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_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8)) 520#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 521#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8)) 522#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 523#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 524#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 525#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 526#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8)) 527#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8)) 528#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 529#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 530#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 531#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 532#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 533#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 534#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 535#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 536#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 537#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 538#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 539#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 540#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 541#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 542#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8)) 543#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8)) 544#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) 545 546/* 547** CAPI3REF: Flags For File Open Operations 548** 549** These bit values are intended for use in the 550** 3rd parameter to the [sqlite3_open_v2()] interface and 551** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 552*/ 553#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 554#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 555#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 556#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 557#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 558#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 559#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 560#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 561#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 562#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 563#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 564#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 565#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 566#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 567#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 568#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 569#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 570#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 571#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 572#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 573#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */ 574 575/* Reserved: 0x00F00000 */ 576 577/* 578** CAPI3REF: Device Characteristics 579** 580** The xDeviceCharacteristics method of the [sqlite3_io_methods] 581** object returns an integer which is a vector of these 582** bit values expressing I/O characteristics of the mass storage 583** device that holds the file that the [sqlite3_io_methods] 584** refers to. 585** 586** The SQLITE_IOCAP_ATOMIC property means that all writes of 587** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 588** mean that writes of blocks that are nnn bytes in size and 589** are aligned to an address which is an integer multiple of 590** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 591** that when data is appended to a file, the data is appended 592** first then the size of the file is extended, never the other 593** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 594** information is written to disk in the same order as calls 595** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 596** after reboot following a crash or power loss, the only bytes in a 597** file that were written at the application level might have changed 598** and that adjacent bytes, even bytes within the same sector are 599** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 600** flag indicates that a file cannot be deleted when open. The 601** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 602** read-only media and cannot be changed even by processes with 603** elevated privileges. 604** 605** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying 606** filesystem supports doing multiple write operations atomically when those 607** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and 608** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. 609*/ 610#define SQLITE_IOCAP_ATOMIC 0x00000001 611#define SQLITE_IOCAP_ATOMIC512 0x00000002 612#define SQLITE_IOCAP_ATOMIC1K 0x00000004 613#define SQLITE_IOCAP_ATOMIC2K 0x00000008 614#define SQLITE_IOCAP_ATOMIC4K 0x00000010 615#define SQLITE_IOCAP_ATOMIC8K 0x00000020 616#define SQLITE_IOCAP_ATOMIC16K 0x00000040 617#define SQLITE_IOCAP_ATOMIC32K 0x00000080 618#define SQLITE_IOCAP_ATOMIC64K 0x00000100 619#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 620#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 621#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 622#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 623#define SQLITE_IOCAP_IMMUTABLE 0x00002000 624#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000 625 626/* 627** CAPI3REF: File Locking Levels 628** 629** SQLite uses one of these integer values as the second 630** argument to calls it makes to the xLock() and xUnlock() methods 631** of an [sqlite3_io_methods] object. 632*/ 633#define SQLITE_LOCK_NONE 0 634#define SQLITE_LOCK_SHARED 1 635#define SQLITE_LOCK_RESERVED 2 636#define SQLITE_LOCK_PENDING 3 637#define SQLITE_LOCK_EXCLUSIVE 4 638 639/* 640** CAPI3REF: Synchronization Type Flags 641** 642** When SQLite invokes the xSync() method of an 643** [sqlite3_io_methods] object it uses a combination of 644** these integer values as the second argument. 645** 646** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 647** sync operation only needs to flush data to mass storage. Inode 648** information need not be flushed. If the lower four bits of the flag 649** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 650** If the lower four bits equal SQLITE_SYNC_FULL, that means 651** to use Mac OS X style fullsync instead of fsync(). 652** 653** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 654** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 655** settings. The [synchronous pragma] determines when calls to the 656** xSync VFS method occur and applies uniformly across all platforms. 657** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 658** energetic or rigorous or forceful the sync operations are and 659** only make a difference on Mac OSX for the default SQLite code. 660** (Third-party VFS implementations might also make the distinction 661** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 662** operating systems natively supported by SQLite, only Mac OSX 663** cares about the difference.) 664*/ 665#define SQLITE_SYNC_NORMAL 0x00002 666#define SQLITE_SYNC_FULL 0x00003 667#define SQLITE_SYNC_DATAONLY 0x00010 668 669/* 670** CAPI3REF: OS Interface Open File Handle 671** 672** An [sqlite3_file] object represents an open file in the 673** [sqlite3_vfs | OS interface layer]. Individual OS interface 674** implementations will 675** want to subclass this object by appending additional fields 676** for their own use. The pMethods entry is a pointer to an 677** [sqlite3_io_methods] object that defines methods for performing 678** I/O operations on the open file. 679*/ 680typedef struct sqlite3_file sqlite3_file; 681struct sqlite3_file { 682 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 683}; 684 685/* 686** CAPI3REF: OS Interface File Virtual Methods Object 687** 688** Every file opened by the [sqlite3_vfs.xOpen] method populates an 689** [sqlite3_file] object (or, more commonly, a subclass of the 690** [sqlite3_file] object) with a pointer to an instance of this object. 691** This object defines the methods used to perform various operations 692** against the open file represented by the [sqlite3_file] object. 693** 694** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 695** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 696** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 697** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 698** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 699** to NULL. 700** 701** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 702** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 703** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 704** flag may be ORed in to indicate that only the data of the file 705** and not its inode needs to be synced. 706** 707** The integer values to xLock() and xUnlock() are one of 708** <ul> 709** <li> [SQLITE_LOCK_NONE], 710** <li> [SQLITE_LOCK_SHARED], 711** <li> [SQLITE_LOCK_RESERVED], 712** <li> [SQLITE_LOCK_PENDING], or 713** <li> [SQLITE_LOCK_EXCLUSIVE]. 714** </ul> 715** xLock() increases the lock. xUnlock() decreases the lock. 716** The xCheckReservedLock() method checks whether any database connection, 717** either in this process or in some other process, is holding a RESERVED, 718** PENDING, or EXCLUSIVE lock on the file. It returns true 719** if such a lock exists and false otherwise. 720** 721** The xFileControl() method is a generic interface that allows custom 722** VFS implementations to directly control an open file using the 723** [sqlite3_file_control()] interface. The second "op" argument is an 724** integer opcode. The third argument is a generic pointer intended to 725** point to a structure that may contain arguments or space in which to 726** write return values. Potential uses for xFileControl() might be 727** functions to enable blocking locks with timeouts, to change the 728** locking strategy (for example to use dot-file locks), to inquire 729** about the status of a lock, or to break stale locks. The SQLite 730** core reserves all opcodes less than 100 for its own use. 731** A [file control opcodes | list of opcodes] less than 100 is available. 732** Applications that define a custom xFileControl method should use opcodes 733** greater than 100 to avoid conflicts. VFS implementations should 734** return [SQLITE_NOTFOUND] for file control opcodes that they do not 735** recognize. 736** 737** The xSectorSize() method returns the sector size of the 738** device that underlies the file. The sector size is the 739** minimum write that can be performed without disturbing 740** other bytes in the file. The xDeviceCharacteristics() 741** method returns a bit vector describing behaviors of the 742** underlying device: 743** 744** <ul> 745** <li> [SQLITE_IOCAP_ATOMIC] 746** <li> [SQLITE_IOCAP_ATOMIC512] 747** <li> [SQLITE_IOCAP_ATOMIC1K] 748** <li> [SQLITE_IOCAP_ATOMIC2K] 749** <li> [SQLITE_IOCAP_ATOMIC4K] 750** <li> [SQLITE_IOCAP_ATOMIC8K] 751** <li> [SQLITE_IOCAP_ATOMIC16K] 752** <li> [SQLITE_IOCAP_ATOMIC32K] 753** <li> [SQLITE_IOCAP_ATOMIC64K] 754** <li> [SQLITE_IOCAP_SAFE_APPEND] 755** <li> [SQLITE_IOCAP_SEQUENTIAL] 756** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN] 757** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE] 758** <li> [SQLITE_IOCAP_IMMUTABLE] 759** <li> [SQLITE_IOCAP_BATCH_ATOMIC] 760** </ul> 761** 762** The SQLITE_IOCAP_ATOMIC property means that all writes of 763** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 764** mean that writes of blocks that are nnn bytes in size and 765** are aligned to an address which is an integer multiple of 766** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 767** that when data is appended to a file, the data is appended 768** first then the size of the file is extended, never the other 769** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 770** information is written to disk in the same order as calls 771** to xWrite(). 772** 773** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 774** in the unread portions of the buffer with zeros. A VFS that 775** fails to zero-fill short reads might seem to work. However, 776** failure to zero-fill short reads will eventually lead to 777** database corruption. 778*/ 779typedef struct sqlite3_io_methods sqlite3_io_methods; 780struct sqlite3_io_methods { 781 int iVersion; 782 int (*xClose)(sqlite3_file*); 783 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 784 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 785 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 786 int (*xSync)(sqlite3_file*, int flags); 787 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 788 int (*xLock)(sqlite3_file*, int); 789 int (*xUnlock)(sqlite3_file*, int); 790 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 791 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 792 int (*xSectorSize)(sqlite3_file*); 793 int (*xDeviceCharacteristics)(sqlite3_file*); 794 /* Methods above are valid for version 1 */ 795 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 796 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 797 void (*xShmBarrier)(sqlite3_file*); 798 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 799 /* Methods above are valid for version 2 */ 800 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 801 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 802 /* Methods above are valid for version 3 */ 803 /* Additional methods may be added in future releases */ 804}; 805 806/* 807** CAPI3REF: Standard File Control Opcodes 808** KEYWORDS: {file control opcodes} {file control opcode} 809** 810** These integer constants are opcodes for the xFileControl method 811** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 812** interface. 813** 814** <ul> 815** <li>[[SQLITE_FCNTL_LOCKSTATE]] 816** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 817** opcode causes the xFileControl method to write the current state of 818** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 819** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 820** into an integer that the pArg argument points to. This capability 821** is used during testing and is only available when the SQLITE_TEST 822** compile-time option is used. 823** 824** <li>[[SQLITE_FCNTL_SIZE_HINT]] 825** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 826** layer a hint of how large the database file will grow to be during the 827** current transaction. This hint is not guaranteed to be accurate but it 828** is often close. The underlying VFS might choose to preallocate database 829** file space based on this hint in order to help writes to the database 830** file run faster. 831** 832** <li>[[SQLITE_FCNTL_SIZE_LIMIT]] 833** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that 834** implements [sqlite3_deserialize()] to set an upper bound on the size 835** of the in-memory database. The argument is a pointer to a [sqlite3_int64]. 836** If the integer pointed to is negative, then it is filled in with the 837** current limit. Otherwise the limit is set to the larger of the value 838** of the integer pointed to and the current database size. The integer 839** pointed to is set to the new limit. 840** 841** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 842** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 843** extends and truncates the database file in chunks of a size specified 844** by the user. The fourth argument to [sqlite3_file_control()] should 845** point to an integer (type int) containing the new chunk-size to use 846** for the nominated database. Allocating database file space in large 847** chunks (say 1MB at a time), may reduce file-system fragmentation and 848** improve performance on some systems. 849** 850** <li>[[SQLITE_FCNTL_FILE_POINTER]] 851** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 852** to the [sqlite3_file] object associated with a particular database 853** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER]. 854** 855** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]] 856** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer 857** to the [sqlite3_file] object associated with the journal file (either 858** the [rollback journal] or the [write-ahead log]) for a particular database 859** connection. See also [SQLITE_FCNTL_FILE_POINTER]. 860** 861** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 862** No longer in use. 863** 864** <li>[[SQLITE_FCNTL_SYNC]] 865** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 866** sent to the VFS immediately before the xSync method is invoked on a 867** database file descriptor. Or, if the xSync method is not invoked 868** because the user has configured SQLite with 869** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 870** of the xSync method. In most cases, the pointer argument passed with 871** this file-control is NULL. However, if the database file is being synced 872** as part of a multi-database commit, the argument points to a nul-terminated 873** string containing the transactions master-journal file name. VFSes that 874** do not need this signal should silently ignore this opcode. Applications 875** should not call [sqlite3_file_control()] with this opcode as doing so may 876** disrupt the operation of the specialized VFSes that do require it. 877** 878** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 879** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 880** and sent to the VFS after a transaction has been committed immediately 881** but before the database is unlocked. VFSes that do not need this signal 882** should silently ignore this opcode. Applications should not call 883** [sqlite3_file_control()] with this opcode as doing so may disrupt the 884** operation of the specialized VFSes that do require it. 885** 886** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 887** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 888** retry counts and intervals for certain disk I/O operations for the 889** windows [VFS] in order to provide robustness in the presence of 890** anti-virus programs. By default, the windows VFS will retry file read, 891** file write, and file delete operations up to 10 times, with a delay 892** of 25 milliseconds before the first retry and with the delay increasing 893** by an additional 25 milliseconds with each subsequent retry. This 894** opcode allows these two values (10 retries and 25 milliseconds of delay) 895** to be adjusted. The values are changed for all database connections 896** within the same process. The argument is a pointer to an array of two 897** integers where the first integer is the new retry count and the second 898** integer is the delay. If either integer is negative, then the setting 899** is not changed but instead the prior value of that setting is written 900** into the array entry, allowing the current retry settings to be 901** interrogated. The zDbName parameter is ignored. 902** 903** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 904** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 905** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 906** write ahead log ([WAL file]) and shared memory 907** files used for transaction control 908** are automatically deleted when the latest connection to the database 909** closes. Setting persistent WAL mode causes those files to persist after 910** close. Persisting the files is useful when other processes that do not 911** have write permission on the directory containing the database file want 912** to read the database file, as the WAL and shared memory files must exist 913** in order for the database to be readable. The fourth parameter to 914** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 915** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 916** WAL mode. If the integer is -1, then it is overwritten with the current 917** WAL persistence setting. 