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 "--VERS--" 127#define SQLITE_VERSION_NUMBER --VERSION-NUMBER-- 128#define SQLITE_SOURCE_ID "--SOURCE-ID--" 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_EXTERN const char sqlite3_version[]; 163const char *sqlite3_libversion(void); 164const char *sqlite3_sourceid(void); 165int 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 190int sqlite3_compileoption_used(const char *zOptName); 191const char *sqlite3_compileoption_get(int N); 192#else 193# define sqlite3_compileoption_used(X) 0 194# define sqlite3_compileoption_get(X) ((void*)0) 195#endif 196 197/* 198** CAPI3REF: Test To See If The Library Is Threadsafe 199** 200** ^The sqlite3_threadsafe() function returns zero if and only if 201** SQLite was compiled with mutexing code omitted due to the 202** [SQLITE_THREADSAFE] compile-time option being set to 0. 203** 204** SQLite can be compiled with or without mutexes. When 205** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 206** are enabled and SQLite is threadsafe. When the 207** [SQLITE_THREADSAFE] macro is 0, 208** the mutexes are omitted. Without the mutexes, it is not safe 209** to use SQLite concurrently from more than one thread. 210** 211** Enabling mutexes incurs a measurable performance penalty. 212** So if speed is of utmost importance, it makes sense to disable 213** the mutexes. But for maximum safety, mutexes should be enabled. 214** ^The default behavior is for mutexes to be enabled. 215** 216** This interface can be used by an application to make sure that the 217** version of SQLite that it is linking against was compiled with 218** the desired setting of the [SQLITE_THREADSAFE] macro. 219** 220** This interface only reports on the compile-time mutex setting 221** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 222** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 223** can be fully or partially disabled using a call to [sqlite3_config()] 224** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 225** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the 226** sqlite3_threadsafe() function shows only the compile-time setting of 227** thread safety, not any run-time changes to that setting made by 228** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 229** is unchanged by calls to sqlite3_config().)^ 230** 231** See the [threading mode] documentation for additional information. 232*/ 233int sqlite3_threadsafe(void); 234 235/* 236** CAPI3REF: Database Connection Handle 237** KEYWORDS: {database connection} {database connections} 238** 239** Each open SQLite database is represented by a pointer to an instance of 240** the opaque structure named "sqlite3". It is useful to think of an sqlite3 241** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 242** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 243** and [sqlite3_close_v2()] are its destructors. There are many other 244** interfaces (such as 245** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 246** [sqlite3_busy_timeout()] to name but three) that are methods on an 247** sqlite3 object. 248*/ 249typedef struct sqlite3 sqlite3; 250 251/* 252** CAPI3REF: 64-Bit Integer Types 253** KEYWORDS: sqlite_int64 sqlite_uint64 254** 255** Because there is no cross-platform way to specify 64-bit integer types 256** SQLite includes typedefs for 64-bit signed and unsigned integers. 257** 258** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 259** The sqlite_int64 and sqlite_uint64 types are supported for backwards 260** compatibility only. 261** 262** ^The sqlite3_int64 and sqlite_int64 types can store integer values 263** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 264** sqlite3_uint64 and sqlite_uint64 types can store integer values 265** between 0 and +18446744073709551615 inclusive. 266*/ 267#ifdef SQLITE_INT64_TYPE 268 typedef SQLITE_INT64_TYPE sqlite_int64; 269# ifdef SQLITE_UINT64_TYPE 270 typedef SQLITE_UINT64_TYPE sqlite_uint64; 271# else 272 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 273# endif 274#elif defined(_MSC_VER) || defined(__BORLANDC__) 275 typedef __int64 sqlite_int64; 276 typedef unsigned __int64 sqlite_uint64; 277#else 278 typedef long long int sqlite_int64; 279 typedef unsigned long long int sqlite_uint64; 280#endif 281typedef sqlite_int64 sqlite3_int64; 282typedef sqlite_uint64 sqlite3_uint64; 283 284/* 285** If compiling for a processor that lacks floating point support, 286** substitute integer for floating-point. 287*/ 288#ifdef SQLITE_OMIT_FLOATING_POINT 289# define double sqlite3_int64 290#endif 291 292/* 293** CAPI3REF: Closing A Database Connection 294** DESTRUCTOR: sqlite3 295** 296** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 297** for the [sqlite3] object. 298** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 299** the [sqlite3] object is successfully destroyed and all associated 300** resources are deallocated. 301** 302** ^If the database connection is associated with unfinalized prepared 303** statements or unfinished sqlite3_backup objects then sqlite3_close() 304** will leave the database connection open and return [SQLITE_BUSY]. 305** ^If sqlite3_close_v2() is called with unfinalized prepared statements 306** and/or unfinished sqlite3_backups, then the database connection becomes 307** an unusable "zombie" which will automatically be deallocated when the 308** last prepared statement is finalized or the last sqlite3_backup is 309** finished. The sqlite3_close_v2() interface is intended for use with 310** host languages that are garbage collected, and where the order in which 311** destructors are called is arbitrary. 312** 313** Applications should [sqlite3_finalize | finalize] all [prepared statements], 314** [sqlite3_blob_close | close] all [BLOB handles], and 315** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 316** with the [sqlite3] object prior to attempting to close the object. ^If 317** sqlite3_close_v2() is called on a [database connection] that still has 318** outstanding [prepared statements], [BLOB handles], and/or 319** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 320** of resources is deferred until all [prepared statements], [BLOB handles], 321** and [sqlite3_backup] objects are also destroyed. 322** 323** ^If an [sqlite3] object is destroyed while a transaction is open, 324** the transaction is automatically rolled back. 325** 326** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 327** must be either a NULL 328** pointer or an [sqlite3] object pointer obtained 329** from [sqlite3_open()], [sqlite3_open16()], or 330** [sqlite3_open_v2()], and not previously closed. 331** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 332** argument is a harmless no-op. 333*/ 334int sqlite3_close(sqlite3*); 335int sqlite3_close_v2(sqlite3*); 336 337/* 338** The type for a callback function. 339** This is legacy and deprecated. It is included for historical 340** compatibility and is not documented. 341*/ 342typedef int (*sqlite3_callback)(void*,int,char**, char**); 343 344/* 345** CAPI3REF: One-Step Query Execution Interface 346** METHOD: sqlite3 347** 348** The sqlite3_exec() interface is a convenience wrapper around 349** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 350** that allows an application to run multiple statements of SQL 351** without having to use a lot of C code. 352** 353** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 354** semicolon-separate SQL statements passed into its 2nd argument, 355** in the context of the [database connection] passed in as its 1st 356** argument. ^If the callback function of the 3rd argument to 357** sqlite3_exec() is not NULL, then it is invoked for each result row 358** coming out of the evaluated SQL statements. ^The 4th argument to 359** sqlite3_exec() is relayed through to the 1st argument of each 360** callback invocation. ^If the callback pointer to sqlite3_exec() 361** is NULL, then no callback is ever invoked and result rows are 362** ignored. 363** 364** ^If an error occurs while evaluating the SQL statements passed into 365** sqlite3_exec(), then execution of the current statement stops and 366** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 367** is not NULL then any error message is written into memory obtained 368** from [sqlite3_malloc()] and passed back through the 5th parameter. 369** To avoid memory leaks, the application should invoke [sqlite3_free()] 370** on error message strings returned through the 5th parameter of 371** sqlite3_exec() after the error message string is no longer needed. 372** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 373** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 374** NULL before returning. 375** 376** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 377** routine returns SQLITE_ABORT without invoking the callback again and 378** without running any subsequent SQL statements. 379** 380** ^The 2nd argument to the sqlite3_exec() callback function is the 381** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 382** callback is an array of pointers to strings obtained as if from 383** [sqlite3_column_text()], one for each column. ^If an element of a 384** result row is NULL then the corresponding string pointer for the 385** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 386** sqlite3_exec() callback is an array of pointers to strings where each 387** entry represents the name of corresponding result column as obtained 388** from [sqlite3_column_name()]. 389** 390** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 391** to an empty string, or a pointer that contains only whitespace and/or 392** SQL comments, then no SQL statements are evaluated and the database 393** is not changed. 394** 395** Restrictions: 396** 397** <ul> 398** <li> The application must ensure that the 1st parameter to sqlite3_exec() 399** is a valid and open [database connection]. 400** <li> The application must not close the [database connection] specified by 401** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 402** <li> The application must not modify the SQL statement text passed into 403** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 404** </ul> 405*/ 406int sqlite3_exec( 407 sqlite3*, /* An open database */ 408 const char *sql, /* SQL to be evaluated */ 409 int (*callback)(void*,int,char**,char**), /* Callback function */ 410 void *, /* 1st argument to callback */ 411 char **errmsg /* Error msg written here */ 412); 413 414/* 415** CAPI3REF: Result Codes 416** KEYWORDS: {result code definitions} 417** 418** Many SQLite functions return an integer result code from the set shown 419** here in order to indicate success or failure. 420** 421** New error codes may be added in future versions of SQLite. 422** 423** See also: [extended result code definitions] 424*/ 425#define SQLITE_OK 0 /* Successful result */ 426/* beginning-of-error-codes */ 427#define SQLITE_ERROR 1 /* Generic error */ 428#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 429#define SQLITE_PERM 3 /* Access permission denied */ 430#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 431#define SQLITE_BUSY 5 /* The database file is locked */ 432#define SQLITE_LOCKED 6 /* A table in the database is locked */ 433#define SQLITE_NOMEM 7 /* A malloc() failed */ 434#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 435#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 436#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 437#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 438#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 439#define SQLITE_FULL 13 /* Insertion failed because database is full */ 440#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 441#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 442#define SQLITE_EMPTY 16 /* Internal use only */ 443#define SQLITE_SCHEMA 17 /* The database schema changed */ 444#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 445#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 446#define SQLITE_MISMATCH 20 /* Data type mismatch */ 447#define SQLITE_MISUSE 21 /* Library used incorrectly */ 448#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 449#define SQLITE_AUTH 23 /* Authorization denied */ 450#define SQLITE_FORMAT 24 /* Not used */ 451#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 452#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 453#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 454#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 455#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 456#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 457/* end-of-error-codes */ 458 459/* 460** CAPI3REF: Extended Result Codes 461** KEYWORDS: {extended result code definitions} 462** 463** In its default configuration, SQLite API routines return one of 30 integer 464** [result codes]. However, experience has shown that many of 465** these result codes are too coarse-grained. They do not provide as 466** much information about problems as programmers might like. In an effort to 467** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8] 468** and later) include 469** support for additional result codes that provide more detailed information 470** about errors. These [extended result codes] are enabled or disabled 471** on a per database connection basis using the 472** [sqlite3_extended_result_codes()] API. Or, the extended code for 473** the most recent error can be obtained using 474** [sqlite3_extended_errcode()]. 475*/ 476#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8)) 477#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8)) 478#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8)) 479#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 480#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 481#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 482#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 483#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 484#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 485#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 486#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 487#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 488#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 489#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 490#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 491#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 492#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 493#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 494#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 495#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 496#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 497#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 498#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 499#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 500#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 501#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 502#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 503#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 504#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 505#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8)) 506#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8)) 507#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8)) 508#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8)) 509#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8)) 510#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 511#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8)) 512#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 513#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 514#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 515#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 516#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 517#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 518#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */ 519#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 520#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 521#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 522#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 523#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 524#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 525#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 526#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 527#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 528#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 529#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 530#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 531#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 532#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 533#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 534#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 535#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 536#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 537#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 538#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 539#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 540#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 541#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 542#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 543 544/* 545** CAPI3REF: Flags For File Open Operations 546** 547** These bit values are intended for use in the 548** 3rd parameter to the [sqlite3_open_v2()] interface and 549** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 550*/ 551#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 552#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 553#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 554#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 555#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 556#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 557#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 558#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 559#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 560#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 561#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 562#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 563#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 564#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 565#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 566#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 567#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 568#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 569#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 570#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 571 572/* Reserved: 0x00F00000 */ 573 574/* 575** CAPI3REF: Device Characteristics 576** 577** The xDeviceCharacteristics method of the [sqlite3_io_methods] 578** object returns an integer which is a vector of these 579** bit values expressing I/O characteristics of the mass storage 580** device that holds the file that the [sqlite3_io_methods] 581** refers to. 582** 583** The SQLITE_IOCAP_ATOMIC property means that all writes of 584** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 585** mean that writes of blocks that are nnn bytes in size and 586** are aligned to an address which is an integer multiple of 587** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 588** that when data is appended to a file, the data is appended 589** first then the size of the file is extended, never the other 590** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 591** information is written to disk in the same order as calls 592** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 593** after reboot following a crash or power loss, the only bytes in a 594** file that were written at the application level might have changed 595** and that adjacent bytes, even bytes within the same sector are 596** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 597** flag indicates that a file cannot be deleted when open. The 598** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 599** read-only media and cannot be changed even by processes with 600** elevated privileges. 601** 602** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 603** filesystem supports doing multiple write operations atomically when those 604** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 605** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 606*/ 607#define SQLITE_IOCAP_ATOMIC 0x00000001 608#define SQLITE_IOCAP_ATOMIC512 0x00000002 609#define SQLITE_IOCAP_ATOMIC1K 0x00000004 610#define SQLITE_IOCAP_ATOMIC2K 0x00000008 611#define SQLITE_IOCAP_ATOMIC4K 0x00000010 612#define SQLITE_IOCAP_ATOMIC8K 0x00000020 613#define SQLITE_IOCAP_ATOMIC16K 0x00000040 614#define SQLITE_IOCAP_ATOMIC32K 0x00000080 615#define SQLITE_IOCAP_ATOMIC64K 0x00000100 616#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 617#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 618#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 619#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 620#define SQLITE_IOCAP_IMMUTABLE 0x00002000 621#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 622 623/* 624** CAPI3REF: File Locking Levels 625** 626** SQLite uses one of these integer values as the second 627** argument to calls it makes to the xLock() and xUnlock() methods 628** of an [sqlite3_io_methods] object. 629*/ 630#define SQLITE_LOCK_NONE 0 631#define SQLITE_LOCK_SHARED 1 632#define SQLITE_LOCK_RESERVED 2 633#define SQLITE_LOCK_PENDING 3 634#define SQLITE_LOCK_EXCLUSIVE 4 635 636/* 637** CAPI3REF: Synchronization Type Flags 638** 639** When SQLite invokes the xSync() method of an 640** [sqlite3_io_methods] object it uses a combination of 641** these integer values as the second argument. 642** 643** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 644** sync operation only needs to flush data to mass storage. Inode 645** information need not be flushed. If the lower four bits of the flag 646** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 647** If the lower four bits equal SQLITE_SYNC_FULL, that means 648** to use Mac OS X style fullsync instead of fsync(). 649** 650** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 651** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 652** settings. The [synchronous pragma] determines when calls to the 653** xSync VFS method occur and applies uniformly across all platforms. 654** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 655** energetic or rigorous or forceful the sync operations are and 656** only make a difference on Mac OSX for the default SQLite code. 657** (Third-party VFS implementations might also make the distinction 658** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 659** operating systems natively supported by SQLite, only Mac OSX 660** cares about the difference.) 661*/ 662#define SQLITE_SYNC_NORMAL 0x00002 663#define SQLITE_SYNC_FULL 0x00003 664#define SQLITE_SYNC_DATAONLY 0x00010 665 666/* 667** CAPI3REF: OS Interface Open File Handle 668** 669** An [sqlite3_file] object represents an open file in the 670** [sqlite3_vfs | OS interface layer]. Individual OS interface 671** implementations will 672** want to subclass this object by appending additional fields 673** for their own use. The pMethods entry is a pointer to an 674** [sqlite3_io_methods] object that defines methods for performing 675** I/O operations on the open file. 676*/ 677typedef struct sqlite3_file sqlite3_file; 678struct sqlite3_file { 679 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 680}; 681 682/* 683** CAPI3REF: OS Interface File Virtual Methods Object 684** 685** Every file opened by the [sqlite3_vfs.xOpen] method populates an 686** [sqlite3_file] object (or, more commonly, a subclass of the 687** [sqlite3_file] object) with a pointer to an instance of this object. 688** This object defines the methods used to perform various operations 689** against the open file represented by the [sqlite3_file] object. 690** 691** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 692** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 693** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 694** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 695** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 696** to NULL. 697** 698** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 699** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 700** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 701** flag may be ORed in to indicate that only the data of the file 702** and not its inode needs to be synced. 703** 704** The integer values to xLock() and xUnlock() are one of 705** <ul> 706** <li> [SQLITE_LOCK_NONE], 707** <li> [SQLITE_LOCK_SHARED], 708** <li> [SQLITE_LOCK_RESERVED], 709** <li> [SQLITE_LOCK_PENDING], or 710** <li> [SQLITE_LOCK_EXCLUSIVE]. 711** </ul> 712** xLock() increases the lock. xUnlock() decreases the lock. 713** The xCheckReservedLock() method checks whether any database connection, 714** either in this process or in some other process, is holding a RESERVED, 715** PENDING, or EXCLUSIVE lock on the file. It returns true 716** if such a lock exists and false otherwise. 717** 718** The xFileControl() method is a generic interface that allows custom 719** VFS implementations to directly control an open file using the 720** [sqlite3_file_control()] interface. The second "op" argument is an 721** integer opcode. The third argument is a generic pointer intended to 722** point to a structure that may contain arguments or space in which to 723** write return values. Potential uses for xFileControl() might be 724** functions to enable blocking locks with timeouts, to change the 725** locking strategy (for example to use dot-file locks), to inquire 726** about the status of a lock, or to break stale locks. The SQLite 727** core reserves all opcodes less than 100 for its own use. 728** A [file control opcodes | list of opcodes] less than 100 is available. 729** Applications that define a custom xFileControl method should use opcodes 730** greater than 100 to avoid conflicts. VFS implementations should 731** return [SQLITE_NOTFOUND] for file control opcodes that they do not 732** recognize. 733** 734** The xSectorSize() method returns the sector size of the 735** device that underlies the file. The sector size is the 736** minimum write that can be performed without disturbing 737** other bytes in the file. The xDeviceCharacteristics() 738** method returns a bit vector describing behaviors of the 739** underlying device: 740** 741** <ul> 742** <li> [SQLITE_IOCAP_ATOMIC] 743** <li> [SQLITE_IOCAP_ATOMIC512] 744** <li> [SQLITE_IOCAP_ATOMIC1K] 745** <li> [SQLITE_IOCAP_ATOMIC2K] 746** <li> [SQLITE_IOCAP_ATOMIC4K] 747** <li> [SQLITE_IOCAP_ATOMIC8K] 748** <li> [SQLITE_IOCAP_ATOMIC16K] 749** <li> [SQLITE_IOCAP_ATOMIC32K] 750** <li> [SQLITE_IOCAP_ATOMIC64K] 751** <li> [SQLITE_IOCAP_SAFE_APPEND] 752** <li> [SQLITE_IOCAP_SEQUENTIAL] 753** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 754** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 755** <li> [SQLITE_IOCAP_IMMUTABLE] 756** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 757** </ul> 758** 759** The SQLITE_IOCAP_ATOMIC property means that all writes of 760** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 761** mean that writes of blocks that are nnn bytes in size and 762** are aligned to an address which is an integer multiple of 763** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 764** that when data is appended to a file, the data is appended 765** first then the size of the file is extended, never the other 766** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 767** information is written to disk in the same order as calls 768** to xWrite(). 769** 770** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 771** in the unread portions of the buffer with zeros. A VFS that 772** fails to zero-fill short reads might seem to work. However, 773** failure to zero-fill short reads will eventually lead to 774** database corruption. 775*/ 776typedef struct sqlite3_io_methods sqlite3_io_methods; 777struct sqlite3_io_methods { 778 int iVersion; 779 int (*xClose)(sqlite3_file*); 780 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 781 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 782 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 783 int (*xSync)(sqlite3_file*, int flags); 784 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 785 int (*xLock)(sqlite3_file*, int); 786 int (*xUnlock)(sqlite3_file*, int); 787 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 788 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 789 int (*xSectorSize)(sqlite3_file*); 790 int (*xDeviceCharacteristics)(sqlite3_file*); 791 /* Methods above are valid for version 1 */ 792 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 793 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 794 void (*xShmBarrier)(sqlite3_file*); 795 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 796 /* Methods above are valid for version 2 */ 797 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 798 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 799 /* Methods above are valid for version 3 */ 800 /* Additional methods may be added in future releases */ 801}; 802 803/* 804** CAPI3REF: Standard File Control Opcodes 805** KEYWORDS: {file control opcodes} {file control opcode} 806** 807** These integer constants are opcodes for the xFileControl method 808** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 809** interface. 810** 811** <ul> 812** <li>[[SQLITE_FCNTL_LOCKSTATE]] 813** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 814** opcode causes the xFileControl method to write the current state of 815** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 816** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 817** into an integer that the pArg argument points to. This capability 818** is used during testing and is only available when the SQLITE_TEST 819** compile-time option is used. 820** 821** <li>[[SQLITE_FCNTL_SIZE_HINT]] 822** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 823** layer a hint of how large the database file will grow to be during the 824** current transaction. This hint is not guaranteed to be accurate but it 825** is often close. The underlying VFS might choose to preallocate database 826** file space based on this hint in order to help writes to the database 827** file run faster. 828** 829** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 830** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 831** implements [sqlite3_deserialize()] to set an upper bound on the size 832** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 833** If the integer pointed to is negative, then it is filled in with the 834** current limit. Otherwise the limit is set to the larger of the value 835** of the integer pointed to and the current database size. The integer 836** pointed to is set to the new limit. 837** 838** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 839** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 840** extends and truncates the database file in chunks of a size specified 841** by the user. The fourth argument to [sqlite3_file_control()] should 842** point to an integer (type int) containing the new chunk-size to use 843** for the nominated database. Allocating database file space in large 844** chunks (say 1MB at a time), may reduce file-system fragmentation and 845** improve performance on some systems. 846** 847** <li>[[SQLITE_FCNTL_FILE_POINTER]] 848** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 849** to the [sqlite3_file] object associated with a particular database 850** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 851** 852** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 853** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 854** to the [sqlite3_file] object associated with the journal file (either 855** the [rollback journal] or the [write-ahead log]) for a particular database 856** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 857** 858** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 859** No longer in use. 860** 861** <li>[[SQLITE_FCNTL_SYNC]] 862** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 863** sent to the VFS immediately before the xSync method is invoked on a 864** database file descriptor. Or, if the xSync method is not invoked 865** because the user has configured SQLite with 866** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 867** of the xSync method. In most cases, the pointer argument passed with 868** this file-control is NULL. However, if the database file is being synced 869** as part of a multi-database commit, the argument points to a nul-terminated 870** string containing the transactions master-journal file name. VFSes that 871** do not need this signal should silently ignore this opcode. Applications 872** should not call [sqlite3_file_control()] with this opcode as doing so may 873** disrupt the operation of the specialized VFSes that do require it. 874** 875** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 876** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 877** and sent to the VFS after a transaction has been committed immediately 878** but before the database is unlocked. VFSes that do not need this signal 879** should silently ignore this opcode. Applications should not call 880** [sqlite3_file_control()] with this opcode as doing so may disrupt the 881** operation of the specialized VFSes that do require it. 882** 883** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 884** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 885** retry counts and intervals for certain disk I/O operations for the 886** windows [VFS] in order to provide robustness in the presence of 887** anti-virus programs. By default, the windows VFS will retry file read, 888** file write, and file delete operations up to 10 times, with a delay 889** of 25 milliseconds before the first retry and with the delay increasing 890** by an additional 25 milliseconds with each subsequent retry. This 891** opcode allows these two values (10 retries and 25 milliseconds of delay) 892** to be adjusted. The values are changed for all database connections 893** within the same process. The argument is a pointer to an array of two 894** integers where the first integer is the new retry count and the second 895** integer is the delay. If either integer is negative, then the setting 896** is not changed but instead the prior value of that setting is written 897** into the array entry, allowing the current retry settings to be 898** interrogated. The zDbName parameter is ignored. 899** 900** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 901** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 902** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 903** write ahead log ([WAL file]) and shared memory 904** files used for transaction control 905** are automatically deleted when the latest connection to the database 906** closes. Setting persistent WAL mode causes those files to persist after 907** close. Persisting the files is useful when other processes that do not 908** have write permission on the directory containing the database file want 909** to read the database file, as the WAL and shared memory files must exist 910** in order for the database to be readable. The fourth parameter to 911** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 912** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 913** WAL mode. If the integer is -1, then it is overwritten with the current 914** WAL persistence setting. 915** 916** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 917** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 918** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 919** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 920** xDeviceCharacteristics methods. The fourth parameter to 921** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 922** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 923** mode. If the integer is -1, then it is overwritten with the current 924** zero-damage mode setting. 925** 926** <li>[[SQLITE_FCNTL_OVERWRITE]] 927** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 928** a write transaction to indicate that, unless it is rolled back for some 929** reason, the entire database file will be overwritten by the current 930** transaction. This is used by VACUUM operations. 931** 932** <li>[[SQLITE_FCNTL_VFSNAME]] 933** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 934** all [VFSes] in the VFS stack. The names are of all VFS shims and the 935** final bottom-level VFS are written into memory obtained from 936** [sqlite3_malloc()] and the result is stored in the char* variable 937** that the fourth parameter of [sqlite3_file_control()] points to. 938** The caller is responsible for freeing the memory when done. As with 939** all file-control actions, there is no guarantee that this will actually 940** do anything. Callers should initialize the char* variable to a NULL 941** pointer in case this file-control is not implemented. This file-control 942** is intended for diagnostic use only. 943** 944** <li>[[SQLITE_FCNTL_VFS_POINTER]] 945** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 946** [VFSes] currently in use. ^(The argument X in 947** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 948** of type "[sqlite3_vfs] **". This opcodes will set *X 949** to a pointer to the top-level VFS.)^ 950** ^When there are multiple VFS shims in the stack, this opcode finds the 951** upper-most shim only. 952** 953** <li>[[SQLITE_FCNTL_PRAGMA]] 954** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 955** file control is sent to the open [sqlite3_file] object corresponding 956** to the database file to which the pragma statement refers. ^The argument 957** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 958** pointers to strings (char**) in which the second element of the array 959** is the name of the pragma and the third element is the argument to the 960** pragma or NULL if the pragma has no argument. ^The handler for an 961** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 962** of the char** argument point to a string obtained from [sqlite3_mprintf()] 963** or the equivalent and that string will become the result of the pragma or 964** the error message if the pragma fails. ^If the 965** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 966** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 967** file control returns [SQLITE_OK], then the parser assumes that the 968** VFS has handled the PRAGMA itself and the parser generates a no-op 969** prepared statement if result string is NULL, or that returns a copy 970** of the result string if the string is non-NULL. 971** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 972** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 973** that the VFS encountered an error while handling the [PRAGMA] and the 974** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 975** file control occurs at the beginning of pragma statement analysis and so 976** it is able to override built-in [PRAGMA] statements. 977** 978** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 979** ^The [SQLITE_FCNTL_BUSYHANDLER] 980** file-control may be invoked by SQLite on the database file handle 981** shortly after it is opened in order to provide a custom VFS with access 982** to the connections busy-handler callback. The argument is of type (void **) 983** - an array of two (void *) values. The first (void *) actually points 984** to a function of type (int (*)(void *)). In order to invoke the connections 985** busy-handler, this function should be invoked with the second (void *) in 986** the array as the only argument. If it returns non-zero, then the operation 987** should be retried. If it returns zero, the custom VFS should abandon the 988** current operation. 989** 990** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 991** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 992** to have SQLite generate a 993** temporary filename using the same algorithm that is followed to generate 994** temporary filenames for TEMP tables and other internal uses. The 995** argument should be a char** which will be filled with the filename 996** written into memory obtained from [sqlite3_malloc()]. The caller should 997** invoke [sqlite3_free()] on the result to avoid a memory leak. 998** 999** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1000** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1001** maximum number of bytes that will be used for memory-mapped I/O. 1002** The argument is a pointer to a value of type sqlite3_int64 that 1003** is an advisory maximum number of bytes in the file to memory map. The 1004** pointer is overwritten with the old value. The limit is not changed if 1005** the value originally pointed to is negative, and so the current limit 1006** can be queried by passing in a pointer to a negative number. This 1007** file-control is used internally to implement [PRAGMA mmap_size]. 1008** 1009** <li>[[SQLITE_FCNTL_TRACE]] 1010** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1011** to the VFS about what the higher layers of the SQLite stack are doing. 1012** This file control is used by some VFS activity tracing [shims]. 1013** The argument is a zero-terminated string. Higher layers in the 1014** SQLite stack may generate instances of this file control if 1015** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1016** 1017** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1018** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1019** pointer to an integer and it writes a boolean into that integer depending 1020** on whether or not the file has been renamed, moved, or deleted since it 1021** was first opened. 1022** 1023** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1024** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1025** underlying native file handle associated with a file handle. This file 1026** control interprets its argument as a pointer to a native file handle and 1027** writes the resulting value there. 1028** 1029** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1030** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1031** opcode causes the xFileControl method to swap the file handle with the one 1032** pointed to by the pArg argument. This capability is used during testing 1033** and only needs to be supported when SQLITE_TEST is defined. 1034** 1035** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1036** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1037** be advantageous to block on the next WAL lock if the lock is not immediately 1038** available. The WAL subsystem issues this signal during rare 1039** circumstances in order to fix a problem with priority inversion. 1040** Applications should <em>not</em> use this file-control. 1041** 1042** <li>[[SQLITE_FCNTL_ZIPVFS]] 1043** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1044** VFS should return SQLITE_NOTFOUND for this opcode. 1045** 1046** <li>[[SQLITE_FCNTL_RBU]] 1047** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1048** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1049** this opcode. 1050** 1051** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1052** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1053** the file descriptor is placed in "batch write mode", which 1054** means all subsequent write operations will be deferred and done 1055** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1056** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1057** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1058** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1059** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1060** no VFS interface calls on the same [sqlite3_file] file descriptor 1061** except for calls to the xWrite method and the xFileControl method 1062** with [SQLITE_FCNTL_SIZE_HINT]. 1063** 1064** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1065** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1066** operations since the previous successful call to 1067** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1068** This file control returns [SQLITE_OK] if and only if the writes were 1069** all performed successfully and have been committed to persistent storage. 1070** ^Regardless of whether or not it is successful, this file control takes 1071** the file descriptor out of batch write mode so that all subsequent 1072** write operations are independent. 1073** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1074** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1075** 1076** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1077** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1078** operations since the previous successful call to 1079** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1080** ^This file control takes the file descriptor out of batch write mode 1081** so that all subsequent write operations are independent. 1082** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1083** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1084** 1085** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1086** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1087** a file lock using the xLock or xShmLock methods of the VFS to wait 1088** for up to M milliseconds before failing, where M is the single 1089** unsigned integer parameter. 1090** 1091** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1092** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1093** a database file. The argument is a pointer to a 32-bit unsigned integer. 1094** The "data version" for the pager is written into the pointer. The 1095** "data version" changes whenever any change occurs to the corresponding 1096** database file, either through SQL statements on the same database 1097** connection or through transactions committed by separate database 1098** connections possibly in other processes. The [sqlite3_total_changes()] 1099** interface can be used to find if any database on the connection has changed, 1100** but that interface responds to changes on TEMP as well as MAIN and does 1101** not provide a mechanism to detect changes to MAIN only. Also, the 1102** [sqlite3_total_changes()] interface responds to internal changes only and 1103** omits changes made by other database connections. The 1104** [PRAGMA data_version] command provide a mechanism to detect changes to 1105** a single attached database that occur due to other database connections, 1106** but omits changes implemented by the database connection on which it is 1107** called. This file control is the only mechanism to detect changes that 1108** happen either internally or externally and that are associated with 1109** a particular attached database. 1110** </ul> 1111*/ 1112#define SQLITE_FCNTL_LOCKSTATE 1 1113#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1114#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1115#define SQLITE_FCNTL_LAST_ERRNO 4 1116#define SQLITE_FCNTL_SIZE_HINT 5 1117#define SQLITE_FCNTL_CHUNK_SIZE 6 1118#define SQLITE_FCNTL_FILE_POINTER 7 1119#define SQLITE_FCNTL_SYNC_OMITTED 8 1120#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1121#define SQLITE_FCNTL_PERSIST_WAL 10 1122#define SQLITE_FCNTL_OVERWRITE 11 1123#define SQLITE_FCNTL_VFSNAME 12 1124#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1125#define SQLITE_FCNTL_PRAGMA 14 1126#define SQLITE_FCNTL_BUSYHANDLER 15 1127#define SQLITE_FCNTL_TEMPFILENAME 16 1128#define SQLITE_FCNTL_MMAP_SIZE 18 1129#define SQLITE_FCNTL_TRACE 19 1130#define SQLITE_FCNTL_HAS_MOVED 20 1131#define SQLITE_FCNTL_SYNC 21 1132#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1133#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1134#define SQLITE_FCNTL_WAL_BLOCK 24 1135#define SQLITE_FCNTL_ZIPVFS 25 1136#define SQLITE_FCNTL_RBU 26 1137#define SQLITE_FCNTL_VFS_POINTER 27 1138#define SQLITE_FCNTL_JOURNAL_POINTER 28 1139#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1140#define SQLITE_FCNTL_PDB 30 1141#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1142#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1143#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1144#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1145#define SQLITE_FCNTL_DATA_VERSION 35 1146#define SQLITE_FCNTL_SIZE_LIMIT 36 1147 1148/* deprecated names */ 1149#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1150#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1151#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1152 1153 1154/* 1155** CAPI3REF: Mutex Handle 1156** 1157** The mutex module within SQLite defines [sqlite3_mutex] to be an 1158** abstract type for a mutex object. The SQLite core never looks 1159** at the internal representation of an [sqlite3_mutex]. It only 1160** deals with pointers to the [sqlite3_mutex] object. 1161** 1162** Mutexes are created using [sqlite3_mutex_alloc()]. 1163*/ 1164typedef struct sqlite3_mutex sqlite3_mutex; 1165 1166/* 1167** CAPI3REF: Loadable Extension Thunk 1168** 1169** A pointer to the opaque sqlite3_api_routines structure is passed as 1170** the third parameter to entry points of [loadable extensions]. This 1171** structure must be typedefed in order to work around compiler warnings 1172** on some platforms. 1173*/ 1174typedef struct sqlite3_api_routines sqlite3_api_routines; 1175 1176/* 1177** CAPI3REF: OS Interface Object 1178** 1179** An instance of the sqlite3_vfs object defines the interface between 1180** the SQLite core and the underlying operating system. The "vfs" 1181** in the name of the object stands for "virtual file system". See 1182** the [VFS | VFS documentation] for further information. 1183** 1184** The VFS interface is sometimes extended by adding new methods onto 1185** the end. Each time such an extension occurs, the iVersion field 1186** is incremented. The iVersion value started out as 1 in 1187** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1188** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1189** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1190** may be appended to the sqlite3_vfs object and the iVersion value 1191** may increase again in future versions of SQLite. 1192** Note that the structure 1193** of the sqlite3_vfs object changes in the transition from 1194** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1195** and yet the iVersion field was not modified. 1196** 1197** The szOsFile field is the size of the subclassed [sqlite3_file] 1198** structure used by this VFS. mxPathname is the maximum length of 1199** a pathname in this VFS. 1200** 1201** Registered sqlite3_vfs objects are kept on a linked list formed by 1202** the pNext pointer. The [sqlite3_vfs_register()] 1203** and [sqlite3_vfs_unregister()] interfaces manage this list 1204** in a thread-safe way. The [sqlite3_vfs_find()] interface 1205** searches the list. Neither the application code nor the VFS 1206** implementation should use the pNext pointer. 1207** 1208** The pNext field is the only field in the sqlite3_vfs 1209** structure that SQLite will ever modify. SQLite will only access 1210** or modify this field while holding a particular static mutex. 1211** The application should never modify anything within the sqlite3_vfs 1212** object once the object has been registered. 1213** 1214** The zName field holds the name of the VFS module. The name must 1215** be unique across all VFS modules. 1216** 1217** [[sqlite3_vfs.xOpen]] 1218** ^SQLite guarantees that the zFilename parameter to xOpen 1219** is either a NULL pointer or string obtained 1220** from xFullPathname() with an optional suffix added. 1221** ^If a suffix is added to the zFilename parameter, it will 1222** consist of a single "-" character followed by no more than 1223** 11 alphanumeric and/or "-" characters. 1224** ^SQLite further guarantees that 1225** the string will be valid and unchanged until xClose() is 1226** called. Because of the previous sentence, 1227** the [sqlite3_file] can safely store a pointer to the 1228** filename if it needs to remember the filename for some reason. 1229** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1230** must invent its own temporary name for the file. ^Whenever the 1231** xFilename parameter is NULL it will also be the case that the 1232** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1233** 1234** The flags argument to xOpen() includes all bits set in 1235** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1236** or [sqlite3_open16()] is used, then flags includes at least 1237** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1238** If xOpen() opens a file read-only then it sets *pOutFlags to 1239** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1240** 1241** ^(SQLite will also add one of the following flags to the xOpen() 1242** call, depending on the object being opened: 1243** 1244** <ul> 1245** <li> [SQLITE_OPEN_MAIN_DB] 1246** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1247** <li> [SQLITE_OPEN_TEMP_DB] 1248** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1249** <li> [SQLITE_OPEN_TRANSIENT_DB] 1250** <li> [SQLITE_OPEN_SUBJOURNAL] 1251** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1252** <li> [SQLITE_OPEN_WAL] 1253** </ul>)^ 1254** 1255** The file I/O implementation can use the object type flags to 1256** change the way it deals with files. For example, an application 1257** that does not care about crash recovery or rollback might make 1258** the open of a journal file a no-op. Writes to this journal would 1259** also be no-ops, and any attempt to read the journal would return 1260** SQLITE_IOERR. Or the implementation might recognize that a database 1261** file will be doing page-aligned sector reads and writes in a random 1262** order and set up its I/O subsystem accordingly. 1263** 1264** SQLite might also add one of the following flags to the xOpen method: 1265** 1266** <ul> 1267** <li> [SQLITE_OPEN_DELETEONCLOSE] 1268** <li> [SQLITE_OPEN_EXCLUSIVE] 1269** </ul> 1270** 1271** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1272** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1273** will be set for TEMP databases and their journals, transient 1274** databases, and subjournals. 1275** 1276** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1277** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1278** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1279** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1280** SQLITE_OPEN_CREATE, is used to indicate that file should always 1281** be created, and that it is an error if it already exists. 1282** It is <i>not</i> used to indicate the file should be opened 1283** for exclusive access. 1284** 1285** ^At least szOsFile bytes of memory are allocated by SQLite 1286** to hold the [sqlite3_file] structure passed as the third 1287** argument to xOpen. The xOpen method does not have to 1288** allocate the structure; it should just fill it in. Note that 1289** the xOpen method must set the sqlite3_file.pMethods to either 1290** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1291** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1292** element will be valid after xOpen returns regardless of the success 1293** or failure of the xOpen call. 1294** 1295** [[sqlite3_vfs.xAccess]] 1296** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1297** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1298** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1299** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1300** flag is never actually used and is not implemented in the built-in 1301** VFSes of SQLite. The file is named by the second argument and can be a 1302** directory. The xAccess method returns [SQLITE_OK] on success or some 1303** non-zero error code if there is an I/O error or if the name of 1304** the file given in the second argument is illegal. If SQLITE_OK 1305** is returned, then non-zero or zero is written into *pResOut to indicate 1306** whether or not the file is accessible. 1307** 1308** ^SQLite will always allocate at least mxPathname+1 bytes for the 1309** output buffer xFullPathname. The exact size of the output buffer 1310** is also passed as a parameter to both methods. If the output buffer 1311** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1312** handled as a fatal error by SQLite, vfs implementations should endeavor 1313** to prevent this by setting mxPathname to a sufficiently large value. 