int iEnd /* Byte offset of end of token within input text */
11629 )
11630 );
11631};
11632
11633/* Flags that may be passed as the third argument to xTokenize() */
11634#define FTS5_TOKENIZE_QUERY 0x0001
11635#define FTS5_TOKENIZE_PREFIX 0x0002
11636#define FTS5_TOKENIZE_DOCUMENT 0x0004
11637#define FTS5_TOKENIZE_AUX 0x0008
11638
11639/* Flags that may be passed by the tokenizer implementation back to FTS5
11640** as the third argument to the supplied xToken callback. */
11641#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
11642
11643/*
11644** END OF CUSTOM TOKENIZERS
11645*************************************************************************/
11646
11647/*************************************************************************
11648** FTS5 EXTENSION REGISTRATION API
11649*/
11650typedef struct fts5_api fts5_api;
11651struct fts5_api {
11652 int iVersion; /* Currently always set to 2 */
11653
11654 /* Create a new tokenizer */
11655 int (*xCreateTokenizer)(
11656 fts5_api *pApi,
11657 const char *zName,
11658 void *pContext,
11659 fts5_tokenizer *pTokenizer,
11660 void (*xDestroy)(void*)
11661 );
11662
11663 /* Find an existing tokenizer */
11664 int (*xFindTokenizer)(
11665 fts5_api *pApi,
11666 const char *zName,
11667 void **ppContext,
11668 fts5_tokenizer *pTokenizer
11669 );
11670
11671 /* Create a new auxiliary function */
11672 int (*xCreateFunction)(
11673 fts5_api *pApi,
11674 const char *zName,
11675 void *pContext,
11676 fts5_extension_function xFunction,
11677 void (*xDestroy)(void*)
11678 );
11679};
11680
11681/*
11682** END OF REGISTRATION API
11683*************************************************************************/
11684
11685#ifdef __cplusplus
11686} /* end of the 'extern "C"' block */
11687#endif
11688
11689#endif /* _FTS5_H */
11690
11691/******** End of fts5.h *********/
11692