918** 919** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 920** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 921** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 922** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 923** xDeviceCharacteristics methods. The fourth parameter to 924** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 925** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 926** mode. If the integer is -1, then it is overwritten with the current 927** zero-damage mode setting. 928** 929** <li>[[SQLITE_FCNTL_OVERWRITE]] 930** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 931** a write transaction to indicate that, unless it is rolled back for some 932** reason, the entire database file will be overwritten by the current 933** transaction. This is used by VACUUM operations. 934** 935** <li>[[SQLITE_FCNTL_VFSNAME]] 936** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 937** all [VFSes] in the VFS stack. The names are of all VFS shims and the 938** final bottom-level VFS are written into memory obtained from 939** [sqlite3_malloc()] and the result is stored in the char* variable 940** that the fourth parameter of [sqlite3_file_control()] points to. 941** The caller is responsible for freeing the memory when done. As with 942** all file-control actions, there is no guarantee that this will actually 943** do anything. Callers should initialize the char* variable to a NULL 944** pointer in case this file-control is not implemented. This file-control 945** is intended for diagnostic use only. 946** 947** <li>[[SQLITE_FCNTL_VFS_POINTER]] 948** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level 949** [VFSes] currently in use. ^(The argument X in 950** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be 951** of type "[sqlite3_vfs] **". This opcodes will set *X 952** to a pointer to the top-level VFS.)^ 953** ^When there are multiple VFS shims in the stack, this opcode finds the 954** upper-most shim only. 955** 956** <li>[[SQLITE_FCNTL_PRAGMA]] 957** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 958** file control is sent to the open [sqlite3_file] object corresponding 959** to the database file to which the pragma statement refers. ^The argument 960** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 961** pointers to strings (char**) in which the second element of the array 962** is the name of the pragma and the third element is the argument to the 963** pragma or NULL if the pragma has no argument. ^The handler for an 964** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 965** of the char** argument point to a string obtained from [sqlite3_mprintf()] 966** or the equivalent and that string will become the result of the pragma or 967** the error message if the pragma fails. ^If the 968** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 969** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 970** file control returns [SQLITE_OK], then the parser assumes that the 971** VFS has handled the PRAGMA itself and the parser generates a no-op 972** prepared statement if result string is NULL, or that returns a copy 973** of the result string if the string is non-NULL. 974** ^If the [SQLITE_FCNTL_PRAGMA] file control returns 975** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 976** that the VFS encountered an error while handling the [PRAGMA] and the 977** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 978** file control occurs at the beginning of pragma statement analysis and so 979** it is able to override built-in [PRAGMA] statements. 980** 981** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 982** ^The [SQLITE_FCNTL_BUSYHANDLER] 983** file-control may be invoked by SQLite on the database file handle 984** shortly after it is opened in order to provide a custom VFS with access 985** to the connection's busy-handler callback. The argument is of type (void**) 986** - an array of two (void *) values. The first (void *) actually points 987** to a function of type (int (*)(void *)). In order to invoke the connection's 988** busy-handler, this function should be invoked with the second (void *) in 989** the array as the only argument. If it returns non-zero, then the operation 990** should be retried. If it returns zero, the custom VFS should abandon the 991** current operation. 992** 993** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 994** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 995** to have SQLite generate a 996** temporary filename using the same algorithm that is followed to generate 997** temporary filenames for TEMP tables and other internal uses. The 998** argument should be a char** which will be filled with the filename 999** written into memory obtained from [sqlite3_malloc()]. The caller should 1000** invoke [sqlite3_free()] on the result to avoid a memory leak. 1001** 1002** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1003** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1004** maximum number of bytes that will be used for memory-mapped I/O. 1005** The argument is a pointer to a value of type sqlite3_int64 that 1006** is an advisory maximum number of bytes in the file to memory map. The 1007** pointer is overwritten with the old value. The limit is not changed if 1008** the value originally pointed to is negative, and so the current limit 1009** can be queried by passing in a pointer to a negative number. This 1010** file-control is used internally to implement [PRAGMA mmap_size]. 1011** 1012** <li>[[SQLITE_FCNTL_TRACE]] 1013** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1014** to the VFS about what the higher layers of the SQLite stack are doing. 1015** This file control is used by some VFS activity tracing [shims]. 1016** The argument is a zero-terminated string. Higher layers in the 1017** SQLite stack may generate instances of this file control if 1018** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1019** 1020** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1021** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1022** pointer to an integer and it writes a boolean into that integer depending 1023** on whether or not the file has been renamed, moved, or deleted since it 1024** was first opened. 1025** 1026** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]] 1027** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the 1028** underlying native file handle associated with a file handle. This file 1029** control interprets its argument as a pointer to a native file handle and 1030** writes the resulting value there. 1031** 1032** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1033** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1034** opcode causes the xFileControl method to swap the file handle with the one 1035** pointed to by the pArg argument. This capability is used during testing 1036** and only needs to be supported when SQLITE_TEST is defined. 1037** 1038** <li>[[SQLITE_FCNTL_WAL_BLOCK]] 1039** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might 1040** be advantageous to block on the next WAL lock if the lock is not immediately 1041** available. The WAL subsystem issues this signal during rare 1042** circumstances in order to fix a problem with priority inversion. 1043** Applications should <em>not</em> use this file-control. 1044** 1045** <li>[[SQLITE_FCNTL_ZIPVFS]] 1046** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other 1047** VFS should return SQLITE_NOTFOUND for this opcode. 1048** 1049** <li>[[SQLITE_FCNTL_RBU]] 1050** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by 1051** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for 1052** this opcode. 1053** 1054** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]] 1055** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then 1056** the file descriptor is placed in "batch write mode", which 1057** means all subsequent write operations will be deferred and done 1058** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems 1059** that do not support batch atomic writes will return SQLITE_NOTFOUND. 1060** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to 1061** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or 1062** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make 1063** no VFS interface calls on the same [sqlite3_file] file descriptor 1064** except for calls to the xWrite method and the xFileControl method 1065** with [SQLITE_FCNTL_SIZE_HINT]. 1066** 1067** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]] 1068** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write 1069** operations since the previous successful call to 1070** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically. 1071** This file control returns [SQLITE_OK] if and only if the writes were 1072** all performed successfully and have been committed to persistent storage. 1073** ^Regardless of whether or not it is successful, this file control takes 1074** the file descriptor out of batch write mode so that all subsequent 1075** write operations are independent. 1076** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without 1077** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1078** 1079** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]] 1080** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write 1081** operations since the previous successful call to 1082** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back. 1083** ^This file control takes the file descriptor out of batch write mode 1084** so that all subsequent write operations are independent. 1085** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without 1086** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]. 1087** 1088** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]] 1089** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode causes attempts to obtain 1090** a file lock using the xLock or xShmLock methods of the VFS to wait 1091** for up to M milliseconds before failing, where M is the single 1092** unsigned integer parameter. 1093** 1094** <li>[[SQLITE_FCNTL_DATA_VERSION]] 1095** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to 1096** a database file. The argument is a pointer to a 32-bit unsigned integer. 1097** The "data version" for the pager is written into the pointer. The 1098** "data version" changes whenever any change occurs to the corresponding 1099** database file, either through SQL statements on the same database 1100** connection or through transactions committed by separate database 1101** connections possibly in other processes. The [sqlite3_total_changes()] 1102** interface can be used to find if any database on the connection has changed, 1103** but that interface responds to changes on TEMP as well as MAIN and does 1104** not provide a mechanism to detect changes to MAIN only. Also, the 1105** [sqlite3_total_changes()] interface responds to internal changes only and 1106** omits changes made by other database connections. The 1107** [PRAGMA data_version] command provides a mechanism to detect changes to 1108** a single attached database that occur due to other database connections, 1109** but omits changes implemented by the database connection on which it is 1110** called. This file control is the only mechanism to detect changes that 1111** happen either internally or externally and that are associated with 1112** a particular attached database. 1113** </ul> 1114*/ 1115#define SQLITE_FCNTL_LOCKSTATE 1 1116#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2 1117#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3 1118#define SQLITE_FCNTL_LAST_ERRNO 4 1119#define SQLITE_FCNTL_SIZE_HINT 5 1120#define SQLITE_FCNTL_CHUNK_SIZE 6 1121#define SQLITE_FCNTL_FILE_POINTER 7 1122#define SQLITE_FCNTL_SYNC_OMITTED 8 1123#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1124#define SQLITE_FCNTL_PERSIST_WAL 10 1125#define SQLITE_FCNTL_OVERWRITE 11 1126#define SQLITE_FCNTL_VFSNAME 12 1127#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1128#define SQLITE_FCNTL_PRAGMA 14 1129#define SQLITE_FCNTL_BUSYHANDLER 15 1130#define SQLITE_FCNTL_TEMPFILENAME 16 1131#define SQLITE_FCNTL_MMAP_SIZE 18 1132#define SQLITE_FCNTL_TRACE 19 1133#define SQLITE_FCNTL_HAS_MOVED 20 1134#define SQLITE_FCNTL_SYNC 21 1135#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1136#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1137#define SQLITE_FCNTL_WAL_BLOCK 24 1138#define SQLITE_FCNTL_ZIPVFS 25 1139#define SQLITE_FCNTL_RBU 26 1140#define SQLITE_FCNTL_VFS_POINTER 27 1141#define SQLITE_FCNTL_JOURNAL_POINTER 28 1142#define SQLITE_FCNTL_WIN32_GET_HANDLE 29 1143#define SQLITE_FCNTL_PDB 30 1144#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31 1145#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32 1146#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33 1147#define SQLITE_FCNTL_LOCK_TIMEOUT 34 1148#define SQLITE_FCNTL_DATA_VERSION 35 1149#define SQLITE_FCNTL_SIZE_LIMIT 36 1150 1151/* deprecated names */ 1152#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE 1153#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE 1154#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO 1155 1156 1157/* 1158** CAPI3REF: Mutex Handle 1159** 1160** The mutex module within SQLite defines [sqlite3_mutex] to be an 1161** abstract type for a mutex object. The SQLite core never looks 1162** at the internal representation of an [sqlite3_mutex]. It only 1163** deals with pointers to the [sqlite3_mutex] object. 1164** 1165** Mutexes are created using [sqlite3_mutex_alloc()]. 1166*/ 1167typedef struct sqlite3_mutex sqlite3_mutex; 1168 1169/* 1170** CAPI3REF: Loadable Extension Thunk 1171** 1172** A pointer to the opaque sqlite3_api_routines structure is passed as 1173** the third parameter to entry points of [loadable extensions]. This 1174** structure must be typedefed in order to work around compiler warnings 1175** on some platforms. 1176*/ 1177typedef struct sqlite3_api_routines sqlite3_api_routines; 1178 1179/* 1180** CAPI3REF: OS Interface Object 1181** 1182** An instance of the sqlite3_vfs object defines the interface between 1183** the SQLite core and the underlying operating system. The "vfs" 1184** in the name of the object stands for "virtual file system". See 1185** the [VFS | VFS documentation] for further information. 1186** 1187** The VFS interface is sometimes extended by adding new methods onto 1188** the end. Each time such an extension occurs, the iVersion field 1189** is incremented. The iVersion value started out as 1 in 1190** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2 1191** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased 1192** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields 1193** may be appended to the sqlite3_vfs object and the iVersion value 1194** may increase again in future versions of SQLite. 1195** Note that due to an oversight, the structure 1196** of the sqlite3_vfs object changed in the transition from 1197** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0] 1198** and yet the iVersion field was not increased. 1199** 1200** The szOsFile field is the size of the subclassed [sqlite3_file] 1201** structure used by this VFS. mxPathname is the maximum length of 1202** a pathname in this VFS. 1203** 1204** Registered sqlite3_vfs objects are kept on a linked list formed by 1205** the pNext pointer. The [sqlite3_vfs_register()] 1206** and [sqlite3_vfs_unregister()] interfaces manage this list 1207** in a thread-safe way. The [sqlite3_vfs_find()] interface 1208** searches the list. Neither the application code nor the VFS 1209** implementation should use the pNext pointer. 1210** 1211** The pNext field is the only field in the sqlite3_vfs 1212** structure that SQLite will ever modify. SQLite will only access 1213** or modify this field while holding a particular static mutex. 1214** The application should never modify anything within the sqlite3_vfs 1215** object once the object has been registered. 1216** 1217** The zName field holds the name of the VFS module. The name must 1218** be unique across all VFS modules. 1219** 1220** [[sqlite3_vfs.xOpen]] 1221** ^SQLite guarantees that the zFilename parameter to xOpen 1222** is either a NULL pointer or string obtained 1223** from xFullPathname() with an optional suffix added. 1224** ^If a suffix is added to the zFilename parameter, it will 1225** consist of a single "-" character followed by no more than 1226** 11 alphanumeric and/or "-" characters. 1227** ^SQLite further guarantees that 1228** the string will be valid and unchanged until xClose() is 1229** called. Because of the previous sentence, 1230** the [sqlite3_file] can safely store a pointer to the 1231** filename if it needs to remember the filename for some reason. 1232** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1233** must invent its own temporary name for the file. ^Whenever the 1234** xFilename parameter is NULL it will also be the case that the 1235** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1236** 1237** The flags argument to xOpen() includes all bits set in 1238** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1239** or [sqlite3_open16()] is used, then flags includes at least 1240** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1241** If xOpen() opens a file read-only then it sets *pOutFlags to 1242** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1243** 1244** ^(SQLite will also add one of the following flags to the xOpen() 1245** call, depending on the object being opened: 1246** 1247** <ul> 1248** <li> [SQLITE_OPEN_MAIN_DB] 1249** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1250** <li> [SQLITE_OPEN_TEMP_DB] 1251** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1252** <li> [SQLITE_OPEN_TRANSIENT_DB] 1253** <li> [SQLITE_OPEN_SUBJOURNAL] 1254** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1255** <li> [SQLITE_OPEN_WAL] 1256** </ul>)^ 1257** 1258** The file I/O implementation can use the object type flags to 1259** change the way it deals with files. For example, an application 1260** that does not care about crash recovery or rollback might make 1261** the open of a journal file a no-op. Writes to this journal would 1262** also be no-ops, and any attempt to read the journal would return 1263** SQLITE_IOERR. Or the implementation might recognize that a database 1264** file will be doing page-aligned sector reads and writes in a random 1265** order and set up its I/O subsystem accordingly. 1266** 1267** SQLite might also add one of the following flags to the xOpen method: 1268** 1269** <ul> 1270** <li> [SQLITE_OPEN_DELETEONCLOSE] 1271** <li> [SQLITE_OPEN_EXCLUSIVE] 1272** </ul> 1273** 1274** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1275** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1276** will be set for TEMP databases and their journals, transient 1277** databases, and subjournals. 1278** 1279** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1280** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1281** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1282** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1283** SQLITE_OPEN_CREATE, is used to indicate that file should always 1284** be created, and that it is an error if it already exists. 1285** It is <i>not</i> used to indicate the file should be opened 1286** for exclusive access. 1287** 1288** ^At least szOsFile bytes of memory are allocated by SQLite 1289** to hold the [sqlite3_file] structure passed as the third 1290** argument to xOpen. The xOpen method does not have to 1291** allocate the structure; it should just fill it in. Note that 1292** the xOpen method must set the sqlite3_file.pMethods to either 1293** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1294** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1295** element will be valid after xOpen returns regardless of the success 1296** or failure of the xOpen call. 1297** 1298** [[sqlite3_vfs.xAccess]] 1299** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1300** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1301** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1302** to test whether a file is at least readable. The SQLITE_ACCESS_READ 1303** flag is never actually used and is not implemented in the built-in 1304** VFSes of SQLite. The file is named by the second argument and can be a 1305** directory. The xAccess method returns [SQLITE_OK] on success or some 1306** non-zero error code if there is an I/O error or if the name of 1307** the file given in the second argument is illegal. If SQLITE_OK 1308** is returned, then non-zero or zero is written into *pResOut to indicate 1309** whether or not the file is accessible. 