1314** 1315** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1316** interfaces are not strictly a part of the filesystem, but they are 1317** included in the VFS structure for completeness. 1318** The xRandomness() function attempts to return nBytes bytes 1319** of good-quality randomness into zOut. The return value is 1320** the actual number of bytes of randomness obtained. 1321** The xSleep() method causes the calling thread to sleep for at 1322** least the number of microseconds given. ^The xCurrentTime() 1323** method returns a Julian Day Number for the current date and time as 1324** a floating point value. 1325** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1326** Day Number multiplied by 86400000 (the number of milliseconds in 1327** a 24-hour day). 1328** ^SQLite will use the xCurrentTimeInt64() method to get the current 1329** date and time if that method is available (if iVersion is 2 or 1330** greater and the function pointer is not NULL) and will fall back 1331** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1332** 1333** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1334** are not used by the SQLite core. These optional interfaces are provided 1335** by some VFSes to facilitate testing of the VFS code. By overriding 1336** system calls with functions under its control, a test program can 1337** simulate faults and error conditions that would otherwise be difficult 1338** or impossible to induce. The set of system calls that can be overridden 1339** varies from one VFS to another, and from one version of the same VFS to the 1340** next. Applications that use these interfaces must be prepared for any 1341** or all of these interfaces to be NULL or for their behavior to change 1342** from one release to the next. Applications must not attempt to access 1343** any of these methods if the iVersion of the VFS is less than 3. 1344*/ 1345typedef struct sqlite3_vfs sqlite3_vfs; 1346typedef void (*sqlite3_syscall_ptr)(void); 1347struct sqlite3_vfs { 1348 int iVersion; /* Structure version number (currently 3) */ 1349 int szOsFile; /* Size of subclassed sqlite3_file */ 1350 int mxPathname; /* Maximum file pathname length */ 1351 sqlite3_vfs *pNext; /* Next registered VFS */ 1352 const char *zName; /* Name of this virtual file system */ 1353 void *pAppData; /* Pointer to application-specific data */ 1354 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1355 int flags, int *pOutFlags); 1356 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1357 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1358 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1359 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1360 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1361 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1362 void (*xDlClose)(sqlite3_vfs*, void*); 1363 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1364 int (*xSleep)(sqlite3_vfs*, int microseconds); 1365 int (*xCurrentTime)(sqlite3_vfs*, double*); 1366 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1367 /* 1368 ** The methods above are in version 1 of the sqlite_vfs object 1369 ** definition. Those that follow are added in version 2 or later 1370 */ 1371 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1372 /* 1373 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1374 ** Those below are for version 3 and greater. 1375 */ 1376 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1377 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1378 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1379 /* 1380 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1381 ** New fields may be appended in future versions. The iVersion 1382 ** value will increment whenever this happens. 1383 */ 1384}; 1385 1386/* 1387** CAPI3REF: Flags for the xAccess VFS method 1388** 1389** These integer constants can be used as the third parameter to 1390** the xAccess method of an [sqlite3_vfs] object. They determine 1391** what kind of permissions the xAccess method is looking for. 1392** With SQLITE_ACCESS_EXISTS, the xAccess method 1393** simply checks whether the file exists. 1394** With SQLITE_ACCESS_READWRITE, the xAccess method 1395** checks whether the named directory is both readable and writable 1396** (in other words, if files can be added, removed, and renamed within 1397** the directory). 1398** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1399** [temp_store_directory pragma], though this could change in a future 1400** release of SQLite. 1401** With SQLITE_ACCESS_READ, the xAccess method 1402** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1403** currently unused, though it might be used in a future release of 1404** SQLite. 1405*/ 1406#define SQLITE_ACCESS_EXISTS 0 1407#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1408#define SQLITE_ACCESS_READ 2 /* Unused */ 1409 1410/* 1411** CAPI3REF: Flags for the xShmLock VFS method 1412** 1413** These integer constants define the various locking operations 1414** allowed by the xShmLock method of [sqlite3_io_methods]. The 1415** following are the only legal combinations of flags to the 1416** xShmLock method: 1417** 1418** <ul> 1419** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1420** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1421** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1422** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1423** </ul> 1424** 1425** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1426** was given on the corresponding lock. 1427** 1428** The xShmLock method can transition between unlocked and SHARED or 1429** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1430** and EXCLUSIVE. 1431*/ 1432#define SQLITE_SHM_UNLOCK 1 1433#define SQLITE_SHM_LOCK 2 1434#define SQLITE_SHM_SHARED 4 1435#define SQLITE_SHM_EXCLUSIVE 8 1436 1437/* 1438** CAPI3REF: Maximum xShmLock index 1439** 1440** The xShmLock method on [sqlite3_io_methods] may use values 1441** between 0 and this upper bound as its "offset" argument. 1442** The SQLite core will never attempt to acquire or release a 1443** lock outside of this range 1444*/ 1445#define SQLITE_SHM_NLOCK 8 1446 1447 1448/* 1449** CAPI3REF: Initialize The SQLite Library 1450** 1451** ^The sqlite3_initialize() routine initializes the 1452** SQLite library. ^The sqlite3_shutdown() routine 1453** deallocates any resources that were allocated by sqlite3_initialize(). 1454** These routines are designed to aid in process initialization and 1455** shutdown on embedded systems. Workstation applications using 1456** SQLite normally do not need to invoke either of these routines. 1457** 1458** A call to sqlite3_initialize() is an "effective" call if it is 1459** the first time sqlite3_initialize() is invoked during the lifetime of 1460** the process, or if it is the first time sqlite3_initialize() is invoked 1461** following a call to sqlite3_shutdown(). ^(Only an effective call 1462** of sqlite3_initialize() does any initialization. All other calls 1463** are harmless no-ops.)^ 1464** 1465** A call to sqlite3_shutdown() is an "effective" call if it is the first 1466** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1467** an effective call to sqlite3_shutdown() does any deinitialization. 1468** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1469** 1470** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1471** is not. The sqlite3_shutdown() interface must only be called from a 1472** single thread. All open [database connections] must be closed and all 1473** other SQLite resources must be deallocated prior to invoking 1474** sqlite3_shutdown(). 1475** 1476** Among other things, ^sqlite3_initialize() will invoke 1477** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1478** will invoke sqlite3_os_end(). 1479** 1480** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1481** ^If for some reason, sqlite3_initialize() is unable to initialize 1482** the library (perhaps it is unable to allocate a needed resource such 1483** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1484** 1485** ^The sqlite3_initialize() routine is called internally by many other 1486** SQLite interfaces so that an application usually does not need to 1487** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1488** calls sqlite3_initialize() so the SQLite library will be automatically 1489** initialized when [sqlite3_open()] is called if it has not be initialized 1490** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1491** compile-time option, then the automatic calls to sqlite3_initialize() 1492** are omitted and the application must call sqlite3_initialize() directly 1493** prior to using any other SQLite interface. For maximum portability, 1494** it is recommended that applications always invoke sqlite3_initialize() 1495** directly prior to using any other SQLite interface. Future releases 1496** of SQLite may require this. In other words, the behavior exhibited 1497** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1498** default behavior in some future release of SQLite. 1499** 1500** The sqlite3_os_init() routine does operating-system specific 1501** initialization of the SQLite library. The sqlite3_os_end() 1502** routine undoes the effect of sqlite3_os_init(). Typical tasks 1503** performed by these routines include allocation or deallocation 1504** of static resources, initialization of global variables, 1505** setting up a default [sqlite3_vfs] module, or setting up 1506** a default configuration using [sqlite3_config()]. 1507** 1508** The application should never invoke either sqlite3_os_init() 1509** or sqlite3_os_end() directly. The application should only invoke 1510** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1511** interface is called automatically by sqlite3_initialize() and 1512** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1513** implementations for sqlite3_os_init() and sqlite3_os_end() 1514** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1515** When [custom builds | built for other platforms] 1516** (using the [SQLITE_OS_OTHER=1] compile-time 1517** option) the application must supply a suitable implementation for 1518** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1519** implementation of sqlite3_os_init() or sqlite3_os_end() 1520** must return [SQLITE_OK] on success and some other [error code] upon 1521** failure. 1522*/ 1523int sqlite3_initialize(void); 1524int sqlite3_shutdown(void); 1525int sqlite3_os_init(void); 1526int sqlite3_os_end(void); 1527 1528/* 1529** CAPI3REF: Configuring The SQLite Library 1530** 1531** The sqlite3_config() interface is used to make global configuration 1532** changes to SQLite in order to tune SQLite to the specific needs of 1533** the application. The default configuration is recommended for most 1534** applications and so this routine is usually not necessary. It is 1535** provided to support rare applications with unusual needs. 1536** 1537** <b>The sqlite3_config() interface is not threadsafe. The application 1538** must ensure that no other SQLite interfaces are invoked by other 1539** threads while sqlite3_config() is running.</b> 1540** 1541** The sqlite3_config() interface 1542** may only be invoked prior to library initialization using 1543** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1544** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1545** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1546** Note, however, that ^sqlite3_config() can be called as part of the 1547** implementation of an application-defined [sqlite3_os_init()]. 1548** 1549** The first argument to sqlite3_config() is an integer 1550** [configuration option] that determines 1551** what property of SQLite is to be configured. Subsequent arguments 1552** vary depending on the [configuration option] 1553** in the first argument. 1554** 1555** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1556** ^If the option is unknown or SQLite is unable to set the option 1557** then this routine returns a non-zero [error code]. 1558*/ 1559int sqlite3_config(int, ...); 1560 1561/* 1562** CAPI3REF: Configure database connections 1563** METHOD: sqlite3 1564** 1565** The sqlite3_db_config() interface is used to make configuration 1566** changes to a [database connection]. The interface is similar to 1567** [sqlite3_config()] except that the changes apply to a single 1568** [database connection] (specified in the first argument). 1569** 1570** The second argument to sqlite3_db_config(D,V,...) is the 1571** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1572** that indicates what aspect of the [database connection] is being configured. 1573** Subsequent arguments vary depending on the configuration verb. 1574** 1575** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1576** the call is considered successful. 1577*/ 1578int sqlite3_db_config(sqlite3*, int op, ...); 1579 1580/* 1581** CAPI3REF: Memory Allocation Routines 1582** 1583** An instance of this object defines the interface between SQLite 1584** and low-level memory allocation routines. 1585** 1586** This object is used in only one place in the SQLite interface. 1587** A pointer to an instance of this object is the argument to 1588** [sqlite3_config()] when the configuration option is 1589** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1590** By creating an instance of this object 1591** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1592** during configuration, an application can specify an alternative 1593** memory allocation subsystem for SQLite to use for all of its 1594** dynamic memory needs. 1595** 1596** Note that SQLite comes with several [built-in memory allocators] 1597** that are perfectly adequate for the overwhelming majority of applications 1598** and that this object is only useful to a tiny minority of applications 1599** with specialized memory allocation requirements. This object is 1600** also used during testing of SQLite in order to specify an alternative 1601** memory allocator that simulates memory out-of-memory conditions in 1602** order to verify that SQLite recovers gracefully from such 1603** conditions. 1604** 1605** The xMalloc, xRealloc, and xFree methods must work like the 1606** malloc(), realloc() and free() functions from the standard C library. 1607** ^SQLite guarantees that the second argument to 1608** xRealloc is always a value returned by a prior call to xRoundup. 1609** 1610** xSize should return the allocated size of a memory allocation 1611** previously obtained from xMalloc or xRealloc. The allocated size 1612** is always at least as big as the requested size but may be larger. 1613** 1614** The xRoundup method returns what would be the allocated size of 1615** a memory allocation given a particular requested size. Most memory 1616** allocators round up memory allocations at least to the next multiple 1617** of 8. Some allocators round up to a larger multiple or to a power of 2. 1618** Every memory allocation request coming in through [sqlite3_malloc()] 1619** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1620** that causes the corresponding memory allocation to fail. 1621** 1622** The xInit method initializes the memory allocator. For example, 1623** it might allocate any require mutexes or initialize internal data 1624** structures. The xShutdown method is invoked (indirectly) by 1625** [sqlite3_shutdown()] and should deallocate any resources acquired 1626** by xInit. The pAppData pointer is used as the only parameter to 1627** xInit and xShutdown. 1628** 1629** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1630** the xInit method, so the xInit method need not be threadsafe. The 1631** xShutdown method is only called from [sqlite3_shutdown()] so it does 1632** not need to be threadsafe either. For all other methods, SQLite 1633** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1634** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1635** it is by default) and so the methods are automatically serialized. 1636** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1637** methods must be threadsafe or else make their own arrangements for 1638** serialization. 1639** 1640** SQLite will never invoke xInit() more than once without an intervening 1641** call to xShutdown(). 1642*/ 1643typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1644struct sqlite3_mem_methods { 1645 void *(*xMalloc)(int); /* Memory allocation function */ 1646 void (*xFree)(void*); /* Free a prior allocation */ 1647 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1648 int (*xSize)(void*); /* Return the size of an allocation */ 1649 int (*xRoundup)(int); /* Round up request size to allocation size */ 1650 int (*xInit)(void*); /* Initialize the memory allocator */ 1651 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1652 void *pAppData; /* Argument to xInit() and xShutdown() */ 1653}; 1654 1655/* 1656** CAPI3REF: Configuration Options 1657** KEYWORDS: {configuration option} 1658** 1659** These constants are the available integer configuration options that 1660** can be passed as the first argument to the [sqlite3_config()] interface. 1661** 1662** New configuration options may be added in future releases of SQLite. 1663** Existing configuration options might be discontinued. Applications 1664** should check the return code from [sqlite3_config()] to make sure that 1665** the call worked. The [sqlite3_config()] interface will return a 1666** non-zero [error code] if a discontinued or unsupported configuration option 1667** is invoked. 1668** 1669** <dl> 1670** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1671** <dd>There are no arguments to this option. ^This option sets the 1672** [threading mode] to Single-thread. In other words, it disables 1673** all mutexing and puts SQLite into a mode where it can only be used 1674** by a single thread. ^If SQLite is compiled with 1675** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1676** it is not possible to change the [threading mode] from its default 1677** value of Single-thread and so [sqlite3_config()] will return 1678** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1679** configuration option.</dd> 1680** 1681** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1682** <dd>There are no arguments to this option. ^This option sets the 1683** [threading mode] to Multi-thread. In other words, it disables 1684** mutexing on [database connection] and [prepared statement] objects. 1685** The application is responsible for serializing access to 1686** [database connections] and [prepared statements]. But other mutexes 1687** are enabled so that SQLite will be safe to use in a multi-threaded 1688** environment as long as no two threads attempt to use the same 1689** [database connection] at the same time. ^If SQLite is compiled with 1690** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1691** it is not possible to set the Multi-thread [threading mode] and 1692** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1693** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1694** 1695** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1696** <dd>There are no arguments to this option. ^This option sets the 1697** [threading mode] to Serialized. In other words, this option enables 1698** all mutexes including the recursive 1699** mutexes on [database connection] and [prepared statement] objects. 1700** In this mode (which is the default when SQLite is compiled with 1701** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1702** to [database connections] and [prepared statements] so that the 1703** application is free to use the same [database connection] or the 1704** same [prepared statement] in different threads at the same time. 1705** ^If SQLite is compiled with 1706** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1707** it is not possible to set the Serialized [threading mode] and 1708** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1709** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1710** 1711** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1712** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1713** a pointer to an instance of the [sqlite3_mem_methods] structure. 1714** The argument specifies 1715** alternative low-level memory allocation routines to be used in place of 1716** the memory allocation routines built into SQLite.)^ ^SQLite makes 1717** its own private copy of the content of the [sqlite3_mem_methods] structure 1718** before the [sqlite3_config()] call returns.</dd> 1719** 1720** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1721** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1722** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1723** The [sqlite3_mem_methods] 1724** structure is filled with the currently defined memory allocation routines.)^ 1725** This option can be used to overload the default memory allocation 1726** routines with a wrapper that simulations memory allocation failure or 1727** tracks memory usage, for example. </dd> 1728** 1729** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1730** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1731** type int, interpreted as a boolean, which if true provides a hint to 1732** SQLite that it should avoid large memory allocations if possible. 1733** SQLite will run faster if it is free to make large memory allocations, 1734** but some application might prefer to run slower in exchange for 1735** guarantees about memory fragmentation that are possible if large 1736** allocations are avoided. This hint is normally off. 1737** </dd> 1738** 1739** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1740** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1741** interpreted as a boolean, which enables or disables the collection of 1742** memory allocation statistics. ^(When memory allocation statistics are 1743** disabled, the following SQLite interfaces become non-operational: 1744** <ul> 1745** <li> [sqlite3_memory_used()] 1746** <li> [sqlite3_memory_highwater()] 1747** <li> [sqlite3_soft_heap_limit64()] 1748** <li> [sqlite3_status64()] 1749** </ul>)^ 1750** ^Memory allocation statistics are enabled by default unless SQLite is 1751** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1752** allocation statistics are disabled by default. 1753** </dd> 1754** 1755** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1756** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1757** </dd> 1758** 1759** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1760** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1761** that SQLite can use for the database page cache with the default page 1762** cache implementation. 1763** This configuration option is a no-op if an application-define page 1764** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1765** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1766** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1767** and the number of cache lines (N). 1768** The sz argument should be the size of the largest database page 1769** (a power of two between 512 and 65536) plus some extra bytes for each 1770** page header. ^The number of extra bytes needed by the page header 1771** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1772** ^It is harmless, apart from the wasted memory, 1773** for the sz parameter to be larger than necessary. The pMem 1774** argument must be either a NULL pointer or a pointer to an 8-byte 1775** aligned block of memory of at least sz*N bytes, otherwise 1776** subsequent behavior is undefined. 1777** ^When pMem is not NULL, SQLite will strive to use the memory provided 1778** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1779** a page cache line is larger than sz bytes or if all of the pMem buffer 1780** is exhausted. 1781** ^If pMem is NULL and N is non-zero, then each database connection 1782** does an initial bulk allocation for page cache memory 1783** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1784** of -1024*N bytes if N is negative, . ^If additional 1785** page cache memory is needed beyond what is provided by the initial 1786** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1787** additional cache line. </dd> 1788** 1789** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1790** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1791** that SQLite will use for all of its dynamic memory allocation needs 1792** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1793** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1794** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1795** [SQLITE_ERROR] if invoked otherwise. 1796** ^There are three arguments to SQLITE_CONFIG_HEAP: 1797** An 8-byte aligned pointer to the memory, 1798** the number of bytes in the memory buffer, and the minimum allocation size. 1799** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1800** to using its default memory allocator (the system malloc() implementation), 1801** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1802** memory pointer is not NULL then the alternative memory 1803** allocator is engaged to handle all of SQLites memory allocation needs. 1804** The first pointer (the memory pointer) must be aligned to an 8-byte 1805** boundary or subsequent behavior of SQLite will be undefined. 1806** The minimum allocation size is capped at 2**12. Reasonable values 1807** for the minimum allocation size are 2**5 through 2**8.</dd> 1808** 1809** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1810** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1811** pointer to an instance of the [sqlite3_mutex_methods] structure. 1812** The argument specifies alternative low-level mutex routines to be used 1813** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1814** the content of the [sqlite3_mutex_methods] structure before the call to 1815** [sqlite3_config()] returns. ^If SQLite is compiled with 1816** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1817** the entire mutexing subsystem is omitted from the build and hence calls to 1818** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1819** return [SQLITE_ERROR].</dd> 1820** 1821** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1822** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1823** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1824** [sqlite3_mutex_methods] 1825** structure is filled with the currently defined mutex routines.)^ 1826** This option can be used to overload the default mutex allocation 1827** routines with a wrapper used to track mutex usage for performance 1828** profiling or testing, for example. ^If SQLite is compiled with 1829** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1830** the entire mutexing subsystem is omitted from the build and hence calls to 1831** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1832** return [SQLITE_ERROR].</dd> 1833** 1834** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1835** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1836** the default size of lookaside memory on each [database connection]. 1837** The first argument is the 1838** size of each lookaside buffer slot and the second is the number of 1839** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1840** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1841** option to [sqlite3_db_config()] can be used to change the lookaside 1842** configuration on individual connections.)^ </dd> 1843** 1844** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1845** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1846** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1847** the interface to a custom page cache implementation.)^ 1848** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1849** 1850** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1851** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1852** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1853** the current page cache implementation into that object.)^ </dd> 1854** 1855** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1856** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1857** global [error log]. 1858** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1859** function with a call signature of void(*)(void*,int,const char*), 1860** and a pointer to void. ^If the function pointer is not NULL, it is 1861** invoked by [sqlite3_log()] to process each logging event. ^If the 1862** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1863** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1864** passed through as the first parameter to the application-defined logger 1865** function whenever that function is invoked. ^The second parameter to 1866** the logger function is a copy of the first parameter to the corresponding 1867** [sqlite3_log()] call and is intended to be a [result code] or an 1868** [extended result code]. ^The third parameter passed to the logger is 1869** log message after formatting via [sqlite3_snprintf()]. 1870** The SQLite logging interface is not reentrant; the logger function 1871** supplied by the application must not invoke any SQLite interface. 1872** In a multi-threaded application, the application-defined logger 1873** function must be threadsafe. </dd> 1874** 1875** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1876** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1877** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1878** then URI handling is globally disabled.)^ ^If URI handling is globally 1879** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1880** [sqlite3_open16()] or 1881** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1882** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1883** connection is opened. ^If it is globally disabled, filenames are 1884** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1885** database connection is opened. ^(By default, URI handling is globally 1886** disabled. The default value may be changed by compiling with the 1887** [SQLITE_USE_URI] symbol defined.)^ 1888** 1889** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1890** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1891** argument which is interpreted as a boolean in order to enable or disable 1892** the use of covering indices for full table scans in the query optimizer. 1893** ^The default setting is determined 1894** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1895** if that compile-time option is omitted. 1896** The ability to disable the use of covering indices for full table scans 1897** is because some incorrectly coded legacy applications might malfunction 1898** when the optimization is enabled. Providing the ability to 1899** disable the optimization allows the older, buggy application code to work 1900** without change even with newer versions of SQLite. 1901** 1902** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1903** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1904** <dd> These options are obsolete and should not be used by new code. 1905** They are retained for backwards compatibility but are now no-ops. 1906** </dd> 1907** 1908** [[SQLITE_CONFIG_SQLLOG]] 1909** <dt>SQLITE_CONFIG_SQLLOG 1910** <dd>This option is only available if sqlite is compiled with the 1911** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1912** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1913** The second should be of type (void*). The callback is invoked by the library 1914** in three separate circumstances, identified by the value passed as the 1915** fourth parameter. If the fourth parameter is 0, then the database connection 1916** passed as the second argument has just been opened. The third argument 1917** points to a buffer containing the name of the main database file. If the 1918** fourth parameter is 1, then the SQL statement that the third parameter 1919** points to has just been executed. Or, if the fourth parameter is 2, then 1920** the connection being passed as the second parameter is being closed. The 1921** third parameter is passed NULL In this case. An example of using this 1922** configuration option can be seen in the "test_sqllog.c" source file in 1923** the canonical SQLite source tree.</dd> 1924** 1925** [[SQLITE_CONFIG_MMAP_SIZE]] 1926** <dt>SQLITE_CONFIG_MMAP_SIZE 1927** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1928** that are the default mmap size limit (the default setting for 1929** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1930** ^The default setting can be overridden by each database connection using 1931** either the [PRAGMA mmap_size] command, or by using the 1932** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1933** will be silently truncated if necessary so that it does not exceed the 1934** compile-time maximum mmap size set by the 1935** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1936** ^If either argument to this option is negative, then that argument is 1937** changed to its compile-time default. 1938** 1939** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1940** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1941** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1942** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1943** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1944** that specifies the maximum size of the created heap. 1945** 1946** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1947** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1948** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1949** is a pointer to an integer and writes into that integer the number of extra 1950** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1951** The amount of extra space required can change depending on the compiler, 1952** target platform, and SQLite version. 1953** 1954** [[SQLITE_CONFIG_PMASZ]] 1955** <dt>SQLITE_CONFIG_PMASZ 1956** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1957** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1958** sorter to that integer. The default minimum PMA Size is set by the 1959** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1960** to help with sort operations when multithreaded sorting 1961** is enabled (using the [PRAGMA threads] command) and the amount of content 1962** to be sorted exceeds the page size times the minimum of the 1963** [PRAGMA cache_size] setting and this value. 1964** 1965** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1966** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1967** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1968** becomes the [statement journal] spill-to-disk threshold. 1969** [Statement journals] are held in memory until their size (in bytes) 1970** exceeds this threshold, at which point they are written to disk. 1971** Or if the threshold is -1, statement journals are always held 1972** exclusively in memory. 1973** Since many statement journals never become large, setting the spill 1974** threshold to a value such as 64KiB can greatly reduce the amount of 1975** I/O required to support statement rollback. 1976** The default value for this setting is controlled by the 1977** [SQLITE_STMTJRNL_SPILL] compile-time option. 1978** 1979** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1980** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1981** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1982** of type (int) - the new value of the sorter-reference size threshold. 1983** Usually, when SQLite uses an external sort to order records according 1984** to an ORDER BY clause, all fields required by the caller are present in the 1985** sorted records. However, if SQLite determines based on the declared type 1986** of a table column that its values are likely to be very large - larger 1987** than the configured sorter-reference size threshold - then a reference 1988** is stored in each sorted record and the required column values loaded 1989** from the database as records are returned in sorted order. The default 1990** value for this option is to never use this optimization. Specifying a 1991** negative value for this option restores the default behaviour. 1992** This option is only available if SQLite is compiled with the 1993** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1994** 1995** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 1996** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 1997** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 1998** [sqlite3_int64] parameter which is the default maximum size for an in-memory 1999** database created using [sqlite3_deserialize()]. This default maximum 2000** size can be adjusted up or down for individual databases using the 2001** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2002** configuration setting is never used, then the default maximum is determined 2003** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2004** compile-time option is not set, then the default maximum is 1073741824. 2005** </dl> 2006*/ 2007#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2008#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2009#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2010#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2011#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2012#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2013#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2014#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2015#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2016#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2017#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2018/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2019#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2020#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2021#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2022#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2023#define SQLITE_CONFIG_URI 17 /* int */ 2024#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2025#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2026#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2027#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2028#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2029#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2030#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2031#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2032#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2033#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2034#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2035#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2036 2037/* 2038** CAPI3REF: Database Connection Configuration Options 2039** 2040** These constants are the available integer configuration options that 2041** can be passed as the second argument to the [sqlite3_db_config()] interface. 2042** 2043** New configuration options may be added in future releases of SQLite. 2044** Existing configuration options might be discontinued. Applications 2045** should check the return code from [sqlite3_db_config()] to make sure that 2046** the call worked. ^The [sqlite3_db_config()] interface will return a 2047** non-zero [error code] if a discontinued or unsupported configuration option 2048** is invoked. 2049** 2050** <dl> 2051** [[SQLITE_DBCONFIG_LOOKASIDE]] 2052** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2053** <dd> ^This option takes three additional arguments that determine the 2054** [lookaside memory allocator] configuration for the [database connection]. 2055** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2056** pointer to a memory buffer to use for lookaside memory. 2057** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2058** may be NULL in which case SQLite will allocate the 2059** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2060** size of each lookaside buffer slot. ^The third argument is the number of 2061** slots. The size of the buffer in the first argument must be greater than 2062** or equal to the product of the second and third arguments. The buffer 2063** must be aligned to an 8-byte boundary. ^If the second argument to 2064** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2065** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2066** configuration for a database connection can only be changed when that 2067** connection is not currently using lookaside memory, or in other words 2068** when the "current value" returned by 2069** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2070** Any attempt to change the lookaside memory configuration when lookaside 2071** memory is in use leaves the configuration unchanged and returns 2072** [SQLITE_BUSY].)^</dd> 2073** 2074** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2075** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2076** <dd> ^This option is used to enable or disable the enforcement of 2077** [foreign key constraints]. There should be two additional arguments. 2078** The first argument is an integer which is 0 to disable FK enforcement, 2079** positive to enable FK enforcement or negative to leave FK enforcement 2080** unchanged. The second parameter is a pointer to an integer into which 2081** is written 0 or 1 to indicate whether FK enforcement is off or on 2082** following this call. The second parameter may be a NULL pointer, in 2083** which case the FK enforcement setting is not reported back. </dd> 2084** 2085** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2086** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2087** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2088** There should be two additional arguments. 2089** The first argument is an integer which is 0 to disable triggers, 2090** positive to enable triggers or negative to leave the setting unchanged. 2091** The second parameter is a pointer to an integer into which 2092** is written 0 or 1 to indicate whether triggers are disabled or enabled 2093** following this call. The second parameter may be a NULL pointer, in 2094** which case the trigger setting is not reported back. </dd> 2095** 2096** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2097** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2098** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2099** There should be two additional arguments. 2100** The first argument is an integer which is 0 to disable views, 2101** positive to enable views or negative to leave the setting unchanged. 2102** The second parameter is a pointer to an integer into which 2103** is written 0 or 1 to indicate whether views are disabled or enabled 2104** following this call. The second parameter may be a NULL pointer, in 2105** which case the view setting is not reported back. </dd> 2106** 2107** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2108** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2109** <dd> ^This option is used to enable or disable the 2110** [fts3_tokenizer()] function which is part of the 2111** [FTS3] full-text search engine extension. 2112** There should be two additional arguments. 2113** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2114** positive to enable fts3_tokenizer() or negative to leave the setting 2115** unchanged. 2116** The second parameter is a pointer to an integer into which 2117** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2118** following this call. The second parameter may be a NULL pointer, in 2119** which case the new setting is not reported back. </dd> 2120** 2121** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2122** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2123** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2124** interface independently of the [load_extension()] SQL function. 2125** The [sqlite3_enable_load_extension()] API enables or disables both the 2126** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2127** There should be two additional arguments. 2128** When the first argument to this interface is 1, then only the C-API is 2129** enabled and the SQL function remains disabled. If the first argument to 2130** this interface is 0, then both the C-API and the SQL function are disabled. 2131** If the first argument is -1, then no changes are made to state of either the 2132** C-API or the SQL function. 2133** The second parameter is a pointer to an integer into which 2134** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2135** is disabled or enabled following this call. The second parameter may 2136** be a NULL pointer, in which case the new setting is not reported back. 2137** </dd> 2138** 2139** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2140** <dd> ^This option is used to change the name of the "main" database 2141** schema. ^The sole argument is a pointer to a constant UTF8 string 2142** which will become the new schema name in place of "main". ^SQLite 2143** does not make a copy of the new main schema name string, so the application 2144** must ensure that the argument passed into this DBCONFIG option is unchanged 2145** until after the database connection closes. 2146** </dd> 2147** 2148** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2149** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2150** <dd> Usually, when a database in wal mode is closed or detached from a 2151** database handle, SQLite checks if this will mean that there are now no 2152** connections at all to the database. If so, it performs a checkpoint 2153** operation before closing the connection. This option may be used to 2154** override this behaviour. The first parameter passed to this operation 2155** is an integer - positive to disable checkpoints-on-close, or zero (the 2156** default) to enable them, and negative to leave the setting unchanged. 2157** The second parameter is a pointer to an integer 2158** into which is written 0 or 1 to indicate whether checkpoints-on-close 2159** have been disabled - 0 if they are not disabled, 1 if they are. 2160** </dd> 2161** 2162** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2163** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2164** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2165** a single SQL query statement will always use the same algorithm regardless 2166** of values of [bound parameters].)^ The QPSG disables some query optimizations 2167** that look at the values of bound parameters, which can make some queries 2168** slower. But the QPSG has the advantage of more predictable behavior. With 2169** the QPSG active, SQLite will always use the same query plan in the field as 2170** was used during testing in the lab. 2171** The first argument to this setting is an integer which is 0 to disable 2172** the QPSG, positive to enable QPSG, or negative to leave the setting 2173** unchanged. The second parameter is a pointer to an integer into which 2174** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2175** following this call. 2176** </dd> 2177** 2178** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2179** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2180** include output for any operations performed by trigger programs. This 2181** option is used to set or clear (the default) a flag that governs this 2182** behavior. The first parameter passed to this operation is an integer - 2183** positive to enable output for trigger programs, or zero to disable it, 2184** or negative to leave the setting unchanged. 2185** The second parameter is a pointer to an integer into which is written 2186** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2187** it is not disabled, 1 if it is. 2188** </dd> 2189** 2190** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2191** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2192** [VACUUM] in order to reset a database back to an empty database 2193** with no schema and no content. The following process works even for 2194** a badly corrupted database file: 2195** <ol> 2196** <li> If the database connection is newly opened, make sure it has read the 2197** database schema by preparing then discarding some query against the 2198** database, or calling sqlite3_table_column_metadata(), ignoring any 2199** errors. This step is only necessary if the application desires to keep 2200** the database in WAL mode after the reset if it was in WAL mode before 2201** the reset. 2202** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2203** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2204** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2205** </ol> 2206** Because resetting a database is destructive and irreversible, the 2207** process requires the use of this obscure API and multiple steps to help 2208** ensure that it does not happen by accident. 2209** 2210** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2211** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2212** "defensive" flag for a database connection. When the defensive 2213** flag is enabled, language features that allow ordinary SQL to 2214** deliberately corrupt the database file are disabled. The disabled 2215** features include but are not limited to the following: 2216** <ul> 2217** <li> The [PRAGMA writable_schema=ON] statement. 2218** <li> The [PRAGMA journal_mode=OFF] statement. 2219** <li> Writes to the [sqlite_dbpage] virtual table. 2220** <li> Direct writes to [shadow tables]. 2221** </ul> 2222** </dd> 2223** 2224** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2225** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2226** "writable_schema" flag. This has the same effect and is logically equivalent 2227** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2228** The first argument to this setting is an integer which is 0 to disable 2229** the writable_schema, positive to enable writable_schema, or negative to 2230** leave the setting unchanged. The second parameter is a pointer to an 2231** integer into which is written 0 or 1 to indicate whether the writable_schema 2232** is enabled or disabled following this call. 2233** </dd> 2234** 2235** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2236** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2237** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2238** the legacy behavior of the [ALTER TABLE RENAME] command such it 2239** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2240** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2241** additional information. This feature can also be turned on and off 2242** using the [PRAGMA legacy_alter_table] statement. 2243** </dd> 2244** 2245** [[SQLITE_DBCONFIG_DQS_DML]] 2246** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2247** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2248** the legacy [double-quoted string literal] misfeature for DML statement 2249** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2250** default value of this setting is determined by the [-DSQLITE_DQS] 2251** compile-time option. 2252** </dd> 2253** 2254** [[SQLITE_DBCONFIG_DQS_DDL]] 2255** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2256** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2257** the legacy [double-quoted string literal] misfeature for DDL statements, 2258** such as CREATE TABLE and CREATE INDEX. The 2259** default value of this setting is determined by the [-DSQLITE_DQS] 2260** compile-time option. 2261** </dd> 2262** </dl> 2263*/ 2264#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2265#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2266#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2267#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2268#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2269#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2270#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2271#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2272#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2273#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2274#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2275#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2276#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2277#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2278#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2279#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2280#define SQLITE_DBCONFIG_MAX 1015 /* Largest DBCONFIG */ 2281 2282/* 2283** CAPI3REF: Enable Or Disable Extended Result Codes 2284** METHOD: sqlite3 2285** 2286** ^The sqlite3_extended_result_codes() routine enables or disables the 2287** [extended result codes] feature of SQLite. ^The extended result 2288** codes are disabled by default for historical compatibility. 2289*/ 2290int sqlite3_extended_result_codes(sqlite3*, int onoff); 2291 2292/* 2293** CAPI3REF: Last Insert Rowid 2294** METHOD: sqlite3 2295** 2296** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2297** has a unique 64-bit signed 2298** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2299** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2300** names are not also used by explicitly declared columns. ^If 2301** the table has a column of type [INTEGER PRIMARY KEY] then that column 2302** is another alias for the rowid. 2303** 2304** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2305** the most recent successful [INSERT] into a rowid table or [virtual table] 2306** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2307** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2308** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2309** zero. 2310** 2311** As well as being set automatically as rows are inserted into database 2312** tables, the value returned by this function may be set explicitly by 2313** [sqlite3_set_last_insert_rowid()] 2314** 2315** Some virtual table implementations may INSERT rows into rowid tables as 2316** part of committing a transaction (e.g. to flush data accumulated in memory 2317** to disk). In this case subsequent calls to this function return the rowid 2318** associated with these internal INSERT operations, which leads to 2319** unintuitive results. Virtual table implementations that do write to rowid 2320** tables in this way can avoid this problem by restoring the original 2321** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2322** control to the user. 2323** 2324** ^(If an [INSERT] occurs within a trigger then this routine will 2325** return the [rowid] of the inserted row as long as the trigger is 2326** running. Once the trigger program ends, the value returned 2327** by this routine reverts to what it was before the trigger was fired.)^ 2328** 2329** ^An [INSERT] that fails due to a constraint violation is not a 2330** successful [INSERT] and does not change the value returned by this 2331** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2332** and INSERT OR ABORT make no changes to the return value of this 2333** routine when their insertion fails. ^(When INSERT OR REPLACE 2334** encounters a constraint violation, it does not fail. The 2335** INSERT continues to completion after deleting rows that caused 2336** the constraint problem so INSERT OR REPLACE will always change 2337** the return value of this interface.)^ 2338** 2339** ^For the purposes of this routine, an [INSERT] is considered to 2340** be successful even if it is subsequently rolled back. 2341** 2342** This function is accessible to SQL statements via the 2343** [last_insert_rowid() SQL function]. 2344** 2345** If a separate thread performs a new [INSERT] on the same 2346** database connection while the [sqlite3_last_insert_rowid()] 2347** function is running and thus changes the last insert [rowid], 2348** then the value returned by [sqlite3_last_insert_rowid()] is 2349** unpredictable and might not equal either the old or the new 2350** last insert [rowid]. 2351*/ 2352sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2353 2354/* 2355** CAPI3REF: Set the Last Insert Rowid value. 2356** METHOD: sqlite3 2357** 2358** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2359** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2360** without inserting a row into the database. 2361*/ 2362void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2363 2364/* 2365** CAPI3REF: Count The Number Of Rows Modified 2366** METHOD: sqlite3 2367** 2368** ^This function returns the number of rows modified, inserted or 2369** deleted by the most recently completed INSERT, UPDATE or DELETE 2370** statement on the database connection specified by the only parameter. 2371** ^Executing any other type of SQL statement does not modify the value 2372** returned by this function. 