1310** 1311** ^SQLite will always allocate at least mxPathname+1 bytes for the 1312** output buffer xFullPathname. The exact size of the output buffer 1313** is also passed as a parameter to both methods. If the output buffer 1314** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1315** handled as a fatal error by SQLite, vfs implementations should endeavor 1316** to prevent this by setting mxPathname to a sufficiently large value. 1317** 1318** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1319** interfaces are not strictly a part of the filesystem, but they are 1320** included in the VFS structure for completeness. 1321** The xRandomness() function attempts to return nBytes bytes 1322** of good-quality randomness into zOut. The return value is 1323** the actual number of bytes of randomness obtained. 1324** The xSleep() method causes the calling thread to sleep for at 1325** least the number of microseconds given. ^The xCurrentTime() 1326** method returns a Julian Day Number for the current date and time as 1327** a floating point value. 1328** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1329** Day Number multiplied by 86400000 (the number of milliseconds in 1330** a 24-hour day). 1331** ^SQLite will use the xCurrentTimeInt64() method to get the current 1332** date and time if that method is available (if iVersion is 2 or 1333** greater and the function pointer is not NULL) and will fall back 1334** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1335** 1336** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1337** are not used by the SQLite core. These optional interfaces are provided 1338** by some VFSes to facilitate testing of the VFS code. By overriding 1339** system calls with functions under its control, a test program can 1340** simulate faults and error conditions that would otherwise be difficult 1341** or impossible to induce. The set of system calls that can be overridden 1342** varies from one VFS to another, and from one version of the same VFS to the 1343** next. Applications that use these interfaces must be prepared for any 1344** or all of these interfaces to be NULL or for their behavior to change 1345** from one release to the next. Applications must not attempt to access 1346** any of these methods if the iVersion of the VFS is less than 3. 1347*/ 1348typedef struct sqlite3_vfs sqlite3_vfs; 1349typedef void (*sqlite3_syscall_ptr)(void); 1350struct sqlite3_vfs { 1351 int iVersion; /* Structure version number (currently 3) */ 1352 int szOsFile; /* Size of subclassed sqlite3_file */ 1353 int mxPathname; /* Maximum file pathname length */ 1354 sqlite3_vfs *pNext; /* Next registered VFS */ 1355 const char *zName; /* Name of this virtual file system */ 1356 void *pAppData; /* Pointer to application-specific data */ 1357 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1358 int flags, int *pOutFlags); 1359 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1360 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1361 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1362 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1363 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1364 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1365 void (*xDlClose)(sqlite3_vfs*, void*); 1366 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1367 int (*xSleep)(sqlite3_vfs*, int microseconds); 1368 int (*xCurrentTime)(sqlite3_vfs*, double*); 1369 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1370 /* 1371 ** The methods above are in version 1 of the sqlite_vfs object 1372 ** definition. Those that follow are added in version 2 or later 1373 */ 1374 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1375 /* 1376 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1377 ** Those below are for version 3 and greater. 1378 */ 1379 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1380 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1381 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1382 /* 1383 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1384 ** New fields may be appended in future versions. The iVersion 1385 ** value will increment whenever this happens. 1386 */ 1387}; 1388 1389/* 1390** CAPI3REF: Flags for the xAccess VFS method 1391** 1392** These integer constants can be used as the third parameter to 1393** the xAccess method of an [sqlite3_vfs] object. They determine 1394** what kind of permissions the xAccess method is looking for. 1395** With SQLITE_ACCESS_EXISTS, the xAccess method 1396** simply checks whether the file exists. 1397** With SQLITE_ACCESS_READWRITE, the xAccess method 1398** checks whether the named directory is both readable and writable 1399** (in other words, if files can be added, removed, and renamed within 1400** the directory). 1401** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1402** [temp_store_directory pragma], though this could change in a future 1403** release of SQLite. 1404** With SQLITE_ACCESS_READ, the xAccess method 1405** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1406** currently unused, though it might be used in a future release of 1407** SQLite. 1408*/ 1409#define SQLITE_ACCESS_EXISTS 0 1410#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1411#define SQLITE_ACCESS_READ 2 /* Unused */ 1412 1413/* 1414** CAPI3REF: Flags for the xShmLock VFS method 1415** 1416** These integer constants define the various locking operations 1417** allowed by the xShmLock method of [sqlite3_io_methods]. The 1418** following are the only legal combinations of flags to the 1419** xShmLock method: 1420** 1421** <ul> 1422** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1423** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1424** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1425** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1426** </ul> 1427** 1428** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1429** was given on the corresponding lock. 1430** 1431** The xShmLock method can transition between unlocked and SHARED or 1432** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1433** and EXCLUSIVE. 1434*/ 1435#define SQLITE_SHM_UNLOCK 1 1436#define SQLITE_SHM_LOCK 2 1437#define SQLITE_SHM_SHARED 4 1438#define SQLITE_SHM_EXCLUSIVE 8 1439 1440/* 1441** CAPI3REF: Maximum xShmLock index 1442** 1443** The xShmLock method on [sqlite3_io_methods] may use values 1444** between 0 and this upper bound as its "offset" argument. 1445** The SQLite core will never attempt to acquire or release a 1446** lock outside of this range 1447*/ 1448#define SQLITE_SHM_NLOCK 8 1449 1450 1451/* 1452** CAPI3REF: Initialize The SQLite Library 1453** 1454** ^The sqlite3_initialize() routine initializes the 1455** SQLite library. ^The sqlite3_shutdown() routine 1456** deallocates any resources that were allocated by sqlite3_initialize(). 1457** These routines are designed to aid in process initialization and 1458** shutdown on embedded systems. Workstation applications using 1459** SQLite normally do not need to invoke either of these routines. 1460** 1461** A call to sqlite3_initialize() is an "effective" call if it is 1462** the first time sqlite3_initialize() is invoked during the lifetime of 1463** the process, or if it is the first time sqlite3_initialize() is invoked 1464** following a call to sqlite3_shutdown(). ^(Only an effective call 1465** of sqlite3_initialize() does any initialization. All other calls 1466** are harmless no-ops.)^ 1467** 1468** A call to sqlite3_shutdown() is an "effective" call if it is the first 1469** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1470** an effective call to sqlite3_shutdown() does any deinitialization. 1471** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1472** 1473** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1474** is not. The sqlite3_shutdown() interface must only be called from a 1475** single thread. All open [database connections] must be closed and all 1476** other SQLite resources must be deallocated prior to invoking 1477** sqlite3_shutdown(). 1478** 1479** Among other things, ^sqlite3_initialize() will invoke 1480** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1481** will invoke sqlite3_os_end(). 1482** 1483** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1484** ^If for some reason, sqlite3_initialize() is unable to initialize 1485** the library (perhaps it is unable to allocate a needed resource such 1486** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1487** 1488** ^The sqlite3_initialize() routine is called internally by many other 1489** SQLite interfaces so that an application usually does not need to 1490** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1491** calls sqlite3_initialize() so the SQLite library will be automatically 1492** initialized when [sqlite3_open()] is called if it has not be initialized 1493** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1494** compile-time option, then the automatic calls to sqlite3_initialize() 1495** are omitted and the application must call sqlite3_initialize() directly 1496** prior to using any other SQLite interface. For maximum portability, 1497** it is recommended that applications always invoke sqlite3_initialize() 1498** directly prior to using any other SQLite interface. Future releases 1499** of SQLite may require this. In other words, the behavior exhibited 1500** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1501** default behavior in some future release of SQLite. 1502** 1503** The sqlite3_os_init() routine does operating-system specific 1504** initialization of the SQLite library. The sqlite3_os_end() 1505** routine undoes the effect of sqlite3_os_init(). Typical tasks 1506** performed by these routines include allocation or deallocation 1507** of static resources, initialization of global variables, 1508** setting up a default [sqlite3_vfs] module, or setting up 1509** a default configuration using [sqlite3_config()]. 1510** 1511** The application should never invoke either sqlite3_os_init() 1512** or sqlite3_os_end() directly. The application should only invoke 1513** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1514** interface is called automatically by sqlite3_initialize() and 1515** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1516** implementations for sqlite3_os_init() and sqlite3_os_end() 1517** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1518** When [custom builds | built for other platforms] 1519** (using the [SQLITE_OS_OTHER=1] compile-time 1520** option) the application must supply a suitable implementation for 1521** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1522** implementation of sqlite3_os_init() or sqlite3_os_end() 1523** must return [SQLITE_OK] on success and some other [error code] upon 1524** failure. 1525*/ 1526int sqlite3_initialize(void); 1527int sqlite3_shutdown(void); 1528int sqlite3_os_init(void); 1529int sqlite3_os_end(void); 1530 1531/* 1532** CAPI3REF: Configuring The SQLite Library 1533** 1534** The sqlite3_config() interface is used to make global configuration 1535** changes to SQLite in order to tune SQLite to the specific needs of 1536** the application. The default configuration is recommended for most 1537** applications and so this routine is usually not necessary. It is 1538** provided to support rare applications with unusual needs. 1539** 1540** <b>The sqlite3_config() interface is not threadsafe. The application 1541** must ensure that no other SQLite interfaces are invoked by other 1542** threads while sqlite3_config() is running.</b> 1543** 1544** The sqlite3_config() interface 1545** may only be invoked prior to library initialization using 1546** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1547** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1548** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1549** Note, however, that ^sqlite3_config() can be called as part of the 1550** implementation of an application-defined [sqlite3_os_init()]. 1551** 1552** The first argument to sqlite3_config() is an integer 1553** [configuration option] that determines 1554** what property of SQLite is to be configured. Subsequent arguments 1555** vary depending on the [configuration option] 1556** in the first argument. 1557** 1558** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1559** ^If the option is unknown or SQLite is unable to set the option 1560** then this routine returns a non-zero [error code]. 1561*/ 1562int sqlite3_config(int, ...); 1563 1564/* 1565** CAPI3REF: Configure database connections 1566** METHOD: sqlite3 1567** 1568** The sqlite3_db_config() interface is used to make configuration 1569** changes to a [database connection]. The interface is similar to 1570** [sqlite3_config()] except that the changes apply to a single 1571** [database connection] (specified in the first argument). 1572** 1573** The second argument to sqlite3_db_config(D,V,...) is the 1574** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1575** that indicates what aspect of the [database connection] is being configured. 1576** Subsequent arguments vary depending on the configuration verb. 1577** 1578** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1579** the call is considered successful. 1580*/ 1581int sqlite3_db_config(sqlite3*, int op, ...); 1582 1583/* 1584** CAPI3REF: Memory Allocation Routines 1585** 1586** An instance of this object defines the interface between SQLite 1587** and low-level memory allocation routines. 1588** 1589** This object is used in only one place in the SQLite interface. 1590** A pointer to an instance of this object is the argument to 1591** [sqlite3_config()] when the configuration option is 1592** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1593** By creating an instance of this object 1594** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1595** during configuration, an application can specify an alternative 1596** memory allocation subsystem for SQLite to use for all of its 1597** dynamic memory needs. 1598** 1599** Note that SQLite comes with several [built-in memory allocators] 1600** that are perfectly adequate for the overwhelming majority of applications 1601** and that this object is only useful to a tiny minority of applications 1602** with specialized memory allocation requirements. This object is 1603** also used during testing of SQLite in order to specify an alternative 1604** memory allocator that simulates memory out-of-memory conditions in 1605** order to verify that SQLite recovers gracefully from such 1606** conditions. 1607** 1608** The xMalloc, xRealloc, and xFree methods must work like the 1609** malloc(), realloc() and free() functions from the standard C library. 1610** ^SQLite guarantees that the second argument to 1611** xRealloc is always a value returned by a prior call to xRoundup. 1612** 1613** xSize should return the allocated size of a memory allocation 1614** previously obtained from xMalloc or xRealloc. The allocated size 1615** is always at least as big as the requested size but may be larger. 1616** 1617** The xRoundup method returns what would be the allocated size of 1618** a memory allocation given a particular requested size. Most memory 1619** allocators round up memory allocations at least to the next multiple 1620** of 8. Some allocators round up to a larger multiple or to a power of 2. 1621** Every memory allocation request coming in through [sqlite3_malloc()] 1622** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1623** that causes the corresponding memory allocation to fail. 1624** 1625** The xInit method initializes the memory allocator. For example, 1626** it might allocate any required mutexes or initialize internal data 1627** structures. The xShutdown method is invoked (indirectly) by 1628** [sqlite3_shutdown()] and should deallocate any resources acquired 1629** by xInit. The pAppData pointer is used as the only parameter to 1630** xInit and xShutdown. 1631** 1632** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1633** the xInit method, so the xInit method need not be threadsafe. The 1634** xShutdown method is only called from [sqlite3_shutdown()] so it does 1635** not need to be threadsafe either. For all other methods, SQLite 1636** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1637** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1638** it is by default) and so the methods are automatically serialized. 1639** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1640** methods must be threadsafe or else make their own arrangements for 1641** serialization. 1642** 1643** SQLite will never invoke xInit() more than once without an intervening 1644** call to xShutdown(). 1645*/ 1646typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1647struct sqlite3_mem_methods { 1648 void *(*xMalloc)(int); /* Memory allocation function */ 1649 void (*xFree)(void*); /* Free a prior allocation */ 1650 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1651 int (*xSize)(void*); /* Return the size of an allocation */ 1652 int (*xRoundup)(int); /* Round up request size to allocation size */ 1653 int (*xInit)(void*); /* Initialize the memory allocator */ 1654 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1655 void *pAppData; /* Argument to xInit() and xShutdown() */ 1656}; 1657 1658/* 1659** CAPI3REF: Configuration Options 1660** KEYWORDS: {configuration option} 1661** 1662** These constants are the available integer configuration options that 1663** can be passed as the first argument to the [sqlite3_config()] interface. 1664** 1665** New configuration options may be added in future releases of SQLite. 1666** Existing configuration options might be discontinued. Applications 1667** should check the return code from [sqlite3_config()] to make sure that 1668** the call worked. The [sqlite3_config()] interface will return a 1669** non-zero [error code] if a discontinued or unsupported configuration option 1670** is invoked. 1671** 1672** <dl> 1673** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1674** <dd>There are no arguments to this option. ^This option sets the 1675** [threading mode] to Single-thread. In other words, it disables 1676** all mutexing and puts SQLite into a mode where it can only be used 1677** by a single thread. ^If SQLite is compiled with 1678** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1679** it is not possible to change the [threading mode] from its default 1680** value of Single-thread and so [sqlite3_config()] will return 1681** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1682** configuration option.</dd> 1683** 1684** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1685** <dd>There are no arguments to this option. ^This option sets the 1686** [threading mode] to Multi-thread. In other words, it disables 1687** mutexing on [database connection] and [prepared statement] objects. 1688** The application is responsible for serializing access to 1689** [database connections] and [prepared statements]. But other mutexes 1690** are enabled so that SQLite will be safe to use in a multi-threaded 1691** environment as long as no two threads attempt to use the same 1692** [database connection] at the same time. ^If SQLite is compiled with 1693** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1694** it is not possible to set the Multi-thread [threading mode] and 1695** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1696** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1697** 1698** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1699** <dd>There are no arguments to this option. ^This option sets the 1700** [threading mode] to Serialized. In other words, this option enables 1701** all mutexes including the recursive 1702** mutexes on [database connection] and [prepared statement] objects. 1703** In this mode (which is the default when SQLite is compiled with 1704** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1705** to [database connections] and [prepared statements] so that the 1706** application is free to use the same [database connection] or the 1707** same [prepared statement] in different threads at the same time. 1708** ^If SQLite is compiled with 1709** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1710** it is not possible to set the Serialized [threading mode] and 1711** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1712** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1713** 1714** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1715** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is 1716** a pointer to an instance of the [sqlite3_mem_methods] structure. 1717** The argument specifies 1718** alternative low-level memory allocation routines to be used in place of 1719** the memory allocation routines built into SQLite.)^ ^SQLite makes 1720** its own private copy of the content of the [sqlite3_mem_methods] structure 1721** before the [sqlite3_config()] call returns.</dd> 1722** 1723** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1724** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which 1725** is a pointer to an instance of the [sqlite3_mem_methods] structure. 1726** The [sqlite3_mem_methods] 1727** structure is filled with the currently defined memory allocation routines.)^ 1728** This option can be used to overload the default memory allocation 1729** routines with a wrapper that simulations memory allocation failure or 1730** tracks memory usage, for example. </dd> 1731** 1732** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt> 1733** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of 1734** type int, interpreted as a boolean, which if true provides a hint to 1735** SQLite that it should avoid large memory allocations if possible. 1736** SQLite will run faster if it is free to make large memory allocations, 1737** but some application might prefer to run slower in exchange for 1738** guarantees about memory fragmentation that are possible if large 1739** allocations are avoided. This hint is normally off. 1740** </dd> 1741** 1742** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1743** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int, 1744** interpreted as a boolean, which enables or disables the collection of 1745** memory allocation statistics. ^(When memory allocation statistics are 1746** disabled, the following SQLite interfaces become non-operational: 1747** <ul> 1748** <li> [sqlite3_hard_heap_limit64()] 1749** <li> [sqlite3_memory_used()] 1750** <li> [sqlite3_memory_highwater()] 1751** <li> [sqlite3_soft_heap_limit64()] 1752** <li> [sqlite3_status64()] 1753** </ul>)^ 1754** ^Memory allocation statistics are enabled by default unless SQLite is 1755** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1756** allocation statistics are disabled by default. 1757** </dd> 1758** 1759** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1760** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used. 1761** </dd> 1762** 1763** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1764** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool 1765** that SQLite can use for the database page cache with the default page 1766** cache implementation. 1767** This configuration option is a no-op if an application-defined page 1768** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2]. 1769** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to 1770** 8-byte aligned memory (pMem), the size of each page cache line (sz), 1771** and the number of cache lines (N). 1772** The sz argument should be the size of the largest database page 1773** (a power of two between 512 and 65536) plus some extra bytes for each 1774** page header. ^The number of extra bytes needed by the page header 1775** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ]. 1776** ^It is harmless, apart from the wasted memory, 1777** for the sz parameter to be larger than necessary. The pMem 1778** argument must be either a NULL pointer or a pointer to an 8-byte 1779** aligned block of memory of at least sz*N bytes, otherwise 1780** subsequent behavior is undefined. 1781** ^When pMem is not NULL, SQLite will strive to use the memory provided 1782** to satisfy page cache needs, falling back to [sqlite3_malloc()] if 1783** a page cache line is larger than sz bytes or if all of the pMem buffer 1784** is exhausted. 1785** ^If pMem is NULL and N is non-zero, then each database connection 1786** does an initial bulk allocation for page cache memory 1787** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or 1788** of -1024*N bytes if N is negative, . ^If additional 1789** page cache memory is needed beyond what is provided by the initial 1790** allocation, then SQLite goes to [sqlite3_malloc()] separately for each 1791** additional cache line. </dd> 1792** 1793** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1794** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer 1795** that SQLite will use for all of its dynamic memory allocation needs 1796** beyond those provided for by [SQLITE_CONFIG_PAGECACHE]. 1797** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled 1798** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns 1799** [SQLITE_ERROR] if invoked otherwise. 1800** ^There are three arguments to SQLITE_CONFIG_HEAP: 1801** An 8-byte aligned pointer to the memory, 1802** the number of bytes in the memory buffer, and the minimum allocation size. 1803** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1804** to using its default memory allocator (the system malloc() implementation), 1805** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1806** memory pointer is not NULL then the alternative memory 1807** allocator is engaged to handle all of SQLites memory allocation needs. 1808** The first pointer (the memory pointer) must be aligned to an 8-byte 1809** boundary or subsequent behavior of SQLite will be undefined. 1810** The minimum allocation size is capped at 2**12. Reasonable values 1811** for the minimum allocation size are 2**5 through 2**8.</dd> 1812** 1813** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1814** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a 1815** pointer to an instance of the [sqlite3_mutex_methods] structure. 1816** The argument specifies alternative low-level mutex routines to be used 1817** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of 1818** the content of the [sqlite3_mutex_methods] structure before the call to 1819** [sqlite3_config()] returns. ^If SQLite is compiled with 1820** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1821** the entire mutexing subsystem is omitted from the build and hence calls to 1822** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1823** return [SQLITE_ERROR].</dd> 1824** 1825** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1826** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which 1827** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The 1828** [sqlite3_mutex_methods] 1829** structure is filled with the currently defined mutex routines.)^ 1830** This option can be used to overload the default mutex allocation 1831** routines with a wrapper used to track mutex usage for performance 1832** profiling or testing, for example. ^If SQLite is compiled with 1833** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1834** the entire mutexing subsystem is omitted from the build and hence calls to 1835** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1836** return [SQLITE_ERROR].</dd> 1837** 1838** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1839** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine 1840** the default size of lookaside memory on each [database connection]. 1841** The first argument is the 1842** size of each lookaside buffer slot and the second is the number of 1843** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE 1844** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1845** option to [sqlite3_db_config()] can be used to change the lookaside 1846** configuration on individual connections.)^ </dd> 1847** 1848** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1849** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is 1850** a pointer to an [sqlite3_pcache_methods2] object. This object specifies 1851** the interface to a custom page cache implementation.)^ 1852** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd> 1853** 1854** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1855** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which 1856** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of 1857** the current page cache implementation into that object.)^ </dd> 1858** 1859** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1860** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1861** global [error log]. 1862** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1863** function with a call signature of void(*)(void*,int,const char*), 1864** and a pointer to void. ^If the function pointer is not NULL, it is 1865** invoked by [sqlite3_log()] to process each logging event. ^If the 1866** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1867** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1868** passed through as the first parameter to the application-defined logger 1869** function whenever that function is invoked. ^The second parameter to 1870** the logger function is a copy of the first parameter to the corresponding 1871** [sqlite3_log()] call and is intended to be a [result code] or an 1872** [extended result code]. ^The third parameter passed to the logger is 1873** log message after formatting via [sqlite3_snprintf()]. 1874** The SQLite logging interface is not reentrant; the logger function 1875** supplied by the application must not invoke any SQLite interface. 1876** In a multi-threaded application, the application-defined logger 1877** function must be threadsafe. </dd> 1878** 1879** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1880** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int. 1881** If non-zero, then URI handling is globally enabled. If the parameter is zero, 1882** then URI handling is globally disabled.)^ ^If URI handling is globally 1883** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()], 1884** [sqlite3_open16()] or 1885** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1886** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1887** connection is opened. ^If it is globally disabled, filenames are 1888** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1889** database connection is opened. ^(By default, URI handling is globally 1890** disabled. The default value may be changed by compiling with the 1891** [SQLITE_USE_URI] symbol defined.)^ 1892** 1893** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1894** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer 1895** argument which is interpreted as a boolean in order to enable or disable 1896** the use of covering indices for full table scans in the query optimizer. 1897** ^The default setting is determined 1898** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1899** if that compile-time option is omitted. 1900** The ability to disable the use of covering indices for full table scans 1901** is because some incorrectly coded legacy applications might malfunction 1902** when the optimization is enabled. Providing the ability to 1903** disable the optimization allows the older, buggy application code to work 1904** without change even with newer versions of SQLite. 1905** 1906** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1907** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1908** <dd> These options are obsolete and should not be used by new code. 1909** They are retained for backwards compatibility but are now no-ops. 1910** </dd> 1911** 1912** [[SQLITE_CONFIG_SQLLOG]] 1913** <dt>SQLITE_CONFIG_SQLLOG 1914** <dd>This option is only available if sqlite is compiled with the 1915** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1916** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1917** The second should be of type (void*). The callback is invoked by the library 1918** in three separate circumstances, identified by the value passed as the 1919** fourth parameter. If the fourth parameter is 0, then the database connection 1920** passed as the second argument has just been opened. The third argument 1921** points to a buffer containing the name of the main database file. If the 1922** fourth parameter is 1, then the SQL statement that the third parameter 1923** points to has just been executed. Or, if the fourth parameter is 2, then 1924** the connection being passed as the second parameter is being closed. The 1925** third parameter is passed NULL In this case. An example of using this 1926** configuration option can be seen in the "test_sqllog.c" source file in 1927** the canonical SQLite source tree.</dd> 1928** 1929** [[SQLITE_CONFIG_MMAP_SIZE]] 1930** <dt>SQLITE_CONFIG_MMAP_SIZE 1931** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1932** that are the default mmap size limit (the default setting for 1933** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1934** ^The default setting can be overridden by each database connection using 1935** either the [PRAGMA mmap_size] command, or by using the 1936** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1937** will be silently truncated if necessary so that it does not exceed the 1938** compile-time maximum mmap size set by the 1939** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1940** ^If either argument to this option is negative, then that argument is 1941** changed to its compile-time default. 1942** 1943** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1944** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1945** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is 1946** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro 1947** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1948** that specifies the maximum size of the created heap. 1949** 1950** [[SQLITE_CONFIG_PCACHE_HDRSZ]] 1951** <dt>SQLITE_CONFIG_PCACHE_HDRSZ 1952** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which 1953** is a pointer to an integer and writes into that integer the number of extra 1954** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE]. 1955** The amount of extra space required can change depending on the compiler, 1956** target platform, and SQLite version. 1957** 1958** [[SQLITE_CONFIG_PMASZ]] 1959** <dt>SQLITE_CONFIG_PMASZ 1960** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which 1961** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded 1962** sorter to that integer. The default minimum PMA Size is set by the 1963** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched 1964** to help with sort operations when multithreaded sorting 1965** is enabled (using the [PRAGMA threads] command) and the amount of content 1966** to be sorted exceeds the page size times the minimum of the 1967** [PRAGMA cache_size] setting and this value. 1968** 1969** [[SQLITE_CONFIG_STMTJRNL_SPILL]] 1970** <dt>SQLITE_CONFIG_STMTJRNL_SPILL 1971** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which 1972** becomes the [statement journal] spill-to-disk threshold. 1973** [Statement journals] are held in memory until their size (in bytes) 1974** exceeds this threshold, at which point they are written to disk. 1975** Or if the threshold is -1, statement journals are always held 1976** exclusively in memory. 1977** Since many statement journals never become large, setting the spill 1978** threshold to a value such as 64KiB can greatly reduce the amount of 1979** I/O required to support statement rollback. 1980** The default value for this setting is controlled by the 1981** [SQLITE_STMTJRNL_SPILL] compile-time option. 1982** 1983** [[SQLITE_CONFIG_SORTERREF_SIZE]] 1984** <dt>SQLITE_CONFIG_SORTERREF_SIZE 1985** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter 1986** of type (int) - the new value of the sorter-reference size threshold. 1987** Usually, when SQLite uses an external sort to order records according 1988** to an ORDER BY clause, all fields required by the caller are present in the 1989** sorted records. However, if SQLite determines based on the declared type 1990** of a table column that its values are likely to be very large - larger 1991** than the configured sorter-reference size threshold - then a reference 1992** is stored in each sorted record and the required column values loaded 1993** from the database as records are returned in sorted order. The default 1994** value for this option is to never use this optimization. Specifying a 1995** negative value for this option restores the default behaviour. 1996** This option is only available if SQLite is compiled with the 1997** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option. 1998** 1999** [[SQLITE_CONFIG_MEMDB_MAXSIZE]] 2000** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE 2001** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter 2002** [sqlite3_int64] parameter which is the default maximum size for an in-memory 2003** database created using [sqlite3_deserialize()]. This default maximum 2004** size can be adjusted up or down for individual databases using the 2005** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this 2006** configuration setting is never used, then the default maximum is determined 2007** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that 2008** compile-time option is not set, then the default maximum is 1073741824. 2009** </dl> 2010*/ 2011#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 2012#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 2013#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 2014#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 2015#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 2016#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */ 2017#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 2018#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 2019#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 2020#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 2021#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 2022/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 2023#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 2024#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 2025#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 2026#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 2027#define SQLITE_CONFIG_URI 17 /* int */ 2028#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 2029#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 2030#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 2031#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 2032#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 2033#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 2034#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */ 2035#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */ 2036#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */ 2037#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */ 2038#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */ 2039#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */ 2040 2041/* 2042** CAPI3REF: Database Connection Configuration Options 2043** 2044** These constants are the available integer configuration options that 2045** can be passed as the second argument to the [sqlite3_db_config()] interface. 2046** 2047** New configuration options may be added in future releases of SQLite. 2048** Existing configuration options might be discontinued. Applications 2049** should check the return code from [sqlite3_db_config()] to make sure that 2050** the call worked. ^The [sqlite3_db_config()] interface will return a 2051** non-zero [error code] if a discontinued or unsupported configuration option 2052** is invoked. 