2373** 2374** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2375** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2376** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2377** 2378** Changes to a view that are intercepted by 2379** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2380** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2381** DELETE statement run on a view is always zero. Only changes made to real 2382** tables are counted. 2383** 2384** Things are more complicated if the sqlite3_changes() function is 2385** executed while a trigger program is running. This may happen if the 2386** program uses the [changes() SQL function], or if some other callback 2387** function invokes sqlite3_changes() directly. Essentially: 2388** 2389** <ul> 2390** <li> ^(Before entering a trigger program the value returned by 2391** sqlite3_changes() function is saved. After the trigger program 2392** has finished, the original value is restored.)^ 2393** 2394** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2395** statement sets the value returned by sqlite3_changes() 2396** upon completion as normal. Of course, this value will not include 2397** any changes performed by sub-triggers, as the sqlite3_changes() 2398** value will be saved and restored after each sub-trigger has run.)^ 2399** </ul> 2400** 2401** ^This means that if the changes() SQL function (or similar) is used 2402** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2403** returns the value as set when the calling statement began executing. 2404** ^If it is used by the second or subsequent such statement within a trigger 2405** program, the value returned reflects the number of rows modified by the 2406** previous INSERT, UPDATE or DELETE statement within the same trigger. 2407** 2408** If a separate thread makes changes on the same database connection 2409** while [sqlite3_changes()] is running then the value returned 2410** is unpredictable and not meaningful. 2411** 2412** See also: 2413** <ul> 2414** <li> the [sqlite3_total_changes()] interface 2415** <li> the [count_changes pragma] 2416** <li> the [changes() SQL function] 2417** <li> the [data_version pragma] 2418** </ul> 2419*/ 2420int sqlite3_changes(sqlite3*); 2421 2422/* 2423** CAPI3REF: Total Number Of Rows Modified 2424** METHOD: sqlite3 2425** 2426** ^This function returns the total number of rows inserted, modified or 2427** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2428** since the database connection was opened, including those executed as 2429** part of trigger programs. ^Executing any other type of SQL statement 2430** does not affect the value returned by sqlite3_total_changes(). 2431** 2432** ^Changes made as part of [foreign key actions] are included in the 2433** count, but those made as part of REPLACE constraint resolution are 2434** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2435** are not counted. 2436** 2437** The [sqlite3_total_changes(D)] interface only reports the number 2438** of rows that changed due to SQL statement run against database 2439** connection D. Any changes by other database connections are ignored. 2440** To detect changes against a database file from other database 2441** connections use the [PRAGMA data_version] command or the 2442** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2443** 2444** If a separate thread makes changes on the same database connection 2445** while [sqlite3_total_changes()] is running then the value 2446** returned is unpredictable and not meaningful. 2447** 2448** See also: 2449** <ul> 2450** <li> the [sqlite3_changes()] interface 2451** <li> the [count_changes pragma] 2452** <li> the [changes() SQL function] 2453** <li> the [data_version pragma] 2454** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2455** </ul> 2456*/ 2457int sqlite3_total_changes(sqlite3*); 2458 2459/* 2460** CAPI3REF: Interrupt A Long-Running Query 2461** METHOD: sqlite3 2462** 2463** ^This function causes any pending database operation to abort and 2464** return at its earliest opportunity. This routine is typically 2465** called in response to a user action such as pressing "Cancel" 2466** or Ctrl-C where the user wants a long query operation to halt 2467** immediately. 2468** 2469** ^It is safe to call this routine from a thread different from the 2470** thread that is currently running the database operation. But it 2471** is not safe to call this routine with a [database connection] that 2472** is closed or might close before sqlite3_interrupt() returns. 2473** 2474** ^If an SQL operation is very nearly finished at the time when 2475** sqlite3_interrupt() is called, then it might not have an opportunity 2476** to be interrupted and might continue to completion. 2477** 2478** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2479** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2480** that is inside an explicit transaction, then the entire transaction 2481** will be rolled back automatically. 2482** 2483** ^The sqlite3_interrupt(D) call is in effect until all currently running 2484** SQL statements on [database connection] D complete. ^Any new SQL statements 2485** that are started after the sqlite3_interrupt() call and before the 2486** running statements reaches zero are interrupted as if they had been 2487** running prior to the sqlite3_interrupt() call. ^New SQL statements 2488** that are started after the running statement count reaches zero are 2489** not effected by the sqlite3_interrupt(). 2490** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2491** SQL statements is a no-op and has no effect on SQL statements 2492** that are started after the sqlite3_interrupt() call returns. 2493*/ 2494void sqlite3_interrupt(sqlite3*); 2495 2496/* 2497** CAPI3REF: Determine If An SQL Statement Is Complete 2498** 2499** These routines are useful during command-line input to determine if the 2500** currently entered text seems to form a complete SQL statement or 2501** if additional input is needed before sending the text into 2502** SQLite for parsing. ^These routines return 1 if the input string 2503** appears to be a complete SQL statement. ^A statement is judged to be 2504** complete if it ends with a semicolon token and is not a prefix of a 2505** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2506** string literals or quoted identifier names or comments are not 2507** independent tokens (they are part of the token in which they are 2508** embedded) and thus do not count as a statement terminator. ^Whitespace 2509** and comments that follow the final semicolon are ignored. 2510** 2511** ^These routines return 0 if the statement is incomplete. ^If a 2512** memory allocation fails, then SQLITE_NOMEM is returned. 2513** 2514** ^These routines do not parse the SQL statements thus 2515** will not detect syntactically incorrect SQL. 2516** 2517** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2518** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2519** automatically by sqlite3_complete16(). If that initialization fails, 2520** then the return value from sqlite3_complete16() will be non-zero 2521** regardless of whether or not the input SQL is complete.)^ 2522** 2523** The input to [sqlite3_complete()] must be a zero-terminated 2524** UTF-8 string. 2525** 2526** The input to [sqlite3_complete16()] must be a zero-terminated 2527** UTF-16 string in native byte order. 2528*/ 2529int sqlite3_complete(const char *sql); 2530int sqlite3_complete16(const void *sql); 2531 2532/* 2533** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2534** KEYWORDS: {busy-handler callback} {busy handler} 2535** METHOD: sqlite3 2536** 2537** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2538** that might be invoked with argument P whenever 2539** an attempt is made to access a database table associated with 2540** [database connection] D when another thread 2541** or process has the table locked. 2542** The sqlite3_busy_handler() interface is used to implement 2543** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2544** 2545** ^If the busy callback is NULL, then [SQLITE_BUSY] 2546** is returned immediately upon encountering the lock. ^If the busy callback 2547** is not NULL, then the callback might be invoked with two arguments. 2548** 2549** ^The first argument to the busy handler is a copy of the void* pointer which 2550** is the third argument to sqlite3_busy_handler(). ^The second argument to 2551** the busy handler callback is the number of times that the busy handler has 2552** been invoked previously for the same locking event. ^If the 2553** busy callback returns 0, then no additional attempts are made to 2554** access the database and [SQLITE_BUSY] is returned 2555** to the application. 2556** ^If the callback returns non-zero, then another attempt 2557** is made to access the database and the cycle repeats. 2558** 2559** The presence of a busy handler does not guarantee that it will be invoked 2560** when there is lock contention. ^If SQLite determines that invoking the busy 2561** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2562** to the application instead of invoking the 2563** busy handler. 2564** Consider a scenario where one process is holding a read lock that 2565** it is trying to promote to a reserved lock and 2566** a second process is holding a reserved lock that it is trying 2567** to promote to an exclusive lock. The first process cannot proceed 2568** because it is blocked by the second and the second process cannot 2569** proceed because it is blocked by the first. If both processes 2570** invoke the busy handlers, neither will make any progress. Therefore, 2571** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2572** will induce the first process to release its read lock and allow 2573** the second process to proceed. 2574** 2575** ^The default busy callback is NULL. 2576** 2577** ^(There can only be a single busy handler defined for each 2578** [database connection]. Setting a new busy handler clears any 2579** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2580** or evaluating [PRAGMA busy_timeout=N] will change the 2581** busy handler and thus clear any previously set busy handler. 2582** 2583** The busy callback should not take any actions which modify the 2584** database connection that invoked the busy handler. In other words, 2585** the busy handler is not reentrant. Any such actions 2586** result in undefined behavior. 2587** 2588** A busy handler must not close the database connection 2589** or [prepared statement] that invoked the busy handler. 2590*/ 2591int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2592 2593/* 2594** CAPI3REF: Set A Busy Timeout 2595** METHOD: sqlite3 2596** 2597** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2598** for a specified amount of time when a table is locked. ^The handler 2599** will sleep multiple times until at least "ms" milliseconds of sleeping 2600** have accumulated. ^After at least "ms" milliseconds of sleeping, 2601** the handler returns 0 which causes [sqlite3_step()] to return 2602** [SQLITE_BUSY]. 2603** 2604** ^Calling this routine with an argument less than or equal to zero 2605** turns off all busy handlers. 2606** 2607** ^(There can only be a single busy handler for a particular 2608** [database connection] at any given moment. If another busy handler 2609** was defined (using [sqlite3_busy_handler()]) prior to calling 2610** this routine, that other busy handler is cleared.)^ 2611** 2612** See also: [PRAGMA busy_timeout] 2613*/ 2614int sqlite3_busy_timeout(sqlite3*, int ms); 2615 2616/* 2617** CAPI3REF: Convenience Routines For Running Queries 2618** METHOD: sqlite3 2619** 2620** This is a legacy interface that is preserved for backwards compatibility. 2621** Use of this interface is not recommended. 2622** 2623** Definition: A <b>result table</b> is memory data structure created by the 2624** [sqlite3_get_table()] interface. A result table records the 2625** complete query results from one or more queries. 2626** 2627** The table conceptually has a number of rows and columns. But 2628** these numbers are not part of the result table itself. These 2629** numbers are obtained separately. Let N be the number of rows 2630** and M be the number of columns. 2631** 2632** A result table is an array of pointers to zero-terminated UTF-8 strings. 2633** There are (N+1)*M elements in the array. The first M pointers point 2634** to zero-terminated strings that contain the names of the columns. 2635** The remaining entries all point to query results. NULL values result 2636** in NULL pointers. All other values are in their UTF-8 zero-terminated 2637** string representation as returned by [sqlite3_column_text()]. 2638** 2639** A result table might consist of one or more memory allocations. 2640** It is not safe to pass a result table directly to [sqlite3_free()]. 2641** A result table should be deallocated using [sqlite3_free_table()]. 2642** 2643** ^(As an example of the result table format, suppose a query result 2644** is as follows: 2645** 2646** <blockquote><pre> 2647** Name | Age 2648** ----------------------- 2649** Alice | 43 2650** Bob | 28 2651** Cindy | 21 2652** </pre></blockquote> 2653** 2654** There are two column (M==2) and three rows (N==3). Thus the 2655** result table has 8 entries. Suppose the result table is stored 2656** in an array names azResult. Then azResult holds this content: 2657** 2658** <blockquote><pre> 2659** azResult[0] = "Name"; 2660** azResult[1] = "Age"; 2661** azResult[2] = "Alice"; 2662** azResult[3] = "43"; 2663** azResult[4] = "Bob"; 2664** azResult[5] = "28"; 2665** azResult[6] = "Cindy"; 2666** azResult[7] = "21"; 2667** </pre></blockquote>)^ 2668** 2669** ^The sqlite3_get_table() function evaluates one or more 2670** semicolon-separated SQL statements in the zero-terminated UTF-8 2671** string of its 2nd parameter and returns a result table to the 2672** pointer given in its 3rd parameter. 2673** 2674** After the application has finished with the result from sqlite3_get_table(), 2675** it must pass the result table pointer to sqlite3_free_table() in order to 2676** release the memory that was malloced. Because of the way the 2677** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2678** function must not try to call [sqlite3_free()] directly. Only 2679** [sqlite3_free_table()] is able to release the memory properly and safely. 2680** 2681** The sqlite3_get_table() interface is implemented as a wrapper around 2682** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2683** to any internal data structures of SQLite. It uses only the public 2684** interface defined here. As a consequence, errors that occur in the 2685** wrapper layer outside of the internal [sqlite3_exec()] call are not 2686** reflected in subsequent calls to [sqlite3_errcode()] or 2687** [sqlite3_errmsg()]. 2688*/ 2689int sqlite3_get_table( 2690 sqlite3 *db, /* An open database */ 2691 const char *zSql, /* SQL to be evaluated */ 2692 char ***pazResult, /* Results of the query */ 2693 int *pnRow, /* Number of result rows written here */ 2694 int *pnColumn, /* Number of result columns written here */ 2695 char **pzErrmsg /* Error msg written here */ 2696); 2697void sqlite3_free_table(char **result); 2698 2699/* 2700** CAPI3REF: Formatted String Printing Functions 2701** 2702** These routines are work-alikes of the "printf()" family of functions 2703** from the standard C library. 2704** These routines understand most of the common formatting options from 2705** the standard library printf() 2706** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2707** See the [built-in printf()] documentation for details. 2708** 2709** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2710** results into memory obtained from [sqlite3_malloc64()]. 2711** The strings returned by these two routines should be 2712** released by [sqlite3_free()]. ^Both routines return a 2713** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2714** memory to hold the resulting string. 2715** 2716** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2717** the standard C library. The result is written into the 2718** buffer supplied as the second parameter whose size is given by 2719** the first parameter. Note that the order of the 2720** first two parameters is reversed from snprintf().)^ This is an 2721** historical accident that cannot be fixed without breaking 2722** backwards compatibility. ^(Note also that sqlite3_snprintf() 2723** returns a pointer to its buffer instead of the number of 2724** characters actually written into the buffer.)^ We admit that 2725** the number of characters written would be a more useful return 2726** value but we cannot change the implementation of sqlite3_snprintf() 2727** now without breaking compatibility. 2728** 2729** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2730** guarantees that the buffer is always zero-terminated. ^The first 2731** parameter "n" is the total size of the buffer, including space for 2732** the zero terminator. So the longest string that can be completely 2733** written will be n-1 characters. 2734** 2735** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2736** 2737** See also: [built-in printf()], [printf() SQL function] 2738*/ 2739char *sqlite3_mprintf(const char*,...); 2740char *sqlite3_vmprintf(const char*, va_list); 2741char *sqlite3_snprintf(int,char*,const char*, ...); 2742char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2743 2744/* 2745** CAPI3REF: Memory Allocation Subsystem 2746** 2747** The SQLite core uses these three routines for all of its own 2748** internal memory allocation needs. "Core" in the previous sentence 2749** does not include operating-system specific VFS implementation. The 2750** Windows VFS uses native malloc() and free() for some operations. 2751** 2752** ^The sqlite3_malloc() routine returns a pointer to a block 2753** of memory at least N bytes in length, where N is the parameter. 2754** ^If sqlite3_malloc() is unable to obtain sufficient free 2755** memory, it returns a NULL pointer. ^If the parameter N to 2756** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2757** a NULL pointer. 2758** 2759** ^The sqlite3_malloc64(N) routine works just like 2760** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2761** of a signed 32-bit integer. 2762** 2763** ^Calling sqlite3_free() with a pointer previously returned 2764** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2765** that it might be reused. ^The sqlite3_free() routine is 2766** a no-op if is called with a NULL pointer. Passing a NULL pointer 2767** to sqlite3_free() is harmless. After being freed, memory 2768** should neither be read nor written. Even reading previously freed 2769** memory might result in a segmentation fault or other severe error. 2770** Memory corruption, a segmentation fault, or other severe error 2771** might result if sqlite3_free() is called with a non-NULL pointer that 2772** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2773** 2774** ^The sqlite3_realloc(X,N) interface attempts to resize a 2775** prior memory allocation X to be at least N bytes. 2776** ^If the X parameter to sqlite3_realloc(X,N) 2777** is a NULL pointer then its behavior is identical to calling 2778** sqlite3_malloc(N). 2779** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2780** negative then the behavior is exactly the same as calling 2781** sqlite3_free(X). 2782** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2783** of at least N bytes in size or NULL if insufficient memory is available. 2784** ^If M is the size of the prior allocation, then min(N,M) bytes 2785** of the prior allocation are copied into the beginning of buffer returned 2786** by sqlite3_realloc(X,N) and the prior allocation is freed. 2787** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2788** prior allocation is not freed. 2789** 2790** ^The sqlite3_realloc64(X,N) interfaces works the same as 2791** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2792** of a 32-bit signed integer. 2793** 2794** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2795** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2796** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2797** ^The value returned by sqlite3_msize(X) might be larger than the number 2798** of bytes requested when X was allocated. ^If X is a NULL pointer then 2799** sqlite3_msize(X) returns zero. If X points to something that is not 2800** the beginning of memory allocation, or if it points to a formerly 2801** valid memory allocation that has now been freed, then the behavior 2802** of sqlite3_msize(X) is undefined and possibly harmful. 2803** 2804** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2805** sqlite3_malloc64(), and sqlite3_realloc64() 2806** is always aligned to at least an 8 byte boundary, or to a 2807** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2808** option is used. 2809** 2810** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2811** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2812** implementation of these routines to be omitted. That capability 2813** is no longer provided. Only built-in memory allocators can be used. 2814** 2815** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2816** the system malloc() and free() directly when converting 2817** filenames between the UTF-8 encoding used by SQLite 2818** and whatever filename encoding is used by the particular Windows 2819** installation. Memory allocation errors were detected, but 2820** they were reported back as [SQLITE_CANTOPEN] or 2821** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2822** 2823** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2824** must be either NULL or else pointers obtained from a prior 2825** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2826** not yet been released. 2827** 2828** The application must not read or write any part of 2829** a block of memory after it has been released using 2830** [sqlite3_free()] or [sqlite3_realloc()]. 2831*/ 2832void *sqlite3_malloc(int); 2833void *sqlite3_malloc64(sqlite3_uint64); 2834void *sqlite3_realloc(void*, int); 2835void *sqlite3_realloc64(void*, sqlite3_uint64); 2836void sqlite3_free(void*); 2837sqlite3_uint64 sqlite3_msize(void*); 2838 2839/* 2840** CAPI3REF: Memory Allocator Statistics 2841** 2842** SQLite provides these two interfaces for reporting on the status 2843** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2844** routines, which form the built-in memory allocation subsystem. 2845** 2846** ^The [sqlite3_memory_used()] routine returns the number of bytes 2847** of memory currently outstanding (malloced but not freed). 2848** ^The [sqlite3_memory_highwater()] routine returns the maximum 2849** value of [sqlite3_memory_used()] since the high-water mark 2850** was last reset. ^The values returned by [sqlite3_memory_used()] and 2851** [sqlite3_memory_highwater()] include any overhead 2852** added by SQLite in its implementation of [sqlite3_malloc()], 2853** but not overhead added by the any underlying system library 2854** routines that [sqlite3_malloc()] may call. 2855** 2856** ^The memory high-water mark is reset to the current value of 2857** [sqlite3_memory_used()] if and only if the parameter to 2858** [sqlite3_memory_highwater()] is true. ^The value returned 2859** by [sqlite3_memory_highwater(1)] is the high-water mark 2860** prior to the reset. 2861*/ 2862sqlite3_int64 sqlite3_memory_used(void); 2863sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2864 2865/* 2866** CAPI3REF: Pseudo-Random Number Generator 2867** 2868** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2869** select random [ROWID | ROWIDs] when inserting new records into a table that 2870** already uses the largest possible [ROWID]. The PRNG is also used for 2871** the build-in random() and randomblob() SQL functions. This interface allows 2872** applications to access the same PRNG for other purposes. 2873** 2874** ^A call to this routine stores N bytes of randomness into buffer P. 2875** ^The P parameter can be a NULL pointer. 2876** 2877** ^If this routine has not been previously called or if the previous 2878** call had N less than one or a NULL pointer for P, then the PRNG is 2879** seeded using randomness obtained from the xRandomness method of 2880** the default [sqlite3_vfs] object. 2881** ^If the previous call to this routine had an N of 1 or more and a 2882** non-NULL P then the pseudo-randomness is generated 2883** internally and without recourse to the [sqlite3_vfs] xRandomness 2884** method. 2885*/ 2886void sqlite3_randomness(int N, void *P); 2887 2888/* 2889** CAPI3REF: Compile-Time Authorization Callbacks 2890** METHOD: sqlite3 2891** KEYWORDS: {authorizer callback} 2892** 2893** ^This routine registers an authorizer callback with a particular 2894** [database connection], supplied in the first argument. 2895** ^The authorizer callback is invoked as SQL statements are being compiled 2896** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2897** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2898** and [sqlite3_prepare16_v3()]. ^At various 2899** points during the compilation process, as logic is being created 2900** to perform various actions, the authorizer callback is invoked to 2901** see if those actions are allowed. ^The authorizer callback should 2902** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2903** specific action but allow the SQL statement to continue to be 2904** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2905** rejected with an error. ^If the authorizer callback returns 2906** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2907** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2908** the authorizer will fail with an error message. 2909** 2910** When the callback returns [SQLITE_OK], that means the operation 2911** requested is ok. ^When the callback returns [SQLITE_DENY], the 2912** [sqlite3_prepare_v2()] or equivalent call that triggered the 2913** authorizer will fail with an error message explaining that 2914** access is denied. 2915** 2916** ^The first parameter to the authorizer callback is a copy of the third 2917** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2918** to the callback is an integer [SQLITE_COPY | action code] that specifies 2919** the particular action to be authorized. ^The third through sixth parameters 2920** to the callback are either NULL pointers or zero-terminated strings 2921** that contain additional details about the action to be authorized. 2922** Applications must always be prepared to encounter a NULL pointer in any 2923** of the third through the sixth parameters of the authorization callback. 2924** 2925** ^If the action code is [SQLITE_READ] 2926** and the callback returns [SQLITE_IGNORE] then the 2927** [prepared statement] statement is constructed to substitute 2928** a NULL value in place of the table column that would have 2929** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2930** return can be used to deny an untrusted user access to individual 2931** columns of a table. 2932** ^When a table is referenced by a [SELECT] but no column values are 2933** extracted from that table (for example in a query like 2934** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2935** is invoked once for that table with a column name that is an empty string. 2936** ^If the action code is [SQLITE_DELETE] and the callback returns 2937** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2938** [truncate optimization] is disabled and all rows are deleted individually. 2939** 2940** An authorizer is used when [sqlite3_prepare | preparing] 2941** SQL statements from an untrusted source, to ensure that the SQL statements 2942** do not try to access data they are not allowed to see, or that they do not 2943** try to execute malicious statements that damage the database. For 2944** example, an application may allow a user to enter arbitrary 2945** SQL queries for evaluation by a database. But the application does 2946** not want the user to be able to make arbitrary changes to the 2947** database. An authorizer could then be put in place while the 2948** user-entered SQL is being [sqlite3_prepare | prepared] that 2949** disallows everything except [SELECT] statements. 2950** 2951** Applications that need to process SQL from untrusted sources 2952** might also consider lowering resource limits using [sqlite3_limit()] 2953** and limiting database size using the [max_page_count] [PRAGMA] 2954** in addition to using an authorizer. 2955** 2956** ^(Only a single authorizer can be in place on a database connection 2957** at a time. Each call to sqlite3_set_authorizer overrides the 2958** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2959** The authorizer is disabled by default. 2960** 2961** The authorizer callback must not do anything that will modify 2962** the database connection that invoked the authorizer callback. 2963** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2964** database connections for the meaning of "modify" in this paragraph. 2965** 2966** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2967** statement might be re-prepared during [sqlite3_step()] due to a 2968** schema change. Hence, the application should ensure that the 2969** correct authorizer callback remains in place during the [sqlite3_step()]. 2970** 2971** ^Note that the authorizer callback is invoked only during 2972** [sqlite3_prepare()] or its variants. Authorization is not 2973** performed during statement evaluation in [sqlite3_step()], unless 2974** as stated in the previous paragraph, sqlite3_step() invokes 2975** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2976*/ 2977int sqlite3_set_authorizer( 2978 sqlite3*, 2979 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2980 void *pUserData 2981); 2982 2983/* 2984** CAPI3REF: Authorizer Return Codes 2985** 2986** The [sqlite3_set_authorizer | authorizer callback function] must 2987** return either [SQLITE_OK] or one of these two constants in order 2988** to signal SQLite whether or not the action is permitted. See the 2989** [sqlite3_set_authorizer | authorizer documentation] for additional 2990** information. 2991** 2992** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2993** returned from the [sqlite3_vtab_on_conflict()] interface. 2994*/ 2995#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2996#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2997 2998/* 2999** CAPI3REF: Authorizer Action Codes 3000** 3001** The [sqlite3_set_authorizer()] interface registers a callback function 3002** that is invoked to authorize certain SQL statement actions. The 3003** second parameter to the callback is an integer code that specifies 3004** what action is being authorized. These are the integer action codes that 3005** the authorizer callback may be passed. 3006** 3007** These action code values signify what kind of operation is to be 3008** authorized. The 3rd and 4th parameters to the authorization 3009** callback function will be parameters or NULL depending on which of these 3010** codes is used as the second parameter. ^(The 5th parameter to the 3011** authorizer callback is the name of the database ("main", "temp", 3012** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3013** is the name of the inner-most trigger or view that is responsible for 3014** the access attempt or NULL if this access attempt is directly from 3015** top-level SQL code. 3016*/ 3017/******************************************* 3rd ************ 4th ***********/ 3018#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3019#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3020#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3021#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3022#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3023#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3024#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3025#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3026#define SQLITE_DELETE 9 /* Table Name NULL */ 3027#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3028#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3029#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3030#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3031#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3032#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3033#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3034#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3035#define SQLITE_INSERT 18 /* Table Name NULL */ 3036#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3037#define SQLITE_READ 20 /* Table Name Column Name */ 3038#define SQLITE_SELECT 21 /* NULL NULL */ 3039#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3040#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3041#define SQLITE_ATTACH 24 /* Filename NULL */ 3042#define SQLITE_DETACH 25 /* Database Name NULL */ 3043#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3044#define SQLITE_REINDEX 27 /* Index Name NULL */ 3045#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3046#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3047#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3048#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3049#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3050#define SQLITE_COPY 0 /* No longer used */ 3051#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3052 3053/* 3054** CAPI3REF: Tracing And Profiling Functions 3055** METHOD: sqlite3 3056** 3057** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3058** instead of the routines described here. 3059** 3060** These routines register callback functions that can be used for 3061** tracing and profiling the execution of SQL statements. 3062** 3063** ^The callback function registered by sqlite3_trace() is invoked at 3064** various times when an SQL statement is being run by [sqlite3_step()]. 3065** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3066** SQL statement text as the statement first begins executing. 3067** ^(Additional sqlite3_trace() callbacks might occur 3068** as each triggered subprogram is entered. The callbacks for triggers 3069** contain a UTF-8 SQL comment that identifies the trigger.)^ 3070** 3071** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3072** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3073** 3074** ^The callback function registered by sqlite3_profile() is invoked 3075** as each SQL statement finishes. ^The profile callback contains 3076** the original statement text and an estimate of wall-clock time 3077** of how long that statement took to run. ^The profile callback 3078** time is in units of nanoseconds, however the current implementation 3079** is only capable of millisecond resolution so the six least significant 3080** digits in the time are meaningless. Future versions of SQLite 3081** might provide greater resolution on the profiler callback. Invoking 3082** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3083** profile callback. 3084*/ 3085SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3086 void(*xTrace)(void*,const char*), void*); 3087SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3088 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3089 3090/* 3091** CAPI3REF: SQL Trace Event Codes 3092** KEYWORDS: SQLITE_TRACE 3093** 3094** These constants identify classes of events that can be monitored 3095** using the [sqlite3_trace_v2()] tracing logic. The M argument 3096** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3097** the following constants. ^The first argument to the trace callback 3098** is one of the following constants. 3099** 3100** New tracing constants may be added in future releases. 3101** 3102** ^A trace callback has four arguments: xCallback(T,C,P,X). 3103** ^The T argument is one of the integer type codes above. 3104** ^The C argument is a copy of the context pointer passed in as the 3105** fourth argument to [sqlite3_trace_v2()]. 3106** The P and X arguments are pointers whose meanings depend on T. 3107** 3108** <dl> 3109** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3110** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3111** first begins running and possibly at other times during the 3112** execution of the prepared statement, such as at the start of each 3113** trigger subprogram. ^The P argument is a pointer to the 3114** [prepared statement]. ^The X argument is a pointer to a string which 3115** is the unexpanded SQL text of the prepared statement or an SQL comment 3116** that indicates the invocation of a trigger. ^The callback can compute 3117** the same text that would have been returned by the legacy [sqlite3_trace()] 3118** interface by using the X argument when X begins with "--" and invoking 3119** [sqlite3_expanded_sql(P)] otherwise. 3120** 3121** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3122** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3123** information as is provided by the [sqlite3_profile()] callback. 3124** ^The P argument is a pointer to the [prepared statement] and the 3125** X argument points to a 64-bit integer which is the estimated of 3126** the number of nanosecond that the prepared statement took to run. 3127** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3128** 3129** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3130** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3131** statement generates a single row of result. 3132** ^The P argument is a pointer to the [prepared statement] and the 3133** X argument is unused. 3134** 3135** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3136** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3137** connection closes. 3138** ^The P argument is a pointer to the [database connection] object 3139** and the X argument is unused. 3140** </dl> 3141*/ 3142#define SQLITE_TRACE_STMT 0x01 3143#define SQLITE_TRACE_PROFILE 0x02 3144#define SQLITE_TRACE_ROW 0x04 3145#define SQLITE_TRACE_CLOSE 0x08 3146 3147/* 3148** CAPI3REF: SQL Trace Hook 3149** METHOD: sqlite3 3150** 3151** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3152** function X against [database connection] D, using property mask M 3153** and context pointer P. ^If the X callback is 3154** NULL or if the M mask is zero, then tracing is disabled. The 3155** M argument should be the bitwise OR-ed combination of 3156** zero or more [SQLITE_TRACE] constants. 3157** 3158** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3159** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3160** 3161** ^The X callback is invoked whenever any of the events identified by 3162** mask M occur. ^The integer return value from the callback is currently 3163** ignored, though this may change in future releases. Callback 3164** implementations should return zero to ensure future compatibility. 3165** 3166** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3167** ^The T argument is one of the [SQLITE_TRACE] 3168** constants to indicate why the callback was invoked. 3169** ^The C argument is a copy of the context pointer. 3170** The P and X arguments are pointers whose meanings depend on T. 3171** 3172** The sqlite3_trace_v2() interface is intended to replace the legacy 3173** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3174** are deprecated. 3175*/ 3176int sqlite3_trace_v2( 3177 sqlite3*, 3178 unsigned uMask, 3179 int(*xCallback)(unsigned,void*,void*,void*), 3180 void *pCtx 3181); 3182 3183/* 3184** CAPI3REF: Query Progress Callbacks 3185** METHOD: sqlite3 3186** 3187** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3188** function X to be invoked periodically during long running calls to 3189** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3190** database connection D. An example use for this 3191** interface is to keep a GUI updated during a large query. 3192** 3193** ^The parameter P is passed through as the only parameter to the 3194** callback function X. ^The parameter N is the approximate number of 3195** [virtual machine instructions] that are evaluated between successive 3196** invocations of the callback X. ^If N is less than one then the progress 3197** handler is disabled. 3198** 3199** ^Only a single progress handler may be defined at one time per 3200** [database connection]; setting a new progress handler cancels the 3201** old one. ^Setting parameter X to NULL disables the progress handler. 3202** ^The progress handler is also disabled by setting N to a value less 3203** than 1. 3204** 3205** ^If the progress callback returns non-zero, the operation is 3206** interrupted. This feature can be used to implement a 3207** "Cancel" button on a GUI progress dialog box. 3208** 3209** The progress handler callback must not do anything that will modify 3210** the database connection that invoked the progress handler. 3211** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3212** database connections for the meaning of "modify" in this paragraph. 3213** 3214*/ 3215void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3216 3217/* 3218** CAPI3REF: Opening A New Database Connection 3219** CONSTRUCTOR: sqlite3 3220** 3221** ^These routines open an SQLite database file as specified by the 3222** filename argument. ^The filename argument is interpreted as UTF-8 for 3223** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3224** order for sqlite3_open16(). ^(A [database connection] handle is usually 3225** returned in *ppDb, even if an error occurs. The only exception is that 3226** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3227** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3228** object.)^ ^(If the database is opened (and/or created) successfully, then 3229** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3230** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3231** an English language description of the error following a failure of any 3232** of the sqlite3_open() routines. 3233** 3234** ^The default encoding will be UTF-8 for databases created using 3235** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3236** created using sqlite3_open16() will be UTF-16 in the native byte order. 3237** 3238** Whether or not an error occurs when it is opened, resources 3239** associated with the [database connection] handle should be released by 3240** passing it to [sqlite3_close()] when it is no longer required. 3241** 3242** The sqlite3_open_v2() interface works like sqlite3_open() 3243** except that it accepts two additional parameters for additional control 3244** over the new database connection. ^(The flags parameter to 3245** sqlite3_open_v2() can take one of 3246** the following three values, optionally combined with the 3247** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3248** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3249** 3250** <dl> 3251** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3252** <dd>The database is opened in read-only mode. If the database does not 3253** already exist, an error is returned.</dd>)^ 3254** 3255** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3256** <dd>The database is opened for reading and writing if possible, or reading 3257** only if the file is write protected by the operating system. In either 3258** case the database must already exist, otherwise an error is returned.</dd>)^ 3259** 3260** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3261** <dd>The database is opened for reading and writing, and is created if 3262** it does not already exist. This is the behavior that is always used for 3263** sqlite3_open() and sqlite3_open16().</dd>)^ 3264** </dl> 3265** 3266** If the 3rd parameter to sqlite3_open_v2() is not one of the 3267** combinations shown above optionally combined with other 3268** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3269** then the behavior is undefined. 3270** 3271** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3272** opens in the multi-thread [threading mode] as long as the single-thread 3273** mode has not been set at compile-time or start-time. ^If the 3274** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3275** in the serialized [threading mode] unless single-thread was 3276** previously selected at compile-time or start-time. 3277** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3278** eligible to use [shared cache mode], regardless of whether or not shared 3279** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3280** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3281** participate in [shared cache mode] even if it is enabled. 3282** 3283** ^The fourth parameter to sqlite3_open_v2() is the name of the 3284** [sqlite3_vfs] object that defines the operating system interface that 3285** the new database connection should use. ^If the fourth parameter is 3286** a NULL pointer then the default [sqlite3_vfs] object is used. 3287** 3288** ^If the filename is ":memory:", then a private, temporary in-memory database 3289** is created for the connection. ^This in-memory database will vanish when 3290** the database connection is closed. Future versions of SQLite might 3291** make use of additional special filenames that begin with the ":" character. 3292** It is recommended that when a database filename actually does begin with 3293** a ":" character you should prefix the filename with a pathname such as 3294** "./" to avoid ambiguity. 3295** 3296** ^If the filename is an empty string, then a private, temporary 3297** on-disk database will be created. ^This private database will be 3298** automatically deleted as soon as the database connection is closed. 3299** 3300** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3301** 3302** ^If [URI filename] interpretation is enabled, and the filename argument 3303** begins with "file:", then the filename is interpreted as a URI. ^URI 3304** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3305** set in the third argument to sqlite3_open_v2(), or if it has 3306** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3307** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3308** URI filename interpretation is turned off 3309** by default, but future releases of SQLite might enable URI filename 3310** interpretation by default. See "[URI filenames]" for additional 3311** information. 3312** 3313** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3314** authority, then it must be either an empty string or the string 3315** "localhost". ^If the authority is not an empty string or "localhost", an 3316** error is returned to the caller. ^The fragment component of a URI, if 3317** present, is ignored. 3318** 3319** ^SQLite uses the path component of the URI as the name of the disk file 3320** which contains the database. ^If the path begins with a '/' character, 3321** then it is interpreted as an absolute path. ^If the path does not begin 3322** with a '/' (meaning that the authority section is omitted from the URI) 3323** then the path is interpreted as a relative path. 3324** ^(On windows, the first component of an absolute path 3325** is a drive specification (e.g. "C:").)^ 3326** 3327** [[core URI query parameters]] 3328** The query component of a URI may contain parameters that are interpreted 3329** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3330** SQLite and its built-in [VFSes] interpret the 3331** following query parameters: 3332** 3333** <ul> 3334** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3335** a VFS object that provides the operating system interface that should 3336** be used to access the database file on disk. ^If this option is set to 3337** an empty string the default VFS object is used. ^Specifying an unknown 3338** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3339** present, then the VFS specified by the option takes precedence over 3340** the value passed as the fourth parameter to sqlite3_open_v2(). 3341** 3342** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3343** "rwc", or "memory". Attempting to set it to any other value is 3344** an error)^. 3345** ^If "ro" is specified, then the database is opened for read-only 3346** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3347** third argument to sqlite3_open_v2(). ^If the mode option is set to 3348** "rw", then the database is opened for read-write (but not create) 3349** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3350** been set. ^Value "rwc" is equivalent to setting both 3351** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3352** set to "memory" then a pure [in-memory database] that never reads 3353** or writes from disk is used. ^It is an error to specify a value for 3354** the mode parameter that is less restrictive than that specified by 3355** the flags passed in the third parameter to sqlite3_open_v2(). 3356** 3357** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3358** "private". ^Setting it to "shared" is equivalent to setting the 3359** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3360** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3361** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3362** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3363** a URI filename, its value overrides any behavior requested by setting 3364** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3365** 3366** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3367** [powersafe overwrite] property does or does not apply to the 3368** storage media on which the database file resides. 3369** 3370** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3371** which if set disables file locking in rollback journal modes. This 3372** is useful for accessing a database on a filesystem that does not 3373** support locking. Caution: Database corruption might result if two 3374** or more processes write to the same database and any one of those 3375** processes uses nolock=1. 3376** 3377** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3378** parameter that indicates that the database file is stored on 3379** read-only media. ^When immutable is set, SQLite assumes that the 3380** database file cannot be changed, even by a process with higher 3381** privilege, and so the database is opened read-only and all locking 3382** and change detection is disabled. Caution: Setting the immutable 3383** property on a database file that does in fact change can result 3384** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3385** See also: [SQLITE_IOCAP_IMMUTABLE]. 3386** 3387** </ul> 3388** 3389** ^Specifying an unknown parameter in the query component of a URI is not an 3390** error. Future versions of SQLite might understand additional query 3391** parameters. See "[query parameters with special meaning to SQLite]" for 3392** additional information. 3393** 3394** [[URI filename examples]] <h3>URI filename examples</h3> 3395** 3396** <table border="1" align=center cellpadding=5> 3397** <tr><th> URI filenames <th> Results 3398** <tr><td> file:data.db <td> 3399** Open the file "data.db" in the current directory. 3400** <tr><td> file:/home/fred/data.db<br> 3401** file:///home/fred/data.db <br> 3402** file://localhost/home/fred/data.db <br> <td> 3403** Open the database file "/home/fred/data.db". 3404** <tr><td> file://darkstar/home/fred/data.db <td> 3405** An error. "darkstar" is not a recognized authority. 3406** <tr><td style="white-space:nowrap"> 3407** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3408** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3409** C:. Note that the %20 escaping in this example is not strictly 3410** necessary - space characters can be used literally 3411** in URI filenames. 3412** <tr><td> file:data.db?mode=ro&cache=private <td> 3413** Open file "data.db" in the current directory for read-only access. 3414** Regardless of whether or not shared-cache mode is enabled by 3415** default, use a private cache. 3416** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3417** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3418** that uses dot-files in place of posix advisory locking. 3419** <tr><td> file:data.db?mode=readonly <td> 3420** An error. "readonly" is not a valid option for the "mode" parameter. 3421** </table> 3422** 3423** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3424** query components of a URI. A hexadecimal escape sequence consists of a 3425** percent sign - "%" - followed by exactly two hexadecimal digits 3426** specifying an octet value. ^Before the path or query components of a 3427** URI filename are interpreted, they are encoded using UTF-8 and all 3428** hexadecimal escape sequences replaced by a single byte containing the 3429** corresponding octet. If this process generates an invalid UTF-8 encoding, 3430** the results are undefined. 3431** 3432** <b>Note to Windows users:</b> The encoding used for the filename argument 3433** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3434** codepage is currently defined. Filenames containing international 3435** characters must be converted to UTF-8 prior to passing them into 3436** sqlite3_open() or sqlite3_open_v2(). 3437** 3438** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3439** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3440** features that require the use of temporary files may fail. 3441** 3442** See also: [sqlite3_temp_directory] 3443*/ 3444int sqlite3_open( 3445 const char *filename, /* Database filename (UTF-8) */ 3446 sqlite3 **ppDb /* OUT: SQLite db handle */ 3447); 3448int sqlite3_open16( 3449 const void *filename, /* Database filename (UTF-16) */ 3450 sqlite3 **ppDb /* OUT: SQLite db handle */ 3451); 3452int sqlite3_open_v2( 3453 const char *filename, /* Database filename (UTF-8) */ 3454 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3455 int flags, /* Flags */ 3456 const char *zVfs /* Name of VFS module to use */ 3457); 3458 3459/* 3460** CAPI3REF: Obtain Values For URI Parameters 3461** 3462** These are utility routines, useful to VFS implementations, that check 3463** to see if a database file was a URI that contained a specific query 3464** parameter, and if so obtains the value of that query parameter. 3465** 3466** If F is the database filename pointer passed into the xOpen() method of 3467** a VFS implementation when the flags parameter to xOpen() has one or 3468** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3469** P is the name of the query parameter, then 3470** sqlite3_uri_parameter(F,P) returns the value of the P 3471** parameter if it exists or a NULL pointer if P does not appear as a 3472** query parameter on F. If P is a query parameter of F 3473** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3474** a pointer to an empty string. 3475** 3476** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3477** parameter and returns true (1) or false (0) according to the value 3478** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3479** value of query parameter P is one of "yes", "true", or "on" in any 3480** case or if the value begins with a non-zero number. The 3481** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3482** query parameter P is one of "no", "false", or "off" in any case or 3483** if the value begins with a numeric zero. If P is not a query 3484** parameter on F or if the value of P is does not match any of the 3485** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3486** 3487** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3488** 64-bit signed integer and returns that integer, or D if P does not 3489** exist. If the value of P is something other than an integer, then 3490** zero is returned. 3491** 3492** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3493** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3494** is not a database file pathname pointer that SQLite passed into the xOpen 3495** VFS method, then the behavior of this routine is undefined and probably 3496** undesirable. 3497** 3498** See the [URI filename] documentation for additional information. 3499*/ 3500const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3501int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3502sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3503 3504 3505/* 3506** CAPI3REF: Error Codes And Messages 3507** METHOD: sqlite3 3508** 3509** ^If the most recent sqlite3_* API call associated with 3510** [database connection] D failed, then the sqlite3_errcode(D) interface 3511** returns the numeric [result code] or [extended result code] for that 3512** API call. 3513** ^The sqlite3_extended_errcode() 3514** interface is the same except that it always returns the 3515** [extended result code] even when extended result codes are 3516** disabled. 