2053** 2054** <dl> 2055** [[SQLITE_DBCONFIG_LOOKASIDE]] 2056** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 2057** <dd> ^This option takes three additional arguments that determine the 2058** [lookaside memory allocator] configuration for the [database connection]. 2059** ^The first argument (the third parameter to [sqlite3_db_config()] is a 2060** pointer to a memory buffer to use for lookaside memory. 2061** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 2062** may be NULL in which case SQLite will allocate the 2063** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 2064** size of each lookaside buffer slot. ^The third argument is the number of 2065** slots. The size of the buffer in the first argument must be greater than 2066** or equal to the product of the second and third arguments. The buffer 2067** must be aligned to an 8-byte boundary. ^If the second argument to 2068** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 2069** rounded down to the next smaller multiple of 8. ^(The lookaside memory 2070** configuration for a database connection can only be changed when that 2071** connection is not currently using lookaside memory, or in other words 2072** when the "current value" returned by 2073** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 2074** Any attempt to change the lookaside memory configuration when lookaside 2075** memory is in use leaves the configuration unchanged and returns 2076** [SQLITE_BUSY].)^</dd> 2077** 2078** [[SQLITE_DBCONFIG_ENABLE_FKEY]] 2079** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 2080** <dd> ^This option is used to enable or disable the enforcement of 2081** [foreign key constraints]. There should be two additional arguments. 2082** The first argument is an integer which is 0 to disable FK enforcement, 2083** positive to enable FK enforcement or negative to leave FK enforcement 2084** unchanged. The second parameter is a pointer to an integer into which 2085** is written 0 or 1 to indicate whether FK enforcement is off or on 2086** following this call. The second parameter may be a NULL pointer, in 2087** which case the FK enforcement setting is not reported back. </dd> 2088** 2089** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]] 2090** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 2091** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 2092** There should be two additional arguments. 2093** The first argument is an integer which is 0 to disable triggers, 2094** positive to enable triggers or negative to leave the setting unchanged. 2095** The second parameter is a pointer to an integer into which 2096** is written 0 or 1 to indicate whether triggers are disabled or enabled 2097** following this call. The second parameter may be a NULL pointer, in 2098** which case the trigger setting is not reported back. </dd> 2099** 2100** [[SQLITE_DBCONFIG_ENABLE_VIEW]] 2101** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt> 2102** <dd> ^This option is used to enable or disable [CREATE VIEW | views]. 2103** There should be two additional arguments. 2104** The first argument is an integer which is 0 to disable views, 2105** positive to enable views or negative to leave the setting unchanged. 2106** The second parameter is a pointer to an integer into which 2107** is written 0 or 1 to indicate whether views are disabled or enabled 2108** following this call. The second parameter may be a NULL pointer, in 2109** which case the view setting is not reported back. </dd> 2110** 2111** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]] 2112** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt> 2113** <dd> ^This option is used to enable or disable the 2114** [fts3_tokenizer()] function which is part of the 2115** [FTS3] full-text search engine extension. 2116** There should be two additional arguments. 2117** The first argument is an integer which is 0 to disable fts3_tokenizer() or 2118** positive to enable fts3_tokenizer() or negative to leave the setting 2119** unchanged. 2120** The second parameter is a pointer to an integer into which 2121** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled 2122** following this call. The second parameter may be a NULL pointer, in 2123** which case the new setting is not reported back. </dd> 2124** 2125** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]] 2126** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt> 2127** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()] 2128** interface independently of the [load_extension()] SQL function. 2129** The [sqlite3_enable_load_extension()] API enables or disables both the 2130** C-API [sqlite3_load_extension()] and the SQL function [load_extension()]. 2131** There should be two additional arguments. 2132** When the first argument to this interface is 1, then only the C-API is 2133** enabled and the SQL function remains disabled. If the first argument to 2134** this interface is 0, then both the C-API and the SQL function are disabled. 2135** If the first argument is -1, then no changes are made to state of either the 2136** C-API or the SQL function. 2137** The second parameter is a pointer to an integer into which 2138** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface 2139** is disabled or enabled following this call. The second parameter may 2140** be a NULL pointer, in which case the new setting is not reported back. 2141** </dd> 2142** 2143** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt> 2144** <dd> ^This option is used to change the name of the "main" database 2145** schema. ^The sole argument is a pointer to a constant UTF8 string 2146** which will become the new schema name in place of "main". ^SQLite 2147** does not make a copy of the new main schema name string, so the application 2148** must ensure that the argument passed into this DBCONFIG option is unchanged 2149** until after the database connection closes. 2150** </dd> 2151** 2152** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]] 2153** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt> 2154** <dd> Usually, when a database in wal mode is closed or detached from a 2155** database handle, SQLite checks if this will mean that there are now no 2156** connections at all to the database. If so, it performs a checkpoint 2157** operation before closing the connection. This option may be used to 2158** override this behaviour. The first parameter passed to this operation 2159** is an integer - positive to disable checkpoints-on-close, or zero (the 2160** default) to enable them, and negative to leave the setting unchanged. 2161** The second parameter is a pointer to an integer 2162** into which is written 0 or 1 to indicate whether checkpoints-on-close 2163** have been disabled - 0 if they are not disabled, 1 if they are. 2164** </dd> 2165** 2166** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt> 2167** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates 2168** the [query planner stability guarantee] (QPSG). When the QPSG is active, 2169** a single SQL query statement will always use the same algorithm regardless 2170** of values of [bound parameters].)^ The QPSG disables some query optimizations 2171** that look at the values of bound parameters, which can make some queries 2172** slower. But the QPSG has the advantage of more predictable behavior. With 2173** the QPSG active, SQLite will always use the same query plan in the field as 2174** was used during testing in the lab. 2175** The first argument to this setting is an integer which is 0 to disable 2176** the QPSG, positive to enable QPSG, or negative to leave the setting 2177** unchanged. The second parameter is a pointer to an integer into which 2178** is written 0 or 1 to indicate whether the QPSG is disabled or enabled 2179** following this call. 2180** </dd> 2181** 2182** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt> 2183** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not 2184** include output for any operations performed by trigger programs. This 2185** option is used to set or clear (the default) a flag that governs this 2186** behavior. The first parameter passed to this operation is an integer - 2187** positive to enable output for trigger programs, or zero to disable it, 2188** or negative to leave the setting unchanged. 2189** The second parameter is a pointer to an integer into which is written 2190** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if 2191** it is not disabled, 1 if it is. 2192** </dd> 2193** 2194** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt> 2195** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run 2196** [VACUUM] in order to reset a database back to an empty database 2197** with no schema and no content. The following process works even for 2198** a badly corrupted database file: 2199** <ol> 2200** <li> If the database connection is newly opened, make sure it has read the 2201** database schema by preparing then discarding some query against the 2202** database, or calling sqlite3_table_column_metadata(), ignoring any 2203** errors. This step is only necessary if the application desires to keep 2204** the database in WAL mode after the reset if it was in WAL mode before 2205** the reset. 2206** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0); 2207** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0); 2208** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0); 2209** </ol> 2210** Because resetting a database is destructive and irreversible, the 2211** process requires the use of this obscure API and multiple steps to help 2212** ensure that it does not happen by accident. 2213** 2214** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt> 2215** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the 2216** "defensive" flag for a database connection. When the defensive 2217** flag is enabled, language features that allow ordinary SQL to 2218** deliberately corrupt the database file are disabled. The disabled 2219** features include but are not limited to the following: 2220** <ul> 2221** <li> The [PRAGMA writable_schema=ON] statement. 2222** <li> The [PRAGMA journal_mode=OFF] statement. 2223** <li> Writes to the [sqlite_dbpage] virtual table. 2224** <li> Direct writes to [shadow tables]. 2225** </ul> 2226** </dd> 2227** 2228** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt> 2229** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the 2230** "writable_schema" flag. This has the same effect and is logically equivalent 2231** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF]. 2232** The first argument to this setting is an integer which is 0 to disable 2233** the writable_schema, positive to enable writable_schema, or negative to 2234** leave the setting unchanged. The second parameter is a pointer to an 2235** integer into which is written 0 or 1 to indicate whether the writable_schema 2236** is enabled or disabled following this call. 2237** </dd> 2238** 2239** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]] 2240** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt> 2241** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates 2242** the legacy behavior of the [ALTER TABLE RENAME] command such it 2243** behaves as it did prior to [version 3.24.0] (2018-06-04). See the 2244** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for 2245** additional information. This feature can also be turned on and off 2246** using the [PRAGMA legacy_alter_table] statement. 2247** </dd> 2248** 2249** [[SQLITE_DBCONFIG_DQS_DML]] 2250** <dt>SQLITE_DBCONFIG_DQS_DML</td> 2251** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates 2252** the legacy [double-quoted string literal] misfeature for DML statements 2253** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The 2254** default value of this setting is determined by the [-DSQLITE_DQS] 2255** compile-time option. 2256** </dd> 2257** 2258** [[SQLITE_DBCONFIG_DQS_DDL]] 2259** <dt>SQLITE_DBCONFIG_DQS_DDL</td> 2260** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates 2261** the legacy [double-quoted string literal] misfeature for DDL statements, 2262** such as CREATE TABLE and CREATE INDEX. The 2263** default value of this setting is determined by the [-DSQLITE_DQS] 2264** compile-time option. 2265** </dd> 2266** 2267** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]] 2268** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td> 2269** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates 2270** the legacy file format flag. When activated, this flag causes all newly 2271** created database file to have a schema format version number (the 4-byte 2272** integer found at offset 44 into the database header) of 1. This in turn 2273** means that the resulting database file will be readable and writable by 2274** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting, 2275** newly created databases are generally not understandable by SQLite versions 2276** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there 2277** is now scarcely any need to generated database files that are compatible 2278** all the way back to version 3.0.0, and so this setting is of little 2279** practical use, but is provided so that SQLite can continue to claim the 2280** ability to generate new database files that are compatible with version 2281** 3.0.0. 2282** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on, 2283** the [VACUUM] command will fail with an obscure error when attempting to 2284** process a table with generated columns and a descending index. This is 2285** not considered a bug since SQLite versions 3.3.0 and earlier do not support 2286** either generated columns or decending indexes. 2287** </dd> 2288** </dl> 2289*/ 2290#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */ 2291#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 2292#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 2293#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 2294#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */ 2295#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */ 2296#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */ 2297#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */ 2298#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */ 2299#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */ 2300#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */ 2301#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */ 2302#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */ 2303#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */ 2304#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */ 2305#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */ 2306#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */ 2307#define SQLITE_DBCONFIG_MAX 1016 /* Largest DBCONFIG */ 2308 2309/* 2310** CAPI3REF: Enable Or Disable Extended Result Codes 2311** METHOD: sqlite3 2312** 2313** ^The sqlite3_extended_result_codes() routine enables or disables the 2314** [extended result codes] feature of SQLite. ^The extended result 2315** codes are disabled by default for historical compatibility. 2316*/ 2317int sqlite3_extended_result_codes(sqlite3*, int onoff); 2318 2319/* 2320** CAPI3REF: Last Insert Rowid 2321** METHOD: sqlite3 2322** 2323** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 2324** has a unique 64-bit signed 2325** integer key called the [ROWID | "rowid"]. ^The rowid is always available 2326** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 2327** names are not also used by explicitly declared columns. ^If 2328** the table has a column of type [INTEGER PRIMARY KEY] then that column 2329** is another alias for the rowid. 2330** 2331** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of 2332** the most recent successful [INSERT] into a rowid table or [virtual table] 2333** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not 2334** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred 2335** on the database connection D, then sqlite3_last_insert_rowid(D) returns 2336** zero. 2337** 2338** As well as being set automatically as rows are inserted into database 2339** tables, the value returned by this function may be set explicitly by 2340** [sqlite3_set_last_insert_rowid()] 2341** 2342** Some virtual table implementations may INSERT rows into rowid tables as 2343** part of committing a transaction (e.g. to flush data accumulated in memory 2344** to disk). In this case subsequent calls to this function return the rowid 2345** associated with these internal INSERT operations, which leads to 2346** unintuitive results. Virtual table implementations that do write to rowid 2347** tables in this way can avoid this problem by restoring the original 2348** rowid value using [sqlite3_set_last_insert_rowid()] before returning 2349** control to the user. 2350** 2351** ^(If an [INSERT] occurs within a trigger then this routine will 2352** return the [rowid] of the inserted row as long as the trigger is 2353** running. Once the trigger program ends, the value returned 2354** by this routine reverts to what it was before the trigger was fired.)^ 2355** 2356** ^An [INSERT] that fails due to a constraint violation is not a 2357** successful [INSERT] and does not change the value returned by this 2358** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 2359** and INSERT OR ABORT make no changes to the return value of this 2360** routine when their insertion fails. ^(When INSERT OR REPLACE 2361** encounters a constraint violation, it does not fail. The 2362** INSERT continues to completion after deleting rows that caused 2363** the constraint problem so INSERT OR REPLACE will always change 2364** the return value of this interface.)^ 2365** 2366** ^For the purposes of this routine, an [INSERT] is considered to 2367** be successful even if it is subsequently rolled back. 2368** 2369** This function is accessible to SQL statements via the 2370** [last_insert_rowid() SQL function]. 2371** 2372** If a separate thread performs a new [INSERT] on the same 2373** database connection while the [sqlite3_last_insert_rowid()] 2374** function is running and thus changes the last insert [rowid], 2375** then the value returned by [sqlite3_last_insert_rowid()] is 2376** unpredictable and might not equal either the old or the new 2377** last insert [rowid]. 2378*/ 2379sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 2380 2381/* 2382** CAPI3REF: Set the Last Insert Rowid value. 2383** METHOD: sqlite3 2384** 2385** The sqlite3_set_last_insert_rowid(D, R) method allows the application to 2386** set the value returned by calling sqlite3_last_insert_rowid(D) to R 2387** without inserting a row into the database. 2388*/ 2389void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64); 2390 2391/* 2392** CAPI3REF: Count The Number Of Rows Modified 2393** METHOD: sqlite3 2394** 2395** ^This function returns the number of rows modified, inserted or 2396** deleted by the most recently completed INSERT, UPDATE or DELETE 2397** statement on the database connection specified by the only parameter. 2398** ^Executing any other type of SQL statement does not modify the value 2399** returned by this function. 2400** 2401** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are 2402** considered - auxiliary changes caused by [CREATE TRIGGER | triggers], 2403** [foreign key actions] or [REPLACE] constraint resolution are not counted. 2404** 2405** Changes to a view that are intercepted by 2406** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value 2407** returned by sqlite3_changes() immediately after an INSERT, UPDATE or 2408** DELETE statement run on a view is always zero. Only changes made to real 2409** tables are counted. 2410** 2411** Things are more complicated if the sqlite3_changes() function is 2412** executed while a trigger program is running. This may happen if the 2413** program uses the [changes() SQL function], or if some other callback 2414** function invokes sqlite3_changes() directly. Essentially: 2415** 2416** <ul> 2417** <li> ^(Before entering a trigger program the value returned by 2418** sqlite3_changes() function is saved. After the trigger program 2419** has finished, the original value is restored.)^ 2420** 2421** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE 2422** statement sets the value returned by sqlite3_changes() 2423** upon completion as normal. Of course, this value will not include 2424** any changes performed by sub-triggers, as the sqlite3_changes() 2425** value will be saved and restored after each sub-trigger has run.)^ 2426** </ul> 2427** 2428** ^This means that if the changes() SQL function (or similar) is used 2429** by the first INSERT, UPDATE or DELETE statement within a trigger, it 2430** returns the value as set when the calling statement began executing. 2431** ^If it is used by the second or subsequent such statement within a trigger 2432** program, the value returned reflects the number of rows modified by the 2433** previous INSERT, UPDATE or DELETE statement within the same trigger. 2434** 2435** If a separate thread makes changes on the same database connection 2436** while [sqlite3_changes()] is running then the value returned 2437** is unpredictable and not meaningful. 2438** 2439** See also: 2440** <ul> 2441** <li> the [sqlite3_total_changes()] interface 2442** <li> the [count_changes pragma] 2443** <li> the [changes() SQL function] 2444** <li> the [data_version pragma] 2445** </ul> 2446*/ 2447int sqlite3_changes(sqlite3*); 2448 2449/* 2450** CAPI3REF: Total Number Of Rows Modified 2451** METHOD: sqlite3 2452** 2453** ^This function returns the total number of rows inserted, modified or 2454** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed 2455** since the database connection was opened, including those executed as 2456** part of trigger programs. ^Executing any other type of SQL statement 2457** does not affect the value returned by sqlite3_total_changes(). 2458** 2459** ^Changes made as part of [foreign key actions] are included in the 2460** count, but those made as part of REPLACE constraint resolution are 2461** not. ^Changes to a view that are intercepted by INSTEAD OF triggers 2462** are not counted. 2463** 2464** The [sqlite3_total_changes(D)] interface only reports the number 2465** of rows that changed due to SQL statement run against database 2466** connection D. Any changes by other database connections are ignored. 2467** To detect changes against a database file from other database 2468** connections use the [PRAGMA data_version] command or the 2469** [SQLITE_FCNTL_DATA_VERSION] [file control]. 2470** 2471** If a separate thread makes changes on the same database connection 2472** while [sqlite3_total_changes()] is running then the value 2473** returned is unpredictable and not meaningful. 2474** 2475** See also: 2476** <ul> 2477** <li> the [sqlite3_changes()] interface 2478** <li> the [count_changes pragma] 2479** <li> the [changes() SQL function] 2480** <li> the [data_version pragma] 2481** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control] 2482** </ul> 2483*/ 2484int sqlite3_total_changes(sqlite3*); 2485 2486/* 2487** CAPI3REF: Interrupt A Long-Running Query 2488** METHOD: sqlite3 2489** 2490** ^This function causes any pending database operation to abort and 2491** return at its earliest opportunity. This routine is typically 2492** called in response to a user action such as pressing "Cancel" 2493** or Ctrl-C where the user wants a long query operation to halt 2494** immediately. 2495** 2496** ^It is safe to call this routine from a thread different from the 2497** thread that is currently running the database operation. But it 2498** is not safe to call this routine with a [database connection] that 2499** is closed or might close before sqlite3_interrupt() returns. 2500** 2501** ^If an SQL operation is very nearly finished at the time when 2502** sqlite3_interrupt() is called, then it might not have an opportunity 2503** to be interrupted and might continue to completion. 2504** 2505** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2506** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2507** that is inside an explicit transaction, then the entire transaction 2508** will be rolled back automatically. 2509** 2510** ^The sqlite3_interrupt(D) call is in effect until all currently running 2511** SQL statements on [database connection] D complete. ^Any new SQL statements 2512** that are started after the sqlite3_interrupt() call and before the 2513** running statement count reaches zero are interrupted as if they had been 2514** running prior to the sqlite3_interrupt() call. ^New SQL statements 2515** that are started after the running statement count reaches zero are 2516** not effected by the sqlite3_interrupt(). 2517** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2518** SQL statements is a no-op and has no effect on SQL statements 2519** that are started after the sqlite3_interrupt() call returns. 2520*/ 2521void sqlite3_interrupt(sqlite3*); 2522 2523/* 2524** CAPI3REF: Determine If An SQL Statement Is Complete 2525** 2526** These routines are useful during command-line input to determine if the 2527** currently entered text seems to form a complete SQL statement or 2528** if additional input is needed before sending the text into 2529** SQLite for parsing. ^These routines return 1 if the input string 2530** appears to be a complete SQL statement. ^A statement is judged to be 2531** complete if it ends with a semicolon token and is not a prefix of a 2532** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2533** string literals or quoted identifier names or comments are not 2534** independent tokens (they are part of the token in which they are 2535** embedded) and thus do not count as a statement terminator. ^Whitespace 2536** and comments that follow the final semicolon are ignored. 2537** 2538** ^These routines return 0 if the statement is incomplete. ^If a 2539** memory allocation fails, then SQLITE_NOMEM is returned. 2540** 2541** ^These routines do not parse the SQL statements thus 2542** will not detect syntactically incorrect SQL. 2543** 2544** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2545** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2546** automatically by sqlite3_complete16(). If that initialization fails, 2547** then the return value from sqlite3_complete16() will be non-zero 2548** regardless of whether or not the input SQL is complete.)^ 2549** 2550** The input to [sqlite3_complete()] must be a zero-terminated 2551** UTF-8 string. 2552** 2553** The input to [sqlite3_complete16()] must be a zero-terminated 2554** UTF-16 string in native byte order. 2555*/ 2556int sqlite3_complete(const char *sql); 2557int sqlite3_complete16(const void *sql); 2558 2559/* 2560** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2561** KEYWORDS: {busy-handler callback} {busy handler} 2562** METHOD: sqlite3 2563** 2564** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2565** that might be invoked with argument P whenever 2566** an attempt is made to access a database table associated with 2567** [database connection] D when another thread 2568** or process has the table locked. 2569** The sqlite3_busy_handler() interface is used to implement 2570** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2571** 2572** ^If the busy callback is NULL, then [SQLITE_BUSY] 2573** is returned immediately upon encountering the lock. ^If the busy callback 2574** is not NULL, then the callback might be invoked with two arguments. 2575** 2576** ^The first argument to the busy handler is a copy of the void* pointer which 2577** is the third argument to sqlite3_busy_handler(). ^The second argument to 2578** the busy handler callback is the number of times that the busy handler has 2579** been invoked previously for the same locking event. ^If the 2580** busy callback returns 0, then no additional attempts are made to 2581** access the database and [SQLITE_BUSY] is returned 2582** to the application. 2583** ^If the callback returns non-zero, then another attempt 2584** is made to access the database and the cycle repeats. 2585** 2586** The presence of a busy handler does not guarantee that it will be invoked 2587** when there is lock contention. ^If SQLite determines that invoking the busy 2588** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2589** to the application instead of invoking the 2590** busy handler. 2591** Consider a scenario where one process is holding a read lock that 2592** it is trying to promote to a reserved lock and 2593** a second process is holding a reserved lock that it is trying 2594** to promote to an exclusive lock. The first process cannot proceed 2595** because it is blocked by the second and the second process cannot 2596** proceed because it is blocked by the first. If both processes 2597** invoke the busy handlers, neither will make any progress. Therefore, 2598** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2599** will induce the first process to release its read lock and allow 2600** the second process to proceed. 2601** 2602** ^The default busy callback is NULL. 2603** 2604** ^(There can only be a single busy handler defined for each 2605** [database connection]. Setting a new busy handler clears any 2606** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2607** or evaluating [PRAGMA busy_timeout=N] will change the 2608** busy handler and thus clear any previously set busy handler. 2609** 2610** The busy callback should not take any actions which modify the 2611** database connection that invoked the busy handler. In other words, 2612** the busy handler is not reentrant. Any such actions 2613** result in undefined behavior. 2614** 2615** A busy handler must not close the database connection 2616** or [prepared statement] that invoked the busy handler. 2617*/ 2618int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*); 2619 2620/* 2621** CAPI3REF: Set A Busy Timeout 2622** METHOD: sqlite3 2623** 2624** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2625** for a specified amount of time when a table is locked. ^The handler 2626** will sleep multiple times until at least "ms" milliseconds of sleeping 2627** have accumulated. ^After at least "ms" milliseconds of sleeping, 2628** the handler returns 0 which causes [sqlite3_step()] to return 2629** [SQLITE_BUSY]. 2630** 2631** ^Calling this routine with an argument less than or equal to zero 2632** turns off all busy handlers. 2633** 2634** ^(There can only be a single busy handler for a particular 2635** [database connection] at any given moment. If another busy handler 2636** was defined (using [sqlite3_busy_handler()]) prior to calling 2637** this routine, that other busy handler is cleared.)^ 2638** 2639** See also: [PRAGMA busy_timeout] 2640*/ 2641int sqlite3_busy_timeout(sqlite3*, int ms); 2642 2643/* 2644** CAPI3REF: Convenience Routines For Running Queries 2645** METHOD: sqlite3 2646** 2647** This is a legacy interface that is preserved for backwards compatibility. 2648** Use of this interface is not recommended. 2649** 2650** Definition: A <b>result table</b> is memory data structure created by the 2651** [sqlite3_get_table()] interface. A result table records the 2652** complete query results from one or more queries. 2653** 2654** The table conceptually has a number of rows and columns. But 2655** these numbers are not part of the result table itself. These 2656** numbers are obtained separately. Let N be the number of rows 2657** and M be the number of columns. 2658** 2659** A result table is an array of pointers to zero-terminated UTF-8 strings. 2660** There are (N+1)*M elements in the array. The first M pointers point 2661** to zero-terminated strings that contain the names of the columns. 2662** The remaining entries all point to query results. NULL values result 2663** in NULL pointers. All other values are in their UTF-8 zero-terminated 2664** string representation as returned by [sqlite3_column_text()]. 2665** 2666** A result table might consist of one or more memory allocations. 2667** It is not safe to pass a result table directly to [sqlite3_free()]. 2668** A result table should be deallocated using [sqlite3_free_table()]. 2669** 2670** ^(As an example of the result table format, suppose a query result 2671** is as follows: 2672** 2673** <blockquote><pre> 2674** Name | Age 2675** ----------------------- 2676** Alice | 43 2677** Bob | 28 2678** Cindy | 21 2679** </pre></blockquote> 2680** 2681** There are two columns (M==2) and three rows (N==3). Thus the 2682** result table has 8 entries. Suppose the result table is stored 2683** in an array named azResult. Then azResult holds this content: 2684** 2685** <blockquote><pre> 2686** azResult[0] = "Name"; 2687** azResult[1] = "Age"; 2688** azResult[2] = "Alice"; 2689** azResult[3] = "43"; 2690** azResult[4] = "Bob"; 2691** azResult[5] = "28"; 2692** azResult[6] = "Cindy"; 2693** azResult[7] = "21"; 2694** </pre></blockquote>)^ 2695** 2696** ^The sqlite3_get_table() function evaluates one or more 2697** semicolon-separated SQL statements in the zero-terminated UTF-8 2698** string of its 2nd parameter and returns a result table to the 2699** pointer given in its 3rd parameter. 2700** 2701** After the application has finished with the result from sqlite3_get_table(), 2702** it must pass the result table pointer to sqlite3_free_table() in order to 2703** release the memory that was malloced. Because of the way the 2704** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2705** function must not try to call [sqlite3_free()] directly. Only 2706** [sqlite3_free_table()] is able to release the memory properly and safely. 2707** 2708** The sqlite3_get_table() interface is implemented as a wrapper around 2709** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2710** to any internal data structures of SQLite. It uses only the public 2711** interface defined here. As a consequence, errors that occur in the 2712** wrapper layer outside of the internal [sqlite3_exec()] call are not 2713** reflected in subsequent calls to [sqlite3_errcode()] or 2714** [sqlite3_errmsg()]. 2715*/ 2716int sqlite3_get_table( 2717 sqlite3 *db, /* An open database */ 2718 const char *zSql, /* SQL to be evaluated */ 2719 char ***pazResult, /* Results of the query */ 2720 int *pnRow, /* Number of result rows written here */ 2721 int *pnColumn, /* Number of result columns written here */ 2722 char **pzErrmsg /* Error msg written here */ 2723); 2724void sqlite3_free_table(char **result); 2725 2726/* 2727** CAPI3REF: Formatted String Printing Functions 2728** 2729** These routines are work-alikes of the "printf()" family of functions 2730** from the standard C library. 2731** These routines understand most of the common formatting options from 2732** the standard library printf() 2733** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]). 2734** See the [built-in printf()] documentation for details. 2735** 2736** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2737** results into memory obtained from [sqlite3_malloc64()]. 2738** The strings returned by these two routines should be 2739** released by [sqlite3_free()]. ^Both routines return a 2740** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough 2741** memory to hold the resulting string. 2742** 2743** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2744** the standard C library. The result is written into the 2745** buffer supplied as the second parameter whose size is given by 2746** the first parameter. Note that the order of the 2747** first two parameters is reversed from snprintf().)^ This is an 2748** historical accident that cannot be fixed without breaking 2749** backwards compatibility. ^(Note also that sqlite3_snprintf() 2750** returns a pointer to its buffer instead of the number of 2751** characters actually written into the buffer.)^ We admit that 2752** the number of characters written would be a more useful return 2753** value but we cannot change the implementation of sqlite3_snprintf() 2754** now without breaking compatibility. 2755** 2756** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2757** guarantees that the buffer is always zero-terminated. ^The first 2758** parameter "n" is the total size of the buffer, including space for 2759** the zero terminator. So the longest string that can be completely 2760** written will be n-1 characters. 2761** 2762** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2763** 2764** See also: [built-in printf()], [printf() SQL function] 2765*/ 2766char *sqlite3_mprintf(const char*,...); 2767char *sqlite3_vmprintf(const char*, va_list); 2768char *sqlite3_snprintf(int,char*,const char*, ...); 2769char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2770 2771/* 2772** CAPI3REF: Memory Allocation Subsystem 2773** 2774** The SQLite core uses these three routines for all of its own 2775** internal memory allocation needs. "Core" in the previous sentence 2776** does not include operating-system specific VFS implementation. The 2777** Windows VFS uses native malloc() and free() for some operations. 2778** 2779** ^The sqlite3_malloc() routine returns a pointer to a block 2780** of memory at least N bytes in length, where N is the parameter. 2781** ^If sqlite3_malloc() is unable to obtain sufficient free 2782** memory, it returns a NULL pointer. ^If the parameter N to 2783** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2784** a NULL pointer. 2785** 2786** ^The sqlite3_malloc64(N) routine works just like 2787** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead 2788** of a signed 32-bit integer. 2789** 2790** ^Calling sqlite3_free() with a pointer previously returned 2791** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2792** that it might be reused. ^The sqlite3_free() routine is 2793** a no-op if is called with a NULL pointer. Passing a NULL pointer 2794** to sqlite3_free() is harmless. After being freed, memory 2795** should neither be read nor written. Even reading previously freed 2796** memory might result in a segmentation fault or other severe error. 2797** Memory corruption, a segmentation fault, or other severe error 2798** might result if sqlite3_free() is called with a non-NULL pointer that 2799** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2800** 2801** ^The sqlite3_realloc(X,N) interface attempts to resize a 2802** prior memory allocation X to be at least N bytes. 2803** ^If the X parameter to sqlite3_realloc(X,N) 2804** is a NULL pointer then its behavior is identical to calling 2805** sqlite3_malloc(N). 2806** ^If the N parameter to sqlite3_realloc(X,N) is zero or 2807** negative then the behavior is exactly the same as calling 2808** sqlite3_free(X). 2809** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation 2810** of at least N bytes in size or NULL if insufficient memory is available. 2811** ^If M is the size of the prior allocation, then min(N,M) bytes 2812** of the prior allocation are copied into the beginning of buffer returned 2813** by sqlite3_realloc(X,N) and the prior allocation is freed. 2814** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the 2815** prior allocation is not freed. 2816** 2817** ^The sqlite3_realloc64(X,N) interfaces works the same as 2818** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead 2819** of a 32-bit signed integer. 2820** 2821** ^If X is a memory allocation previously obtained from sqlite3_malloc(), 2822** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then 2823** sqlite3_msize(X) returns the size of that memory allocation in bytes. 2824** ^The value returned by sqlite3_msize(X) might be larger than the number 2825** of bytes requested when X was allocated. ^If X is a NULL pointer then 2826** sqlite3_msize(X) returns zero. If X points to something that is not 2827** the beginning of memory allocation, or if it points to a formerly 2828** valid memory allocation that has now been freed, then the behavior 2829** of sqlite3_msize(X) is undefined and possibly harmful. 2830** 2831** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(), 2832** sqlite3_malloc64(), and sqlite3_realloc64() 2833** is always aligned to at least an 8 byte boundary, or to a 2834** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2835** option is used. 2836** 2837** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2838** must be either NULL or else pointers obtained from a prior 2839** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2840** not yet been released. 