3517** 3518** The values returned by sqlite3_errcode() and/or 3519** sqlite3_extended_errcode() might change with each API call. 3520** Except, there are some interfaces that are guaranteed to never 3521** change the value of the error code. The error-code preserving 3522** interfaces are: 3523** 3524** <ul> 3525** <li> sqlite3_errcode() 3526** <li> sqlite3_extended_errcode() 3527** <li> sqlite3_errmsg() 3528** <li> sqlite3_errmsg16() 3529** </ul> 3530** 3531** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3532** text that describes the error, as either UTF-8 or UTF-16 respectively. 3533** ^(Memory to hold the error message string is managed internally. 3534** The application does not need to worry about freeing the result. 3535** However, the error string might be overwritten or deallocated by 3536** subsequent calls to other SQLite interface functions.)^ 3537** 3538** ^The sqlite3_errstr() interface returns the English-language text 3539** that describes the [result code], as UTF-8. 3540** ^(Memory to hold the error message string is managed internally 3541** and must not be freed by the application)^. 3542** 3543** When the serialized [threading mode] is in use, it might be the 3544** case that a second error occurs on a separate thread in between 3545** the time of the first error and the call to these interfaces. 3546** When that happens, the second error will be reported since these 3547** interfaces always report the most recent result. To avoid 3548** this, each thread can obtain exclusive use of the [database connection] D 3549** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3550** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3551** all calls to the interfaces listed here are completed. 3552** 3553** If an interface fails with SQLITE_MISUSE, that means the interface 3554** was invoked incorrectly by the application. In that case, the 3555** error code and message may or may not be set. 3556*/ 3557int sqlite3_errcode(sqlite3 *db); 3558int sqlite3_extended_errcode(sqlite3 *db); 3559const char *sqlite3_errmsg(sqlite3*); 3560const void *sqlite3_errmsg16(sqlite3*); 3561const char *sqlite3_errstr(int); 3562 3563/* 3564** CAPI3REF: Prepared Statement Object 3565** KEYWORDS: {prepared statement} {prepared statements} 3566** 3567** An instance of this object represents a single SQL statement that 3568** has been compiled into binary form and is ready to be evaluated. 3569** 3570** Think of each SQL statement as a separate computer program. The 3571** original SQL text is source code. A prepared statement object 3572** is the compiled object code. All SQL must be converted into a 3573** prepared statement before it can be run. 3574** 3575** The life-cycle of a prepared statement object usually goes like this: 3576** 3577** <ol> 3578** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3579** <li> Bind values to [parameters] using the sqlite3_bind_*() 3580** interfaces. 3581** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3582** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3583** to step 2. Do this zero or more times. 3584** <li> Destroy the object using [sqlite3_finalize()]. 3585** </ol> 3586*/ 3587typedef struct sqlite3_stmt sqlite3_stmt; 3588 3589/* 3590** CAPI3REF: Run-time Limits 3591** METHOD: sqlite3 3592** 3593** ^(This interface allows the size of various constructs to be limited 3594** on a connection by connection basis. The first parameter is the 3595** [database connection] whose limit is to be set or queried. The 3596** second parameter is one of the [limit categories] that define a 3597** class of constructs to be size limited. The third parameter is the 3598** new limit for that construct.)^ 3599** 3600** ^If the new limit is a negative number, the limit is unchanged. 3601** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3602** [limits | hard upper bound] 3603** set at compile-time by a C preprocessor macro called 3604** [limits | SQLITE_MAX_<i>NAME</i>]. 3605** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3606** ^Attempts to increase a limit above its hard upper bound are 3607** silently truncated to the hard upper bound. 3608** 3609** ^Regardless of whether or not the limit was changed, the 3610** [sqlite3_limit()] interface returns the prior value of the limit. 3611** ^Hence, to find the current value of a limit without changing it, 3612** simply invoke this interface with the third parameter set to -1. 3613** 3614** Run-time limits are intended for use in applications that manage 3615** both their own internal database and also databases that are controlled 3616** by untrusted external sources. An example application might be a 3617** web browser that has its own databases for storing history and 3618** separate databases controlled by JavaScript applications downloaded 3619** off the Internet. The internal databases can be given the 3620** large, default limits. Databases managed by external sources can 3621** be given much smaller limits designed to prevent a denial of service 3622** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3623** interface to further control untrusted SQL. The size of the database 3624** created by an untrusted script can be contained using the 3625** [max_page_count] [PRAGMA]. 3626** 3627** New run-time limit categories may be added in future releases. 3628*/ 3629int sqlite3_limit(sqlite3*, int id, int newVal); 3630 3631/* 3632** CAPI3REF: Run-Time Limit Categories 3633** KEYWORDS: {limit category} {*limit categories} 3634** 3635** These constants define various performance limits 3636** that can be lowered at run-time using [sqlite3_limit()]. 3637** The synopsis of the meanings of the various limits is shown below. 3638** Additional information is available at [limits | Limits in SQLite]. 3639** 3640** <dl> 3641** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3642** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3643** 3644** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3645** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3646** 3647** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3648** <dd>The maximum number of columns in a table definition or in the 3649** result set of a [SELECT] or the maximum number of columns in an index 3650** or in an ORDER BY or GROUP BY clause.</dd>)^ 3651** 3652** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3653** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3654** 3655** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3656** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3657** 3658** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3659** <dd>The maximum number of instructions in a virtual machine program 3660** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3661** the equivalent tries to allocate space for more than this many opcodes 3662** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3663** 3664** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3665** <dd>The maximum number of arguments on a function.</dd>)^ 3666** 3667** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3668** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3669** 3670** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3671** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3672** <dd>The maximum length of the pattern argument to the [LIKE] or 3673** [GLOB] operators.</dd>)^ 3674** 3675** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3676** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3677** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3678** 3679** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3680** <dd>The maximum depth of recursion for triggers.</dd>)^ 3681** 3682** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3683** <dd>The maximum number of auxiliary worker threads that a single 3684** [prepared statement] may start.</dd>)^ 3685** </dl> 3686*/ 3687#define SQLITE_LIMIT_LENGTH 0 3688#define SQLITE_LIMIT_SQL_LENGTH 1 3689#define SQLITE_LIMIT_COLUMN 2 3690#define SQLITE_LIMIT_EXPR_DEPTH 3 3691#define SQLITE_LIMIT_COMPOUND_SELECT 4 3692#define SQLITE_LIMIT_VDBE_OP 5 3693#define SQLITE_LIMIT_FUNCTION_ARG 6 3694#define SQLITE_LIMIT_ATTACHED 7 3695#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3696#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3697#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3698#define SQLITE_LIMIT_WORKER_THREADS 11 3699 3700/* 3701** CAPI3REF: Prepare Flags 3702** 3703** These constants define various flags that can be passed into 3704** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3705** [sqlite3_prepare16_v3()] interfaces. 3706** 3707** New flags may be added in future releases of SQLite. 3708** 3709** <dl> 3710** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3711** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3712** that the prepared statement will be retained for a long time and 3713** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3714** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3715** be used just once or at most a few times and then destroyed using 3716** [sqlite3_finalize()] relatively soon. The current implementation acts 3717** on this hint by avoiding the use of [lookaside memory] so as not to 3718** deplete the limited store of lookaside memory. Future versions of 3719** SQLite may act on this hint differently. 3720** 3721** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3722** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3723** to be required for any prepared statement that wanted to use the 3724** [sqlite3_normalized_sql()] interface. However, the 3725** [sqlite3_normalized_sql()] interface is now available to all 3726** prepared statements, regardless of whether or not they use this 3727** flag. 3728** 3729** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3730** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3731** to return an error (error code SQLITE_ERROR) if the statement uses 3732** any virtual tables. 3733** </dl> 3734*/ 3735#define SQLITE_PREPARE_PERSISTENT 0x01 3736#define SQLITE_PREPARE_NORMALIZE 0x02 3737#define SQLITE_PREPARE_NO_VTAB 0x04 3738 3739/* 3740** CAPI3REF: Compiling An SQL Statement 3741** KEYWORDS: {SQL statement compiler} 3742** METHOD: sqlite3 3743** CONSTRUCTOR: sqlite3_stmt 3744** 3745** To execute an SQL statement, it must first be compiled into a byte-code 3746** program using one of these routines. Or, in other words, these routines 3747** are constructors for the [prepared statement] object. 3748** 3749** The preferred routine to use is [sqlite3_prepare_v2()]. The 3750** [sqlite3_prepare()] interface is legacy and should be avoided. 3751** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3752** for special purposes. 3753** 3754** The use of the UTF-8 interfaces is preferred, as SQLite currently 3755** does all parsing using UTF-8. The UTF-16 interfaces are provided 3756** as a convenience. The UTF-16 interfaces work by converting the 3757** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3758** 3759** The first argument, "db", is a [database connection] obtained from a 3760** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3761** [sqlite3_open16()]. The database connection must not have been closed. 3762** 3763** The second argument, "zSql", is the statement to be compiled, encoded 3764** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3765** and sqlite3_prepare_v3() 3766** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3767** and sqlite3_prepare16_v3() use UTF-16. 3768** 3769** ^If the nByte argument is negative, then zSql is read up to the 3770** first zero terminator. ^If nByte is positive, then it is the 3771** number of bytes read from zSql. ^If nByte is zero, then no prepared 3772** statement is generated. 3773** If the caller knows that the supplied string is nul-terminated, then 3774** there is a small performance advantage to passing an nByte parameter that 3775** is the number of bytes in the input string <i>including</i> 3776** the nul-terminator. 3777** 3778** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3779** past the end of the first SQL statement in zSql. These routines only 3780** compile the first statement in zSql, so *pzTail is left pointing to 3781** what remains uncompiled. 3782** 3783** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3784** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3785** to NULL. ^If the input text contains no SQL (if the input is an empty 3786** string or a comment) then *ppStmt is set to NULL. 3787** The calling procedure is responsible for deleting the compiled 3788** SQL statement using [sqlite3_finalize()] after it has finished with it. 3789** ppStmt may not be NULL. 3790** 3791** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3792** otherwise an [error code] is returned. 3793** 3794** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3795** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3796** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3797** are retained for backwards compatibility, but their use is discouraged. 3798** ^In the "vX" interfaces, the prepared statement 3799** that is returned (the [sqlite3_stmt] object) contains a copy of the 3800** original SQL text. This causes the [sqlite3_step()] interface to 3801** behave differently in three ways: 3802** 3803** <ol> 3804** <li> 3805** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3806** always used to do, [sqlite3_step()] will automatically recompile the SQL 3807** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3808** retries will occur before sqlite3_step() gives up and returns an error. 3809** </li> 3810** 3811** <li> 3812** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3813** [error codes] or [extended error codes]. ^The legacy behavior was that 3814** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3815** and the application would have to make a second call to [sqlite3_reset()] 3816** in order to find the underlying cause of the problem. With the "v2" prepare 3817** interfaces, the underlying reason for the error is returned immediately. 3818** </li> 3819** 3820** <li> 3821** ^If the specific value bound to [parameter | host parameter] in the 3822** WHERE clause might influence the choice of query plan for a statement, 3823** then the statement will be automatically recompiled, as if there had been 3824** a schema change, on the first [sqlite3_step()] call following any change 3825** to the [sqlite3_bind_text | bindings] of that [parameter]. 3826** ^The specific value of WHERE-clause [parameter] might influence the 3827** choice of query plan if the parameter is the left-hand side of a [LIKE] 3828** or [GLOB] operator or if the parameter is compared to an indexed column 3829** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 3830** </li> 3831** </ol> 3832** 3833** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3834** the extra prepFlags parameter, which is a bit array consisting of zero or 3835** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3836** sqlite3_prepare_v2() interface works exactly the same as 3837** sqlite3_prepare_v3() with a zero prepFlags parameter. 3838*/ 3839int sqlite3_prepare( 3840 sqlite3 *db, /* Database handle */ 3841 const char *zSql, /* SQL statement, UTF-8 encoded */ 3842 int nByte, /* Maximum length of zSql in bytes. */ 3843 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3844 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3845); 3846int sqlite3_prepare_v2( 3847 sqlite3 *db, /* Database handle */ 3848 const char *zSql, /* SQL statement, UTF-8 encoded */ 3849 int nByte, /* Maximum length of zSql in bytes. */ 3850 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3851 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3852); 3853int sqlite3_prepare_v3( 3854 sqlite3 *db, /* Database handle */ 3855 const char *zSql, /* SQL statement, UTF-8 encoded */ 3856 int nByte, /* Maximum length of zSql in bytes. */ 3857 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3858 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3859 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3860); 3861int sqlite3_prepare16( 3862 sqlite3 *db, /* Database handle */ 3863 const void *zSql, /* SQL statement, UTF-16 encoded */ 3864 int nByte, /* Maximum length of zSql in bytes. */ 3865 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3866 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3867); 3868int sqlite3_prepare16_v2( 3869 sqlite3 *db, /* Database handle */ 3870 const void *zSql, /* SQL statement, UTF-16 encoded */ 3871 int nByte, /* Maximum length of zSql in bytes. */ 3872 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3873 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3874); 3875int sqlite3_prepare16_v3( 3876 sqlite3 *db, /* Database handle */ 3877 const void *zSql, /* SQL statement, UTF-16 encoded */ 3878 int nByte, /* Maximum length of zSql in bytes. */ 3879 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3880 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3881 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3882); 3883 3884/* 3885** CAPI3REF: Retrieving Statement SQL 3886** METHOD: sqlite3_stmt 3887** 3888** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3889** SQL text used to create [prepared statement] P if P was 3890** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3891** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3892** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3893** string containing the SQL text of prepared statement P with 3894** [bound parameters] expanded. 3895** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 3896** string containing the normalized SQL text of prepared statement P. The 3897** semantics used to normalize a SQL statement are unspecified and subject 3898** to change. At a minimum, literal values will be replaced with suitable 3899** placeholders. 3900** 3901** ^(For example, if a prepared statement is created using the SQL 3902** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3903** and parameter :xyz is unbound, then sqlite3_sql() will return 3904** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3905** will return "SELECT 2345,NULL".)^ 3906** 3907** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3908** is available to hold the result, or if the result would exceed the 3909** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3910** 3911** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3912** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3913** option causes sqlite3_expanded_sql() to always return NULL. 3914** 3915** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 3916** are managed by SQLite and are automatically freed when the prepared 3917** statement is finalized. 3918** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3919** is obtained from [sqlite3_malloc()] and must be free by the application 3920** by passing it to [sqlite3_free()]. 3921*/ 3922const char *sqlite3_sql(sqlite3_stmt *pStmt); 3923char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3924const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 3925 3926/* 3927** CAPI3REF: Determine If An SQL Statement Writes The Database 3928** METHOD: sqlite3_stmt 3929** 3930** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3931** and only if the [prepared statement] X makes no direct changes to 3932** the content of the database file. 3933** 3934** Note that [application-defined SQL functions] or 3935** [virtual tables] might change the database indirectly as a side effect. 3936** ^(For example, if an application defines a function "eval()" that 3937** calls [sqlite3_exec()], then the following SQL statement would 3938** change the database file through side-effects: 3939** 3940** <blockquote><pre> 3941** SELECT eval('DELETE FROM t1') FROM t2; 3942** </pre></blockquote> 3943** 3944** But because the [SELECT] statement does not change the database file 3945** directly, sqlite3_stmt_readonly() would still return true.)^ 3946** 3947** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3948** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3949** since the statements themselves do not actually modify the database but 3950** rather they control the timing of when other statements modify the 3951** database. ^The [ATTACH] and [DETACH] statements also cause 3952** sqlite3_stmt_readonly() to return true since, while those statements 3953** change the configuration of a database connection, they do not make 3954** changes to the content of the database files on disk. 3955** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3956** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3957** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3958** sqlite3_stmt_readonly() returns false for those commands. 3959*/ 3960int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3961 3962/* 3963** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 3964** METHOD: sqlite3_stmt 3965** 3966** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 3967** prepared statement S is an EXPLAIN statement, or 2 if the 3968** statement S is an EXPLAIN QUERY PLAN. 3969** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 3970** an ordinary statement or a NULL pointer. 3971*/ 3972int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 3973 3974/* 3975** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3976** METHOD: sqlite3_stmt 3977** 3978** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3979** [prepared statement] S has been stepped at least once using 3980** [sqlite3_step(S)] but has neither run to completion (returned 3981** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3982** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3983** interface returns false if S is a NULL pointer. If S is not a 3984** NULL pointer and is not a pointer to a valid [prepared statement] 3985** object, then the behavior is undefined and probably undesirable. 3986** 3987** This interface can be used in combination [sqlite3_next_stmt()] 3988** to locate all prepared statements associated with a database 3989** connection that are in need of being reset. This can be used, 3990** for example, in diagnostic routines to search for prepared 3991** statements that are holding a transaction open. 3992*/ 3993int sqlite3_stmt_busy(sqlite3_stmt*); 3994 3995/* 3996** CAPI3REF: Dynamically Typed Value Object 3997** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3998** 3999** SQLite uses the sqlite3_value object to represent all values 4000** that can be stored in a database table. SQLite uses dynamic typing 4001** for the values it stores. ^Values stored in sqlite3_value objects 4002** can be integers, floating point values, strings, BLOBs, or NULL. 4003** 4004** An sqlite3_value object may be either "protected" or "unprotected". 4005** Some interfaces require a protected sqlite3_value. Other interfaces 4006** will accept either a protected or an unprotected sqlite3_value. 4007** Every interface that accepts sqlite3_value arguments specifies 4008** whether or not it requires a protected sqlite3_value. The 4009** [sqlite3_value_dup()] interface can be used to construct a new 4010** protected sqlite3_value from an unprotected sqlite3_value. 4011** 4012** The terms "protected" and "unprotected" refer to whether or not 4013** a mutex is held. An internal mutex is held for a protected 4014** sqlite3_value object but no mutex is held for an unprotected 4015** sqlite3_value object. If SQLite is compiled to be single-threaded 4016** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4017** or if SQLite is run in one of reduced mutex modes 4018** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4019** then there is no distinction between protected and unprotected 4020** sqlite3_value objects and they can be used interchangeably. However, 4021** for maximum code portability it is recommended that applications 4022** still make the distinction between protected and unprotected 4023** sqlite3_value objects even when not strictly required. 4024** 4025** ^The sqlite3_value objects that are passed as parameters into the 4026** implementation of [application-defined SQL functions] are protected. 4027** ^The sqlite3_value object returned by 4028** [sqlite3_column_value()] is unprotected. 4029** Unprotected sqlite3_value objects may only be used as arguments 4030** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4031** [sqlite3_value_dup()]. 4032** The [sqlite3_value_blob | sqlite3_value_type()] family of 4033** interfaces require protected sqlite3_value objects. 4034*/ 4035typedef struct sqlite3_value sqlite3_value; 4036 4037/* 4038** CAPI3REF: SQL Function Context Object 4039** 4040** The context in which an SQL function executes is stored in an 4041** sqlite3_context object. ^A pointer to an sqlite3_context object 4042** is always first parameter to [application-defined SQL functions]. 4043** The application-defined SQL function implementation will pass this 4044** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4045** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4046** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4047** and/or [sqlite3_set_auxdata()]. 4048*/ 4049typedef struct sqlite3_context sqlite3_context; 4050 4051/* 4052** CAPI3REF: Binding Values To Prepared Statements 4053** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4054** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4055** METHOD: sqlite3_stmt 4056** 4057** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4058** literals may be replaced by a [parameter] that matches one of following 4059** templates: 4060** 4061** <ul> 4062** <li> ? 4063** <li> ?NNN 4064** <li> :VVV 4065** <li> @VVV 4066** <li> $VVV 4067** </ul> 4068** 4069** In the templates above, NNN represents an integer literal, 4070** and VVV represents an alphanumeric identifier.)^ ^The values of these 4071** parameters (also called "host parameter names" or "SQL parameters") 4072** can be set using the sqlite3_bind_*() routines defined here. 4073** 4074** ^The first argument to the sqlite3_bind_*() routines is always 4075** a pointer to the [sqlite3_stmt] object returned from 4076** [sqlite3_prepare_v2()] or its variants. 4077** 4078** ^The second argument is the index of the SQL parameter to be set. 4079** ^The leftmost SQL parameter has an index of 1. ^When the same named 4080** SQL parameter is used more than once, second and subsequent 4081** occurrences have the same index as the first occurrence. 4082** ^The index for named parameters can be looked up using the 4083** [sqlite3_bind_parameter_index()] API if desired. ^The index 4084** for "?NNN" parameters is the value of NNN. 4085** ^The NNN value must be between 1 and the [sqlite3_limit()] 4086** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 4087** 4088** ^The third argument is the value to bind to the parameter. 4089** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4090** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4091** is ignored and the end result is the same as sqlite3_bind_null(). 4092** 4093** ^(In those routines that have a fourth argument, its value is the 4094** number of bytes in the parameter. To be clear: the value is the 4095** number of <u>bytes</u> in the value, not the number of characters.)^ 4096** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4097** is negative, then the length of the string is 4098** the number of bytes up to the first zero terminator. 4099** If the fourth parameter to sqlite3_bind_blob() is negative, then 4100** the behavior is undefined. 4101** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4102** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4103** that parameter must be the byte offset 4104** where the NUL terminator would occur assuming the string were NUL 4105** terminated. If any NUL characters occur at byte offsets less than 4106** the value of the fourth parameter then the resulting string value will 4107** contain embedded NULs. The result of expressions involving strings 4108** with embedded NULs is undefined. 4109** 4110** ^The fifth argument to the BLOB and string binding interfaces 4111** is a destructor used to dispose of the BLOB or 4112** string after SQLite has finished with it. ^The destructor is called 4113** to dispose of the BLOB or string even if the call to the bind API fails, 4114** except the destructor is not called if the third parameter is a NULL 4115** pointer or the fourth parameter is negative. 4116** ^If the fifth argument is 4117** the special value [SQLITE_STATIC], then SQLite assumes that the 4118** information is in static, unmanaged space and does not need to be freed. 4119** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4120** SQLite makes its own private copy of the data immediately, before 4121** the sqlite3_bind_*() routine returns. 4122** 4123** ^The sixth argument to sqlite3_bind_text64() must be one of 4124** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4125** to specify the encoding of the text in the third parameter. If 4126** the sixth argument to sqlite3_bind_text64() is not one of the 4127** allowed values shown above, or if the text encoding is different 4128** from the encoding specified by the sixth parameter, then the behavior 4129** is undefined. 4130** 4131** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4132** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4133** (just an integer to hold its size) while it is being processed. 4134** Zeroblobs are intended to serve as placeholders for BLOBs whose 4135** content is later written using 4136** [sqlite3_blob_open | incremental BLOB I/O] routines. 4137** ^A negative value for the zeroblob results in a zero-length BLOB. 4138** 4139** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4140** [prepared statement] S to have an SQL value of NULL, but to also be 4141** associated with the pointer P of type T. ^D is either a NULL pointer or 4142** a pointer to a destructor function for P. ^SQLite will invoke the 4143** destructor D with a single argument of P when it is finished using 4144** P. The T parameter should be a static string, preferably a string 4145** literal. The sqlite3_bind_pointer() routine is part of the 4146** [pointer passing interface] added for SQLite 3.20.0. 4147** 4148** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4149** for the [prepared statement] or with a prepared statement for which 4150** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4151** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4152** routine is passed a [prepared statement] that has been finalized, the 4153** result is undefined and probably harmful. 4154** 4155** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4156** ^Unbound parameters are interpreted as NULL. 4157** 4158** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4159** [error code] if anything goes wrong. 4160** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4161** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4162** [SQLITE_MAX_LENGTH]. 4163** ^[SQLITE_RANGE] is returned if the parameter 4164** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4165** 4166** See also: [sqlite3_bind_parameter_count()], 4167** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4168*/ 4169int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4170int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4171 void(*)(void*)); 4172int sqlite3_bind_double(sqlite3_stmt*, int, double); 4173int sqlite3_bind_int(sqlite3_stmt*, int, int); 4174int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4175int sqlite3_bind_null(sqlite3_stmt*, int); 4176int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4177int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4178int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4179 void(*)(void*), unsigned char encoding); 4180int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4181int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4182int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4183int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4184 4185/* 4186** CAPI3REF: Number Of SQL Parameters 4187** METHOD: sqlite3_stmt 4188** 4189** ^This routine can be used to find the number of [SQL parameters] 4190** in a [prepared statement]. SQL parameters are tokens of the 4191** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4192** placeholders for values that are [sqlite3_bind_blob | bound] 4193** to the parameters at a later time. 4194** 4195** ^(This routine actually returns the index of the largest (rightmost) 4196** parameter. For all forms except ?NNN, this will correspond to the 4197** number of unique parameters. If parameters of the ?NNN form are used, 4198** there may be gaps in the list.)^ 4199** 4200** See also: [sqlite3_bind_blob|sqlite3_bind()], 4201** [sqlite3_bind_parameter_name()], and 4202** [sqlite3_bind_parameter_index()]. 4203*/ 4204int sqlite3_bind_parameter_count(sqlite3_stmt*); 4205 4206/* 4207** CAPI3REF: Name Of A Host Parameter 4208** METHOD: sqlite3_stmt 4209** 4210** ^The sqlite3_bind_parameter_name(P,N) interface returns 4211** the name of the N-th [SQL parameter] in the [prepared statement] P. 4212** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4213** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4214** respectively. 4215** In other words, the initial ":" or "$" or "@" or "?" 4216** is included as part of the name.)^ 4217** ^Parameters of the form "?" without a following integer have no name 4218** and are referred to as "nameless" or "anonymous parameters". 4219** 4220** ^The first host parameter has an index of 1, not 0. 4221** 4222** ^If the value N is out of range or if the N-th parameter is 4223** nameless, then NULL is returned. ^The returned string is 4224** always in UTF-8 encoding even if the named parameter was 4225** originally specified as UTF-16 in [sqlite3_prepare16()], 4226** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4227** 4228** See also: [sqlite3_bind_blob|sqlite3_bind()], 4229** [sqlite3_bind_parameter_count()], and 4230** [sqlite3_bind_parameter_index()]. 4231*/ 4232const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4233 4234/* 4235** CAPI3REF: Index Of A Parameter With A Given Name 4236** METHOD: sqlite3_stmt 4237** 4238** ^Return the index of an SQL parameter given its name. ^The 4239** index value returned is suitable for use as the second 4240** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4241** is returned if no matching parameter is found. ^The parameter 4242** name must be given in UTF-8 even if the original statement 4243** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4244** [sqlite3_prepare16_v3()]. 4245** 4246** See also: [sqlite3_bind_blob|sqlite3_bind()], 4247** [sqlite3_bind_parameter_count()], and 4248** [sqlite3_bind_parameter_name()]. 4249*/ 4250int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4251 4252/* 4253** CAPI3REF: Reset All Bindings On A Prepared Statement 4254** METHOD: sqlite3_stmt 4255** 4256** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4257** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4258** ^Use this routine to reset all host parameters to NULL. 4259*/ 4260int sqlite3_clear_bindings(sqlite3_stmt*); 4261 4262/* 4263** CAPI3REF: Number Of Columns In A Result Set 4264** METHOD: sqlite3_stmt 4265** 4266** ^Return the number of columns in the result set returned by the 4267** [prepared statement]. ^If this routine returns 0, that means the 4268** [prepared statement] returns no data (for example an [UPDATE]). 4269** ^However, just because this routine returns a positive number does not 4270** mean that one or more rows of data will be returned. ^A SELECT statement 4271** will always have a positive sqlite3_column_count() but depending on the 4272** WHERE clause constraints and the table content, it might return no rows. 4273** 4274** See also: [sqlite3_data_count()] 4275*/ 4276int sqlite3_column_count(sqlite3_stmt *pStmt); 4277 4278/* 4279** CAPI3REF: Column Names In A Result Set 4280** METHOD: sqlite3_stmt 4281** 4282** ^These routines return the name assigned to a particular column 4283** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4284** interface returns a pointer to a zero-terminated UTF-8 string 4285** and sqlite3_column_name16() returns a pointer to a zero-terminated 4286** UTF-16 string. ^The first parameter is the [prepared statement] 4287** that implements the [SELECT] statement. ^The second parameter is the 4288** column number. ^The leftmost column is number 0. 4289** 4290** ^The returned string pointer is valid until either the [prepared statement] 4291** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4292** reprepared by the first call to [sqlite3_step()] for a particular run 4293** or until the next call to 4294** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4295** 4296** ^If sqlite3_malloc() fails during the processing of either routine 4297** (for example during a conversion from UTF-8 to UTF-16) then a 4298** NULL pointer is returned. 4299** 4300** ^The name of a result column is the value of the "AS" clause for 4301** that column, if there is an AS clause. If there is no AS clause 4302** then the name of the column is unspecified and may change from 4303** one release of SQLite to the next. 4304*/ 4305const char *sqlite3_column_name(sqlite3_stmt*, int N); 4306const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4307 4308/* 4309** CAPI3REF: Source Of Data In A Query Result 4310** METHOD: sqlite3_stmt 4311** 4312** ^These routines provide a means to determine the database, table, and 4313** table column that is the origin of a particular result column in 4314** [SELECT] statement. 4315** ^The name of the database or table or column can be returned as 4316** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4317** the database name, the _table_ routines return the table name, and 4318** the origin_ routines return the column name. 4319** ^The returned string is valid until the [prepared statement] is destroyed 4320** using [sqlite3_finalize()] or until the statement is automatically 4321** reprepared by the first call to [sqlite3_step()] for a particular run 4322** or until the same information is requested 4323** again in a different encoding. 4324** 4325** ^The names returned are the original un-aliased names of the 4326** database, table, and column. 4327** 4328** ^The first argument to these interfaces is a [prepared statement]. 4329** ^These functions return information about the Nth result column returned by 4330** the statement, where N is the second function argument. 4331** ^The left-most column is column 0 for these routines. 4332** 4333** ^If the Nth column returned by the statement is an expression or 4334** subquery and is not a column value, then all of these functions return 4335** NULL. ^These routine might also return NULL if a memory allocation error 4336** occurs. ^Otherwise, they return the name of the attached database, table, 4337** or column that query result column was extracted from. 4338** 4339** ^As with all other SQLite APIs, those whose names end with "16" return 4340** UTF-16 encoded strings and the other functions return UTF-8. 4341** 4342** ^These APIs are only available if the library was compiled with the 4343** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4344** 4345** If two or more threads call one or more of these routines against the same 4346** prepared statement and column at the same time then the results are 4347** undefined. 4348** 4349** If two or more threads call one or more 4350** [sqlite3_column_database_name | column metadata interfaces] 4351** for the same [prepared statement] and result column 4352** at the same time then the results are undefined. 4353*/ 4354const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4355const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4356const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4357const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4358const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4359const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4360 4361/* 4362** CAPI3REF: Declared Datatype Of A Query Result 4363** METHOD: sqlite3_stmt 4364** 4365** ^(The first parameter is a [prepared statement]. 4366** If this statement is a [SELECT] statement and the Nth column of the 4367** returned result set of that [SELECT] is a table column (not an 4368** expression or subquery) then the declared type of the table 4369** column is returned.)^ ^If the Nth column of the result set is an 4370** expression or subquery, then a NULL pointer is returned. 4371** ^The returned string is always UTF-8 encoded. 4372** 4373** ^(For example, given the database schema: 4374** 4375** CREATE TABLE t1(c1 VARIANT); 4376** 4377** and the following statement to be compiled: 4378** 4379** SELECT c1 + 1, c1 FROM t1; 4380** 4381** this routine would return the string "VARIANT" for the second result 4382** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4383** 4384** ^SQLite uses dynamic run-time typing. ^So just because a column 4385** is declared to contain a particular type does not mean that the 4386** data stored in that column is of the declared type. SQLite is 4387** strongly typed, but the typing is dynamic not static. ^Type 4388** is associated with individual values, not with the containers 4389** used to hold those values. 4390*/ 4391const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4392const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4393 4394/* 4395** CAPI3REF: Evaluate An SQL Statement 4396** METHOD: sqlite3_stmt 4397** 4398** After a [prepared statement] has been prepared using any of 4399** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4400** or [sqlite3_prepare16_v3()] or one of the legacy 4401** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4402** must be called one or more times to evaluate the statement. 4403** 4404** The details of the behavior of the sqlite3_step() interface depend 4405** on whether the statement was prepared using the newer "vX" interfaces 4406** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4407** [sqlite3_prepare16_v2()] or the older legacy 4408** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4409** new "vX" interface is recommended for new applications but the legacy 4410** interface will continue to be supported. 4411** 4412** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4413** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4414** ^With the "v2" interface, any of the other [result codes] or 4415** [extended result codes] might be returned as well. 4416** 4417** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4418** database locks it needs to do its job. ^If the statement is a [COMMIT] 4419** or occurs outside of an explicit transaction, then you can retry the 4420** statement. If the statement is not a [COMMIT] and occurs within an 4421** explicit transaction then you should rollback the transaction before 4422** continuing. 4423** 4424** ^[SQLITE_DONE] means that the statement has finished executing 4425** successfully. sqlite3_step() should not be called again on this virtual 4426** machine without first calling [sqlite3_reset()] to reset the virtual 4427** machine back to its initial state. 4428** 4429** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4430** is returned each time a new row of data is ready for processing by the 4431** caller. The values may be accessed using the [column access functions]. 4432** sqlite3_step() is called again to retrieve the next row of data. 4433** 4434** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4435** violation) has occurred. sqlite3_step() should not be called again on 4436** the VM. More information may be found by calling [sqlite3_errmsg()]. 4437** ^With the legacy interface, a more specific error code (for example, 4438** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4439** can be obtained by calling [sqlite3_reset()] on the 4440** [prepared statement]. ^In the "v2" interface, 4441** the more specific error code is returned directly by sqlite3_step(). 4442** 4443** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4444** Perhaps it was called on a [prepared statement] that has 4445** already been [sqlite3_finalize | finalized] or on one that had 4446** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4447** be the case that the same database connection is being used by two or 4448** more threads at the same moment in time. 4449** 4450** For all versions of SQLite up to and including 3.6.23.1, a call to 4451** [sqlite3_reset()] was required after sqlite3_step() returned anything 4452** other than [SQLITE_ROW] before any subsequent invocation of 4453** sqlite3_step(). Failure to reset the prepared statement using 4454** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4455** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4456** sqlite3_step() began 4457** calling [sqlite3_reset()] automatically in this circumstance rather 4458** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4459** break because any application that ever receives an SQLITE_MISUSE error 4460** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4461** can be used to restore the legacy behavior. 4462** 4463** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4464** API always returns a generic error code, [SQLITE_ERROR], following any 4465** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4466** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4467** specific [error codes] that better describes the error. 4468** We admit that this is a goofy design. The problem has been fixed 4469** with the "v2" interface. If you prepare all of your SQL statements 4470** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4471** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4472** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4473** then the more specific [error codes] are returned directly 4474** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4475*/ 4476int sqlite3_step(sqlite3_stmt*); 4477 4478/* 4479** CAPI3REF: Number of columns in a result set 4480** METHOD: sqlite3_stmt 4481** 4482** ^The sqlite3_data_count(P) interface returns the number of columns in the 4483** current row of the result set of [prepared statement] P. 4484** ^If prepared statement P does not have results ready to return 4485** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 4486** interfaces) then sqlite3_data_count(P) returns 0. 4487** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4488** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4489** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4490** will return non-zero if previous call to [sqlite3_step](P) returned 4491** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4492** where it always returns zero since each step of that multi-step 4493** pragma returns 0 columns of data. 4494** 4495** See also: [sqlite3_column_count()] 4496*/ 4497int sqlite3_data_count(sqlite3_stmt *pStmt); 4498 4499/* 4500** CAPI3REF: Fundamental Datatypes 4501** KEYWORDS: SQLITE_TEXT 4502** 4503** ^(Every value in SQLite has one of five fundamental datatypes: 4504** 4505** <ul> 4506** <li> 64-bit signed integer 4507** <li> 64-bit IEEE floating point number 4508** <li> string 4509** <li> BLOB 4510** <li> NULL 4511** </ul>)^ 4512** 4513** These constants are codes for each of those types. 4514** 4515** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4516** for a completely different meaning. Software that links against both 4517** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4518** SQLITE_TEXT. 4519*/ 4520#define SQLITE_INTEGER 1 4521#define SQLITE_FLOAT 2 4522#define SQLITE_BLOB 4 4523#define SQLITE_NULL 5 4524#ifdef SQLITE_TEXT 4525# undef SQLITE_TEXT 4526#else 4527# define SQLITE_TEXT 3 4528#endif 4529#define SQLITE3_TEXT 3 4530 4531/* 4532** CAPI3REF: Result Values From A Query 4533** KEYWORDS: {column access functions} 4534** METHOD: sqlite3_stmt 4535** 4536** <b>Summary:</b> 4537** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4538** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4539** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4540** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4541** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4542** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4543** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4544** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4545** [sqlite3_value|unprotected sqlite3_value] object. 4546** <tr><td> <td> <td> 4547** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4548** or a UTF-8 TEXT result in bytes 4549** <tr><td><b>sqlite3_column_bytes16 </b> 4550** <td>→ <td>Size of UTF-16 4551** TEXT in bytes 4552** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4553** datatype of the result 4554** </table></blockquote> 4555** 4556** <b>Details:</b> 4557** 4558** ^These routines return information about a single column of the current 4559** result row of a query. ^In every case the first argument is a pointer 4560** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4561** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4562** and the second argument is the index of the column for which information 4563** should be returned. ^The leftmost column of the result set has the index 0. 4564** ^The number of columns in the result can be determined using 4565** [sqlite3_column_count()]. 4566** 4567** If the SQL statement does not currently point to a valid row, or if the 4568** column index is out of range, the result is undefined. 4569** These routines may only be called when the most recent call to 4570** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4571** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4572** If any of these routines are called after [sqlite3_reset()] or 4573** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4574** something other than [SQLITE_ROW], the results are undefined. 4575** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4576** are called from a different thread while any of these routines 4577** are pending, then the results are undefined. 4578** 4579** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4580** each return the value of a result column in a specific data format. If 4581** the result column is not initially in the requested format (for example, 4582** if the query returns an integer but the sqlite3_column_text() interface 4583** is used to extract the value) then an automatic type conversion is performed. 4584** 4585** ^The sqlite3_column_type() routine returns the 4586** [SQLITE_INTEGER | datatype code] for the initial data type 4587** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4588** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4589** The return value of sqlite3_column_type() can be used to decide which 4590** of the first six interface should be used to extract the column value. 4591** The value returned by sqlite3_column_type() is only meaningful if no 4592** automatic type conversions have occurred for the value in question. 4593** After a type conversion, the result of calling sqlite3_column_type() 4594** is undefined, though harmless. Future 4595** versions of SQLite may change the behavior of sqlite3_column_type() 4596** following a type conversion. 4597** 4598** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4599** or sqlite3_column_bytes16() interfaces can be used to determine the size 4600** of that BLOB or string. 4601** 4602** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4603** routine returns the number of bytes in that BLOB or string. 4604** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4605** the string to UTF-8 and then returns the number of bytes. 4606** ^If the result is a numeric value then sqlite3_column_bytes() uses 4607** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4608** the number of bytes in that string. 4609** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4610** 4611** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4612** routine returns the number of bytes in that BLOB or string. 4613** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4614** the string to UTF-16 and then returns the number of bytes. 4615** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4616** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4617** the number of bytes in that string. 4618** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4619** 4620** ^The values returned by [sqlite3_column_bytes()] and 4621** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4622** of the string. ^For clarity: the values returned by 4623** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4624** bytes in the string, not the number of characters. 4625** 4626** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4627** even empty strings, are always zero-terminated. ^The return 4628** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4629** 4630** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4631** [unprotected sqlite3_value] object. In a multithreaded environment, 4632** an unprotected sqlite3_value object may only be used safely with 4633** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4634** If the [unprotected sqlite3_value] object returned by 4635** [sqlite3_column_value()] is used in any other way, including calls 4636** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4637** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4638** Hence, the sqlite3_column_value() interface 4639** is normally only useful within the implementation of 4640** [application-defined SQL functions] or [virtual tables], not within 4641** top-level application code. 4642** 4643** The these routines may attempt to convert the datatype of the result. 4644** ^For example, if the internal representation is FLOAT and a text result 4645** is requested, [sqlite3_snprintf()] is used internally to perform the 4646** conversion automatically. ^(The following table details the conversions 4647** that are applied: 4648** 4649** <blockquote> 4650** <table border="1"> 4651** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4652** 4653** <tr><td> NULL <td> INTEGER <td> Result is 0 4654** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4655** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4656** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4657** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4658** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4659** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4660** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4661** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4662** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4663** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4664** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4665** <tr><td> TEXT <td> BLOB <td> No change 4666** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4667** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4668** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4669** </table> 4670** </blockquote>)^ 4671** 4672** Note that when type conversions occur, pointers returned by prior 4673** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4674** sqlite3_column_text16() may be invalidated. 4675** Type conversions and pointer invalidations might occur 4676** in the following cases: 4677** 4678** <ul> 4679** <li> The initial content is a BLOB and sqlite3_column_text() or 4680** sqlite3_column_text16() is called. A zero-terminator might 4681** need to be added to the string.</li> 4682** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4683** sqlite3_column_text16() is called. The content must be converted 4684** to UTF-16.</li> 4685** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4686** sqlite3_column_text() is called. The content must be converted 4687** to UTF-8.</li> 4688** </ul> 4689** 4690** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4691** not invalidate a prior pointer, though of course the content of the buffer 4692** that the prior pointer references will have been modified. Other kinds 4693** of conversion are done in place when it is possible, but sometimes they 4694** are not possible and in those cases prior pointers are invalidated. 4695** 4696** The safest policy is to invoke these routines 4697** in one of the following ways: 4698** 4699** <ul> 4700** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4701** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4702** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4703** </ul> 4704** 4705** In other words, you should call sqlite3_column_text(), 4706** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4707** into the desired format, then invoke sqlite3_column_bytes() or 4708** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4709** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4710** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4711** with calls to sqlite3_column_bytes(). 