2841** 2842** The application must not read or write any part of 2843** a block of memory after it has been released using 2844** [sqlite3_free()] or [sqlite3_realloc()]. 2845*/ 2846void *sqlite3_malloc(int); 2847void *sqlite3_malloc64(sqlite3_uint64); 2848void *sqlite3_realloc(void*, int); 2849void *sqlite3_realloc64(void*, sqlite3_uint64); 2850void sqlite3_free(void*); 2851sqlite3_uint64 sqlite3_msize(void*); 2852 2853/* 2854** CAPI3REF: Memory Allocator Statistics 2855** 2856** SQLite provides these two interfaces for reporting on the status 2857** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2858** routines, which form the built-in memory allocation subsystem. 2859** 2860** ^The [sqlite3_memory_used()] routine returns the number of bytes 2861** of memory currently outstanding (malloced but not freed). 2862** ^The [sqlite3_memory_highwater()] routine returns the maximum 2863** value of [sqlite3_memory_used()] since the high-water mark 2864** was last reset. ^The values returned by [sqlite3_memory_used()] and 2865** [sqlite3_memory_highwater()] include any overhead 2866** added by SQLite in its implementation of [sqlite3_malloc()], 2867** but not overhead added by the any underlying system library 2868** routines that [sqlite3_malloc()] may call. 2869** 2870** ^The memory high-water mark is reset to the current value of 2871** [sqlite3_memory_used()] if and only if the parameter to 2872** [sqlite3_memory_highwater()] is true. ^The value returned 2873** by [sqlite3_memory_highwater(1)] is the high-water mark 2874** prior to the reset. 2875*/ 2876sqlite3_int64 sqlite3_memory_used(void); 2877sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2878 2879/* 2880** CAPI3REF: Pseudo-Random Number Generator 2881** 2882** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2883** select random [ROWID | ROWIDs] when inserting new records into a table that 2884** already uses the largest possible [ROWID]. The PRNG is also used for 2885** the built-in random() and randomblob() SQL functions. This interface allows 2886** applications to access the same PRNG for other purposes. 2887** 2888** ^A call to this routine stores N bytes of randomness into buffer P. 2889** ^The P parameter can be a NULL pointer. 2890** 2891** ^If this routine has not been previously called or if the previous 2892** call had N less than one or a NULL pointer for P, then the PRNG is 2893** seeded using randomness obtained from the xRandomness method of 2894** the default [sqlite3_vfs] object. 2895** ^If the previous call to this routine had an N of 1 or more and a 2896** non-NULL P then the pseudo-randomness is generated 2897** internally and without recourse to the [sqlite3_vfs] xRandomness 2898** method. 2899*/ 2900void sqlite3_randomness(int N, void *P); 2901 2902/* 2903** CAPI3REF: Compile-Time Authorization Callbacks 2904** METHOD: sqlite3 2905** KEYWORDS: {authorizer callback} 2906** 2907** ^This routine registers an authorizer callback with a particular 2908** [database connection], supplied in the first argument. 2909** ^The authorizer callback is invoked as SQL statements are being compiled 2910** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2911** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()], 2912** and [sqlite3_prepare16_v3()]. ^At various 2913** points during the compilation process, as logic is being created 2914** to perform various actions, the authorizer callback is invoked to 2915** see if those actions are allowed. ^The authorizer callback should 2916** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2917** specific action but allow the SQL statement to continue to be 2918** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2919** rejected with an error. ^If the authorizer callback returns 2920** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2921** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2922** the authorizer will fail with an error message. 2923** 2924** When the callback returns [SQLITE_OK], that means the operation 2925** requested is ok. ^When the callback returns [SQLITE_DENY], the 2926** [sqlite3_prepare_v2()] or equivalent call that triggered the 2927** authorizer will fail with an error message explaining that 2928** access is denied. 2929** 2930** ^The first parameter to the authorizer callback is a copy of the third 2931** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2932** to the callback is an integer [SQLITE_COPY | action code] that specifies 2933** the particular action to be authorized. ^The third through sixth parameters 2934** to the callback are either NULL pointers or zero-terminated strings 2935** that contain additional details about the action to be authorized. 2936** Applications must always be prepared to encounter a NULL pointer in any 2937** of the third through the sixth parameters of the authorization callback. 2938** 2939** ^If the action code is [SQLITE_READ] 2940** and the callback returns [SQLITE_IGNORE] then the 2941** [prepared statement] statement is constructed to substitute 2942** a NULL value in place of the table column that would have 2943** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2944** return can be used to deny an untrusted user access to individual 2945** columns of a table. 2946** ^When a table is referenced by a [SELECT] but no column values are 2947** extracted from that table (for example in a query like 2948** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback 2949** is invoked once for that table with a column name that is an empty string. 2950** ^If the action code is [SQLITE_DELETE] and the callback returns 2951** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2952** [truncate optimization] is disabled and all rows are deleted individually. 2953** 2954** An authorizer is used when [sqlite3_prepare | preparing] 2955** SQL statements from an untrusted source, to ensure that the SQL statements 2956** do not try to access data they are not allowed to see, or that they do not 2957** try to execute malicious statements that damage the database. For 2958** example, an application may allow a user to enter arbitrary 2959** SQL queries for evaluation by a database. But the application does 2960** not want the user to be able to make arbitrary changes to the 2961** database. An authorizer could then be put in place while the 2962** user-entered SQL is being [sqlite3_prepare | prepared] that 2963** disallows everything except [SELECT] statements. 2964** 2965** Applications that need to process SQL from untrusted sources 2966** might also consider lowering resource limits using [sqlite3_limit()] 2967** and limiting database size using the [max_page_count] [PRAGMA] 2968** in addition to using an authorizer. 2969** 2970** ^(Only a single authorizer can be in place on a database connection 2971** at a time. Each call to sqlite3_set_authorizer overrides the 2972** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2973** The authorizer is disabled by default. 2974** 2975** The authorizer callback must not do anything that will modify 2976** the database connection that invoked the authorizer callback. 2977** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2978** database connections for the meaning of "modify" in this paragraph. 2979** 2980** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2981** statement might be re-prepared during [sqlite3_step()] due to a 2982** schema change. Hence, the application should ensure that the 2983** correct authorizer callback remains in place during the [sqlite3_step()]. 2984** 2985** ^Note that the authorizer callback is invoked only during 2986** [sqlite3_prepare()] or its variants. Authorization is not 2987** performed during statement evaluation in [sqlite3_step()], unless 2988** as stated in the previous paragraph, sqlite3_step() invokes 2989** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2990*/ 2991int sqlite3_set_authorizer( 2992 sqlite3*, 2993 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2994 void *pUserData 2995); 2996 2997/* 2998** CAPI3REF: Authorizer Return Codes 2999** 3000** The [sqlite3_set_authorizer | authorizer callback function] must 3001** return either [SQLITE_OK] or one of these two constants in order 3002** to signal SQLite whether or not the action is permitted. See the 3003** [sqlite3_set_authorizer | authorizer documentation] for additional 3004** information. 3005** 3006** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 3007** returned from the [sqlite3_vtab_on_conflict()] interface. 3008*/ 3009#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 3010#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 3011 3012/* 3013** CAPI3REF: Authorizer Action Codes 3014** 3015** The [sqlite3_set_authorizer()] interface registers a callback function 3016** that is invoked to authorize certain SQL statement actions. The 3017** second parameter to the callback is an integer code that specifies 3018** what action is being authorized. These are the integer action codes that 3019** the authorizer callback may be passed. 3020** 3021** These action code values signify what kind of operation is to be 3022** authorized. The 3rd and 4th parameters to the authorization 3023** callback function will be parameters or NULL depending on which of these 3024** codes is used as the second parameter. ^(The 5th parameter to the 3025** authorizer callback is the name of the database ("main", "temp", 3026** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 3027** is the name of the inner-most trigger or view that is responsible for 3028** the access attempt or NULL if this access attempt is directly from 3029** top-level SQL code. 3030*/ 3031/******************************************* 3rd ************ 4th ***********/ 3032#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 3033#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 3034#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 3035#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 3036#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 3037#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 3038#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 3039#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 3040#define SQLITE_DELETE 9 /* Table Name NULL */ 3041#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 3042#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 3043#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 3044#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 3045#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 3046#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 3047#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 3048#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 3049#define SQLITE_INSERT 18 /* Table Name NULL */ 3050#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 3051#define SQLITE_READ 20 /* Table Name Column Name */ 3052#define SQLITE_SELECT 21 /* NULL NULL */ 3053#define SQLITE_TRANSACTION 22 /* Operation NULL */ 3054#define SQLITE_UPDATE 23 /* Table Name Column Name */ 3055#define SQLITE_ATTACH 24 /* Filename NULL */ 3056#define SQLITE_DETACH 25 /* Database Name NULL */ 3057#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 3058#define SQLITE_REINDEX 27 /* Index Name NULL */ 3059#define SQLITE_ANALYZE 28 /* Table Name NULL */ 3060#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 3061#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 3062#define SQLITE_FUNCTION 31 /* NULL Function Name */ 3063#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 3064#define SQLITE_COPY 0 /* No longer used */ 3065#define SQLITE_RECURSIVE 33 /* NULL NULL */ 3066 3067/* 3068** CAPI3REF: Tracing And Profiling Functions 3069** METHOD: sqlite3 3070** 3071** These routines are deprecated. Use the [sqlite3_trace_v2()] interface 3072** instead of the routines described here. 3073** 3074** These routines register callback functions that can be used for 3075** tracing and profiling the execution of SQL statements. 3076** 3077** ^The callback function registered by sqlite3_trace() is invoked at 3078** various times when an SQL statement is being run by [sqlite3_step()]. 3079** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 3080** SQL statement text as the statement first begins executing. 3081** ^(Additional sqlite3_trace() callbacks might occur 3082** as each triggered subprogram is entered. The callbacks for triggers 3083** contain a UTF-8 SQL comment that identifies the trigger.)^ 3084** 3085** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 3086** the length of [bound parameter] expansion in the output of sqlite3_trace(). 3087** 3088** ^The callback function registered by sqlite3_profile() is invoked 3089** as each SQL statement finishes. ^The profile callback contains 3090** the original statement text and an estimate of wall-clock time 3091** of how long that statement took to run. ^The profile callback 3092** time is in units of nanoseconds, however the current implementation 3093** is only capable of millisecond resolution so the six least significant 3094** digits in the time are meaningless. Future versions of SQLite 3095** might provide greater resolution on the profiler callback. Invoking 3096** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the 3097** profile callback. 3098*/ 3099SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*, 3100 void(*xTrace)(void*,const char*), void*); 3101SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*, 3102 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 3103 3104/* 3105** CAPI3REF: SQL Trace Event Codes 3106** KEYWORDS: SQLITE_TRACE 3107** 3108** These constants identify classes of events that can be monitored 3109** using the [sqlite3_trace_v2()] tracing logic. The M argument 3110** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of 3111** the following constants. ^The first argument to the trace callback 3112** is one of the following constants. 3113** 3114** New tracing constants may be added in future releases. 3115** 3116** ^A trace callback has four arguments: xCallback(T,C,P,X). 3117** ^The T argument is one of the integer type codes above. 3118** ^The C argument is a copy of the context pointer passed in as the 3119** fourth argument to [sqlite3_trace_v2()]. 3120** The P and X arguments are pointers whose meanings depend on T. 3121** 3122** <dl> 3123** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt> 3124** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement 3125** first begins running and possibly at other times during the 3126** execution of the prepared statement, such as at the start of each 3127** trigger subprogram. ^The P argument is a pointer to the 3128** [prepared statement]. ^The X argument is a pointer to a string which 3129** is the unexpanded SQL text of the prepared statement or an SQL comment 3130** that indicates the invocation of a trigger. ^The callback can compute 3131** the same text that would have been returned by the legacy [sqlite3_trace()] 3132** interface by using the X argument when X begins with "--" and invoking 3133** [sqlite3_expanded_sql(P)] otherwise. 3134** 3135** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt> 3136** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same 3137** information as is provided by the [sqlite3_profile()] callback. 3138** ^The P argument is a pointer to the [prepared statement] and the 3139** X argument points to a 64-bit integer which is the estimated of 3140** the number of nanosecond that the prepared statement took to run. 3141** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes. 3142** 3143** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt> 3144** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared 3145** statement generates a single row of result. 3146** ^The P argument is a pointer to the [prepared statement] and the 3147** X argument is unused. 3148** 3149** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt> 3150** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database 3151** connection closes. 3152** ^The P argument is a pointer to the [database connection] object 3153** and the X argument is unused. 3154** </dl> 3155*/ 3156#define SQLITE_TRACE_STMT 0x01 3157#define SQLITE_TRACE_PROFILE 0x02 3158#define SQLITE_TRACE_ROW 0x04 3159#define SQLITE_TRACE_CLOSE 0x08 3160 3161/* 3162** CAPI3REF: SQL Trace Hook 3163** METHOD: sqlite3 3164** 3165** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback 3166** function X against [database connection] D, using property mask M 3167** and context pointer P. ^If the X callback is 3168** NULL or if the M mask is zero, then tracing is disabled. The 3169** M argument should be the bitwise OR-ed combination of 3170** zero or more [SQLITE_TRACE] constants. 3171** 3172** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides 3173** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2(). 3174** 3175** ^The X callback is invoked whenever any of the events identified by 3176** mask M occur. ^The integer return value from the callback is currently 3177** ignored, though this may change in future releases. Callback 3178** implementations should return zero to ensure future compatibility. 3179** 3180** ^A trace callback is invoked with four arguments: callback(T,C,P,X). 3181** ^The T argument is one of the [SQLITE_TRACE] 3182** constants to indicate why the callback was invoked. 3183** ^The C argument is a copy of the context pointer. 3184** The P and X arguments are pointers whose meanings depend on T. 3185** 3186** The sqlite3_trace_v2() interface is intended to replace the legacy 3187** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which 3188** are deprecated. 3189*/ 3190int sqlite3_trace_v2( 3191 sqlite3*, 3192 unsigned uMask, 3193 int(*xCallback)(unsigned,void*,void*,void*), 3194 void *pCtx 3195); 3196 3197/* 3198** CAPI3REF: Query Progress Callbacks 3199** METHOD: sqlite3 3200** 3201** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 3202** function X to be invoked periodically during long running calls to 3203** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 3204** database connection D. An example use for this 3205** interface is to keep a GUI updated during a large query. 3206** 3207** ^The parameter P is passed through as the only parameter to the 3208** callback function X. ^The parameter N is the approximate number of 3209** [virtual machine instructions] that are evaluated between successive 3210** invocations of the callback X. ^If N is less than one then the progress 3211** handler is disabled. 3212** 3213** ^Only a single progress handler may be defined at one time per 3214** [database connection]; setting a new progress handler cancels the 3215** old one. ^Setting parameter X to NULL disables the progress handler. 3216** ^The progress handler is also disabled by setting N to a value less 3217** than 1. 3218** 3219** ^If the progress callback returns non-zero, the operation is 3220** interrupted. This feature can be used to implement a 3221** "Cancel" button on a GUI progress dialog box. 3222** 3223** The progress handler callback must not do anything that will modify 3224** the database connection that invoked the progress handler. 3225** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 3226** database connections for the meaning of "modify" in this paragraph. 3227** 3228*/ 3229void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 3230 3231/* 3232** CAPI3REF: Opening A New Database Connection 3233** CONSTRUCTOR: sqlite3 3234** 3235** ^These routines open an SQLite database file as specified by the 3236** filename argument. ^The filename argument is interpreted as UTF-8 for 3237** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 3238** order for sqlite3_open16(). ^(A [database connection] handle is usually 3239** returned in *ppDb, even if an error occurs. The only exception is that 3240** if SQLite is unable to allocate memory to hold the [sqlite3] object, 3241** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 3242** object.)