4712** 4713** ^The pointers returned are valid until a type conversion occurs as 4714** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4715** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4716** and BLOBs is freed automatically. Do not pass the pointers returned 4717** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4718** [sqlite3_free()]. 4719** 4720** As long as the input parameters are correct, these routines will only 4721** fail if an out-of-memory error occurs during a format conversion. 4722** Only the following subset of interfaces are subject to out-of-memory 4723** errors: 4724** 4725** <ul> 4726** <li> sqlite3_column_blob() 4727** <li> sqlite3_column_text() 4728** <li> sqlite3_column_text16() 4729** <li> sqlite3_column_bytes() 4730** <li> sqlite3_column_bytes16() 4731** </ul> 4732** 4733** If an out-of-memory error occurs, then the return value from these 4734** routines is the same as if the column had contained an SQL NULL value. 4735** Valid SQL NULL returns can be distinguished from out-of-memory errors 4736** by invoking the [sqlite3_errcode()] immediately after the suspect 4737** return value is obtained and before any 4738** other SQLite interface is called on the same [database connection]. 4739*/ 4740const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4741double sqlite3_column_double(sqlite3_stmt*, int iCol); 4742int sqlite3_column_int(sqlite3_stmt*, int iCol); 4743sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4744const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4745const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4746sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4747int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4748int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4749int sqlite3_column_type(sqlite3_stmt*, int iCol); 4750 4751/* 4752** CAPI3REF: Destroy A Prepared Statement Object 4753** DESTRUCTOR: sqlite3_stmt 4754** 4755** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4756** ^If the most recent evaluation of the statement encountered no errors 4757** or if the statement is never been evaluated, then sqlite3_finalize() returns 4758** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4759** sqlite3_finalize(S) returns the appropriate [error code] or 4760** [extended error code]. 4761** 4762** ^The sqlite3_finalize(S) routine can be called at any point during 4763** the life cycle of [prepared statement] S: 4764** before statement S is ever evaluated, after 4765** one or more calls to [sqlite3_reset()], or after any call 4766** to [sqlite3_step()] regardless of whether or not the statement has 4767** completed execution. 4768** 4769** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4770** 4771** The application must finalize every [prepared statement] in order to avoid 4772** resource leaks. It is a grievous error for the application to try to use 4773** a prepared statement after it has been finalized. Any use of a prepared 4774** statement after it has been finalized can result in undefined and 4775** undesirable behavior such as segfaults and heap corruption. 4776*/ 4777int sqlite3_finalize(sqlite3_stmt *pStmt); 4778 4779/* 4780** CAPI3REF: Reset A Prepared Statement Object 4781** METHOD: sqlite3_stmt 4782** 4783** The sqlite3_reset() function is called to reset a [prepared statement] 4784** object back to its initial state, ready to be re-executed. 4785** ^Any SQL statement variables that had values bound to them using 4786** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4787** Use [sqlite3_clear_bindings()] to reset the bindings. 4788** 4789** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4790** back to the beginning of its program. 4791** 4792** ^If the most recent call to [sqlite3_step(S)] for the 4793** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4794** or if [sqlite3_step(S)] has never before been called on S, 4795** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4796** 4797** ^If the most recent call to [sqlite3_step(S)] for the 4798** [prepared statement] S indicated an error, then 4799** [sqlite3_reset(S)] returns an appropriate [error code]. 4800** 4801** ^The [sqlite3_reset(S)] interface does not change the values 4802** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4803*/ 4804int sqlite3_reset(sqlite3_stmt *pStmt); 4805 4806/* 4807** CAPI3REF: Create Or Redefine SQL Functions 4808** KEYWORDS: {function creation routines} 4809** KEYWORDS: {application-defined SQL function} 4810** KEYWORDS: {application-defined SQL functions} 4811** METHOD: sqlite3 4812** 4813** ^These functions (collectively known as "function creation routines") 4814** are used to add SQL functions or aggregates or to redefine the behavior 4815** of existing SQL functions or aggregates. The only differences between 4816** the three "sqlite3_create_function*" routines are the text encoding 4817** expected for the second parameter (the name of the function being 4818** created) and the presence or absence of a destructor callback for 4819** the application data pointer. Function sqlite3_create_window_function() 4820** is similar, but allows the user to supply the extra callback functions 4821** needed by [aggregate window functions]. 4822** 4823** ^The first parameter is the [database connection] to which the SQL 4824** function is to be added. ^If an application uses more than one database 4825** connection then application-defined SQL functions must be added 4826** to each database connection separately. 4827** 4828** ^The second parameter is the name of the SQL function to be created or 4829** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4830** representation, exclusive of the zero-terminator. ^Note that the name 4831** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4832** ^Any attempt to create a function with a longer name 4833** will result in [SQLITE_MISUSE] being returned. 4834** 4835** ^The third parameter (nArg) 4836** is the number of arguments that the SQL function or 4837** aggregate takes. ^If this parameter is -1, then the SQL function or 4838** aggregate may take any number of arguments between 0 and the limit 4839** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4840** parameter is less than -1 or greater than 127 then the behavior is 4841** undefined. 4842** 4843** ^The fourth parameter, eTextRep, specifies what 4844** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4845** its parameters. The application should set this parameter to 4846** [SQLITE_UTF16LE] if the function implementation invokes 4847** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4848** implementation invokes [sqlite3_value_text16be()] on an input, or 4849** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4850** otherwise. ^The same SQL function may be registered multiple times using 4851** different preferred text encodings, with different implementations for 4852** each encoding. 4853** ^When multiple implementations of the same function are available, SQLite 4854** will pick the one that involves the least amount of data conversion. 4855** 4856** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4857** to signal that the function will always return the same result given 4858** the same inputs within a single SQL statement. Most SQL functions are 4859** deterministic. The built-in [random()] SQL function is an example of a 4860** function that is not deterministic. The SQLite query planner is able to 4861** perform additional optimizations on deterministic functions, so use 4862** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4863** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 4864** flag, which if present prevents the function from being invoked from 4865** within VIEWs or TRIGGERs. 4866** 4867** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4868** function can gain access to this pointer using [sqlite3_user_data()].)^ 4869** 4870** ^The sixth, seventh and eighth parameters passed to the three 4871** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4872** pointers to C-language functions that implement the SQL function or 4873** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4874** callback only; NULL pointers must be passed as the xStep and xFinal 4875** parameters. ^An aggregate SQL function requires an implementation of xStep 4876** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4877** SQL function or aggregate, pass NULL pointers for all three function 4878** callbacks. 4879** 4880** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4881** and xInverse) passed to sqlite3_create_window_function are pointers to 4882** C-language callbacks that implement the new function. xStep and xFinal 4883** must both be non-NULL. xValue and xInverse may either both be NULL, in 4884** which case a regular aggregate function is created, or must both be 4885** non-NULL, in which case the new function may be used as either an aggregate 4886** or aggregate window function. More details regarding the implementation 4887** of aggregate window functions are 4888** [user-defined window functions|available here]. 4889** 4890** ^(If the final parameter to sqlite3_create_function_v2() or 4891** sqlite3_create_window_function() is not NULL, then it is destructor for 4892** the application data pointer. The destructor is invoked when the function 4893** is deleted, either by being overloaded or when the database connection 4894** closes.)^ ^The destructor is also invoked if the call to 4895** sqlite3_create_function_v2() fails. ^When the destructor callback is 4896** invoked, it is passed a single argument which is a copy of the application 4897** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4898** 4899** ^It is permitted to register multiple implementations of the same 4900** functions with the same name but with either differing numbers of 4901** arguments or differing preferred text encodings. ^SQLite will use 4902** the implementation that most closely matches the way in which the 4903** SQL function is used. ^A function implementation with a non-negative 4904** nArg parameter is a better match than a function implementation with 4905** a negative nArg. ^A function where the preferred text encoding 4906** matches the database encoding is a better 4907** match than a function where the encoding is different. 4908** ^A function where the encoding difference is between UTF16le and UTF16be 4909** is a closer match than a function where the encoding difference is 4910** between UTF8 and UTF16. 4911** 4912** ^Built-in functions may be overloaded by new application-defined functions. 4913** 4914** ^An application-defined function is permitted to call other 4915** SQLite interfaces. However, such calls must not 4916** close the database connection nor finalize or reset the prepared 4917** statement in which the function is running. 4918*/ 4919int sqlite3_create_function( 4920 sqlite3 *db, 4921 const char *zFunctionName, 4922 int nArg, 4923 int eTextRep, 4924 void *pApp, 4925 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4926 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4927 void (*xFinal)(sqlite3_context*) 4928); 4929int sqlite3_create_function16( 4930 sqlite3 *db, 4931 const void *zFunctionName, 4932 int nArg, 4933 int eTextRep, 4934 void *pApp, 4935 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4936 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4937 void (*xFinal)(sqlite3_context*) 4938); 4939int sqlite3_create_function_v2( 4940 sqlite3 *db, 4941 const char *zFunctionName, 4942 int nArg, 4943 int eTextRep, 4944 void *pApp, 4945 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4946 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4947 void (*xFinal)(sqlite3_context*), 4948 void(*xDestroy)(void*) 4949); 4950int sqlite3_create_window_function( 4951 sqlite3 *db, 4952 const char *zFunctionName, 4953 int nArg, 4954 int eTextRep, 4955 void *pApp, 4956 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4957 void (*xFinal)(sqlite3_context*), 4958 void (*xValue)(sqlite3_context*), 4959 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4960 void(*xDestroy)(void*) 4961); 4962 4963/* 4964** CAPI3REF: Text Encodings 4965** 4966** These constant define integer codes that represent the various 4967** text encodings supported by SQLite. 4968*/ 4969#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4970#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4971#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4972#define SQLITE_UTF16 4 /* Use native byte order */ 4973#define SQLITE_ANY 5 /* Deprecated */ 4974#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4975 4976/* 4977** CAPI3REF: Function Flags 4978** 4979** These constants may be ORed together with the 4980** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4981** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4982** [sqlite3_create_function_v2()]. 4983** 4984** The SQLITE_DETERMINISTIC flag means that the new function will always 4985** maps the same inputs into the same output. The abs() function is 4986** deterministic, for example, but randomblob() is not. 4987** 4988** The SQLITE_DIRECTONLY flag means that the function may only be invoked 4989** from top-level SQL, and cannot be used in VIEWs or TRIGGERs. 4990*/ 4991#define SQLITE_DETERMINISTIC 0x000000800 4992#define SQLITE_DIRECTONLY 0x000080000 4993 4994/* 4995** CAPI3REF: Deprecated Functions 4996** DEPRECATED 4997** 4998** These functions are [deprecated]. In order to maintain 4999** backwards compatibility with older code, these functions continue 5000** to be supported. However, new applications should avoid 5001** the use of these functions. To encourage programmers to avoid 5002** these functions, we will not explain what they do. 5003*/ 5004#ifndef SQLITE_OMIT_DEPRECATED 5005SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5006SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5007SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5008SQLITE_DEPRECATED int sqlite3_global_recover(void); 5009SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5010SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5011 void*,sqlite3_int64); 5012#endif 5013 5014/* 5015** CAPI3REF: Obtaining SQL Values 5016** METHOD: sqlite3_value 5017** 5018** <b>Summary:</b> 5019** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5020** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5021** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5022** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5023** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5024** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5025** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5026** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5027** the native byteorder 5028** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5029** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5030** <tr><td> <td> <td> 5031** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5032** or a UTF-8 TEXT in bytes 5033** <tr><td><b>sqlite3_value_bytes16 </b> 5034** <td>→ <td>Size of UTF-16 5035** TEXT in bytes 5036** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5037** datatype of the value 5038** <tr><td><b>sqlite3_value_numeric_type </b> 5039** <td>→ <td>Best numeric datatype of the value 5040** <tr><td><b>sqlite3_value_nochange </b> 5041** <td>→ <td>True if the column is unchanged in an UPDATE 5042** against a virtual table. 5043** <tr><td><b>sqlite3_value_frombind </b> 5044** <td>→ <td>True if value originated from a [bound parameter] 5045** </table></blockquote> 5046** 5047** <b>Details:</b> 5048** 5049** These routines extract type, size, and content information from 5050** [protected sqlite3_value] objects. Protected sqlite3_value objects 5051** are used to pass parameter information into implementation of 5052** [application-defined SQL functions] and [virtual tables]. 5053** 5054** These routines work only with [protected sqlite3_value] objects. 5055** Any attempt to use these routines on an [unprotected sqlite3_value] 5056** is not threadsafe. 5057** 5058** ^These routines work just like the corresponding [column access functions] 5059** except that these routines take a single [protected sqlite3_value] object 5060** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5061** 5062** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5063** in the native byte-order of the host machine. ^The 5064** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5065** extract UTF-16 strings as big-endian and little-endian respectively. 5066** 5067** ^If [sqlite3_value] object V was initialized 5068** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5069** and if X and Y are strings that compare equal according to strcmp(X,Y), 5070** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5071** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5072** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5073** 5074** ^(The sqlite3_value_type(V) interface returns the 5075** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5076** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5077** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5078** Other interfaces might change the datatype for an sqlite3_value object. 5079** For example, if the datatype is initially SQLITE_INTEGER and 5080** sqlite3_value_text(V) is called to extract a text value for that 5081** integer, then subsequent calls to sqlite3_value_type(V) might return 5082** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5083** occurs is undefined and may change from one release of SQLite to the next. 5084** 5085** ^(The sqlite3_value_numeric_type() interface attempts to apply 5086** numeric affinity to the value. This means that an attempt is 5087** made to convert the value to an integer or floating point. If 5088** such a conversion is possible without loss of information (in other 5089** words, if the value is a string that looks like a number) 5090** then the conversion is performed. Otherwise no conversion occurs. 5091** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5092** 5093** ^Within the [xUpdate] method of a [virtual table], the 5094** sqlite3_value_nochange(X) interface returns true if and only if 5095** the column corresponding to X is unchanged by the UPDATE operation 5096** that the xUpdate method call was invoked to implement and if 5097** and the prior [xColumn] method call that was invoked to extracted 5098** the value for that column returned without setting a result (probably 5099** because it queried [sqlite3_vtab_nochange()] and found that the column 5100** was unchanging). ^Within an [xUpdate] method, any value for which 5101** sqlite3_value_nochange(X) is true will in all other respects appear 5102** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5103** than within an [xUpdate] method call for an UPDATE statement, then 5104** the return value is arbitrary and meaningless. 5105** 5106** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5107** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5108** interfaces. ^If X comes from an SQL literal value, or a table column, 5109** and expression, then sqlite3_value_frombind(X) returns zero. 5110** 5111** Please pay particular attention to the fact that the pointer returned 5112** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5113** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5114** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5115** or [sqlite3_value_text16()]. 5116** 5117** These routines must be called from the same thread as 5118** the SQL function that supplied the [sqlite3_value*] parameters. 5119** 5120** As long as the input parameter is correct, these routines can only 5121** fail if an out-of-memory error occurs during a format conversion. 5122** Only the following subset of interfaces are subject to out-of-memory 5123** errors: 5124** 5125** <ul> 5126** <li> sqlite3_value_blob() 5127** <li> sqlite3_value_text() 5128** <li> sqlite3_value_text16() 5129** <li> sqlite3_value_text16le() 5130** <li> sqlite3_value_text16be() 5131** <li> sqlite3_value_bytes() 5132** <li> sqlite3_value_bytes16() 5133** </ul> 5134** 5135** If an out-of-memory error occurs, then the return value from these 5136** routines is the same as if the column had contained an SQL NULL value. 5137** Valid SQL NULL returns can be distinguished from out-of-memory errors 5138** by invoking the [sqlite3_errcode()] immediately after the suspect 5139** return value is obtained and before any 5140** other SQLite interface is called on the same [database connection]. 5141*/ 5142const void *sqlite3_value_blob(sqlite3_value*); 5143double sqlite3_value_double(sqlite3_value*); 5144int sqlite3_value_int(sqlite3_value*); 5145sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5146void *sqlite3_value_pointer(sqlite3_value*, const char*); 5147const unsigned char *sqlite3_value_text(sqlite3_value*); 5148const void *sqlite3_value_text16(sqlite3_value*); 5149const void *sqlite3_value_text16le(sqlite3_value*); 5150const void *sqlite3_value_text16be(sqlite3_value*); 5151int sqlite3_value_bytes(sqlite3_value*); 5152int sqlite3_value_bytes16(sqlite3_value*); 5153int sqlite3_value_type(sqlite3_value*); 5154int sqlite3_value_numeric_type(sqlite3_value*); 5155int sqlite3_value_nochange(sqlite3_value*); 5156int sqlite3_value_frombind(sqlite3_value*); 5157 5158/* 5159** CAPI3REF: Finding The Subtype Of SQL Values 5160** METHOD: sqlite3_value 5161** 5162** The sqlite3_value_subtype(V) function returns the subtype for 5163** an [application-defined SQL function] argument V. The subtype 5164** information can be used to pass a limited amount of context from 5165** one SQL function to another. Use the [sqlite3_result_subtype()] 5166** routine to set the subtype for the return value of an SQL function. 5167*/ 5168unsigned int sqlite3_value_subtype(sqlite3_value*); 5169 5170/* 5171** CAPI3REF: Copy And Free SQL Values 5172** METHOD: sqlite3_value 5173** 5174** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5175** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5176** is a [protected sqlite3_value] object even if the input is not. 5177** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5178** memory allocation fails. 5179** 5180** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5181** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5182** then sqlite3_value_free(V) is a harmless no-op. 5183*/ 5184sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5185void sqlite3_value_free(sqlite3_value*); 5186 5187/* 5188** CAPI3REF: Obtain Aggregate Function Context 5189** METHOD: sqlite3_context 5190** 5191** Implementations of aggregate SQL functions use this 5192** routine to allocate memory for storing their state. 5193** 5194** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5195** for a particular aggregate function, SQLite 5196** allocates N of memory, zeroes out that memory, and returns a pointer 5197** to the new memory. ^On second and subsequent calls to 5198** sqlite3_aggregate_context() for the same aggregate function instance, 5199** the same buffer is returned. Sqlite3_aggregate_context() is normally 5200** called once for each invocation of the xStep callback and then one 5201** last time when the xFinal callback is invoked. ^(When no rows match 5202** an aggregate query, the xStep() callback of the aggregate function 5203** implementation is never called and xFinal() is called exactly once. 5204** In those cases, sqlite3_aggregate_context() might be called for the 5205** first time from within xFinal().)^ 5206** 5207** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5208** when first called if N is less than or equal to zero or if a memory 5209** allocate error occurs. 5210** 5211** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5212** determined by the N parameter on first successful call. Changing the 5213** value of N in subsequent call to sqlite3_aggregate_context() within 5214** the same aggregate function instance will not resize the memory 5215** allocation.)^ Within the xFinal callback, it is customary to set 5216** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5217** pointless memory allocations occur. 5218** 5219** ^SQLite automatically frees the memory allocated by 5220** sqlite3_aggregate_context() when the aggregate query concludes. 5221** 5222** The first parameter must be a copy of the 5223** [sqlite3_context | SQL function context] that is the first parameter 5224** to the xStep or xFinal callback routine that implements the aggregate 5225** function. 5226** 5227** This routine must be called from the same thread in which 5228** the aggregate SQL function is running. 5229*/ 5230void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5231 5232/* 5233** CAPI3REF: User Data For Functions 5234** METHOD: sqlite3_context 5235** 5236** ^The sqlite3_user_data() interface returns a copy of 5237** the pointer that was the pUserData parameter (the 5th parameter) 5238** of the [sqlite3_create_function()] 5239** and [sqlite3_create_function16()] routines that originally 5240** registered the application defined function. 5241** 5242** This routine must be called from the same thread in which 5243** the application-defined function is running. 5244*/ 5245void *sqlite3_user_data(sqlite3_context*); 5246 5247/* 5248** CAPI3REF: Database Connection For Functions 5249** METHOD: sqlite3_context 5250** 5251** ^The sqlite3_context_db_handle() interface returns a copy of 5252** the pointer to the [database connection] (the 1st parameter) 5253** of the [sqlite3_create_function()] 5254** and [sqlite3_create_function16()] routines that originally 5255** registered the application defined function. 5256*/ 5257sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5258 5259/* 5260** CAPI3REF: Function Auxiliary Data 5261** METHOD: sqlite3_context 5262** 5263** These functions may be used by (non-aggregate) SQL functions to 5264** associate metadata with argument values. If the same value is passed to 5265** multiple invocations of the same SQL function during query execution, under 5266** some circumstances the associated metadata may be preserved. An example 5267** of where this might be useful is in a regular-expression matching 5268** function. The compiled version of the regular expression can be stored as 5269** metadata associated with the pattern string. 5270** Then as long as the pattern string remains the same, 5271** the compiled regular expression can be reused on multiple 5272** invocations of the same function. 5273** 5274** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5275** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5276** value to the application-defined function. ^N is zero for the left-most 5277** function argument. ^If there is no metadata 5278** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5279** returns a NULL pointer. 5280** 5281** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5282** argument of the application-defined function. ^Subsequent 5283** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5284** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5285** NULL if the metadata has been discarded. 5286** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5287** SQLite will invoke the destructor function X with parameter P exactly 5288** once, when the metadata is discarded. 5289** SQLite is free to discard the metadata at any time, including: <ul> 5290** <li> ^(when the corresponding function parameter changes)^, or 5291** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5292** SQL statement)^, or 5293** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5294** parameter)^, or 5295** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5296** allocation error occurs.)^ </ul> 5297** 5298** Note the last bullet in particular. The destructor X in 5299** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5300** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5301** should be called near the end of the function implementation and the 5302** function implementation should not make any use of P after 5303** sqlite3_set_auxdata() has been called. 5304** 5305** ^(In practice, metadata is preserved between function calls for 5306** function parameters that are compile-time constants, including literal 5307** values and [parameters] and expressions composed from the same.)^ 5308** 5309** The value of the N parameter to these interfaces should be non-negative. 5310** Future enhancements may make use of negative N values to define new 5311** kinds of function caching behavior. 5312** 5313** These routines must be called from the same thread in which 5314** the SQL function is running. 5315*/ 5316void *sqlite3_get_auxdata(sqlite3_context*, int N); 5317void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5318 5319 5320/* 5321** CAPI3REF: Constants Defining Special Destructor Behavior 5322** 5323** These are special values for the destructor that is passed in as the 5324** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5325** argument is SQLITE_STATIC, it means that the content pointer is constant 5326** and will never change. It does not need to be destroyed. ^The 5327** SQLITE_TRANSIENT value means that the content will likely change in 5328** the near future and that SQLite should make its own private copy of 5329** the content before returning. 5330** 5331** The typedef is necessary to work around problems in certain 5332** C++ compilers. 5333*/ 5334typedef void (*sqlite3_destructor_type)(void*); 5335#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5336#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5337 5338/* 5339** CAPI3REF: Setting The Result Of An SQL Function 5340** METHOD: sqlite3_context 5341** 5342** These routines are used by the xFunc or xFinal callbacks that 5343** implement SQL functions and aggregates. See 5344** [sqlite3_create_function()] and [sqlite3_create_function16()] 5345** for additional information. 5346** 5347** These functions work very much like the [parameter binding] family of 5348** functions used to bind values to host parameters in prepared statements. 5349** Refer to the [SQL parameter] documentation for additional information. 5350** 5351** ^The sqlite3_result_blob() interface sets the result from 5352** an application-defined function to be the BLOB whose content is pointed 5353** to by the second parameter and which is N bytes long where N is the 5354** third parameter. 5355** 5356** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5357** interfaces set the result of the application-defined function to be 5358** a BLOB containing all zero bytes and N bytes in size. 5359** 5360** ^The sqlite3_result_double() interface sets the result from 5361** an application-defined function to be a floating point value specified 5362** by its 2nd argument. 5363** 5364** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5365** cause the implemented SQL function to throw an exception. 5366** ^SQLite uses the string pointed to by the 5367** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5368** as the text of an error message. ^SQLite interprets the error 5369** message string from sqlite3_result_error() as UTF-8. ^SQLite 5370** interprets the string from sqlite3_result_error16() as UTF-16 in native 5371** byte order. ^If the third parameter to sqlite3_result_error() 5372** or sqlite3_result_error16() is negative then SQLite takes as the error 5373** message all text up through the first zero character. 5374** ^If the third parameter to sqlite3_result_error() or 5375** sqlite3_result_error16() is non-negative then SQLite takes that many 5376** bytes (not characters) from the 2nd parameter as the error message. 5377** ^The sqlite3_result_error() and sqlite3_result_error16() 5378** routines make a private copy of the error message text before 5379** they return. Hence, the calling function can deallocate or 5380** modify the text after they return without harm. 5381** ^The sqlite3_result_error_code() function changes the error code 5382** returned by SQLite as a result of an error in a function. ^By default, 5383** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5384** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5385** 5386** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5387** error indicating that a string or BLOB is too long to represent. 5388** 5389** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5390** error indicating that a memory allocation failed. 5391** 5392** ^The sqlite3_result_int() interface sets the return value 5393** of the application-defined function to be the 32-bit signed integer 5394** value given in the 2nd argument. 5395** ^The sqlite3_result_int64() interface sets the return value 5396** of the application-defined function to be the 64-bit signed integer 5397** value given in the 2nd argument. 5398** 5399** ^The sqlite3_result_null() interface sets the return value 5400** of the application-defined function to be NULL. 5401** 5402** ^The sqlite3_result_text(), sqlite3_result_text16(), 5403** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5404** set the return value of the application-defined function to be 5405** a text string which is represented as UTF-8, UTF-16 native byte order, 5406** UTF-16 little endian, or UTF-16 big endian, respectively. 5407** ^The sqlite3_result_text64() interface sets the return value of an 5408** application-defined function to be a text string in an encoding 5409** specified by the fifth (and last) parameter, which must be one 5410** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5411** ^SQLite takes the text result from the application from 5412** the 2nd parameter of the sqlite3_result_text* interfaces. 5413** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5414** is negative, then SQLite takes result text from the 2nd parameter 5415** through the first zero character. 5416** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5417** is non-negative, then as many bytes (not characters) of the text 5418** pointed to by the 2nd parameter are taken as the application-defined 5419** function result. If the 3rd parameter is non-negative, then it 5420** must be the byte offset into the string where the NUL terminator would 5421** appear if the string where NUL terminated. If any NUL characters occur 5422** in the string at a byte offset that is less than the value of the 3rd 5423** parameter, then the resulting string will contain embedded NULs and the 5424** result of expressions operating on strings with embedded NULs is undefined. 5425** ^If the 4th parameter to the sqlite3_result_text* interfaces 5426** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5427** function as the destructor on the text or BLOB result when it has 5428** finished using that result. 5429** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5430** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5431** assumes that the text or BLOB result is in constant space and does not 5432** copy the content of the parameter nor call a destructor on the content 5433** when it has finished using that result. 5434** ^If the 4th parameter to the sqlite3_result_text* interfaces 5435** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5436** then SQLite makes a copy of the result into space obtained 5437** from [sqlite3_malloc()] before it returns. 5438** 5439** ^The sqlite3_result_value() interface sets the result of 5440** the application-defined function to be a copy of the 5441** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5442** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5443** so that the [sqlite3_value] specified in the parameter may change or 5444** be deallocated after sqlite3_result_value() returns without harm. 5445** ^A [protected sqlite3_value] object may always be used where an 5446** [unprotected sqlite3_value] object is required, so either 5447** kind of [sqlite3_value] object can be used with this interface. 5448** 5449** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5450** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5451** also associates the host-language pointer P or type T with that 5452** NULL value such that the pointer can be retrieved within an 5453** [application-defined SQL function] using [sqlite3_value_pointer()]. 5454** ^If the D parameter is not NULL, then it is a pointer to a destructor 5455** for the P parameter. ^SQLite invokes D with P as its only argument 5456** when SQLite is finished with P. The T parameter should be a static 5457** string and preferably a string literal. The sqlite3_result_pointer() 5458** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5459** 5460** If these routines are called from within the different thread 5461** than the one containing the application-defined function that received 5462** the [sqlite3_context] pointer, the results are undefined. 5463*/ 5464void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5465void sqlite3_result_blob64(sqlite3_context*,const void*, 5466 sqlite3_uint64,void(*)(void*)); 5467void sqlite3_result_double(sqlite3_context*, double); 5468void sqlite3_result_error(sqlite3_context*, const char*, int); 5469void sqlite3_result_error16(sqlite3_context*, const void*, int); 5470void sqlite3_result_error_toobig(sqlite3_context*); 5471void sqlite3_result_error_nomem(sqlite3_context*); 5472void sqlite3_result_error_code(sqlite3_context*, int); 5473void sqlite3_result_int(sqlite3_context*, int); 5474void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5475void sqlite3_result_null(sqlite3_context*); 5476void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5477void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5478 void(*)(void*), unsigned char encoding); 5479void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5480void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5481void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5482void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5483void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5484void sqlite3_result_zeroblob(sqlite3_context*, int n); 5485int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5486 5487 5488/* 5489** CAPI3REF: Setting The Subtype Of An SQL Function 5490** METHOD: sqlite3_context 5491** 5492** The sqlite3_result_subtype(C,T) function causes the subtype of 5493** the result from the [application-defined SQL function] with 5494** [sqlite3_context] C to be the value T. Only the lower 8 bits 5495** of the subtype T are preserved in current versions of SQLite; 5496** higher order bits are discarded. 5497** The number of subtype bytes preserved by SQLite might increase 5498** in future releases of SQLite. 5499*/ 5500void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5501 5502/* 5503** CAPI3REF: Define New Collating Sequences 5504** METHOD: sqlite3 5505** 5506** ^These functions add, remove, or modify a [collation] associated 5507** with the [database connection] specified as the first argument. 5508** 5509** ^The name of the collation is a UTF-8 string 5510** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5511** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5512** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5513** considered to be the same name. 5514** 5515** ^(The third argument (eTextRep) must be one of the constants: 5516** <ul> 5517** <li> [SQLITE_UTF8], 5518** <li> [SQLITE_UTF16LE], 5519** <li> [SQLITE_UTF16BE], 5520** <li> [SQLITE_UTF16], or 5521** <li> [SQLITE_UTF16_ALIGNED]. 5522** </ul>)^ 5523** ^The eTextRep argument determines the encoding of strings passed 5524** to the collating function callback, xCallback. 5525** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5526** force strings to be UTF16 with native byte order. 5527** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5528** on an even byte address. 5529** 5530** ^The fourth argument, pArg, is an application data pointer that is passed 5531** through as the first argument to the collating function callback. 5532** 5533** ^The fifth argument, xCallback, is a pointer to the collating function. 5534** ^Multiple collating functions can be registered using the same name but 5535** with different eTextRep parameters and SQLite will use whichever 5536** function requires the least amount of data transformation. 5537** ^If the xCallback argument is NULL then the collating function is 5538** deleted. ^When all collating functions having the same name are deleted, 5539** that collation is no longer usable. 5540** 5541** ^The collating function callback is invoked with a copy of the pArg 5542** application data pointer and with two strings in the encoding specified 5543** by the eTextRep argument. The collating function must return an 5544** integer that is negative, zero, or positive 5545** if the first string is less than, equal to, or greater than the second, 5546** respectively. A collating function must always return the same answer 5547** given the same inputs. If two or more collating functions are registered 5548** to the same collation name (using different eTextRep values) then all 5549** must give an equivalent answer when invoked with equivalent strings. 5550** The collating function must obey the following properties for all 5551** strings A, B, and C: 5552** 5553** <ol> 5554** <li> If A==B then B==A. 5555** <li> If A==B and B==C then A==C. 5556** <li> If A<B THEN B>A. 5557** <li> If A<B and B<C then A<C. 5558** </ol> 5559** 5560** If a collating function fails any of the above constraints and that 5561** collating function is registered and used, then the behavior of SQLite 5562** is undefined. 5563** 5564** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5565** with the addition that the xDestroy callback is invoked on pArg when 5566** the collating function is deleted. 5567** ^Collating functions are deleted when they are overridden by later 5568** calls to the collation creation functions or when the 5569** [database connection] is closed using [sqlite3_close()]. 5570** 5571** ^The xDestroy callback is <u>not</u> called if the 5572** sqlite3_create_collation_v2() function fails. Applications that invoke 5573** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5574** check the return code and dispose of the application data pointer 5575** themselves rather than expecting SQLite to deal with it for them. 5576** This is different from every other SQLite interface. The inconsistency 5577** is unfortunate but cannot be changed without breaking backwards 5578** compatibility. 5579** 5580** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5581*/ 5582int sqlite3_create_collation( 5583 sqlite3*, 5584 const char *zName, 5585 int eTextRep, 5586 void *pArg, 5587 int(*xCompare)(void*,int,const void*,int,const void*) 5588); 5589int sqlite3_create_collation_v2( 5590 sqlite3*, 5591 const char *zName, 5592 int eTextRep, 5593 void *pArg, 5594 int(*xCompare)(void*,int,const void*,int,const void*), 5595 void(*xDestroy)(void*) 5596); 5597int sqlite3_create_collation16( 5598 sqlite3*, 5599 const void *zName, 5600 int eTextRep, 5601 void *pArg, 5602 int(*xCompare)(void*,int,const void*,int,const void*) 5603); 5604 5605/* 5606** CAPI3REF: Collation Needed Callbacks 5607** METHOD: sqlite3 5608** 5609** ^To avoid having to register all collation sequences before a database 5610** can be used, a single callback function may be registered with the 5611** [database connection] to be invoked whenever an undefined collation 5612** sequence is required. 5613** 5614** ^If the function is registered using the sqlite3_collation_needed() API, 5615** then it is passed the names of undefined collation sequences as strings 5616** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5617** the names are passed as UTF-16 in machine native byte order. 5618** ^A call to either function replaces the existing collation-needed callback. 5619** 5620** ^(When the callback is invoked, the first argument passed is a copy 5621** of the second argument to sqlite3_collation_needed() or 5622** sqlite3_collation_needed16(). The second argument is the database 5623** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5624** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5625** sequence function required. The fourth parameter is the name of the 5626** required collation sequence.)^ 5627** 5628** The callback function should register the desired collation using 5629** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5630** [sqlite3_create_collation_v2()]. 5631*/ 5632int sqlite3_collation_needed( 5633 sqlite3*, 5634 void*, 5635 void(*)(void*,sqlite3*,int eTextRep,const char*) 5636); 5637int sqlite3_collation_needed16( 5638 sqlite3*, 5639 void*, 5640 void(*)(void*,sqlite3*,int eTextRep,const void*) 5641); 5642 5643#ifdef SQLITE_HAS_CODEC 5644/* 5645** Specify the key for an encrypted database. This routine should be 5646** called right after sqlite3_open(). 5647** 5648** The code to implement this API is not available in the public release 5649** of SQLite. 5650*/ 5651int sqlite3_key( 5652 sqlite3 *db, /* Database to be rekeyed */ 5653 const void *pKey, int nKey /* The key */ 5654); 5655int sqlite3_key_v2( 5656 sqlite3 *db, /* Database to be rekeyed */ 5657 const char *zDbName, /* Name of the database */ 5658 const void *pKey, int nKey /* The key */ 5659); 5660 5661/* 5662** Change the key on an open database. If the current database is not 5663** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5664** database is decrypted. 5665** 5666** The code to implement this API is not available in the public release 5667** of SQLite. 5668*/ 5669int sqlite3_rekey( 5670 sqlite3 *db, /* Database to be rekeyed */ 5671 const void *pKey, int nKey /* The new key */ 5672); 5673int sqlite3_rekey_v2( 5674 sqlite3 *db, /* Database to be rekeyed */ 5675 const char *zDbName, /* Name of the database */ 5676 const void *pKey, int nKey /* The new key */ 5677); 5678 5679/* 5680** Specify the activation key for a SEE database. Unless 5681** activated, none of the SEE routines will work. 5682*/ 5683void sqlite3_activate_see( 5684 const char *zPassPhrase /* Activation phrase */ 5685); 5686#endif 5687 5688#ifdef SQLITE_ENABLE_CEROD 5689/* 5690** Specify the activation key for a CEROD database. Unless 5691** activated, none of the CEROD routines will work. 5692*/ 5693void sqlite3_activate_cerod( 5694 const char *zPassPhrase /* Activation phrase */ 5695); 5696#endif 5697 5698/* 5699** CAPI3REF: Suspend Execution For A Short Time 5700** 5701** The sqlite3_sleep() function causes the current thread to suspend execution 5702** for at least a number of milliseconds specified in its parameter. 5703** 5704** If the operating system does not support sleep requests with 5705** millisecond time resolution, then the time will be rounded up to 5706** the nearest second. The number of milliseconds of sleep actually 5707** requested from the operating system is returned. 5708** 5709** ^SQLite implements this interface by calling the xSleep() 5710** method of the default [sqlite3_vfs] object. If the xSleep() method 5711** of the default VFS is not implemented correctly, or not implemented at 5712** all, then the behavior of sqlite3_sleep() may deviate from the description 5713** in the previous paragraphs. 5714*/ 5715int sqlite3_sleep(int); 5716 5717/* 5718** CAPI3REF: Name Of The Folder Holding Temporary Files 5719** 5720** ^(If this global variable is made to point to a string which is 5721** the name of a folder (a.k.a. directory), then all temporary files 5722** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5723** will be placed in that directory.)^ ^If this variable 5724** is a NULL pointer, then SQLite performs a search for an appropriate 5725** temporary file directory. 5726** 5727** Applications are strongly discouraged from using this global variable. 5728** It is required to set a temporary folder on Windows Runtime (WinRT). 5729** But for all other platforms, it is highly recommended that applications 5730** neither read nor write this variable. This global variable is a relic 5731** that exists for backwards compatibility of legacy applications and should 5732** be avoided in new projects. 5733** 5734** It is not safe to read or modify this variable in more than one 5735** thread at a time. It is not safe to read or modify this variable 5736** if a [database connection] is being used at the same time in a separate 5737** thread. 5738** It is intended that this variable be set once 5739** as part of process initialization and before any SQLite interface 5740** routines have been called and that this variable remain unchanged 5741** thereafter. 5742** 5743** ^The [temp_store_directory pragma] may modify this variable and cause 5744** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5745** the [temp_store_directory pragma] always assumes that any string 5746** that this variable points to is held in memory obtained from 5747** [sqlite3_malloc] and the pragma may attempt to free that memory 5748** using [sqlite3_free]. 5749** Hence, if this variable is modified directly, either it should be 5750** made NULL or made to point to memory obtained from [sqlite3_malloc] 5751** or else the use of the [temp_store_directory pragma] should be avoided. 5752** Except when requested by the [temp_store_directory pragma], SQLite 5753** does not free the memory that sqlite3_temp_directory points to. If 5754** the application wants that memory to be freed, it must do 5755** so itself, taking care to only do so after all [database connection] 5756** objects have been destroyed. 5757** 5758** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5759** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5760** features that require the use of temporary files may fail. Here is an 5761** example of how to do this using C++ with the Windows Runtime: 5762** 5763** <blockquote><pre> 5764** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5765** TemporaryFolder->Path->Data(); 5766** char zPathBuf[MAX_PATH + 1]; 5767** memset(zPathBuf, 0, sizeof(zPathBuf)); 5768** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5769** NULL, NULL); 5770** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5771** </pre></blockquote> 5772*/ 5773SQLITE_EXTERN char *sqlite3_temp_directory; 5774 5775/* 5776** CAPI3REF: Name Of The Folder Holding Database Files 5777** 5778** ^(If this global variable is made to point to a string which is 5779** the name of a folder (a.k.a. directory), then all database files 5780** specified with a relative pathname and created or accessed by 5781** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5782** to be relative to that directory.)^ ^If this variable is a NULL 5783** pointer, then SQLite assumes that all database files specified 5784** with a relative pathname are relative to the current directory 5785** for the process. Only the windows VFS makes use of this global 5786** variable; it is ignored by the unix VFS. 5787** 5788** Changing the value of this variable while a database connection is 5789** open can result in a corrupt database. 5790** 5791** It is not safe to read or modify this variable in more than one 5792** thread at a time. It is not safe to read or modify this variable 5793** if a [database connection] is being used at the same time in a separate 5794** thread. 5795** It is intended that this variable be set once 5796** as part of process initialization and before any SQLite interface 5797** routines have been called and that this variable remain unchanged 5798** thereafter. 5799** 5800** ^The [data_store_directory pragma] may modify this variable and cause 5801** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5802** the [data_store_directory pragma] always assumes that any string 5803** that this variable points to is held in memory obtained from 5804** [sqlite3_malloc] and the pragma may attempt to free that memory 5805** using [sqlite3_free]. 5806** Hence, if this variable is modified directly, either it should be 5807** made NULL or made to point to memory obtained from [sqlite3_malloc] 5808** or else the use of the [data_store_directory pragma] should be avoided. 5809*/ 5810SQLITE_EXTERN char *sqlite3_data_directory; 5811 5812/* 5813** CAPI3REF: Win32 Specific Interface 5814** 5815** These interfaces are available only on Windows. The 5816** [sqlite3_win32_set_directory] interface is used to set the value associated 5817** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5818** zValue, depending on the value of the type parameter. The zValue parameter 5819** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5820** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5821** prior to being used. The [sqlite3_win32_set_directory] interface returns 5822** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5823** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5824** [sqlite3_data_directory] variable is intended to act as a replacement for 5825** the current directory on the sub-platforms of Win32 where that concept is 5826** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5827** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5828** sqlite3_win32_set_directory interface except the string parameter must be 5829** UTF-8 or UTF-16, respectively. 5830*/ 5831int sqlite3_win32_set_directory( 5832 unsigned long type, /* Identifier for directory being set or reset */ 5833 void *zValue /* New value for directory being set or reset */ 5834); 5835int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5836int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5837 5838/* 5839** CAPI3REF: Win32 Directory Types 5840** 5841** These macros are only available on Windows. They define the allowed values 5842** for the type argument to the [sqlite3_win32_set_directory] interface. 5843*/ 5844#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5845#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5846 5847/* 5848** CAPI3REF: Test For Auto-Commit Mode 5849** KEYWORDS: {autocommit mode} 5850** METHOD: sqlite3 5851** 5852** ^The sqlite3_get_autocommit() interface returns non-zero or 5853** zero if the given database connection is or is not in autocommit mode, 5854** respectively. ^Autocommit mode is on by default. 5855** ^Autocommit mode is disabled by a [BEGIN] statement. 5856** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5857** 5858** If certain kinds of errors occur on a statement within a multi-statement 5859** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5860** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5861** transaction might be rolled back automatically. The only way to 5862** find out whether SQLite automatically rolled back the transaction after 5863** an error is to use this function. 5864** 5865** If another thread changes the autocommit status of the database 5866** connection while this routine is running, then the return value 5867** is undefined. 5868*/ 5869int sqlite3_get_autocommit(sqlite3*); 5870 5871/* 5872** CAPI3REF: Find The Database Handle Of A Prepared Statement 5873** METHOD: sqlite3_stmt 5874** 5875** ^The sqlite3_db_handle interface returns the [database connection] handle 5876** to which a [prepared statement] belongs. ^The [database connection] 5877** returned by sqlite3_db_handle is the same [database connection] 5878** that was the first argument 5879** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5880** create the statement in the first place. 5881*/ 5882sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5883 5884/* 5885** CAPI3REF: Return The Filename For A Database Connection 5886** METHOD: sqlite3 5887** 5888** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 5889** associated with database N of connection D. ^The main database file 5890** has the name "main". If there is no attached database N on the database 5891** connection D, or if database N is a temporary or in-memory database, then 5892** this function will return either a NULL pointer or an empty string. 5893** 5894** ^The filename returned by this function is the output of the 5895** xFullPathname method of the [VFS]. ^In other words, the filename 5896** will be an absolute pathname, even if the filename used 5897** to open the database originally was a URI or relative pathname. 5898*/ 5899const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5900 5901/* 5902** CAPI3REF: Determine if a database is read-only 5903** METHOD: sqlite3 5904** 5905** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5906** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5907** the name of a database on connection D. 5908*/ 5909int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5910 5911/* 5912** CAPI3REF: Find the next prepared statement 5913** METHOD: sqlite3 5914** 5915** ^This interface returns a pointer to the next [prepared statement] after 5916** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5917** then this interface returns a pointer to the first prepared statement 5918** associated with the database connection pDb. ^If no prepared statement 5919** satisfies the conditions of this routine, it returns NULL. 5920** 5921** The [database connection] pointer D in a call to 5922** [sqlite3_next_stmt(D,S)] must refer to an open database 5923** connection and in particular must not be a NULL pointer. 5924*/ 5925sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5926 5927/* 5928** CAPI3REF: Commit And Rollback Notification Callbacks 5929** METHOD: sqlite3 5930** 5931** ^The sqlite3_commit_hook() interface registers a callback 5932** function to be invoked whenever a transaction is [COMMIT | committed]. 5933** ^Any callback set by a previous call to sqlite3_commit_hook() 5934** for the same database connection is overridden. 5935** ^The sqlite3_rollback_hook() interface registers a callback 5936** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5937** ^Any callback set by a previous call to sqlite3_rollback_hook() 5938** for the same database connection is overridden. 5939** ^The pArg argument is passed through to the callback. 5940** ^If the callback on a commit hook function returns non-zero, 5941** then the commit is converted into a rollback. 5942** 5943** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5944** return the P argument from the previous call of the same function 5945** on the same [database connection] D, or NULL for 5946** the first call for each function on D. 5947** 5948** The commit and rollback hook callbacks are not reentrant. 5949** The callback implementation must not do anything that will modify 5950** the database connection that invoked the callback. Any actions 5951** to modify the database connection must be deferred until after the 5952** completion of the [sqlite3_step()] call that triggered the commit 5953** or rollback hook in the first place. 5954** Note that running any other SQL statements, including SELECT statements, 5955** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5956** the database connections for the meaning of "modify" in this paragraph. 5957** 5958** ^Registering a NULL function disables the callback. 5959** 5960** ^When the commit hook callback routine returns zero, the [COMMIT] 5961** operation is allowed to continue normally. ^If the commit hook 5962** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5963** ^The rollback hook is invoked on a rollback that results from a commit 5964** hook returning non-zero, just as it would be with any other rollback. 5965** 5966** ^For the purposes of this API, a transaction is said to have been 5967** rolled back if an explicit "ROLLBACK" statement is executed, or 5968** an error or constraint causes an implicit rollback to occur. 5969** ^The rollback callback is not invoked if a transaction is 5970** automatically rolled back because the database connection is closed. 5971** 5972** See also the [sqlite3_update_hook()] interface. 5973*/ 5974void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5975void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5976 5977/* 5978** CAPI3REF: Data Change Notification Callbacks 5979** METHOD: sqlite3 5980** 5981** ^The sqlite3_update_hook() interface registers a callback function 5982** with the [database connection] identified by the first argument 5983** to be invoked whenever a row is updated, inserted or deleted in 5984** a [rowid table]. 5985** ^Any callback set by a previous call to this function 5986** for the same database connection is overridden. 5987** 5988** ^The second argument is a pointer to the function to invoke when a 5989** row is updated, inserted or deleted in a rowid table. 5990** ^The first argument to the callback is a copy of the third argument 5991** to sqlite3_update_hook(). 5992** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5993** or [SQLITE_UPDATE], depending on the operation that caused the callback 5994** to be invoked. 5995** ^The third and fourth arguments to the callback contain pointers to the 5996** database and table name containing the affected row. 5997** ^The final callback parameter is the [rowid] of the row. 5998** ^In the case of an update, this is the [rowid] after the update takes place. 5999** 6000** ^(The update hook is not invoked when internal system tables are 6001** modified (i.e. sqlite_master and sqlite_sequence).)^ 6002** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6003** 6004** ^In the current implementation, the update hook 6005** is not invoked when conflicting rows are deleted because of an 6006** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6007** invoked when rows are deleted using the [truncate optimization]. 6008** The exceptions defined in this paragraph might change in a future 6009** release of SQLite. 6010** 6011** The update hook implementation must not do anything that will modify 6012** the database connection that invoked the update hook. Any actions 6013** to modify the database connection must be deferred until after the 6014** completion of the [sqlite3_step()] call that triggered the update hook. 6015** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6016** database connections for the meaning of "modify" in this paragraph. 6017** 6018** ^The sqlite3_update_hook(D,C,P) function 6019** returns the P argument from the previous call 6020** on the same [database connection] D, or NULL for 6021** the first call on D. 6022** 6023** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6024** and [sqlite3_preupdate_hook()] interfaces. 6025*/ 6026void *sqlite3_update_hook( 6027 sqlite3*, 6028 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6029 void* 6030); 6031 6032/* 6033** CAPI3REF: Enable Or Disable Shared Pager Cache 6034** 6035** ^(This routine enables or disables the sharing of the database cache 6036** and schema data structures between [database connection | connections] 6037** to the same database. Sharing is enabled if the argument is true 6038** and disabled if the argument is false.)^ 6039** 6040** ^Cache sharing is enabled and disabled for an entire process. 6041** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6042** In prior versions of SQLite, 6043** sharing was enabled or disabled for each thread separately. 6044** 6045** ^(The cache sharing mode set by this interface effects all subsequent 6046** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6047** Existing database connections continue use the sharing mode 6048** that was in effect at the time they were opened.)^ 6049** 6050** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6051** successfully. An [error code] is returned otherwise.)^ 6052** 6053** ^Shared cache is disabled by default. But this might change in 6054** future releases of SQLite. Applications that care about shared 6055** cache setting should set it explicitly. 6056** 6057** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6058** and will always return SQLITE_MISUSE. On those systems, 6059** shared cache mode should be enabled per-database connection via 6060** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6061** 6062** This interface is threadsafe on processors where writing a 6063** 32-bit integer is atomic. 6064** 6065** See Also: [SQLite Shared-Cache Mode] 6066*/ 6067int sqlite3_enable_shared_cache(int); 6068 6069/* 6070** CAPI3REF: Attempt To Free Heap Memory 6071** 6072** ^The sqlite3_release_memory() interface attempts to free N bytes 6073** of heap memory by deallocating non-essential memory allocations 6074** held by the database library. Memory used to cache database 6075** pages to improve performance is an example of non-essential memory. 6076** ^sqlite3_release_memory() returns the number of bytes actually freed, 6077** which might be more or less than the amount requested. 6078** ^The sqlite3_release_memory() routine is a no-op returning zero 6079** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6080** 6081** See also: [sqlite3_db_release_memory()] 6082*/ 6083int sqlite3_release_memory(int); 6084 6085/* 6086** CAPI3REF: Free Memory Used By A Database Connection 6087** METHOD: sqlite3 6088** 6089** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6090** memory as possible from database connection D. Unlike the 6091** [sqlite3_release_memory()] interface, this interface is in effect even 6092** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6093** omitted. 6094** 6095** See also: [sqlite3_release_memory()] 6096*/ 6097int sqlite3_db_release_memory(sqlite3*); 6098 6099/* 6100** CAPI3REF: Impose A Limit On Heap Size 6101** 6102** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6103** soft limit on the amount of heap memory that may be allocated by SQLite. 6104** ^SQLite strives to keep heap memory utilization below the soft heap 6105** limit by reducing the number of pages held in the page cache 6106** as heap memory usages approaches the limit. 6107** ^The soft heap limit is "soft" because even though SQLite strives to stay 6108** below the limit, it will exceed the limit rather than generate 6109** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6110** is advisory only. 6111** 6112** ^The return value from sqlite3_soft_heap_limit64() is the size of 6113** the soft heap limit prior to the call, or negative in the case of an 6114** error. ^If the argument N is negative 6115** then no change is made to the soft heap limit. Hence, the current 6116** size of the soft heap limit can be determined by invoking 6117** sqlite3_soft_heap_limit64() with a negative argument. 6118** 6119** ^If the argument N is zero then the soft heap limit is disabled. 6120** 6121** ^(The soft heap limit is not enforced in the current implementation 6122** if one or more of following conditions are true: 6123** 6124** <ul> 6125** <li> The soft heap limit is set to zero. 6126** <li> Memory accounting is disabled using a combination of the 6127** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6128** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6129** <li> An alternative page cache implementation is specified using 6130** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6131** <li> The page cache allocates from its own memory pool supplied 6132** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6133** from the heap. 6134** </ul>)^ 6135** 6136** Beginning with SQLite [version 3.7.3] ([dateof:3.7.3]), 6137** the soft heap limit is enforced 6138** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 6139** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 6140** the soft heap limit is enforced on every memory allocation. Without 6141** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 6142** when memory is allocated by the page cache. Testing suggests that because 6143** the page cache is the predominate memory user in SQLite, most 6144** applications will achieve adequate soft heap limit enforcement without 6145** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6146** 6147** The circumstances under which SQLite will enforce the soft heap limit may 6148** changes in future releases of SQLite. 6149*/ 6150sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6151 6152/* 6153** CAPI3REF: Deprecated Soft Heap Limit Interface 6154** DEPRECATED 6155** 6156** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6157** interface. This routine is provided for historical compatibility 6158** only. All new applications should use the 6159** [sqlite3_soft_heap_limit64()] interface rather than this one. 6160*/ 6161SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6162 6163 6164/* 6165** CAPI3REF: Extract Metadata About A Column Of A Table 6166** METHOD: sqlite3 6167** 6168** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6169** information about column C of table T in database D 6170** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6171** interface returns SQLITE_OK and fills in the non-NULL pointers in 6172** the final five arguments with appropriate values if the specified 6173** column exists. ^The sqlite3_table_column_metadata() interface returns 6174** SQLITE_ERROR and if the specified column does not exist. 6175** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6176** NULL pointer, then this routine simply checks for the existence of the 6177** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6178** does not. If the table name parameter T in a call to 6179** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6180** undefined behavior. 6181** 6182** ^The column is identified by the second, third and fourth parameters to 6183** this function. ^(The second parameter is either the name of the database 6184** (i.e. "main", "temp", or an attached database) containing the specified 6185** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6186** for the table using the same algorithm used by the database engine to 6187** resolve unqualified table references. 6188** 6189** ^The third and fourth parameters to this function are the table and column 6190** name of the desired column, respectively. 6191** 6192** ^Metadata is returned by writing to the memory locations passed as the 5th 6193** and subsequent parameters to this function. ^Any of these arguments may be 6194** NULL, in which case the corresponding element of metadata is omitted. 6195** 6196** ^(<blockquote> 6197** <table border="1"> 6198** <tr><th> Parameter <th> Output<br>Type <th> Description 6199** 6200** <tr><td> 5th <td> const char* <td> Data type 6201** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6202** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6203** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6204** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6205** </table> 6206** </blockquote>)^ 6207** 6208** ^The memory pointed to by the character pointers returned for the 6209** declaration type and collation sequence is valid until the next 6210** call to any SQLite API function. 6211** 6212** ^If the specified table is actually a view, an [error code] is returned. 6213** 6214** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6215** is not a [WITHOUT ROWID] table and an 6216** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6217** parameters are set for the explicitly declared column. ^(If there is no 6218** [INTEGER PRIMARY KEY] column, then the outputs 6219** for the [rowid] are set as follows: 6220** 6221** <pre> 6222** data type: "INTEGER" 6223** collation sequence: "BINARY" 6224** not null: 0 6225** primary key: 1 6226** auto increment: 0 6227** </pre>)^ 6228** 6229** ^This function causes all database schemas to be read from disk and 6230** parsed, if that has not already been done, and returns an error if 6231** any errors are encountered while loading the schema. 6232*/ 6233int sqlite3_table_column_metadata( 6234 sqlite3 *db, /* Connection handle */ 6235 const char *zDbName, /* Database name or NULL */ 6236 const char *zTableName, /* Table name */ 6237 const char *zColumnName, /* Column name */ 6238 char const **pzDataType, /* OUTPUT: Declared data type */ 6239 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6240 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6241 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6242 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6243); 6244 6245/* 6246** CAPI3REF: Load An Extension 6247** METHOD: sqlite3 6248** 6249** ^This interface loads an SQLite extension library from the named file. 6250** 6251** ^The sqlite3_load_extension() interface attempts to load an 6252** [SQLite extension] library contained in the file zFile. If 6253** the file cannot be loaded directly, attempts are made to load 6254** with various operating-system specific extensions added. 6255** So for example, if "samplelib" cannot be loaded, then names like 6256** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6257** be tried also. 6258** 6259** ^The entry point is zProc. 6260** ^(zProc may be 0, in which case SQLite will try to come up with an 6261** entry point name on its own. It first tries "sqlite3_extension_init". 6262** If that does not work, it constructs a name "sqlite3_X_init" where the 6263** X is consists of the lower-case equivalent of all ASCII alphabetic 6264** characters in the filename from the last "/" to the first following 6265** "." and omitting any initial "lib".)^ 6266** ^The sqlite3_load_extension() interface returns 6267** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6268** ^If an error occurs and pzErrMsg is not 0, then the 6269** [sqlite3_load_extension()] interface shall attempt to 6270** fill *pzErrMsg with error message text stored in memory 6271** obtained from [sqlite3_malloc()]. The calling function 6272** should free this memory by calling [sqlite3_free()]. 6273** 6274** ^Extension loading must be enabled using 6275** [sqlite3_enable_load_extension()] or 6276** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6277** prior to calling this API, 6278** otherwise an error will be returned. 6279** 6280** <b>Security warning:</b> It is recommended that the 6281** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6282** interface. The use of the [sqlite3_enable_load_extension()] interface 6283** should be avoided. This will keep the SQL function [load_extension()] 6284** disabled and prevent SQL injections from giving attackers 6285** access to extension loading capabilities. 6286** 6287** See also the [load_extension() SQL function]. 6288*/ 6289int sqlite3_load_extension( 6290 sqlite3 *db, /* Load the extension into this database connection */ 6291 const char *zFile, /* Name of the shared library containing extension */ 6292 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6293 char **pzErrMsg /* Put error message here if not 0 */ 6294); 6295 6296/* 6297** CAPI3REF: Enable Or Disable Extension Loading 6298** METHOD: sqlite3 6299** 6300** ^So as not to open security holes in older applications that are 6301** unprepared to deal with [extension loading], and as a means of disabling 6302** [extension loading] while evaluating user-entered SQL, the following API 6303** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6304** 6305** ^Extension loading is off by default. 6306** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6307** to turn extension loading on and call it with onoff==0 to turn 6308** it back off again. 6309** 6310** ^This interface enables or disables both the C-API 6311** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6312** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6313** to enable or disable only the C-API.)^ 6314** 6315** <b>Security warning:</b> It is recommended that extension loading 6316** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6317** rather than this interface, so the [load_extension()] SQL function 6318** remains disabled. This will prevent SQL injections from giving attackers 6319** access to extension loading capabilities. 6320*/ 6321int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6322 6323/* 6324** CAPI3REF: Automatically Load Statically Linked Extensions 6325** 6326** ^This interface causes the xEntryPoint() function to be invoked for 6327** each new [database connection] that is created. The idea here is that 6328** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6329** that is to be automatically loaded into all new database connections. 6330** 6331** ^(Even though the function prototype shows that xEntryPoint() takes 6332** no arguments and returns void, SQLite invokes xEntryPoint() with three 6333** arguments and expects an integer result as if the signature of the 6334** entry point where as follows: 6335** 6336** <blockquote><pre> 6337** int xEntryPoint( 6338** sqlite3 *db, 6339** const char **pzErrMsg, 6340** const struct sqlite3_api_routines *pThunk 6341** ); 6342** </pre></blockquote>)^ 6343** 6344** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6345** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6346** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6347** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6348** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6349** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6350** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6351** 6352** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6353** on the list of automatic extensions is a harmless no-op. ^No entry point 6354** will be called more than once for each database connection that is opened. 6355** 6356** See also: [sqlite3_reset_auto_extension()] 6357** and [sqlite3_cancel_auto_extension()] 6358*/ 6359int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6360 6361/* 6362** CAPI3REF: Cancel Automatic Extension Loading 6363** 6364** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6365** initialization routine X that was registered using a prior call to 6366** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6367** routine returns 1 if initialization routine X was successfully 6368** unregistered and it returns 0 if X was not on the list of initialization 6369** routines. 6370*/ 6371int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6372 6373/* 6374** CAPI3REF: Reset Automatic Extension Loading 6375** 6376** ^This interface disables all automatic extensions previously 6377** registered using [sqlite3_auto_extension()]. 6378*/ 6379void sqlite3_reset_auto_extension(void); 6380 6381/* 6382** The interface to the virtual-table mechanism is currently considered 6383** to be experimental. The interface might change in incompatible ways. 6384** If this is a problem for you, do not use the interface at this time. 6385** 6386** When the virtual-table mechanism stabilizes, we will declare the 6387** interface fixed, support it indefinitely, and remove this comment. 6388*/ 6389 6390/* 6391** Structures used by the virtual table interface 6392*/ 6393typedef struct sqlite3_vtab sqlite3_vtab; 6394typedef struct sqlite3_index_info sqlite3_index_info; 6395typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6396typedef struct sqlite3_module sqlite3_module; 6397 6398/* 6399** CAPI3REF: Virtual Table Object 6400** KEYWORDS: sqlite3_module {virtual table module} 6401** 6402** This structure, sometimes called a "virtual table module", 6403** defines the implementation of a [virtual tables]. 6404** This structure consists mostly of methods for the module. 6405** 6406** ^A virtual table module is created by filling in a persistent 6407** instance of this structure and passing a pointer to that instance 6408** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6409** ^The registration remains valid until it is replaced by a different 6410** module or until the [database connection] closes. The content 6411** of this structure must not change while it is registered with 6412** any database connection. 6413*/ 6414struct sqlite3_module { 6415 int iVersion; 6416 int (*xCreate)(sqlite3*, void *pAux, 6417 int argc, const char *const*argv, 6418 sqlite3_vtab **ppVTab, char**); 6419 int (*xConnect)(sqlite3*, void *pAux, 6420 int argc, const char *const*argv, 6421 sqlite3_vtab **ppVTab, char**); 6422 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6423 int (*xDisconnect)(sqlite3_vtab *pVTab); 6424 int (*xDestroy)(sqlite3_vtab *pVTab); 6425 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6426 int (*xClose)(sqlite3_vtab_cursor*); 6427 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6428 int argc, sqlite3_value **argv); 6429 int (*xNext)(sqlite3_vtab_cursor*); 6430 int (*xEof)(sqlite3_vtab_cursor*); 6431 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6432 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6433 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6434 int (*xBegin)(sqlite3_vtab *pVTab); 6435 int (*xSync)(sqlite3_vtab *pVTab); 6436 int (*xCommit)(sqlite3_vtab *pVTab); 6437 int (*xRollback)(sqlite3_vtab *pVTab); 6438 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6439 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6440 void **ppArg); 6441 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6442 /* The methods above are in version 1 of the sqlite_module object. Those 6443 ** below are for version 2 and greater. */ 6444 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6445 int (*xRelease)(sqlite3_vtab *pVTab, int); 6446 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6447 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6448 ** Those below are for version 3 and greater. */ 6449 int (*xShadowName)(const char*); 6450}; 6451 6452/* 6453** CAPI3REF: Virtual Table Indexing Information 6454** KEYWORDS: sqlite3_index_info 6455** 6456** The sqlite3_index_info structure and its substructures is used as part 6457** of the [virtual table] interface to 6458** pass information into and receive the reply from the [xBestIndex] 6459** method of a [virtual table module]. The fields under **Inputs** are the 6460** inputs to xBestIndex and are read-only. xBestIndex inserts its 6461** results into the **Outputs** fields. 6462** 6463** ^(The aConstraint[] array records WHERE clause constraints of the form: 6464** 6465** <blockquote>column OP expr</blockquote> 6466** 6467** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6468** stored in aConstraint[].op using one of the 6469** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6470** ^(The index of the column is stored in 6471** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6472** expr on the right-hand side can be evaluated (and thus the constraint 6473** is usable) and false if it cannot.)^ 6474** 6475** ^The optimizer automatically inverts terms of the form "expr OP column" 6476** and makes other simplifications to the WHERE clause in an attempt to 6477** get as many WHERE clause terms into the form shown above as possible. 6478** ^The aConstraint[] array only reports WHERE clause terms that are 6479** relevant to the particular virtual table being queried. 6480** 6481** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6482** ^Each term of aOrderBy records a column of the ORDER BY clause. 6483** 6484** The colUsed field indicates which columns of the virtual table may be 6485** required by the current scan. Virtual table columns are numbered from 6486** zero in the order in which they appear within the CREATE TABLE statement 6487** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6488** the corresponding bit is set within the colUsed mask if the column may be 6489** required by SQLite. If the table has at least 64 columns and any column 6490** to the right of the first 63 is required, then bit 63 of colUsed is also 6491** set. In other words, column iCol may be required if the expression 6492** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6493** non-zero. 6494** 6495** The [xBestIndex] method must fill aConstraintUsage[] with information 6496** about what parameters to pass to xFilter. ^If argvIndex>0 then 6497** the right-hand side of the corresponding aConstraint[] is evaluated 6498** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6499** is true, then the constraint is assumed to be fully handled by the 6500** virtual table and is not checked again by SQLite.)^ 6501** 6502** ^The idxNum and idxPtr values are recorded and passed into the 6503** [xFilter] method. 6504** ^[sqlite3_free()] is used to free idxPtr if and only if 6505** needToFreeIdxPtr is true. 6506** 6507** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6508** the correct order to satisfy the ORDER BY clause so that no separate 6509** sorting step is required. 6510** 6511** ^The estimatedCost value is an estimate of the cost of a particular 6512** strategy. A cost of N indicates that the cost of the strategy is similar 6513** to a linear scan of an SQLite table with N rows. A cost of log(N) 6514** indicates that the expense of the operation is similar to that of a 6515** binary search on a unique indexed field of an SQLite table with N rows. 6516** 6517** ^The estimatedRows value is an estimate of the number of rows that 6518** will be returned by the strategy. 6519** 6520** The xBestIndex method may optionally populate the idxFlags field with a 6521** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6522** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6523** assumes that the strategy may visit at most one row. 6524** 6525** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6526** SQLite also assumes that if a call to the xUpdate() method is made as 6527** part of the same statement to delete or update a virtual table row and the 6528** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6529** any database changes. In other words, if the xUpdate() returns 6530** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6531** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6532** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6533** the xUpdate method are automatically rolled back by SQLite. 6534** 6535** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6536** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6537** If a virtual table extension is 6538** used with an SQLite version earlier than 3.8.2, the results of attempting 6539** to read or write the estimatedRows field are undefined (but are likely 6540** to included crashing the application). The estimatedRows field should 6541** therefore only be used if [sqlite3_libversion_number()] returns a 6542** value greater than or equal to 3008002. Similarly, the idxFlags field 6543** was added for [version 3.9.0] ([dateof:3.9.0]). 6544** It may therefore only be used if 6545** sqlite3_libversion_number() returns a value greater than or equal to 6546** 3009000. 6547*/ 6548struct sqlite3_index_info { 6549 /* Inputs */ 6550 int nConstraint; /* Number of entries in aConstraint */ 6551 struct sqlite3_index_constraint { 6552 int iColumn; /* Column constrained. -1 for ROWID */ 6553 unsigned char op; /* Constraint operator */ 6554 unsigned char usable; /* True if this constraint is usable */ 6555 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6556 } *aConstraint; /* Table of WHERE clause constraints */ 6557 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6558 struct sqlite3_index_orderby { 6559 int iColumn; /* Column number */ 6560 unsigned char desc; /* True for DESC. False for ASC. */ 6561 } *aOrderBy; /* The ORDER BY clause */ 6562 /* Outputs */ 6563 struct sqlite3_index_constraint_usage { 6564 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6565 unsigned char omit; /* Do not code a test for this constraint */ 6566 } *aConstraintUsage; 6567 int idxNum; /* Number used to identify the index */ 6568 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6569 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6570 int orderByConsumed; /* True if output is already ordered */ 6571 double estimatedCost; /* Estimated cost of using this index */ 6572 /* Fields below are only available in SQLite 3.8.2 and later */ 6573 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6574 /* Fields below are only available in SQLite 3.9.0 and later */ 6575 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6576 /* Fields below are only available in SQLite 3.10.0 and later */ 6577 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6578}; 6579 6580/* 6581** CAPI3REF: Virtual Table Scan Flags 6582** 6583** Virtual table implementations are allowed to set the 6584** [sqlite3_index_info].idxFlags field to some combination of 6585** these bits. 6586*/ 6587#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6588 6589/* 6590** CAPI3REF: Virtual Table Constraint Operator Codes 6591** 6592** These macros defined the allowed values for the 6593** [sqlite3_index_info].aConstraint[].op field. Each value represents 6594** an operator that is part of a constraint term in the wHERE clause of 6595** a query that uses a [virtual table]. 6596*/ 6597#define SQLITE_INDEX_CONSTRAINT_EQ 2 6598#define SQLITE_INDEX_CONSTRAINT_GT 4 6599#define SQLITE_INDEX_CONSTRAINT_LE 8 6600#define SQLITE_INDEX_CONSTRAINT_LT 16 6601#define SQLITE_INDEX_CONSTRAINT_GE 32 6602#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6603#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6604#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6605#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6606#define SQLITE_INDEX_CONSTRAINT_NE 68 6607#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6608#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6609#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6610#define SQLITE_INDEX_CONSTRAINT_IS 72 6611#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6612 6613/* 6614** CAPI3REF: Register A Virtual Table Implementation 6615** METHOD: sqlite3 6616** 6617** ^These routines are used to register a new [virtual table module] name. 6618** ^Module names must be registered before 6619** creating a new [virtual table] using the module and before using a 6620** preexisting [virtual table] for the module. 6621** 6622** ^The module name is registered on the [database connection] specified 6623** by the first parameter. ^The name of the module is given by the 6624** second parameter. ^The third parameter is a pointer to 6625** the implementation of the [virtual table module]. ^The fourth 6626** parameter is an arbitrary client data pointer that is passed through 6627** into the [xCreate] and [xConnect] methods of the virtual table module 6628** when a new virtual table is be being created or reinitialized. 6629** 6630** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6631** is a pointer to a destructor for the pClientData. ^SQLite will 6632** invoke the destructor function (if it is not NULL) when SQLite 6633** no longer needs the pClientData pointer. ^The destructor will also 6634** be invoked if the call to sqlite3_create_module_v2() fails. 6635** ^The sqlite3_create_module() 6636** interface is equivalent to sqlite3_create_module_v2() with a NULL 6637** destructor. 6638** 6639** ^If the third parameter (the pointer to the sqlite3_module object) is 6640** NULL then no new module is create and any existing modules with the 6641** same name are dropped. 6642** 6643** See also: [sqlite3_drop_modules()] 6644*/ 6645int sqlite3_create_module( 6646 sqlite3 *db, /* SQLite connection to register module with */ 6647 const char *zName, /* Name of the module */ 6648 const sqlite3_module *p, /* Methods for the module */ 6649 void *pClientData /* Client data for xCreate/xConnect */ 6650); 6651int sqlite3_create_module_v2( 6652 sqlite3 *db, /* SQLite connection to register module with */ 6653 const char *zName, /* Name of the module */ 6654 const sqlite3_module *p, /* Methods for the module */ 6655 void *pClientData, /* Client data for xCreate/xConnect */ 6656 void(*xDestroy)(void*) /* Module destructor function */ 6657); 6658 6659/* 6660** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6661** METHOD: sqlite3 6662** 6663** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6664** table modules from database connection D except those named on list L. 6665** The L parameter must be either NULL or a pointer to an array of pointers 6666** to strings where the array is terminated by a single NULL pointer. 6667** ^If the L parameter is NULL, then all virtual table modules are removed. 6668** 6669** See also: [sqlite3_create_module()] 6670*/ 6671int sqlite3_drop_modules( 6672 sqlite3 *db, /* Remove modules from this connection */ 6673 const char **azKeep /* Except, do not remove the ones named here */ 6674); 6675 6676/* 6677** CAPI3REF: Virtual Table Instance Object 6678** KEYWORDS: sqlite3_vtab 6679** 6680** Every [virtual table module] implementation uses a subclass 6681** of this object to describe a particular instance 6682** of the [virtual table]. Each subclass will 6683** be tailored to the specific needs of the module implementation. 6684** The purpose of this superclass is to define certain fields that are 6685** common to all module implementations. 6686** 6687** ^Virtual tables methods can set an error message by assigning a 6688** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6689** take care that any prior string is freed by a call to [sqlite3_free()] 6690** prior to assigning a new string to zErrMsg. ^After the error message 6691** is delivered up to the client application, the string will be automatically 6692** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6693*/ 6694struct sqlite3_vtab { 6695 const sqlite3_module *pModule; /* The module for this virtual table */ 6696 int nRef; /* Number of open cursors */ 6697 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6698 /* Virtual table implementations will typically add additional fields */ 6699}; 6700 6701/* 6702** CAPI3REF: Virtual Table Cursor Object 6703** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6704** 6705** Every [virtual table module] implementation uses a subclass of the 6706** following structure to describe cursors that point into the 6707** [virtual table] and are used 6708** to loop through the virtual table. Cursors are created using the 6709** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6710** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6711** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6712** of the module. Each module implementation will define 6713** the content of a cursor structure to suit its own needs. 6714** 6715** This superclass exists in order to define fields of the cursor that 6716** are common to all implementations. 6717*/ 6718struct sqlite3_vtab_cursor { 6719 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6720 /* Virtual table implementations will typically add additional fields */ 6721}; 6722 6723/* 6724** CAPI3REF: Declare The Schema Of A Virtual Table 6725** 6726** ^The [xCreate] and [xConnect] methods of a 6727** [virtual table module] call this interface 6728** to declare the format (the names and datatypes of the columns) of 6729** the virtual tables they implement. 6730*/ 6731int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6732 6733/* 6734** CAPI3REF: Overload A Function For A Virtual Table 6735** METHOD: sqlite3 6736** 6737** ^(Virtual tables can provide alternative implementations of functions 6738** using the [xFindFunction] method of the [virtual table module]. 6739** But global versions of those functions 6740** must exist in order to be overloaded.)^ 6741** 6742** ^(This API makes sure a global version of a function with a particular 6743** name and number of parameters exists. If no such function exists 6744** before this API is called, a new function is created.)^ ^The implementation 6745** of the new function always causes an exception to be thrown. So 6746** the new function is not good for anything by itself. Its only 6747** purpose is to be a placeholder function that can be overloaded 6748** by a [virtual table]. 6749*/ 6750int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6751 6752/* 6753** The interface to the virtual-table mechanism defined above (back up 6754** to a comment remarkably similar to this one) is currently considered 6755** to be experimental. The interface might change in incompatible ways. 6756** If this is a problem for you, do not use the interface at this time. 6757** 6758** When the virtual-table mechanism stabilizes, we will declare the 6759** interface fixed, support it indefinitely, and remove this comment. 6760*/ 6761 6762/* 6763** CAPI3REF: A Handle To An Open BLOB 6764** KEYWORDS: {BLOB handle} {BLOB handles} 6765** 6766** An instance of this object represents an open BLOB on which 6767** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6768** ^Objects of this type are created by [sqlite3_blob_open()] 6769** and destroyed by [sqlite3_blob_close()]. 6770** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6771** can be used to read or write small subsections of the BLOB. 6772** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6773*/ 6774typedef struct sqlite3_blob sqlite3_blob; 6775 6776/* 6777** CAPI3REF: Open A BLOB For Incremental I/O 6778** METHOD: sqlite3 6779** CONSTRUCTOR: sqlite3_blob 6780** 6781** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6782** in row iRow, column zColumn, table zTable in database zDb; 6783** in other words, the same BLOB that would be selected by: 6784** 6785** <pre> 6786** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6787** </pre>)^ 6788** 6789** ^(Parameter zDb is not the filename that contains the database, but 6790** rather the symbolic name of the database. For attached databases, this is 6791** the name that appears after the AS keyword in the [ATTACH] statement. 6792** For the main database file, the database name is "main". For TEMP 6793** tables, the database name is "temp".)^ 6794** 6795** ^If the flags parameter is non-zero, then the BLOB is opened for read 6796** and write access. ^If the flags parameter is zero, the BLOB is opened for 6797** read-only access. 6798** 6799** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6800** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6801** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6802** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6803** on *ppBlob after this function it returns. 6804** 6805** This function fails with SQLITE_ERROR if any of the following are true: 6806** <ul> 6807** <li> ^(Database zDb does not exist)^, 6808** <li> ^(Table zTable does not exist within database zDb)^, 6809** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6810** <li> ^(Column zColumn does not exist)^, 6811** <li> ^(Row iRow is not present in the table)^, 6812** <li> ^(The specified column of row iRow contains a value that is not 6813** a TEXT or BLOB value)^, 6814** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6815** constraint and the blob is being opened for read/write access)^, 6816** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6817** column zColumn is part of a [child key] definition and the blob is 6818** being opened for read/write access)^. 6819** </ul> 6820** 6821** ^Unless it returns SQLITE_MISUSE, this function sets the 6822** [database connection] error code and message accessible via 6823** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6824** 6825** A BLOB referenced by sqlite3_blob_open() may be read using the 6826** [sqlite3_blob_read()] interface and modified by using 6827** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6828** different row of the same table using the [sqlite3_blob_reopen()] 6829** interface. However, the column, table, or database of a [BLOB handle] 6830** cannot be changed after the [BLOB handle] is opened. 6831** 6832** ^(If the row that a BLOB handle points to is modified by an 6833** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6834** then the BLOB handle is marked as "expired". 6835** This is true if any column of the row is changed, even a column 6836** other than the one the BLOB handle is open on.)^ 6837** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6838** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6839** ^(Changes written into a BLOB prior to the BLOB expiring are not 6840** rolled back by the expiration of the BLOB. Such changes will eventually 6841** commit if the transaction continues to completion.)^ 6842** 6843** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6844** the opened blob. ^The size of a blob may not be changed by this 6845** interface. Use the [UPDATE] SQL command to change the size of a 6846** blob. 6847** 6848** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6849** and the built-in [zeroblob] SQL function may be used to create a 6850** zero-filled blob to read or write using the incremental-blob interface. 6851** 6852** To avoid a resource leak, every open [BLOB handle] should eventually 6853** be released by a call to [sqlite3_blob_close()]. 6854** 6855** See also: [sqlite3_blob_close()], 6856** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6857** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6858*/ 6859int sqlite3_blob_open( 6860 sqlite3*, 6861 const char *zDb, 6862 const char *zTable, 6863 const char *zColumn, 6864 sqlite3_int64 iRow, 6865 int flags, 6866 sqlite3_blob **ppBlob 6867); 6868 6869/* 6870** CAPI3REF: Move a BLOB Handle to a New Row 6871** METHOD: sqlite3_blob 6872** 6873** ^This function is used to move an existing [BLOB handle] so that it points 6874** to a different row of the same database table. ^The new row is identified 6875** by the rowid value passed as the second argument. Only the row can be 6876** changed. ^The database, table and column on which the blob handle is open 6877** remain the same. Moving an existing [BLOB handle] to a new row is 6878** faster than closing the existing handle and opening a new one. 6879** 6880** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6881** it must exist and there must be either a blob or text value stored in 6882** the nominated column.)^ ^If the new row is not present in the table, or if 6883** it does not contain a blob or text value, or if another error occurs, an 6884** SQLite error code is returned and the blob handle is considered aborted. 6885** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6886** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6887** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6888** always returns zero. 6889** 6890** ^This function sets the database handle error code and message. 6891*/ 6892int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6893 6894/* 6895** CAPI3REF: Close A BLOB Handle 6896** DESTRUCTOR: sqlite3_blob 6897** 6898** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6899** unconditionally. Even if this routine returns an error code, the 6900** handle is still closed.)^ 6901** 6902** ^If the blob handle being closed was opened for read-write access, and if 6903** the database is in auto-commit mode and there are no other open read-write 6904** blob handles or active write statements, the current transaction is 6905** committed. ^If an error occurs while committing the transaction, an error 6906** code is returned and the transaction rolled back. 6907** 6908** Calling this function with an argument that is not a NULL pointer or an 6909** open blob handle results in undefined behaviour. ^Calling this routine 6910** with a null pointer (such as would be returned by a failed call to 6911** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6912** is passed a valid open blob handle, the values returned by the 6913** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6914*/ 6915int sqlite3_blob_close(sqlite3_blob *); 6916 6917/* 6918** CAPI3REF: Return The Size Of An Open BLOB 6919** METHOD: sqlite3_blob 6920** 6921** ^Returns the size in bytes of the BLOB accessible via the 6922** successfully opened [BLOB handle] in its only argument. ^The 6923** incremental blob I/O routines can only read or overwriting existing 6924** blob content; they cannot change the size of a blob. 6925** 6926** This routine only works on a [BLOB handle] which has been created 6927** by a prior successful call to [sqlite3_blob_open()] and which has not 6928** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6929** to this routine results in undefined and probably undesirable behavior. 6930*/ 6931int sqlite3_blob_bytes(sqlite3_blob *); 6932 6933/* 6934** CAPI3REF: Read Data From A BLOB Incrementally 6935** METHOD: sqlite3_blob 6936** 6937** ^(This function is used to read data from an open [BLOB handle] into a 6938** caller-supplied buffer. N bytes of data are copied into buffer Z 6939** from the open BLOB, starting at offset iOffset.)^ 6940** 6941** ^If offset iOffset is less than N bytes from the end of the BLOB, 6942** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 6943** less than zero, [SQLITE_ERROR] is returned and no data is read. 6944** ^The size of the blob (and hence the maximum value of N+iOffset) 6945** can be determined using the [sqlite3_blob_bytes()] interface. 6946** 6947** ^An attempt to read from an expired [BLOB handle] fails with an 6948** error code of [SQLITE_ABORT]. 6949** 6950** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 6951** Otherwise, an [error code] or an [extended error code] is returned.)^ 6952** 6953** This routine only works on a [BLOB handle] which has been created 6954** by a prior successful call to [sqlite3_blob_open()] and which has not 6955** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6956** to this routine results in undefined and probably undesirable behavior. 6957** 6958** See also: [sqlite3_blob_write()]. 6959*/ 6960int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 6961 6962/* 6963** CAPI3REF: Write Data Into A BLOB Incrementally 6964** METHOD: sqlite3_blob 6965** 6966** ^(This function is used to write data into an open [BLOB handle] from a 6967** caller-supplied buffer. N bytes of data are copied from the buffer Z 6968** into the open BLOB, starting at offset iOffset.)^ 6969** 6970** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 6971** Otherwise, an [error code] or an [extended error code] is returned.)^ 6972** ^Unless SQLITE_MISUSE is returned, this function sets the 6973** [database connection] error code and message accessible via 6974** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6975** 6976** ^If the [BLOB handle] passed as the first argument was not opened for 6977** writing (the flags parameter to [sqlite3_blob_open()] was zero), 6978** this function returns [SQLITE_READONLY]. 6979** 6980** This function may only modify the contents of the BLOB; it is 6981** not possible to increase the size of a BLOB using this API. 6982** ^If offset iOffset is less than N bytes from the end of the BLOB, 6983** [SQLITE_ERROR] is returned and no data is written. The size of the 6984** BLOB (and hence the maximum value of N+iOffset) can be determined 6985** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 6986** than zero [SQLITE_ERROR] is returned and no data is written. 6987** 6988** ^An attempt to write to an expired [BLOB handle] fails with an 6989** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 6990** before the [BLOB handle] expired are not rolled back by the 6991** expiration of the handle, though of course those changes might 6992** have been overwritten by the statement that expired the BLOB handle 6993** or by other independent statements. 6994** 6995** This routine only works on a [BLOB handle] which has been created 6996** by a prior successful call to [sqlite3_blob_open()] and which has not 6997** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6998** to this routine results in undefined and probably undesirable behavior. 6999** 7000** See also: [sqlite3_blob_read()]. 7001*/ 7002int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7003 7004/* 7005** CAPI3REF: Virtual File System Objects 7006** 7007** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7008** that SQLite uses to interact 7009** with the underlying operating system. Most SQLite builds come with a 7010** single default VFS that is appropriate for the host computer. 7011** New VFSes can be registered and existing VFSes can be unregistered. 7012** The following interfaces are provided. 7013** 7014** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7015** ^Names are case sensitive. 7016** ^Names are zero-terminated UTF-8 strings. 7017** ^If there is no match, a NULL pointer is returned. 7018** ^If zVfsName is NULL then the default VFS is returned. 7019** 7020** ^New VFSes are registered with sqlite3_vfs_register(). 7021** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7022** ^The same VFS can be registered multiple times without injury. 7023** ^To make an existing VFS into the default VFS, register it again 7024** with the makeDflt flag set. If two different VFSes with the 7025** same name are registered, the behavior is undefined. If a 7026** VFS is registered with a name that is NULL or an empty string, 7027** then the behavior is undefined. 7028** 7029** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7030** ^(If the default VFS is unregistered, another VFS is chosen as 7031** the default. The choice for the new VFS is arbitrary.)^ 7032*/ 7033sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7034int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7035int sqlite3_vfs_unregister(sqlite3_vfs*); 7036 7037/* 7038** CAPI3REF: Mutexes 7039** 7040** The SQLite core uses these routines for thread 7041** synchronization. Though they are intended for internal 7042** use by SQLite, code that links against SQLite is 7043** permitted to use any of these routines. 7044** 7045** The SQLite source code contains multiple implementations 7046** of these mutex routines. An appropriate implementation 7047** is selected automatically at compile-time. The following 7048** implementations are available in the SQLite core: 7049** 7050** <ul> 7051** <li> SQLITE_MUTEX_PTHREADS 7052** <li> SQLITE_MUTEX_W32 7053** <li> SQLITE_MUTEX_NOOP 7054** </ul> 7055** 7056** The SQLITE_MUTEX_NOOP implementation is a set of routines 7057** that does no real locking and is appropriate for use in 7058** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7059** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7060** and Windows. 7061** 7062** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7063** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7064** implementation is included with the library. In this case the 7065** application must supply a custom mutex implementation using the 7066** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7067** before calling sqlite3_initialize() or any other public sqlite3_ 7068** function that calls sqlite3_initialize(). 7069** 7070** ^The sqlite3_mutex_alloc() routine allocates a new 7071** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7072** routine returns NULL if it is unable to allocate the requested 7073** mutex. The argument to sqlite3_mutex_alloc() must one of these 7074** integer constants: 7075** 7076** <ul> 7077** <li> SQLITE_MUTEX_FAST 7078** <li> SQLITE_MUTEX_RECURSIVE 7079** <li> SQLITE_MUTEX_STATIC_MASTER 7080** <li> SQLITE_MUTEX_STATIC_MEM 7081** <li> SQLITE_MUTEX_STATIC_OPEN 7082** <li> SQLITE_MUTEX_STATIC_PRNG 7083** <li> SQLITE_MUTEX_STATIC_LRU 7084** <li> SQLITE_MUTEX_STATIC_PMEM 7085** <li> SQLITE_MUTEX_STATIC_APP1 7086** <li> SQLITE_MUTEX_STATIC_APP2 7087** <li> SQLITE_MUTEX_STATIC_APP3 7088** <li> SQLITE_MUTEX_STATIC_VFS1 7089** <li> SQLITE_MUTEX_STATIC_VFS2 7090** <li> SQLITE_MUTEX_STATIC_VFS3 7091** </ul> 7092** 7093** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7094** cause sqlite3_mutex_alloc() to create 7095** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7096** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7097** The mutex implementation does not need to make a distinction 7098** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7099** not want to. SQLite will only request a recursive mutex in 7100** cases where it really needs one. If a faster non-recursive mutex 7101** implementation is available on the host platform, the mutex subsystem 7102** might return such a mutex in response to SQLITE_MUTEX_FAST. 7103** 7104** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7105** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7106** a pointer to a static preexisting mutex. ^Nine static mutexes are 7107** used by the current version of SQLite. Future versions of SQLite 7108** may add additional static mutexes. Static mutexes are for internal 7109** use by SQLite only. Applications that use SQLite mutexes should 7110** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7111** SQLITE_MUTEX_RECURSIVE. 7112** 7113** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7114** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7115** returns a different mutex on every call. ^For the static 7116** mutex types, the same mutex is returned on every call that has 7117** the same type number. 7118** 7119** ^The sqlite3_mutex_free() routine deallocates a previously 7120** allocated dynamic mutex. Attempting to deallocate a static 7121** mutex results in undefined behavior. 7122** 7123** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7124** to enter a mutex. ^If another thread is already within the mutex, 7125** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7126** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7127** upon successful entry. ^(Mutexes created using 7128** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7129** In such cases, the 7130** mutex must be exited an equal number of times before another thread 7131** can enter.)^ If the same thread tries to enter any mutex other 7132** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7133** 7134** ^(Some systems (for example, Windows 95) do not support the operation 7135** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7136** will always return SQLITE_BUSY. The SQLite core only ever uses 7137** sqlite3_mutex_try() as an optimization so this is acceptable 7138** behavior.)^ 7139** 7140** ^The sqlite3_mutex_leave() routine exits a mutex that was 7141** previously entered by the same thread. The behavior 7142** is undefined if the mutex is not currently entered by the 7143** calling thread or is not currently allocated. 7144** 7145** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7146** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7147** behave as no-ops. 7148** 7149** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7150*/ 7151sqlite3_mutex *sqlite3_mutex_alloc(int); 7152void sqlite3_mutex_free(sqlite3_mutex*); 7153void sqlite3_mutex_enter(sqlite3_mutex*); 7154int sqlite3_mutex_try(sqlite3_mutex*); 7155void sqlite3_mutex_leave(sqlite3_mutex*); 7156 7157/* 7158** CAPI3REF: Mutex Methods Object 7159** 7160** An instance of this structure defines the low-level routines 7161** used to allocate and use mutexes. 7162** 7163** Usually, the default mutex implementations provided by SQLite are 7164** sufficient, however the application has the option of substituting a custom 7165** implementation for specialized deployments or systems for which SQLite 7166** does not provide a suitable implementation. In this case, the application 7167** creates and populates an instance of this structure to pass 7168** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7169** Additionally, an instance of this structure can be used as an 7170** output variable when querying the system for the current mutex 7171** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7172** 7173** ^The xMutexInit method defined by this structure is invoked as 7174** part of system initialization by the sqlite3_initialize() function. 7175** ^The xMutexInit routine is called by SQLite exactly once for each 7176** effective call to [sqlite3_initialize()]. 7177** 7178** ^The xMutexEnd method defined by this structure is invoked as 7179** part of system shutdown by the sqlite3_shutdown() function. The 7180** implementation of this method is expected to release all outstanding 7181** resources obtained by the mutex methods implementation, especially 7182** those obtained by the xMutexInit method. ^The xMutexEnd() 7183** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7184** 7185** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7186** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7187** xMutexNotheld) implement the following interfaces (respectively): 7188** 7189** <ul> 7190** <li> [sqlite3_mutex_alloc()] </li> 7191** <li> [sqlite3_mutex_free()] </li> 7192** <li> [sqlite3_mutex_enter()] </li> 7193** <li> [sqlite3_mutex_try()] </li> 7194** <li> [sqlite3_mutex_leave()] </li> 7195** <li> [sqlite3_mutex_held()] </li> 7196** <li> [sqlite3_mutex_notheld()] </li> 7197** </ul>)^ 7198** 7199** The only difference is that the public sqlite3_XXX functions enumerated 7200** above silently ignore any invocations that pass a NULL pointer instead 7201** of a valid mutex handle. The implementations of the methods defined 7202** by this structure are not required to handle this case, the results 7203** of passing a NULL pointer instead of a valid mutex handle are undefined 7204** (i.e. it is acceptable to provide an implementation that segfaults if 7205** it is passed a NULL pointer). 7206** 7207** The xMutexInit() method must be threadsafe. It must be harmless to 7208** invoke xMutexInit() multiple times within the same process and without 7209** intervening calls to xMutexEnd(). Second and subsequent calls to 7210** xMutexInit() must be no-ops. 7211** 7212** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7213** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7214** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7215** memory allocation for a fast or recursive mutex. 7216** 7217** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7218** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7219** If xMutexInit fails in any way, it is expected to clean up after itself 7220** prior to returning. 7221*/ 7222typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7223struct sqlite3_mutex_methods { 7224 int (*xMutexInit)(void); 7225 int (*xMutexEnd)(void); 7226 sqlite3_mutex *(*xMutexAlloc)(int); 7227 void (*xMutexFree)(sqlite3_mutex *); 7228 void (*xMutexEnter)(sqlite3_mutex *); 7229 int (*xMutexTry)(sqlite3_mutex *); 7230 void (*xMutexLeave)(sqlite3_mutex *); 7231 int (*xMutexHeld)(sqlite3_mutex *); 7232 int (*xMutexNotheld)(sqlite3_mutex *); 7233}; 7234 7235/* 7236** CAPI3REF: Mutex Verification Routines 7237** 7238** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7239** are intended for use inside assert() statements. The SQLite core 7240** never uses these routines except inside an assert() and applications 7241** are advised to follow the lead of the core. The SQLite core only 7242** provides implementations for these routines when it is compiled 7243** with the SQLITE_DEBUG flag. External mutex implementations 7244** are only required to provide these routines if SQLITE_DEBUG is 7245** defined and if NDEBUG is not defined. 7246** 7247** These routines should return true if the mutex in their argument 7248** is held or not held, respectively, by the calling thread. 7249** 7250** The implementation is not required to provide versions of these 7251** routines that actually work. If the implementation does not provide working 7252** versions of these routines, it should at least provide stubs that always 7253** return true so that one does not get spurious assertion failures. 7254** 7255** If the argument to sqlite3_mutex_held() is a NULL pointer then 7256** the routine should return 1. This seems counter-intuitive since 7257** clearly the mutex cannot be held if it does not exist. But 7258** the reason the mutex does not exist is because the build is not 7259** using mutexes. And we do not want the assert() containing the 7260** call to sqlite3_mutex_held() to fail, so a non-zero return is 7261** the appropriate thing to do. The sqlite3_mutex_notheld() 7262** interface should also return 1 when given a NULL pointer. 7263*/ 7264#ifndef NDEBUG 7265int sqlite3_mutex_held(sqlite3_mutex*); 7266int sqlite3_mutex_notheld(sqlite3_mutex*); 7267#endif 7268 7269/* 7270** CAPI3REF: Mutex Types 7271** 7272** The [sqlite3_mutex_alloc()] interface takes a single argument 7273** which is one of these integer constants. 7274** 7275** The set of static mutexes may change from one SQLite release to the 7276** next. Applications that override the built-in mutex logic must be 7277** prepared to accommodate additional static mutexes. 7278*/ 7279#define SQLITE_MUTEX_FAST 0 7280#define SQLITE_MUTEX_RECURSIVE 1 7281#define SQLITE_MUTEX_STATIC_MASTER 2 7282#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7283#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7284#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7285#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7286#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7287#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7288#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7289#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7290#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7291#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7292#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7293#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7294#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7295 7296/* 7297** CAPI3REF: Retrieve the mutex for a database connection 7298** METHOD: sqlite3 7299** 7300** ^This interface returns a pointer the [sqlite3_mutex] object that 7301** serializes access to the [database connection] given in the argument 7302** when the [threading mode] is Serialized. 7303** ^If the [threading mode] is Single-thread or Multi-thread then this 7304** routine returns a NULL pointer. 7305*/ 7306sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7307 7308/* 7309** CAPI3REF: Low-Level Control Of Database Files 7310** METHOD: sqlite3 7311** KEYWORDS: {file control} 7312** 7313** ^The [sqlite3_file_control()] interface makes a direct call to the 7314** xFileControl method for the [sqlite3_io_methods] object associated 7315** with a particular database identified by the second argument. ^The 7316** name of the database is "main" for the main database or "temp" for the 7317** TEMP database, or the name that appears after the AS keyword for 7318** databases that are added using the [ATTACH] SQL command. 7319** ^A NULL pointer can be used in place of "main" to refer to the 7320** main database file. 7321** ^The third and fourth parameters to this routine 7322** are passed directly through to the second and third parameters of 7323** the xFileControl method. ^The return value of the xFileControl 7324** method becomes the return value of this routine. 7325** 7326** A few opcodes for [sqlite3_file_control()] are handled directly 7327** by the SQLite core and never invoke the 7328** sqlite3_io_methods.xFileControl method. 7329** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7330** a pointer to the underlying [sqlite3_file] object to be written into 7331** the space pointed to by the 4th parameter. The 7332** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7333** the [sqlite3_file] object associated with the journal file instead of 7334** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7335** a pointer to the underlying [sqlite3_vfs] object for the file. 7336** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7337** from the pager. 7338** 7339** ^If the second parameter (zDbName) does not match the name of any 7340** open database file, then SQLITE_ERROR is returned. ^This error 7341** code is not remembered and will not be recalled by [sqlite3_errcode()] 7342** or [sqlite3_errmsg()]. The underlying xFileControl method might 7343** also return SQLITE_ERROR. There is no way to distinguish between 7344** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7345** xFileControl method. 7346** 7347** See also: [file control opcodes] 7348*/ 7349int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7350 7351/* 7352** CAPI3REF: Testing Interface 7353** 7354** ^The sqlite3_test_control() interface is used to read out internal 7355** state of SQLite and to inject faults into SQLite for testing 7356** purposes. ^The first parameter is an operation code that determines 7357** the number, meaning, and operation of all subsequent parameters. 7358** 7359** This interface is not for use by applications. It exists solely 7360** for verifying the correct operation of the SQLite library. Depending 7361** on how the SQLite library is compiled, this interface might not exist. 7362** 7363** The details of the operation codes, their meanings, the parameters 7364** they take, and what they do are all subject to change without notice. 7365** Unlike most of the SQLite API, this function is not guaranteed to 7366** operate consistently from one release to the next. 7367*/ 7368int sqlite3_test_control(int op, ...); 7369 7370/* 7371** CAPI3REF: Testing Interface Operation Codes 7372** 7373** These constants are the valid operation code parameters used 7374** as the first argument to [sqlite3_test_control()]. 7375** 7376** These parameters and their meanings are subject to change 7377** without notice. These values are for testing purposes only. 7378** Applications should not use any of these parameters or the 7379** [sqlite3_test_control()] interface. 7380*/ 7381#define SQLITE_TESTCTRL_FIRST 5 7382#define SQLITE_TESTCTRL_PRNG_SAVE 5 7383#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7384#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7385#define SQLITE_TESTCTRL_BITVEC_TEST 8 7386#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7387#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7388#define SQLITE_TESTCTRL_PENDING_BYTE 11 7389#define SQLITE_TESTCTRL_ASSERT 12 7390#define SQLITE_TESTCTRL_ALWAYS 13 7391#define SQLITE_TESTCTRL_RESERVE 14 7392#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7393#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7394#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7395#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7396#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7397#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7398#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7399#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7400#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7401#define SQLITE_TESTCTRL_BYTEORDER 22 7402#define SQLITE_TESTCTRL_ISINIT 23 7403#define SQLITE_TESTCTRL_SORTER_MMAP 24 7404#define SQLITE_TESTCTRL_IMPOSTER 25 7405#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7406#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7407#define SQLITE_TESTCTRL_PRNG_SEED 28 7408#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7409#define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7410 7411/* 7412** CAPI3REF: SQL Keyword Checking 7413** 7414** These routines provide access to the set of SQL language keywords 7415** recognized by SQLite. Applications can uses these routines to determine 7416** whether or not a specific identifier needs to be escaped (for example, 7417** by enclosing in double-quotes) so as not to confuse the parser. 7418** 7419** The sqlite3_keyword_count() interface returns the number of distinct 7420** keywords understood by SQLite. 7421** 7422** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7423** makes *Z point to that keyword expressed as UTF8 and writes the number 7424** of bytes in the keyword into *L. The string that *Z points to is not 7425** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7426** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7427** or L are NULL or invalid pointers then calls to 7428** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7429** 7430** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7431** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7432** if it is and zero if not. 7433** 7434** The parser used by SQLite is forgiving. It is often possible to use 7435** a keyword as an identifier as long as such use does not result in a 7436** parsing ambiguity. For example, the statement 7437** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7438** creates a new table named "BEGIN" with three columns named 7439** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7440** using keywords as identifiers. Common techniques used to avoid keyword 7441** name collisions include: 7442** <ul> 7443** <li> Put all identifier names inside double-quotes. This is the official 7444** SQL way to escape identifier names. 7445** <li> Put identifier names inside [...]. This is not standard SQL, 7446** but it is what SQL Server does and so lots of programmers use this 7447** technique. 7448** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7449** with "Z". 7450** <li> Include a digit somewhere in every identifier name. 7451** </ul> 7452** 7453** Note that the number of keywords understood by SQLite can depend on 7454** compile-time options. For example, "VACUUM" is not a keyword if 7455** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7456** new keywords may be added to future releases of SQLite. 7457*/ 7458int sqlite3_keyword_count(void); 7459int sqlite3_keyword_name(int,const char**,int*); 7460int sqlite3_keyword_check(const char*,int); 7461 7462/* 7463** CAPI3REF: Dynamic String Object 7464** KEYWORDS: {dynamic string} 7465** 7466** An instance of the sqlite3_str object contains a dynamically-sized 7467** string under construction. 7468** 7469** The lifecycle of an sqlite3_str object is as follows: 7470** <ol> 7471** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7472** <li> ^Text is appended to the sqlite3_str object using various 7473** methods, such as [sqlite3_str_appendf()]. 7474** <li> ^The sqlite3_str object is destroyed and the string it created 7475** is returned using the [sqlite3_str_finish()] interface. 7476** </ol> 7477*/ 7478typedef struct sqlite3_str sqlite3_str; 7479 7480/* 7481** CAPI3REF: Create A New Dynamic String Object 7482** CONSTRUCTOR: sqlite3_str 7483** 7484** ^The [sqlite3_str_new(D)] interface allocates and initializes 7485** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7486** [sqlite3_str_new()] must be freed by a subsequent call to 7487** [sqlite3_str_finish(X)]. 7488** 7489** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7490** valid [sqlite3_str] object, though in the event of an out-of-memory 7491** error the returned object might be a special singleton that will 7492** silently reject new text, always return SQLITE_NOMEM from 7493** [sqlite3_str_errcode()], always return 0 for 7494** [sqlite3_str_length()], and always return NULL from 7495** [sqlite3_str_finish(X)]. It is always safe to use the value 7496** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7497** to any of the other [sqlite3_str] methods. 7498** 7499** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7500** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7501** length of the string contained in the [sqlite3_str] object will be 7502** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7503** of [SQLITE_MAX_LENGTH]. 7504*/ 7505sqlite3_str *sqlite3_str_new(sqlite3*); 7506 7507/* 7508** CAPI3REF: Finalize A Dynamic String 7509** DESTRUCTOR: sqlite3_str 7510** 7511** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7512** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7513** that contains the constructed string. The calling application should 7514** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7515** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7516** errors were encountered during construction of the string. ^The 7517** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7518** string in [sqlite3_str] object X is zero bytes long. 7519*/ 7520char *sqlite3_str_finish(sqlite3_str*); 7521 7522/* 7523** CAPI3REF: Add Content To A Dynamic String 7524** METHOD: sqlite3_str 7525** 7526** These interfaces add content to an sqlite3_str object previously obtained 7527** from [sqlite3_str_new()]. 7528** 7529** ^The [sqlite3_str_appendf(X,F,...)] and 7530** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7531** functionality of SQLite to append formatted text onto the end of 7532** [sqlite3_str] object X. 7533** 7534** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7535** onto the end of the [sqlite3_str] object X. N must be non-negative. 7536** S must contain at least N non-zero bytes of content. To append a 7537** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7538** method instead. 7539** 7540** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7541** zero-terminated string S onto the end of [sqlite3_str] object X. 7542** 7543** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7544** single-byte character C onto the end of [sqlite3_str] object X. 7545** ^This method can be used, for example, to add whitespace indentation. 7546** 7547** ^The [sqlite3_str_reset(X)] method resets the string under construction 7548** inside [sqlite3_str] object X back to zero bytes in length. 7549** 7550** These methods do not return a result code. ^If an error occurs, that fact 7551** is recorded in the [sqlite3_str] object and can be recovered by a 7552** subsequent call to [sqlite3_str_errcode(X)]. 7553*/ 7554void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7555void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7556void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7557void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7558void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7559void sqlite3_str_reset(sqlite3_str*); 7560 7561/* 7562** CAPI3REF: Status Of A Dynamic String 7563** METHOD: sqlite3_str 7564** 7565** These interfaces return the current status of an [sqlite3_str] object. 7566** 7567** ^If any prior errors have occurred while constructing the dynamic string 7568** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7569** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7570** [SQLITE_NOMEM] following any out-of-memory error, or 7571** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7572** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7573** 7574** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7575** of the dynamic string under construction in [sqlite3_str] object X. 7576** ^The length returned by [sqlite3_str_length(X)] does not include the 7577** zero-termination byte. 7578** 7579** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7580** content of the dynamic string under construction in X. The value 7581** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7582** and might be freed or altered by any subsequent method on the same 7583** [sqlite3_str] object. Applications must not used the pointer returned 7584** [sqlite3_str_value(X)] after any subsequent method call on the same 7585** object. ^Applications may change the content of the string returned 7586** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7587** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7588** write any byte after any subsequent sqlite3_str method call. 7589*/ 7590int sqlite3_str_errcode(sqlite3_str*); 7591int sqlite3_str_length(sqlite3_str*); 7592char *sqlite3_str_value(sqlite3_str*); 7593 7594/* 7595** CAPI3REF: SQLite Runtime Status 7596** 7597** ^These interfaces are used to retrieve runtime status information 7598** about the performance of SQLite, and optionally to reset various 7599** highwater marks. ^The first argument is an integer code for 7600** the specific parameter to measure. ^(Recognized integer codes 7601** are of the form [status parameters | SQLITE_STATUS_...].)^ 7602** ^The current value of the parameter is returned into *pCurrent. 7603** ^The highest recorded value is returned in *pHighwater. ^If the 7604** resetFlag is true, then the highest record value is reset after 7605** *pHighwater is written. ^(Some parameters do not record the highest 7606** value. For those parameters 7607** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7608** ^(Other parameters record only the highwater mark and not the current 7609** value. For these latter parameters nothing is written into *pCurrent.)^ 7610** 7611** ^The sqlite3_status() and sqlite3_status64() routines return 7612** SQLITE_OK on success and a non-zero [error code] on failure. 7613** 7614** If either the current value or the highwater mark is too large to 7615** be represented by a 32-bit integer, then the values returned by 7616** sqlite3_status() are undefined. 7617** 7618** See also: [sqlite3_db_status()] 7619*/ 7620int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7621int sqlite3_status64( 7622 int op, 7623 sqlite3_int64 *pCurrent, 7624 sqlite3_int64 *pHighwater, 7625 int resetFlag 7626); 7627 7628 7629/* 7630** CAPI3REF: Status Parameters 7631** KEYWORDS: {status parameters} 7632** 7633** These integer constants designate various run-time status parameters 7634** that can be returned by [sqlite3_status()]. 7635** 7636** <dl> 7637** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7638** <dd>This parameter is the current amount of memory checked out 7639** using [sqlite3_malloc()], either directly or indirectly. The 7640** figure includes calls made to [sqlite3_malloc()] by the application 7641** and internal memory usage by the SQLite library. Auxiliary page-cache 7642** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7643** this parameter. The amount returned is the sum of the allocation 7644** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7645** 7646** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7647** <dd>This parameter records the largest memory allocation request 7648** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7649** internal equivalents). Only the value returned in the 7650** *pHighwater parameter to [sqlite3_status()] is of interest. 7651** The value written into the *pCurrent parameter is undefined.</dd>)^ 7652** 7653** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7654** <dd>This parameter records the number of separate memory allocations 7655** currently checked out.</dd>)^ 7656** 7657** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7658** <dd>This parameter returns the number of pages used out of the 7659** [pagecache memory allocator] that was configured using 7660** [SQLITE_CONFIG_PAGECACHE]. The 7661** value returned is in pages, not in bytes.</dd>)^ 7662** 7663** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7664** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7665** <dd>This parameter returns the number of bytes of page cache 7666** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7667** buffer and where forced to overflow to [sqlite3_malloc()]. The 7668** returned value includes allocations that overflowed because they 7669** where too large (they were larger than the "sz" parameter to 7670** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7671** no space was left in the page cache.</dd>)^ 7672** 7673** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7674** <dd>This parameter records the largest memory allocation request 7675** handed to [pagecache memory allocator]. Only the value returned in the 7676** *pHighwater parameter to [sqlite3_status()] is of interest. 7677** The value written into the *pCurrent parameter is undefined.</dd>)^ 7678** 7679** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7680** <dd>No longer used.</dd> 7681** 7682** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7683** <dd>No longer used.</dd> 7684** 7685** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7686** <dd>No longer used.</dd> 7687** 7688** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7689** <dd>The *pHighwater parameter records the deepest parser stack. 7690** The *pCurrent value is undefined. The *pHighwater value is only 7691** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7692** </dl> 7693** 7694** New status parameters may be added from time to time. 7695*/ 7696#define SQLITE_STATUS_MEMORY_USED 0 7697#define SQLITE_STATUS_PAGECACHE_USED 1 7698#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7699#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7700#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7701#define SQLITE_STATUS_MALLOC_SIZE 5 7702#define SQLITE_STATUS_PARSER_STACK 6 7703#define SQLITE_STATUS_PAGECACHE_SIZE 7 7704#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7705#define SQLITE_STATUS_MALLOC_COUNT 9 7706 7707/* 7708** CAPI3REF: Database Connection Status 7709** METHOD: sqlite3 7710** 7711** ^This interface is used to retrieve runtime status information 7712** about a single [database connection]. ^The first argument is the 7713** database connection object to be interrogated. ^The second argument 7714** is an integer constant, taken from the set of 7715** [SQLITE_DBSTATUS options], that 7716** determines the parameter to interrogate. The set of 7717** [SQLITE_DBSTATUS options] is likely 7718** to grow in future releases of SQLite. 7719** 7720** ^The current value of the requested parameter is written into *pCur 7721** and the highest instantaneous value is written into *pHiwtr. ^If 7722** the resetFlg is true, then the highest instantaneous value is 7723** reset back down to the current value. 7724** 7725** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7726** non-zero [error code] on failure. 7727** 7728** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7729*/ 7730int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7731 7732/* 7733** CAPI3REF: Status Parameters for database connections 7734** KEYWORDS: {SQLITE_DBSTATUS options} 7735** 7736** These constants are the available integer "verbs" that can be passed as 7737** the second argument to the [sqlite3_db_status()] interface. 7738** 7739** New verbs may be added in future releases of SQLite. Existing verbs 7740** might be discontinued. Applications should check the return code from 7741** [sqlite3_db_status()] to make sure that the call worked. 7742** The [sqlite3_db_status()] interface will return a non-zero error code 7743** if a discontinued or unsupported verb is invoked. 7744** 7745** <dl> 7746** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7747** <dd>This parameter returns the number of lookaside memory slots currently 7748** checked out.</dd>)^ 7749** 7750** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7751** <dd>This parameter returns the number malloc attempts that were 7752** satisfied using lookaside memory. Only the high-water value is meaningful; 7753** the current value is always zero.)^ 7754** 7755** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7756** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7757** <dd>This parameter returns the number malloc attempts that might have 7758** been satisfied using lookaside memory but failed due to the amount of 7759** memory requested being larger than the lookaside slot size. 7760** Only the high-water value is meaningful; 7761** the current value is always zero.)^ 7762** 7763** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7764** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7765** <dd>This parameter returns the number malloc attempts that might have 7766** been satisfied using lookaside memory but failed due to all lookaside 7767** memory already being in use. 7768** Only the high-water value is meaningful; 7769** the current value is always zero.)^ 7770** 7771** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7772** <dd>This parameter returns the approximate number of bytes of heap 7773** memory used by all pager caches associated with the database connection.)^ 7774** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7775** 7776** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7777** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7778** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7779** pager cache is shared between two or more connections the bytes of heap 7780** memory used by that pager cache is divided evenly between the attached 7781** connections.)^ In other words, if none of the pager caches associated 7782** with the database connection are shared, this request returns the same 7783** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7784** shared, the value returned by this call will be smaller than that returned 7785** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7786** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7787** 7788** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7789** <dd>This parameter returns the approximate number of bytes of heap 7790** memory used to store the schema for all databases associated 7791** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7792** ^The full amount of memory used by the schemas is reported, even if the 7793** schema memory is shared with other database connections due to 7794** [shared cache mode] being enabled. 7795** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7796** 7797** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7798** <dd>This parameter returns the approximate number of bytes of heap 7799** and lookaside memory used by all prepared statements associated with 7800** the database connection.)^ 7801** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7802** </dd> 7803** 7804** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7805** <dd>This parameter returns the number of pager cache hits that have 7806** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7807** is always 0. 7808** </dd> 7809** 7810** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7811** <dd>This parameter returns the number of pager cache misses that have 7812** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7813** is always 0. 7814** </dd> 7815** 7816** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7817** <dd>This parameter returns the number of dirty cache entries that have 7818** been written to disk. Specifically, the number of pages written to the 7819** wal file in wal mode databases, or the number of pages written to the 7820** database file in rollback mode databases. Any pages written as part of 7821** transaction rollback or database recovery operations are not included. 7822** If an IO or other error occurs while writing a page to disk, the effect 7823** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7824** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7825** </dd> 7826** 7827** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7828** <dd>This parameter returns the number of dirty cache entries that have 7829** been written to disk in the middle of a transaction due to the page 7830** cache overflowing. Transactions are more efficient if they are written 7831** to disk all at once. When pages spill mid-transaction, that introduces 7832** additional overhead. This parameter can be used help identify 7833** inefficiencies that can be resolve by increasing the cache size. 7834** </dd> 7835** 7836** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7837** <dd>This parameter returns zero for the current value if and only if 7838** all foreign key constraints (deferred or immediate) have been 7839** resolved.)^ ^The highwater mark is always 0. 7840** </dd> 7841** </dl> 7842*/ 7843#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7844#define SQLITE_DBSTATUS_CACHE_USED 1 7845#define SQLITE_DBSTATUS_SCHEMA_USED 2 7846#define SQLITE_DBSTATUS_STMT_USED 3 7847#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7848#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7849#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7850#define SQLITE_DBSTATUS_CACHE_HIT 7 7851#define SQLITE_DBSTATUS_CACHE_MISS 8 7852#define SQLITE_DBSTATUS_CACHE_WRITE 9 7853#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7854#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7855#define SQLITE_DBSTATUS_CACHE_SPILL 12 7856#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7857 7858 7859/* 7860** CAPI3REF: Prepared Statement Status 7861** METHOD: sqlite3_stmt 7862** 7863** ^(Each prepared statement maintains various 7864** [SQLITE_STMTSTATUS counters] that measure the number 7865** of times it has performed specific operations.)^ These counters can 7866** be used to monitor the performance characteristics of the prepared 7867** statements. For example, if the number of table steps greatly exceeds 7868** the number of table searches or result rows, that would tend to indicate 7869** that the prepared statement is using a full table scan rather than 7870** an index. 7871** 7872** ^(This interface is used to retrieve and reset counter values from 7873** a [prepared statement]. The first argument is the prepared statement 7874** object to be interrogated. The second argument 7875** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7876** to be interrogated.)^ 7877** ^The current value of the requested counter is returned. 7878** ^If the resetFlg is true, then the counter is reset to zero after this 7879** interface call returns. 7880** 7881** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7882*/ 7883int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7884 7885/* 7886** CAPI3REF: Status Parameters for prepared statements 7887** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7888** 7889** These preprocessor macros define integer codes that name counter 7890** values associated with the [sqlite3_stmt_status()] interface. 7891** The meanings of the various counters are as follows: 7892** 7893** <dl> 7894** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7895** <dd>^This is the number of times that SQLite has stepped forward in 7896** a table as part of a full table scan. Large numbers for this counter 7897** may indicate opportunities for performance improvement through 7898** careful use of indices.</dd> 7899** 7900** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7901** <dd>^This is the number of sort operations that have occurred. 7902** A non-zero value in this counter may indicate an opportunity to 7903** improvement performance through careful use of indices.</dd> 7904** 7905** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7906** <dd>^This is the number of rows inserted into transient indices that 7907** were created automatically in order to help joins run faster. 7908** A non-zero value in this counter may indicate an opportunity to 7909** improvement performance by adding permanent indices that do not 7910** need to be reinitialized each time the statement is run.</dd> 7911** 7912** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7913** <dd>^This is the number of virtual machine operations executed 7914** by the prepared statement if that number is less than or equal 7915** to 2147483647. The number of virtual machine operations can be 7916** used as a proxy for the total work done by the prepared statement. 7917** If the number of virtual machine operations exceeds 2147483647 7918** then the value returned by this statement status code is undefined. 7919** 7920** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7921** <dd>^This is the number of times that the prepare statement has been 7922** automatically regenerated due to schema changes or change to 7923** [bound parameters] that might affect the query plan. 7924** 7925** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7926** <dd>^This is the number of times that the prepared statement has 7927** been run. A single "run" for the purposes of this counter is one 7928** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7929** The counter is incremented on the first [sqlite3_step()] call of each 7930** cycle. 7931** 7932** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7933** <dd>^This is the approximate number of bytes of heap memory 7934** used to store the prepared statement. ^This value is not actually 7935** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7936** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7937** </dd> 7938** </dl> 7939*/ 7940#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7941#define SQLITE_STMTSTATUS_SORT 2 7942#define SQLITE_STMTSTATUS_AUTOINDEX 3 7943#define SQLITE_STMTSTATUS_VM_STEP 4 7944#define SQLITE_STMTSTATUS_REPREPARE 5 7945#define SQLITE_STMTSTATUS_RUN 6 7946#define SQLITE_STMTSTATUS_MEMUSED 99 7947 7948/* 7949** CAPI3REF: Custom Page Cache Object 7950** 7951** The sqlite3_pcache type is opaque. It is implemented by 7952** the pluggable module. The SQLite core has no knowledge of 7953** its size or internal structure and never deals with the 7954** sqlite3_pcache object except by holding and passing pointers 7955** to the object. 7956** 7957** See [sqlite3_pcache_methods2] for additional information. 7958*/ 7959typedef struct sqlite3_pcache sqlite3_pcache; 7960 7961/* 7962** CAPI3REF: Custom Page Cache Object 7963** 7964** The sqlite3_pcache_page object represents a single page in the 7965** page cache. The page cache will allocate instances of this 7966** object. Various methods of the page cache use pointers to instances 7967** of this object as parameters or as their return value. 7968** 7969** See [sqlite3_pcache_methods2] for additional information. 7970*/ 7971typedef struct sqlite3_pcache_page sqlite3_pcache_page; 7972struct sqlite3_pcache_page { 7973 void *pBuf; /* The content of the page */ 7974 void *pExtra; /* Extra information associated with the page */ 7975}; 7976 7977/* 7978** CAPI3REF: Application Defined Page Cache. 7979** KEYWORDS: {page cache} 7980** 7981** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 7982** register an alternative page cache implementation by passing in an 7983** instance of the sqlite3_pcache_methods2 structure.)^ 7984** In many applications, most of the heap memory allocated by 7985** SQLite is used for the page cache. 7986** By implementing a 7987** custom page cache using this API, an application can better control 7988** the amount of memory consumed by SQLite, the way in which 7989** that memory is allocated and released, and the policies used to 7990** determine exactly which parts of a database file are cached and for 7991** how long. 7992** 7993** The alternative page cache mechanism is an 7994** extreme measure that is only needed by the most demanding applications. 7995** The built-in page cache is recommended for most uses. 7996** 7997** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 7998** internal buffer by SQLite within the call to [sqlite3_config]. Hence 7999** the application may discard the parameter after the call to 8000** [sqlite3_config()] returns.)^ 8001** 8002** [[the xInit() page cache method]] 8003** ^(The xInit() method is called once for each effective 8004** call to [sqlite3_initialize()])^ 8005** (usually only once during the lifetime of the process). ^(The xInit() 8006** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8007** The intent of the xInit() method is to set up global data structures 8008** required by the custom page cache implementation. 8009** ^(If the xInit() method is NULL, then the 8010** built-in default page cache is used instead of the application defined 8011** page cache.)^ 8012** 8013** [[the xShutdown() page cache method]] 8014** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8015** It can be used to clean up 8016** any outstanding resources before process shutdown, if required. 8017** ^The xShutdown() method may be NULL. 8018** 8019** ^SQLite automatically serializes calls to the xInit method, 8020** so the xInit method need not be threadsafe. ^The 8021** xShutdown method is only called from [sqlite3_shutdown()] so it does 8022** not need to be threadsafe either. All other methods must be threadsafe 8023** in multithreaded applications. 8024** 8025** ^SQLite will never invoke xInit() more than once without an intervening 8026** call to xShutdown(). 8027** 8028** [[the xCreate() page cache methods]] 8029** ^SQLite invokes the xCreate() method to construct a new cache instance. 8030** SQLite will typically create one cache instance for each open database file, 8031** though this is not guaranteed. ^The 8032** first parameter, szPage, is the size in bytes of the pages that must 8033** be allocated by the cache. ^szPage will always a power of two. ^The 8034** second parameter szExtra is a number of bytes of extra storage 8035** associated with each page cache entry. ^The szExtra parameter will 8036** a number less than 250. SQLite will use the 8037** extra szExtra bytes on each page to store metadata about the underlying 8038** database page on disk. The value passed into szExtra depends 8039** on the SQLite version, the target platform, and how SQLite was compiled. 8040** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8041** created will be used to cache database pages of a file stored on disk, or 8042** false if it is used for an in-memory database. The cache implementation 8043** does not have to do anything special based with the value of bPurgeable; 8044** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8045** never invoke xUnpin() except to deliberately delete a page. 8046** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8047** false will always have the "discard" flag set to true. 8048** ^Hence, a cache created with bPurgeable false will 8049** never contain any unpinned pages. 8050** 8051** [[the xCachesize() page cache method]] 8052** ^(The xCachesize() method may be called at any time by SQLite to set the 8053** suggested maximum cache-size (number of pages stored by) the cache 8054** instance passed as the first argument. This is the value configured using 8055** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8056** parameter, the implementation is not required to do anything with this 8057** value; it is advisory only. 8058** 8059** [[the xPagecount() page cache methods]] 8060** The xPagecount() method must return the number of pages currently 8061** stored in the cache, both pinned and unpinned. 8062** 8063** [[the xFetch() page cache methods]] 8064** The xFetch() method locates a page in the cache and returns a pointer to 8065** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8066** The pBuf element of the returned sqlite3_pcache_page object will be a 8067** pointer to a buffer of szPage bytes used to store the content of a 8068** single database page. The pExtra element of sqlite3_pcache_page will be 8069** a pointer to the szExtra bytes of extra storage that SQLite has requested 8070** for each entry in the page cache. 8071** 8072** The page to be fetched is determined by the key. ^The minimum key value 8073** is 1. After it has been retrieved using xFetch, the page is considered 8074** to be "pinned". 8075** 8076** If the requested page is already in the page cache, then the page cache 8077** implementation must return a pointer to the page buffer with its content 8078** intact. If the requested page is not already in the cache, then the 8079** cache implementation should use the value of the createFlag 8080** parameter to help it determined what action to take: 8081** 8082** <table border=1 width=85% align=center> 8083** <tr><th> createFlag <th> Behavior when page is not already in cache 8084** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8085** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8086** Otherwise return NULL. 8087** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8088** NULL if allocating a new page is effectively impossible. 8089** </table> 8090** 8091** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8092** will only use a createFlag of 2 after a prior call with a createFlag of 1 8093** failed.)^ In between the to xFetch() calls, SQLite may 8094** attempt to unpin one or more cache pages by spilling the content of 8095** pinned pages to disk and synching the operating system disk cache. 8096** 8097** [[the xUnpin() page cache method]] 8098** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8099** as its second argument. If the third parameter, discard, is non-zero, 8100** then the page must be evicted from the cache. 8101** ^If the discard parameter is 8102** zero, then the page may be discarded or retained at the discretion of 8103** page cache implementation. ^The page cache implementation 8104** may choose to evict unpinned pages at any time. 8105** 8106** The cache must not perform any reference counting. A single 8107** call to xUnpin() unpins the page regardless of the number of prior calls 8108** to xFetch(). 8109** 8110** [[the xRekey() page cache methods]] 8111** The xRekey() method is used to change the key value associated with the 8112** page passed as the second argument. If the cache 8113** previously contains an entry associated with newKey, it must be 8114** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8115** to be pinned. 8116** 8117** When SQLite calls the xTruncate() method, the cache must discard all 8118** existing cache entries with page numbers (keys) greater than or equal 8119** to the value of the iLimit parameter passed to xTruncate(). If any 8120** of these pages are pinned, they are implicitly unpinned, meaning that 8121** they can be safely discarded. 8122** 8123** [[the xDestroy() page cache method]] 8124** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8125** All resources associated with the specified cache should be freed. ^After 8126** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8127** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8128** functions. 8129** 8130** [[the xShrink() page cache method]] 8131** ^SQLite invokes the xShrink() method when it wants the page cache to 8132** free up as much of heap memory as possible. The page cache implementation 8133** is not obligated to free any memory, but well-behaved implementations should 8134** do their best. 8135*/ 8136typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8137struct sqlite3_pcache_methods2 { 8138 int iVersion; 8139 void *pArg; 8140 int (*xInit)(void*); 8141 void (*xShutdown)(void*); 8142 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8143 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8144 int (*xPagecount)(sqlite3_pcache*); 8145 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8146 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8147 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8148 unsigned oldKey, unsigned newKey); 8149 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8150 void (*xDestroy)(sqlite3_pcache*); 8151 void (*xShrink)(sqlite3_pcache*); 8152}; 8153 8154/* 8155** This is the obsolete pcache_methods object that has now been replaced 8156** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8157** retained in the header file for backwards compatibility only. 8158*/ 8159typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8160struct sqlite3_pcache_methods { 8161 void *pArg; 8162 int (*xInit)(void*); 8163 void (*xShutdown)(void*); 8164 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8165 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8166 int (*xPagecount)(sqlite3_pcache*); 8167 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8168 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8169 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8170 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8171 void (*xDestroy)(sqlite3_pcache*); 8172}; 8173 8174 8175/* 8176** CAPI3REF: Online Backup Object 8177** 8178** The sqlite3_backup object records state information about an ongoing 8179** online backup operation. ^The sqlite3_backup object is created by 8180** a call to [sqlite3_backup_init()] and is destroyed by a call to 8181** [sqlite3_backup_finish()]. 8182** 8183** See Also: [Using the SQLite Online Backup API] 8184*/ 8185typedef struct sqlite3_backup sqlite3_backup; 8186 8187/* 8188** CAPI3REF: Online Backup API. 8189** 8190** The backup API copies the content of one database into another. 8191** It is useful either for creating backups of databases or 8192** for copying in-memory databases to or from persistent files. 8193** 8194** See Also: [Using the SQLite Online Backup API] 8195** 8196** ^SQLite holds a write transaction open on the destination database file 8197** for the duration of the backup operation. 8198** ^The source database is read-locked only while it is being read; 8199** it is not locked continuously for the entire backup operation. 8200** ^Thus, the backup may be performed on a live source database without 8201** preventing other database connections from 8202** reading or writing to the source database while the backup is underway. 8203** 8204** ^(To perform a backup operation: 8205** <ol> 8206** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8207** backup, 8208** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8209** the data between the two databases, and finally 8210** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8211** associated with the backup operation. 8212** </ol>)^ 8213** There should be exactly one call to sqlite3_backup_finish() for each 8214** successful call to sqlite3_backup_init(). 8215** 8216** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8217** 8218** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8219** [database connection] associated with the destination database 8220** and the database name, respectively. 8221** ^The database name is "main" for the main database, "temp" for the 8222** temporary database, or the name specified after the AS keyword in 8223** an [ATTACH] statement for an attached database. 8224** ^The S and M arguments passed to 8225** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8226** and database name of the source database, respectively. 8227** ^The source and destination [database connections] (parameters S and D) 8228** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8229** an error. 8230** 8231** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8232** there is already a read or read-write transaction open on the 8233** destination database. 8234** 8235** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8236** returned and an error code and error message are stored in the 8237** destination [database connection] D. 8238** ^The error code and message for the failed call to sqlite3_backup_init() 8239** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8240** [sqlite3_errmsg16()] functions. 8241** ^A successful call to sqlite3_backup_init() returns a pointer to an 8242** [sqlite3_backup] object. 8243** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8244** sqlite3_backup_finish() functions to perform the specified backup 8245** operation. 8246** 8247** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8248** 8249** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8250** the source and destination databases specified by [sqlite3_backup] object B. 8251** ^If N is negative, all remaining source pages are copied. 8252** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8253** are still more pages to be copied, then the function returns [SQLITE_OK]. 8254** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8255** from source to destination, then it returns [SQLITE_DONE]. 8256** ^If an error occurs while running sqlite3_backup_step(B,N), 8257** then an [error code] is returned. ^As well as [SQLITE_OK] and 8258** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8259** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8260** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8261** 8262** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8263** <ol> 8264** <li> the destination database was opened read-only, or 8265** <li> the destination database is using write-ahead-log journaling 8266** and the destination and source page sizes differ, or 8267** <li> the destination database is an in-memory database and the 8268** destination and source page sizes differ. 8269** </ol>)^ 8270** 8271** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8272** the [sqlite3_busy_handler | busy-handler function] 8273** is invoked (if one is specified). ^If the 8274** busy-handler returns non-zero before the lock is available, then 8275** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8276** sqlite3_backup_step() can be retried later. ^If the source 8277** [database connection] 8278** is being used to write to the source database when sqlite3_backup_step() 8279** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8280** case the call to sqlite3_backup_step() can be retried later on. ^(If 8281** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8282** [SQLITE_READONLY] is returned, then 8283** there is no point in retrying the call to sqlite3_backup_step(). These 8284** errors are considered fatal.)^ The application must accept 8285** that the backup operation has failed and pass the backup operation handle 8286** to the sqlite3_backup_finish() to release associated resources. 8287** 8288** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8289** on the destination file. ^The exclusive lock is not released until either 8290** sqlite3_backup_finish() is called or the backup operation is complete 8291** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8292** sqlite3_backup_step() obtains a [shared lock] on the source database that 8293** lasts for the duration of the sqlite3_backup_step() call. 8294** ^Because the source database is not locked between calls to 8295** sqlite3_backup_step(), the source database may be modified mid-way 8296** through the backup process. ^If the source database is modified by an 8297** external process or via a database connection other than the one being 8298** used by the backup operation, then the backup will be automatically 8299** restarted by the next call to sqlite3_backup_step(). ^If the source 8300** database is modified by the using the same database connection as is used 8301** by the backup operation, then the backup database is automatically 8302** updated at the same time. 8303** 8304** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8305** 8306** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8307** application wishes to abandon the backup operation, the application 8308** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8309** ^The sqlite3_backup_finish() interfaces releases all 8310** resources associated with the [sqlite3_backup] object. 8311** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8312** active write-transaction on the destination database is rolled back. 8313** The [sqlite3_backup] object is invalid 8314** and may not be used following a call to sqlite3_backup_finish(). 8315** 8316** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8317** sqlite3_backup_step() errors occurred, regardless or whether or not 8318** sqlite3_backup_step() completed. 8319** ^If an out-of-memory condition or IO error occurred during any prior 8320** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8321** sqlite3_backup_finish() returns the corresponding [error code]. 8322** 8323** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8324** is not a permanent error and does not affect the return value of 8325** sqlite3_backup_finish(). 8326** 8327** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8328** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8329** 8330** ^The sqlite3_backup_remaining() routine returns the number of pages still 8331** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8332** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8333** in the source database at the conclusion of the most recent 8334** sqlite3_backup_step(). 8335** ^(The values returned by these functions are only updated by 8336** sqlite3_backup_step(). If the source database is modified in a way that 8337** changes the size of the source database or the number of pages remaining, 8338** those changes are not reflected in the output of sqlite3_backup_pagecount() 8339** and sqlite3_backup_remaining() until after the next 8340** sqlite3_backup_step().)^ 8341** 8342** <b>Concurrent Usage of Database Handles</b> 8343** 8344** ^The source [database connection] may be used by the application for other 8345** purposes while a backup operation is underway or being initialized. 8346** ^If SQLite is compiled and configured to support threadsafe database 8347** connections, then the source database connection may be used concurrently 8348** from within other threads. 8349** 8350** However, the application must guarantee that the destination 8351** [database connection] is not passed to any other API (by any thread) after 8352** sqlite3_backup_init() is called and before the corresponding call to 8353** sqlite3_backup_finish(). SQLite does not currently check to see 8354** if the application incorrectly accesses the destination [database connection] 8355** and so no error code is reported, but the operations may malfunction 8356** nevertheless. Use of the destination database connection while a 8357** backup is in progress might also also cause a mutex deadlock. 8358** 8359** If running in [shared cache mode], the application must 8360** guarantee that the shared cache used by the destination database 8361** is not accessed while the backup is running. In practice this means 8362** that the application must guarantee that the disk file being 8363** backed up to is not accessed by any connection within the process, 8364** not just the specific connection that was passed to sqlite3_backup_init(). 8365** 8366** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8367** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8368** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8369** APIs are not strictly speaking threadsafe. If they are invoked at the 8370** same time as another thread is invoking sqlite3_backup_step() it is 8371** possible that they return invalid values. 8372*/ 8373sqlite3_backup *sqlite3_backup_init( 8374 sqlite3 *pDest, /* Destination database handle */ 8375 const char *zDestName, /* Destination database name */ 8376 sqlite3 *pSource, /* Source database handle */ 8377 const char *zSourceName /* Source database name */ 8378); 8379int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8380int sqlite3_backup_finish(sqlite3_backup *p); 8381int sqlite3_backup_remaining(sqlite3_backup *p); 8382int sqlite3_backup_pagecount(sqlite3_backup *p); 8383 8384/* 8385** CAPI3REF: Unlock Notification 8386** METHOD: sqlite3 8387** 8388** ^When running in shared-cache mode, a database operation may fail with 8389** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8390** individual tables within the shared-cache cannot be obtained. See 8391** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8392** ^This API may be used to register a callback that SQLite will invoke 8393** when the connection currently holding the required lock relinquishes it. 8394** ^This API is only available if the library was compiled with the 8395** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8396** 8397** See Also: [Using the SQLite Unlock Notification Feature]. 8398** 8399** ^Shared-cache locks are released when a database connection concludes 8400** its current transaction, either by committing it or rolling it back. 8401** 8402** ^When a connection (known as the blocked connection) fails to obtain a 8403** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8404** identity of the database connection (the blocking connection) that 8405** has locked the required resource is stored internally. ^After an 8406** application receives an SQLITE_LOCKED error, it may call the 8407** sqlite3_unlock_notify() method with the blocked connection handle as 8408** the first argument to register for a callback that will be invoked 8409** when the blocking connections current transaction is concluded. ^The 8410** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8411** call that concludes the blocking connections transaction. 8412** 8413** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8414** there is a chance that the blocking connection will have already 8415** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8416** If this happens, then the specified callback is invoked immediately, 8417** from within the call to sqlite3_unlock_notify().)^ 8418** 8419** ^If the blocked connection is attempting to obtain a write-lock on a 8420** shared-cache table, and more than one other connection currently holds 8421** a read-lock on the same table, then SQLite arbitrarily selects one of 8422** the other connections to use as the blocking connection. 8423** 8424** ^(There may be at most one unlock-notify callback registered by a 8425** blocked connection. If sqlite3_unlock_notify() is called when the 8426** blocked connection already has a registered unlock-notify callback, 8427** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8428** called with a NULL pointer as its second argument, then any existing 8429** unlock-notify callback is canceled. ^The blocked connections 8430** unlock-notify callback may also be canceled by closing the blocked 8431** connection using [sqlite3_close()]. 8432** 8433** The unlock-notify callback is not reentrant. If an application invokes 8434** any sqlite3_xxx API functions from within an unlock-notify callback, a 8435** crash or deadlock may be the result. 8436** 8437** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8438** returns SQLITE_OK. 8439** 8440** <b>Callback Invocation Details</b> 8441** 8442** When an unlock-notify callback is registered, the application provides a 8443** single void* pointer that is passed to the callback when it is invoked. 8444** However, the signature of the callback function allows SQLite to pass 8445** it an array of void* context pointers. The first argument passed to 8446** an unlock-notify callback is a pointer to an array of void* pointers, 8447** and the second is the number of entries in the array. 8448** 8449** When a blocking connections transaction is concluded, there may be 8450** more than one blocked connection that has registered for an unlock-notify 8451** callback. ^If two or more such blocked connections have specified the 8452** same callback function, then instead of invoking the callback function 8453** multiple times, it is invoked once with the set of void* context pointers 8454** specified by the blocked connections bundled together into an array. 8455** This gives the application an opportunity to prioritize any actions 8456** related to the set of unblocked database connections. 8457** 8458** <b>Deadlock Detection</b> 8459** 8460** Assuming that after registering for an unlock-notify callback a 8461** database waits for the callback to be issued before taking any further 8462** action (a reasonable assumption), then using this API may cause the 8463** application to deadlock. For example, if connection X is waiting for 8464** connection Y's transaction to be concluded, and similarly connection 8465** Y is waiting on connection X's transaction, then neither connection 8466** will proceed and the system may remain deadlocked indefinitely. 8467** 8468** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8469** detection. ^If a given call to sqlite3_unlock_notify() would put the 8470** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8471** unlock-notify callback is registered. The system is said to be in 8472** a deadlocked state if connection A has registered for an unlock-notify 8473** callback on the conclusion of connection B's transaction, and connection 8474** B has itself registered for an unlock-notify callback when connection 8475** A's transaction is concluded. ^Indirect deadlock is also detected, so 8476** the system is also considered to be deadlocked if connection B has 8477** registered for an unlock-notify callback on the conclusion of connection 8478** C's transaction, where connection C is waiting on connection A. ^Any 8479** number of levels of indirection are allowed. 8480** 8481** <b>The "DROP TABLE" Exception</b> 8482** 8483** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8484** always appropriate to call sqlite3_unlock_notify(). There is however, 8485** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8486** SQLite checks if there are any currently executing SELECT statements 8487** that belong to the same connection. If there are, SQLITE_LOCKED is 8488** returned. In this case there is no "blocking connection", so invoking 8489** sqlite3_unlock_notify() results in the unlock-notify callback being 8490** invoked immediately. If the application then re-attempts the "DROP TABLE" 8491** or "DROP INDEX" query, an infinite loop might be the result. 8492** 8493** One way around this problem is to check the extended error code returned 8494** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8495** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8496** the special "DROP TABLE/INDEX" case, the extended error code is just 8497** SQLITE_LOCKED.)^ 8498*/ 8499int sqlite3_unlock_notify( 8500 sqlite3 *pBlocked, /* Waiting connection */ 8501 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8502 void *pNotifyArg /* Argument to pass to xNotify */ 8503); 8504 8505 8506/* 8507** CAPI3REF: String Comparison 8508** 8509** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8510** and extensions to compare the contents of two buffers containing UTF-8 8511** strings in a case-independent fashion, using the same definition of "case 8512** independence" that SQLite uses internally when comparing identifiers. 8513*/ 8514int sqlite3_stricmp(const char *, const char *); 8515int sqlite3_strnicmp(const char *, const char *, int); 8516 8517/* 8518** CAPI3REF: String Globbing 8519* 8520** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8521** string X matches the [GLOB] pattern P. 8522** ^The definition of [GLOB] pattern matching used in 8523** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8524** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8525** is case sensitive. 8526** 8527** Note that this routine returns zero on a match and non-zero if the strings 8528** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8529** 8530** See also: [sqlite3_strlike()]. 8531*/ 8532int sqlite3_strglob(const char *zGlob, const char *zStr); 8533 8534/* 8535** CAPI3REF: String LIKE Matching 8536* 8537** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8538** string X matches the [LIKE] pattern P with escape character E. 8539** ^The definition of [LIKE] pattern matching used in 8540** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8541** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8542** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8543** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8544** insensitive - equivalent upper and lower case ASCII characters match 8545** one another. 8546** 8547** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8548** only ASCII characters are case folded. 8549** 8550** Note that this routine returns zero on a match and non-zero if the strings 8551** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8552** 8553** See also: [sqlite3_strglob()]. 8554*/ 8555int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8556 8557/* 8558** CAPI3REF: Error Logging Interface 8559** 8560** ^The [sqlite3_log()] interface writes a message into the [error log] 8561** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8562** ^If logging is enabled, the zFormat string and subsequent arguments are 8563** used with [sqlite3_snprintf()] to generate the final output string. 8564** 8565** The sqlite3_log() interface is intended for use by extensions such as 8566** virtual tables, collating functions, and SQL functions. While there is 8567** nothing to prevent an application from calling sqlite3_log(), doing so 8568** is considered bad form. 8569** 8570** The zFormat string must not be NULL. 8571** 8572** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8573** will not use dynamically allocated memory. The log message is stored in 8574** a fixed-length buffer on the stack. If the log message is longer than 8575** a few hundred characters, it will be truncated to the length of the 8576** buffer. 8577*/ 8578void sqlite3_log(int iErrCode, const char *zFormat, ...); 8579 8580/* 8581** CAPI3REF: Write-Ahead Log Commit Hook 8582** METHOD: sqlite3 8583** 8584** ^The [sqlite3_wal_hook()] function is used to register a callback that 8585** is invoked each time data is committed to a database in wal mode. 8586** 8587** ^(The callback is invoked by SQLite after the commit has taken place and 8588** the associated write-lock on the database released)^, so the implementation 8589** may read, write or [checkpoint] the database as required. 8590** 8591** ^The first parameter passed to the callback function when it is invoked 8592** is a copy of the third parameter passed to sqlite3_wal_hook() when 8593** registering the callback. ^The second is a copy of the database handle. 8594** ^The third parameter is the name of the database that was written to - 8595** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8596** is the number of pages currently in the write-ahead log file, 8597** including those that were just committed. 8598** 8599** The callback function should normally return [SQLITE_OK]. ^If an error 8600** code is returned, that error will propagate back up through the 8601** SQLite code base to cause the statement that provoked the callback 8602** to report an error, though the commit will have still occurred. If the 8603** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8604** that does not correspond to any valid SQLite error code, the results 8605** are undefined. 8606** 8607** A single database handle may have at most a single write-ahead log callback 8608** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8609** previously registered write-ahead log callback. ^Note that the 8610** [sqlite3_wal_autocheckpoint()] interface and the 8611** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8612** overwrite any prior [sqlite3_wal_hook()] settings. 8613*/ 8614void *sqlite3_wal_hook( 8615 sqlite3*, 8616 int(*)(void *,sqlite3*,const char*,int), 8617 void* 8618); 8619 8620/* 8621** CAPI3REF: Configure an auto-checkpoint 8622** METHOD: sqlite3 8623** 8624** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8625** [sqlite3_wal_hook()] that causes any database on [database connection] D 8626** to automatically [checkpoint] 8627** after committing a transaction if there are N or 8628** more frames in the [write-ahead log] file. ^Passing zero or 8629** a negative value as the nFrame parameter disables automatic 8630** checkpoints entirely. 8631** 8632** ^The callback registered by this function replaces any existing callback 8633** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8634** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8635** configured by this function. 8636** 8637** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8638** from SQL. 8639** 8640** ^Checkpoints initiated by this mechanism are 8641** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8642** 8643** ^Every new [database connection] defaults to having the auto-checkpoint 8644** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8645** pages. The use of this interface 8646** is only necessary if the default setting is found to be suboptimal 8647** for a particular application. 8648*/ 8649int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8650 8651/* 8652** CAPI3REF: Checkpoint a database 8653** METHOD: sqlite3 8654** 8655** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8656** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8657** 8658** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8659** [write-ahead log] for database X on [database connection] D to be 8660** transferred into the database file and for the write-ahead log to 8661** be reset. See the [checkpointing] documentation for addition 8662** information. 8663** 8664** This interface used to be the only way to cause a checkpoint to 8665** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8666** interface was added. This interface is retained for backwards 8667** compatibility and as a convenience for applications that need to manually 8668** start a callback but which do not need the full power (and corresponding 8669** complication) of [sqlite3_wal_checkpoint_v2()]. 8670*/ 8671int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8672 8673/* 8674** CAPI3REF: Checkpoint a database 8675** METHOD: sqlite3 8676** 8677** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8678** operation on database X of [database connection] D in mode M. Status 8679** information is written back into integers pointed to by L and C.)^ 8680** ^(The M parameter must be a valid [checkpoint mode]:)^ 8681** 8682** <dl> 8683** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8684** ^Checkpoint as many frames as possible without waiting for any database 8685** readers or writers to finish, then sync the database file if all frames 8686** in the log were checkpointed. ^The [busy-handler callback] 8687** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8688** ^On the other hand, passive mode might leave the checkpoint unfinished 8689** if there are concurrent readers or writers. 8690** 8691** <dt>SQLITE_CHECKPOINT_FULL<dd> 8692** ^This mode blocks (it invokes the 8693** [sqlite3_busy_handler|busy-handler callback]) until there is no 8694** database writer and all readers are reading from the most recent database 8695** snapshot. ^It then checkpoints all frames in the log file and syncs the 8696** database file. ^This mode blocks new database writers while it is pending, 8697** but new database readers are allowed to continue unimpeded. 8698** 8699** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8700** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8701** that after checkpointing the log file it blocks (calls the 8702** [busy-handler callback]) 8703** until all readers are reading from the database file only. ^This ensures 8704** that the next writer will restart the log file from the beginning. 8705** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8706** database writer attempts while it is pending, but does not impede readers. 8707** 8708** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8709** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8710** addition that it also truncates the log file to zero bytes just prior 8711** to a successful return. 8712** </dl> 8713** 8714** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8715** the log file or to -1 if the checkpoint could not run because 8716** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8717** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8718** log file (including any that were already checkpointed before the function 8719** was called) or to -1 if the checkpoint could not run due to an error or 8720** because the database is not in WAL mode. ^Note that upon successful 8721** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8722** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8723** 8724** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8725** any other process is running a checkpoint operation at the same time, the 8726** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8727** busy-handler configured, it will not be invoked in this case. 8728** 8729** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8730** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8731** obtained immediately, and a busy-handler is configured, it is invoked and 8732** the writer lock retried until either the busy-handler returns 0 or the lock 8733** is successfully obtained. ^The busy-handler is also invoked while waiting for 8734** database readers as described above. ^If the busy-handler returns 0 before 8735** the writer lock is obtained or while waiting for database readers, the 8736** checkpoint operation proceeds from that point in the same way as 8737** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8738** without blocking any further. ^SQLITE_BUSY is returned in this case. 8739** 8740** ^If parameter zDb is NULL or points to a zero length string, then the 8741** specified operation is attempted on all WAL databases [attached] to 8742** [database connection] db. In this case the 8743** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8744** an SQLITE_BUSY error is encountered when processing one or more of the 8745** attached WAL databases, the operation is still attempted on any remaining 8746** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8747** error occurs while processing an attached database, processing is abandoned 8748** and the error code is returned to the caller immediately. ^If no error 8749** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8750** databases, SQLITE_OK is returned. 8751** 8752** ^If database zDb is the name of an attached database that is not in WAL 8753** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8754** zDb is not NULL (or a zero length string) and is not the name of any 8755** attached database, SQLITE_ERROR is returned to the caller. 8756** 8757** ^Unless it returns SQLITE_MISUSE, 8758** the sqlite3_wal_checkpoint_v2() interface 8759** sets the error information that is queried by 8760** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8761** 8762** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8763** from SQL. 8764*/ 8765int sqlite3_wal_checkpoint_v2( 8766 sqlite3 *db, /* Database handle */ 8767 const char *zDb, /* Name of attached database (or NULL) */ 8768 int eMode, /* SQLITE_CHECKPOINT_* value */ 8769 int *pnLog, /* OUT: Size of WAL log in frames */ 8770 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8771); 8772 8773/* 8774** CAPI3REF: Checkpoint Mode Values 8775** KEYWORDS: {checkpoint mode} 8776** 8777** These constants define all valid values for the "checkpoint mode" passed 8778** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8779** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8780** meaning of each of these checkpoint modes. 8781*/ 8782#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8783#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8784#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8785#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8786 8787/* 8788** CAPI3REF: Virtual Table Interface Configuration 8789** 8790** This function may be called by either the [xConnect] or [xCreate] method 8791** of a [virtual table] implementation to configure 8792** various facets of the virtual table interface. 8793** 8794** If this interface is invoked outside the context of an xConnect or 8795** xCreate virtual table method then the behavior is undefined. 8796** 8797** At present, there is only one option that may be configured using 8798** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8799** may be added in the future. 8800*/ 8801int sqlite3_vtab_config(sqlite3*, int op, ...); 8802 8803/* 8804** CAPI3REF: Virtual Table Configuration Options 8805** 8806** These macros define the various options to the 8807** [sqlite3_vtab_config()] interface that [virtual table] implementations 8808** can use to customize and optimize their behavior. 8809** 8810** <dl> 8811** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 8812** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8813** <dd>Calls of the form 8814** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8815** where X is an integer. If X is zero, then the [virtual table] whose 8816** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8817** support constraints. In this configuration (which is the default) if 8818** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8819** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8820** specified as part of the users SQL statement, regardless of the actual 8821** ON CONFLICT mode specified. 8822** 8823** If X is non-zero, then the virtual table implementation guarantees 8824** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8825** any modifications to internal or persistent data structures have been made. 8826** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8827** is able to roll back a statement or database transaction, and abandon 8828** or continue processing the current SQL statement as appropriate. 8829** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8830** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8831** had been ABORT. 8832** 8833** Virtual table implementations that are required to handle OR REPLACE 8834** must do so within the [xUpdate] method. If a call to the 8835** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8836** CONFLICT policy is REPLACE, the virtual table implementation should 8837** silently replace the appropriate rows within the xUpdate callback and 8838** return SQLITE_OK. Or, if this is not possible, it may return 8839** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8840** constraint handling. 8841** </dl> 8842*/ 8843#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8844 8845/* 8846** CAPI3REF: Determine The Virtual Table Conflict Policy 8847** 8848** This function may only be called from within a call to the [xUpdate] method 8849** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8850** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8851** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8852** of the SQL statement that triggered the call to the [xUpdate] method of the 8853** [virtual table]. 8854*/ 8855int sqlite3_vtab_on_conflict(sqlite3 *); 8856 8857/* 8858** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8859** 8860** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8861** method of a [virtual table], then it returns true if and only if the 8862** column is being fetched as part of an UPDATE operation during which the 8863** column value will not change. Applications might use this to substitute 8864** a return value that is less expensive to compute and that the corresponding 8865** [xUpdate] method understands as a "no-change" value. 8866** 8867** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8868** the column is not changed by the UPDATE statement, then the xColumn 8869** method can optionally return without setting a result, without calling 8870** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8871** In that case, [sqlite3_value_nochange(X)] will return true for the 8872** same column in the [xUpdate] method. 8873*/ 8874int sqlite3_vtab_nochange(sqlite3_context*); 8875 8876/* 8877** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8878** 8879** This function may only be called from within a call to the [xBestIndex] 8880** method of a [virtual table]. 8881** 8882** The first argument must be the sqlite3_index_info object that is the 8883** first parameter to the xBestIndex() method. The second argument must be 8884** an index into the aConstraint[] array belonging to the sqlite3_index_info 8885** structure passed to xBestIndex. This function returns a pointer to a buffer 8886** containing the name of the collation sequence for the corresponding 8887** constraint. 8888*/ 8889SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8890 8891/* 8892** CAPI3REF: Conflict resolution modes 8893** KEYWORDS: {conflict resolution mode} 8894** 8895** These constants are returned by [sqlite3_vtab_on_conflict()] to 8896** inform a [virtual table] implementation what the [ON CONFLICT] mode 8897** is for the SQL statement being evaluated. 8898** 8899** Note that the [SQLITE_IGNORE] constant is also used as a potential 8900** return value from the [sqlite3_set_authorizer()] callback and that 8901** [SQLITE_ABORT] is also a [result code]. 8902*/ 8903#define SQLITE_ROLLBACK 1 8904/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8905#define SQLITE_FAIL 3 8906/* #define SQLITE_ABORT 4 // Also an error code */ 8907#define SQLITE_REPLACE 5 8908 8909/* 8910** CAPI3REF: Prepared Statement Scan Status Opcodes 8911** KEYWORDS: {scanstatus options} 8912** 8913** The following constants can be used for the T parameter to the 8914** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8915** different metric for sqlite3_stmt_scanstatus() to return. 8916** 8917** When the value returned to V is a string, space to hold that string is 8918** managed by the prepared statement S and will be automatically freed when 8919** S is finalized. 8920** 8921** <dl> 8922** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8923** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be 8924** set to the total number of times that the X-th loop has run.</dd> 8925** 8926** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8927** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set 8928** to the total number of rows examined by all iterations of the X-th loop.</dd> 8929** 8930** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8931** <dd>^The "double" variable pointed to by the T parameter will be set to the 8932** query planner's estimate for the average number of rows output from each 8933** iteration of the X-th loop. If the query planner's estimates was accurate, 8934** then this value will approximate the quotient NVISIT/NLOOP and the 8935** product of this value for all prior loops with the same SELECTID will 8936** be the NLOOP value for the current loop. 8937** 8938** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8939** <dd>^The "const char *" variable pointed to by the T parameter will be set 8940** to a zero-terminated UTF-8 string containing the name of the index or table 8941** used for the X-th loop. 8942** 8943** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 8944** <dd>^The "const char *" variable pointed to by the T parameter will be set 8945** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 8946** description for the X-th loop. 8947** 8948** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 8949** <dd>^The "int" variable pointed to by the T parameter will be set to the 8950** "select-id" for the X-th loop. The select-id identifies which query or 8951** subquery the loop is part of. The main query has a select-id of zero. 8952** The select-id is the same value as is output in the first column 8953** of an [EXPLAIN QUERY PLAN] query. 8954** </dl> 8955*/ 8956#define SQLITE_SCANSTAT_NLOOP 0 8957#define SQLITE_SCANSTAT_NVISIT 1 8958#define SQLITE_SCANSTAT_EST 2 8959#define SQLITE_SCANSTAT_NAME 3 8960#define SQLITE_SCANSTAT_EXPLAIN 4 8961#define SQLITE_SCANSTAT_SELECTID 5 8962 8963/* 8964** CAPI3REF: Prepared Statement Scan Status 8965** METHOD: sqlite3_stmt 8966** 8967** This interface returns information about the predicted and measured 8968** performance for pStmt. Advanced applications can use this 8969** interface to compare the predicted and the measured performance and 8970** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 8971** 8972** Since this interface is expected to be rarely used, it is only 8973** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 8974** compile-time option. 8975** 8976** The "iScanStatusOp" parameter determines which status information to return. 8977** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 8978** of this interface is undefined. 8979** ^The requested measurement is written into a variable pointed to by 8980** the "pOut" parameter. 8981** Parameter "idx" identifies the specific loop to retrieve statistics for. 8982** Loops are numbered starting from zero. ^If idx is out of range - less than 8983** zero or greater than or equal to the total number of loops used to implement 8984** the statement - a non-zero value is returned and the variable that pOut 8985** points to is unchanged. 8986** 8987** ^Statistics might not be available for all loops in all statements. ^In cases 8988** where there exist loops with no available statistics, this function behaves 8989** as if the loop did not exist - it returns non-zero and leave the variable 8990** that pOut points to unchanged. 8991** 8992** See also: [sqlite3_stmt_scanstatus_reset()] 8993*/ 8994int sqlite3_stmt_scanstatus( 8995 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 8996 int idx, /* Index of loop to report on */ 8997 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 8998 void *pOut /* Result written here */ 8999); 9000 9001/* 9002** CAPI3REF: Zero Scan-Status Counters 9003** METHOD: sqlite3_stmt 9004** 9005** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9006** 9007** This API is only available if the library is built with pre-processor 9008** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9009*/ 9010void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9011 9012/* 9013** CAPI3REF: Flush caches to disk mid-transaction 9014** 9015** ^If a write-transaction is open on [database connection] D when the 9016** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9017** pages in the pager-cache that are not currently in use are written out 9018** to disk. A dirty page may be in use if a database cursor created by an 9019** active SQL statement is reading from it, or if it is page 1 of a database 9020** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9021** interface flushes caches for all schemas - "main", "temp", and 9022** any [attached] databases. 9023** 9024** ^If this function needs to obtain extra database locks before dirty pages 9025** can be flushed to disk, it does so. ^If those locks cannot be obtained 9026** immediately and there is a busy-handler callback configured, it is invoked 9027** in the usual manner. ^If the required lock still cannot be obtained, then 9028** the database is skipped and an attempt made to flush any dirty pages 9029** belonging to the next (if any) database. ^If any databases are skipped 9030** because locks cannot be obtained, but no other error occurs, this 9031** function returns SQLITE_BUSY. 9032** 9033** ^If any other error occurs while flushing dirty pages to disk (for 9034** example an IO error or out-of-memory condition), then processing is 9035** abandoned and an SQLite [error code] is returned to the caller immediately. 9036** 9037** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9038** 9039** ^This function does not set the database handle error code or message 9040** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9041*/ 9042int sqlite3_db_cacheflush(sqlite3*); 9043 9044/* 9045** CAPI3REF: The pre-update hook. 9046** 9047** ^These interfaces are only available if SQLite is compiled using the 9048** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9049** 9050** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9051** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9052** on a database table. 9053** ^At most one preupdate hook may be registered at a time on a single 9054** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9055** the previous setting. 9056** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9057** with a NULL pointer as the second parameter. 9058** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9059** the first parameter to callbacks. 9060** 9061** ^The preupdate hook only fires for changes to real database tables; the 9062** preupdate hook is not invoked for changes to [virtual tables] or to 9063** system tables like sqlite_master or sqlite_stat1. 9064** 9065** ^The second parameter to the preupdate callback is a pointer to 9066** the [database connection] that registered the preupdate hook. 9067** ^The third parameter to the preupdate callback is one of the constants 9068** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9069** kind of update operation that is about to occur. 9070** ^(The fourth parameter to the preupdate callback is the name of the 9071** database within the database connection that is being modified. This 9072** will be "main" for the main database or "temp" for TEMP tables or 9073** the name given after the AS keyword in the [ATTACH] statement for attached 9074** databases.)^ 9075** ^The fifth parameter to the preupdate callback is the name of the 9076** table that is being modified. 9077** 9078** For an UPDATE or DELETE operation on a [rowid table], the sixth 9079** parameter passed to the preupdate callback is the initial [rowid] of the 9080** row being modified or deleted. For an INSERT operation on a rowid table, 9081** or any operation on a WITHOUT ROWID table, the value of the sixth 9082** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9083** seventh parameter is the final rowid value of the row being inserted 9084** or updated. The value of the seventh parameter passed to the callback 9085** function is not defined for operations on WITHOUT ROWID tables, or for 9086** INSERT operations on rowid tables. 9087** 9088** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9089** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9090** provide additional information about a preupdate event. These routines 9091** may only be called from within a preupdate callback. Invoking any of 9092** these routines from outside of a preupdate callback or with a 9093** [database connection] pointer that is different from the one supplied 9094** to the preupdate callback results in undefined and probably undesirable 9095** behavior. 9096** 9097** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9098** in the row that is being inserted, updated, or deleted. 9099** 9100** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9101** a [protected sqlite3_value] that contains the value of the Nth column of 9102** the table row before it is updated. The N parameter must be between 0 9103** and one less than the number of columns or the behavior will be 9104** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9105** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9106** behavior is undefined. The [sqlite3_value] that P points to 9107** will be destroyed when the preupdate callback returns. 9108** 9109** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9110** a [protected sqlite3_value] that contains the value of the Nth column of 9111** the table row after it is updated. The N parameter must be between 0 9112** and one less than the number of columns or the behavior will be 9113** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9114** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9115** behavior is undefined. The [sqlite3_value] that P points to 9116** will be destroyed when the preupdate callback returns. 9117** 9118** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9119** callback was invoked as a result of a direct insert, update, or delete 9120** operation; or 1 for inserts, updates, or deletes invoked by top-level 9121** triggers; or 2 for changes resulting from triggers called by top-level 9122** triggers; and so forth. 9123** 9124** See also: [sqlite3_update_hook()] 9125*/ 9126#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9127void *sqlite3_preupdate_hook( 9128 sqlite3 *db, 9129 void(*xPreUpdate)( 9130 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9131 sqlite3 *db, /* Database handle */ 9132 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9133 char const *zDb, /* Database name */ 9134 char const *zName, /* Table name */ 9135 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9136 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9137 ), 9138 void* 9139); 9140int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9141int sqlite3_preupdate_count(sqlite3 *); 9142int sqlite3_preupdate_depth(sqlite3 *); 9143int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9144#endif 9145 9146/* 9147** CAPI3REF: Low-level system error code 9148** 9149** ^Attempt to return the underlying operating system error code or error 9150** number that caused the most recent I/O error or failure to open a file. 9151** The return value is OS-dependent. For example, on unix systems, after 9152** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9153** called to get back the underlying "errno" that caused the problem, such 9154** as ENOSPC, EAUTH, EISDIR, and so forth. 9155*/ 9156int sqlite3_system_errno(sqlite3*); 9157 9158/* 9159** CAPI3REF: Database Snapshot 9160** KEYWORDS: {snapshot} {sqlite3_snapshot} 9161** 9162** An instance of the snapshot object records the state of a [WAL mode] 9163** database for some specific point in history. 9164** 9165** In [WAL mode], multiple [database connections] that are open on the 9166** same database file can each be reading a different historical version 9167** of the database file. When a [database connection] begins a read 9168** transaction, that connection sees an unchanging copy of the database 9169** as it existed for the point in time when the transaction first started. 9170** Subsequent changes to the database from other connections are not seen 9171** by the reader until a new read transaction is started. 9172** 9173** The sqlite3_snapshot object records state information about an historical 9174** version of the database file so that it is possible to later open a new read 9175** transaction that sees that historical version of the database rather than 9176** the most recent version. 9177*/ 9178typedef struct sqlite3_snapshot { 9179 unsigned char hidden[48]; 9180} sqlite3_snapshot; 9181 9182/* 9183** CAPI3REF: Record A Database Snapshot 9184** CONSTRUCTOR: sqlite3_snapshot 9185** 9186** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9187** new [sqlite3_snapshot] object that records the current state of 9188** schema S in database connection D. ^On success, the 9189** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9190** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9191** If there is not already a read-transaction open on schema S when 9192** this function is called, one is opened automatically. 9193** 9194** The following must be true for this function to succeed. If any of 9195** the following statements are false when sqlite3_snapshot_get() is 9196** called, SQLITE_ERROR is returned. The final value of *P is undefined 9197** in this case. 9198** 9199** <ul> 9200** <li> The database handle must not be in [autocommit mode]. 9201** 9202** <li> Schema S of [database connection] D must be a [WAL mode] database. 9203** 9204** <li> There must not be a write transaction open on schema S of database 9205** connection D. 9206** 9207** <li> One or more transactions must have been written to the current wal 9208** file since it was created on disk (by any connection). This means 9209** that a snapshot cannot be taken on a wal mode database with no wal 9210** file immediately after it is first opened. At least one transaction 9211** must be written to it first. 9212** </ul> 9213** 9214** This function may also return SQLITE_NOMEM. If it is called with the 9215** database handle in autocommit mode but fails for some other reason, 9216** whether or not a read transaction is opened on schema S is undefined. 9217** 9218** The [sqlite3_snapshot] object returned from a successful call to 9219** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9220** to avoid a memory leak. 9221** 9222** The [sqlite3_snapshot_get()] interface is only available when the 9223** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9224*/ 9225SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9226 sqlite3 *db, 9227 const char *zSchema, 9228 sqlite3_snapshot **ppSnapshot 9229); 9230 9231/* 9232** CAPI3REF: Start a read transaction on an historical snapshot 9233** METHOD: sqlite3_snapshot 9234** 9235** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9236** transaction or upgrades an existing one for schema S of 9237** [database connection] D such that the read transaction refers to 9238** historical [snapshot] P, rather than the most recent change to the 9239** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9240** on success or an appropriate [error code] if it fails. 9241** 9242** ^In order to succeed, the database connection must not be in 9243** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9244** is already a read transaction open on schema S, then the database handle 9245** must have no active statements (SELECT statements that have been passed 9246** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9247** SQLITE_ERROR is returned if either of these conditions is violated, or 9248** if schema S does not exist, or if the snapshot object is invalid. 9249** 9250** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9251** snapshot has been overwritten by a [checkpoint]. In this case 9252** SQLITE_ERROR_SNAPSHOT is returned. 9253** 9254** If there is already a read transaction open when this function is 9255** invoked, then the same read transaction remains open (on the same 9256** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9257** is returned. If another error code - for example SQLITE_PROTOCOL or an 9258** SQLITE_IOERR error code - is returned, then the final state of the 9259** read transaction is undefined. If SQLITE_OK is returned, then the 9260** read transaction is now open on database snapshot P. 9261** 9262** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9263** database connection D does not know that the database file for 9264** schema S is in [WAL mode]. A database connection might not know 9265** that the database file is in [WAL mode] if there has been no prior 9266** I/O on that database connection, or if the database entered [WAL mode] 9267** after the most recent I/O on the database connection.)^ 9268** (Hint: Run "[PRAGMA application_id]" against a newly opened 9269** database connection in order to make it ready to use snapshots.) 9270** 9271** The [sqlite3_snapshot_open()] interface is only available when the 9272** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9273*/ 9274SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9275 sqlite3 *db, 9276 const char *zSchema, 9277 sqlite3_snapshot *pSnapshot 9278); 9279 9280/* 9281** CAPI3REF: Destroy a snapshot 9282** DESTRUCTOR: sqlite3_snapshot 9283** 9284** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9285** The application must eventually free every [sqlite3_snapshot] object 9286** using this routine to avoid a memory leak. 9287** 9288** The [sqlite3_snapshot_free()] interface is only available when the 9289** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9290*/ 9291SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9292 9293/* 9294** CAPI3REF: Compare the ages of two snapshot handles. 9295** METHOD: sqlite3_snapshot 9296** 9297** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9298** of two valid snapshot handles. 9299** 9300** If the two snapshot handles are not associated with the same database 9301** file, the result of the comparison is undefined. 9302** 9303** Additionally, the result of the comparison is only valid if both of the 9304** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9305** last time the wal file was deleted. The wal file is deleted when the 9306** database is changed back to rollback mode or when the number of database 9307** clients drops to zero. If either snapshot handle was obtained before the 9308** wal file was last deleted, the value returned by this function 9309** is undefined. 9310** 9311** Otherwise, this API returns a negative value if P1 refers to an older 9312** snapshot than P2, zero if the two handles refer to the same database 9313** snapshot, and a positive value if P1 is a newer snapshot than P2. 9314** 9315** This interface is only available if SQLite is compiled with the 9316** [SQLITE_ENABLE_SNAPSHOT] option. 9317*/ 9318SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9319 sqlite3_snapshot *p1, 9320 sqlite3_snapshot *p2 9321); 9322 9323/* 9324** CAPI3REF: Recover snapshots from a wal file 9325** METHOD: sqlite3_snapshot 9326** 9327** If a [WAL file] remains on disk after all database connections close 9328** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9329** or because the last process to have the database opened exited without 9330** calling [sqlite3_close()]) and a new connection is subsequently opened 9331** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9332** will only be able to open the last transaction added to the WAL file 9333** even though the WAL file contains other valid transactions. 9334** 9335** This function attempts to scan the WAL file associated with database zDb 9336** of database handle db and make all valid snapshots available to 9337** sqlite3_snapshot_open(). It is an error if there is already a read 9338** transaction open on the database, or if the database is not a WAL mode 9339** database. 9340** 9341** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9342** 9343** This interface is only available if SQLite is compiled with the 9344** [SQLITE_ENABLE_SNAPSHOT] option. 9345*/ 9346SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9347 9348/* 9349** CAPI3REF: Serialize a database 9350** 9351** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9352** that is a serialization of the S database on [database connection] D. 9353** If P is not a NULL pointer, then the size of the database in bytes 9354** is written into *P. 9355** 9356** For an ordinary on-disk database file, the serialization is just a 9357** copy of the disk file. For an in-memory database or a "TEMP" database, 9358** the serialization is the same sequence of bytes which would be written 9359** to disk if that database where backed up to disk. 9360** 9361** The usual case is that sqlite3_serialize() copies the serialization of 9362** the database into memory obtained from [sqlite3_malloc64()] and returns 9363** a pointer to that memory. The caller is responsible for freeing the 9364** returned value to avoid a memory leak. However, if the F argument 9365** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9366** are made, and the sqlite3_serialize() function will return a pointer 9367** to the contiguous memory representation of the database that SQLite 9368** is currently using for that database, or NULL if the no such contiguous 9369** memory representation of the database exists. A contiguous memory 9370** representation of the database will usually only exist if there has 9371** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9372** values of D and S. 9373** The size of the database is written into *P even if the 9374** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9375** of the database exists. 9376** 9377** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9378** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9379** allocation error occurs. 9380** 9381** This interface is only available if SQLite is compiled with the 9382** [SQLITE_ENABLE_DESERIALIZE] option. 9383*/ 9384unsigned char *sqlite3_serialize( 9385 sqlite3 *db, /* The database connection */ 9386 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9387 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9388 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9389); 9390 9391/* 9392** CAPI3REF: Flags for sqlite3_serialize 9393** 9394** Zero or more of the following constants can be OR-ed together for 9395** the F argument to [sqlite3_serialize(D,S,P,F)]. 9396** 9397** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9398** a pointer to contiguous in-memory database that it is currently using, 9399** without making a copy of the database. If SQLite is not currently using 9400** a contiguous in-memory database, then this option causes 9401** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9402** using a contiguous in-memory database if it has been initialized by a 9403** prior call to [sqlite3_deserialize()]. 9404*/ 9405#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9406 9407/* 9408** CAPI3REF: Deserialize a database 9409** 9410** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9411** [database connection] D to disconnect from database S and then 9412** reopen S as an in-memory database based on the serialization contained 9413** in P. The serialized database P is N bytes in size. M is the size of 9414** the buffer P, which might be larger than N. If M is larger than N, and 9415** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9416** permitted to add content to the in-memory database as long as the total 9417** size does not exceed M bytes. 9418** 9419** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9420** invoke sqlite3_free() on the serialization buffer when the database 9421** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9422** SQLite will try to increase the buffer size using sqlite3_realloc64() 9423** if writes on the database cause it to grow larger than M bytes. 9424** 9425** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9426** database is currently in a read transaction or is involved in a backup 9427** operation. 9428** 9429** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9430** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9431** [sqlite3_free()] is invoked on argument P prior to returning. 9432** 9433** This interface is only available if SQLite is compiled with the 9434** [SQLITE_ENABLE_DESERIALIZE] option. 9435*/ 9436int sqlite3_deserialize( 9437 sqlite3 *db, /* The database connection */ 9438 const char *zSchema, /* Which DB to reopen with the deserialization */ 9439 unsigned char *pData, /* The serialized database content */ 9440 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9441 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9442 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9443); 9444 9445/* 9446** CAPI3REF: Flags for sqlite3_deserialize() 9447** 9448** The following are allowed values for 6th argument (the F argument) to 9449** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9450** 9451** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9452** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9453** and that SQLite should take ownership of this memory and automatically 9454** free it when it has finished using it. Without this flag, the caller 9455** is responsible for freeing any dynamically allocated memory. 9456** 9457** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9458** grow the size of the database using calls to [sqlite3_realloc64()]. This 9459** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9460** Without this flag, the deserialized database cannot increase in size beyond 9461** the number of bytes specified by the M parameter. 9462** 9463** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9464** should be treated as read-only. 9465*/ 9466#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9467#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9468#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9469 9470/* 9471** Undo the hack that converts floating point types to integer for 9472** builds on processors without floating point support. 9473*/ 9474#ifdef SQLITE_OMIT_FLOATING_POINT 9475# undef double 9476#endif 9477 9478#ifdef __cplusplus 9479} /* End of the 'extern "C"' block */ 9480#endif 9481#endif /* SQLITE3_H */ 9482