^ ^(If the database is opened (and/or created) successfully, then 3243** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 3244** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 3245** an English language description of the error following a failure of any 3246** of the sqlite3_open() routines. 3247** 3248** ^The default encoding will be UTF-8 for databases created using 3249** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases 3250** created using sqlite3_open16() will be UTF-16 in the native byte order. 3251** 3252** Whether or not an error occurs when it is opened, resources 3253** associated with the [database connection] handle should be released by 3254** passing it to [sqlite3_close()] when it is no longer required. 3255** 3256** The sqlite3_open_v2() interface works like sqlite3_open() 3257** except that it accepts two additional parameters for additional control 3258** over the new database connection. ^(The flags parameter to 3259** sqlite3_open_v2() can take one of 3260** the following three values, optionally combined with the 3261** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 3262** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 3263** 3264** <dl> 3265** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 3266** <dd>The database is opened in read-only mode. If the database does not 3267** already exist, an error is returned.</dd>)^ 3268** 3269** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 3270** <dd>The database is opened for reading and writing if possible, or reading 3271** only if the file is write protected by the operating system. In either 3272** case the database must already exist, otherwise an error is returned.</dd>)^ 3273** 3274** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 3275** <dd>The database is opened for reading and writing, and is created if 3276** it does not already exist. This is the behavior that is always used for 3277** sqlite3_open() and sqlite3_open16().</dd>)^ 3278** </dl> 3279** 3280** If the 3rd parameter to sqlite3_open_v2() is not one of the 3281** combinations shown above optionally combined with other 3282** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 3283** then the behavior is undefined. 3284** 3285** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 3286** opens in the multi-thread [threading mode] as long as the single-thread 3287** mode has not been set at compile-time or start-time. ^If the 3288** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 3289** in the serialized [threading mode] unless single-thread was 3290** previously selected at compile-time or start-time. 3291** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 3292** eligible to use [shared cache mode], regardless of whether or not shared 3293** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 3294** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 3295** participate in [shared cache mode] even if it is enabled. 3296** 3297** ^The fourth parameter to sqlite3_open_v2() is the name of the 3298** [sqlite3_vfs] object that defines the operating system interface that 3299** the new database connection should use. ^If the fourth parameter is 3300** a NULL pointer then the default [sqlite3_vfs] object is used. 3301** 3302** ^If the filename is ":memory:", then a private, temporary in-memory database 3303** is created for the connection. ^This in-memory database will vanish when 3304** the database connection is closed. Future versions of SQLite might 3305** make use of additional special filenames that begin with the ":" character. 3306** It is recommended that when a database filename actually does begin with 3307** a ":" character you should prefix the filename with a pathname such as 3308** "./" to avoid ambiguity. 3309** 3310** ^If the filename is an empty string, then a private, temporary 3311** on-disk database will be created. ^This private database will be 3312** automatically deleted as soon as the database connection is closed. 3313** 3314** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 3315** 3316** ^If [URI filename] interpretation is enabled, and the filename argument 3317** begins with "file:", then the filename is interpreted as a URI. ^URI 3318** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 3319** set in the third argument to sqlite3_open_v2(), or if it has 3320** been enabled globally using the [SQLITE_CONFIG_URI] option with the 3321** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 3322** URI filename interpretation is turned off 3323** by default, but future releases of SQLite might enable URI filename 3324** interpretation by default. See "[URI filenames]" for additional 3325** information. 3326** 3327** URI filenames are parsed according to RFC 3986. ^If the URI contains an 3328** authority, then it must be either an empty string or the string 3329** "localhost". ^If the authority is not an empty string or "localhost", an 3330** error is returned to the caller. ^The fragment component of a URI, if 3331** present, is ignored. 3332** 3333** ^SQLite uses the path component of the URI as the name of the disk file 3334** which contains the database. ^If the path begins with a '/' character, 3335** then it is interpreted as an absolute path. ^If the path does not begin 3336** with a '/' (meaning that the authority section is omitted from the URI) 3337** then the path is interpreted as a relative path. 3338** ^(On windows, the first component of an absolute path 3339** is a drive specification (e.g. "C:").)^ 3340** 3341** [[core URI query parameters]] 3342** The query component of a URI may contain parameters that are interpreted 3343** either by SQLite itself, or by a [VFS | custom VFS implementation]. 3344** SQLite and its built-in [VFSes] interpret the 3345** following query parameters: 3346** 3347** <ul> 3348** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 3349** a VFS object that provides the operating system interface that should 3350** be used to access the database file on disk. ^If this option is set to 3351** an empty string the default VFS object is used. ^Specifying an unknown 3352** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 3353** present, then the VFS specified by the option takes precedence over 3354** the value passed as the fourth parameter to sqlite3_open_v2(). 3355** 3356** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 3357** "rwc", or "memory". Attempting to set it to any other value is 3358** an error)^. 3359** ^If "ro" is specified, then the database is opened for read-only 3360** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 3361** third argument to sqlite3_open_v2(). ^If the mode option is set to 3362** "rw", then the database is opened for read-write (but not create) 3363** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 3364** been set. ^Value "rwc" is equivalent to setting both 3365** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 3366** set to "memory" then a pure [in-memory database] that never reads 3367** or writes from disk is used. ^It is an error to specify a value for 3368** the mode parameter that is less restrictive than that specified by 3369** the flags passed in the third parameter to sqlite3_open_v2(). 3370** 3371** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 3372** "private". ^Setting it to "shared" is equivalent to setting the 3373** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 3374** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 3375** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 3376** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 3377** a URI filename, its value overrides any behavior requested by setting 3378** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 3379** 3380** <li> <b>psow</b>: ^The psow parameter indicates whether or not the 3381** [powersafe overwrite] property does or does not apply to the 3382** storage media on which the database file resides. 3383** 3384** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 3385** which if set disables file locking in rollback journal modes. This 3386** is useful for accessing a database on a filesystem that does not 3387** support locking. Caution: Database corruption might result if two 3388** or more processes write to the same database and any one of those 3389** processes uses nolock=1. 3390** 3391** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 3392** parameter that indicates that the database file is stored on 3393** read-only media. ^When immutable is set, SQLite assumes that the 3394** database file cannot be changed, even by a process with higher 3395** privilege, and so the database is opened read-only and all locking 3396** and change detection is disabled. Caution: Setting the immutable 3397** property on a database file that does in fact change can result 3398** in incorrect query results and/or [SQLITE_CORRUPT] errors. 3399** See also: [SQLITE_IOCAP_IMMUTABLE]. 3400** 3401** </ul> 3402** 3403** ^Specifying an unknown parameter in the query component of a URI is not an 3404** error. Future versions of SQLite might understand additional query 3405** parameters. See "[query parameters with special meaning to SQLite]" for 3406** additional information. 3407** 3408** [[URI filename examples]] <h3>URI filename examples</h3> 3409** 3410** <table border="1" align=center cellpadding=5> 3411** <tr><th> URI filenames <th> Results 3412** <tr><td> file:data.db <td> 3413** Open the file "data.db" in the current directory. 3414** <tr><td> file:/home/fred/data.db<br> 3415** file:///home/fred/data.db <br> 3416** file://localhost/home/fred/data.db <br> <td> 3417** Open the database file "/home/fred/data.db". 3418** <tr><td> file://darkstar/home/fred/data.db <td> 3419** An error. "darkstar" is not a recognized authority. 3420** <tr><td style="white-space:nowrap"> 3421** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 3422** <td> Windows only: Open the file "data.db" on fred's desktop on drive 3423** C:. Note that the %20 escaping in this example is not strictly 3424** necessary - space characters can be used literally 3425** in URI filenames. 3426** <tr><td> file:data.db?mode=ro&cache=private <td> 3427** Open file "data.db" in the current directory for read-only access. 3428** Regardless of whether or not shared-cache mode is enabled by 3429** default, use a private cache. 3430** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 3431** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 3432** that uses dot-files in place of posix advisory locking. 3433** <tr><td> file:data.db?mode=readonly <td> 3434** An error. "readonly" is not a valid option for the "mode" parameter. 3435** </table> 3436** 3437** ^URI hexadecimal escape sequences (%HH) are supported within the path and 3438** query components of a URI. A hexadecimal escape sequence consists of a 3439** percent sign - "%" - followed by exactly two hexadecimal digits 3440** specifying an octet value. ^Before the path or query components of a 3441** URI filename are interpreted, they are encoded using UTF-8 and all 3442** hexadecimal escape sequences replaced by a single byte containing the 3443** corresponding octet. If this process generates an invalid UTF-8 encoding, 3444** the results are undefined. 3445** 3446** <b>Note to Windows users:</b> The encoding used for the filename argument 3447** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 3448** codepage is currently defined. Filenames containing international 3449** characters must be converted to UTF-8 prior to passing them into 3450** sqlite3_open() or sqlite3_open_v2(). 3451** 3452** <b>Note to Windows Runtime users:</b> The temporary directory must be set 3453** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 3454** features that require the use of temporary files may fail. 3455** 3456** See also: [sqlite3_temp_directory] 3457*/ 3458int sqlite3_open( 3459 const char *filename, /* Database filename (UTF-8) */ 3460 sqlite3 **ppDb /* OUT: SQLite db handle */ 3461); 3462int sqlite3_open16( 3463 const void *filename, /* Database filename (UTF-16) */ 3464 sqlite3 **ppDb /* OUT: SQLite db handle */ 3465); 3466int sqlite3_open_v2( 3467 const char *filename, /* Database filename (UTF-8) */ 3468 sqlite3 **ppDb, /* OUT: SQLite db handle */ 3469 int flags, /* Flags */ 3470 const char *zVfs /* Name of VFS module to use */ 3471); 3472 3473/* 3474** CAPI3REF: Obtain Values For URI Parameters 3475** 3476** These are utility routines, useful to VFS implementations, that check 3477** to see if a database file was a URI that contained a specific query 3478** parameter, and if so obtains the value of that query parameter. 3479** 3480** If F is the database filename pointer passed into the xOpen() method of 3481** a VFS implementation when the flags parameter to xOpen() has one or 3482** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3483** P is the name of the query parameter, then 3484** sqlite3_uri_parameter(F,P) returns the value of the P 3485** parameter if it exists or a NULL pointer if P does not appear as a 3486** query parameter on F. If P is a query parameter of F and it 3487** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3488** a pointer to an empty string. 3489** 3490** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3491** parameter and returns true (1) or false (0) according to the value 3492** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3493** value of query parameter P is one of "yes", "true", or "on" in any 3494** case or if the value begins with a non-zero number. The 3495** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3496** query parameter P is one of "no", "false", or "off" in any case or 3497** if the value begins with a numeric zero. If P is not a query 3498** parameter on F or if the value of P does not match any of the 3499** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3500** 3501** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3502** 64-bit signed integer and returns that integer, or D if P does not 3503** exist. If the value of P is something other than an integer, then 3504** zero is returned. 3505** 3506** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3507** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3508** is not a database file pathname pointer that SQLite passed into the xOpen 3509** VFS method, then the behavior of this routine is undefined and probably 3510** undesirable. 3511** 3512** See the [URI filename] documentation for additional information. 3513*/ 3514const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3515int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3516sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3517 3518 3519/* 3520** CAPI3REF: Error Codes And Messages 3521** METHOD: sqlite3 3522** 3523** ^If the most recent sqlite3_* API call associated with 3524** [database connection] D failed, then the sqlite3_errcode(D) interface 3525** returns the numeric [result code] or [extended result code] for that 3526** API call. 3527** ^The sqlite3_extended_errcode() 3528** interface is the same except that it always returns the 3529** [extended result code] even when extended result codes are 3530** disabled. 3531** 3532** The values returned by sqlite3_errcode() and/or 3533** sqlite3_extended_errcode() might change with each API call. 3534** Except, there are some interfaces that are guaranteed to never 3535** change the value of the error code. The error-code preserving 3536** interfaces are: 3537** 3538** <ul> 3539** <li> sqlite3_errcode() 3540** <li> sqlite3_extended_errcode() 3541** <li> sqlite3_errmsg() 3542** <li> sqlite3_errmsg16() 3543** </ul> 3544** 3545** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3546** text that describes the error, as either UTF-8 or UTF-16 respectively. 3547** ^(Memory to hold the error message string is managed internally. 3548** The application does not need to worry about freeing the result. 3549** However, the error string might be overwritten or deallocated by 3550** subsequent calls to other SQLite interface functions.)^ 3551** 3552** ^The sqlite3_errstr() interface returns the English-language text 3553** that describes the [result code], as UTF-8. 3554** ^(Memory to hold the error message string is managed internally 3555** and must not be freed by the application)^. 3556** 3557** When the serialized [threading mode] is in use, it might be the 3558** case that a second error occurs on a separate thread in between 3559** the time of the first error and the call to these interfaces. 3560** When that happens, the second error will be reported since these 3561** interfaces always report the most recent result. To avoid 3562** this, each thread can obtain exclusive use of the [database connection] D 3563** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3564** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3565** all calls to the interfaces listed here are completed. 3566** 3567** If an interface fails with SQLITE_MISUSE, that means the interface 3568** was invoked incorrectly by the application. In that case, the 3569** error code and message may or may not be set. 3570*/ 3571int sqlite3_errcode(sqlite3 *db); 3572int sqlite3_extended_errcode(sqlite3 *db); 3573const char *sqlite3_errmsg(sqlite3*); 3574const void *sqlite3_errmsg16(sqlite3*); 3575const char *sqlite3_errstr(int); 3576 3577/* 3578** CAPI3REF: Prepared Statement Object 3579** KEYWORDS: {prepared statement} {prepared statements} 3580** 3581** An instance of this object represents a single SQL statement that 3582** has been compiled into binary form and is ready to be evaluated. 3583** 3584** Think of each SQL statement as a separate computer program. The 3585** original SQL text is source code. A prepared statement object 3586** is the compiled object code. All SQL must be converted into a 3587** prepared statement before it can be run. 3588** 3589** The life-cycle of a prepared statement object usually goes like this: 3590** 3591** <ol> 3592** <li> Create the prepared statement object using [sqlite3_prepare_v2()]. 3593** <li> Bind values to [parameters] using the sqlite3_bind_*() 3594** interfaces. 3595** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3596** <li> Reset the prepared statement using [sqlite3_reset()] then go back 3597** to step 2. Do this zero or more times. 3598** <li> Destroy the object using [sqlite3_finalize()]. 3599** </ol> 3600*/ 3601typedef struct sqlite3_stmt sqlite3_stmt; 3602 3603/* 3604** CAPI3REF: Run-time Limits 3605** METHOD: sqlite3 3606** 3607** ^(This interface allows the size of various constructs to be limited 3608** on a connection by connection basis. The first parameter is the 3609** [database connection] whose limit is to be set or queried. The 3610** second parameter is one of the [limit categories] that define a 3611** class of constructs to be size limited. The third parameter is the 3612** new limit for that construct.)^ 3613** 3614** ^If the new limit is a negative number, the limit is unchanged. 3615** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3616** [limits | hard upper bound] 3617** set at compile-time by a C preprocessor macro called 3618** [limits | SQLITE_MAX_<i>NAME</i>]. 3619** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3620** ^Attempts to increase a limit above its hard upper bound are 3621** silently truncated to the hard upper bound. 3622** 3623** ^Regardless of whether or not the limit was changed, the 3624** [sqlite3_limit()] interface returns the prior value of the limit. 3625** ^Hence, to find the current value of a limit without changing it, 3626** simply invoke this interface with the third parameter set to -1. 3627** 3628** Run-time limits are intended for use in applications that manage 3629** both their own internal database and also databases that are controlled 3630** by untrusted external sources. An example application might be a 3631** web browser that has its own databases for storing history and 3632** separate databases controlled by JavaScript applications downloaded 3633** off the Internet. The internal databases can be given the 3634** large, default limits. Databases managed by external sources can 3635** be given much smaller limits designed to prevent a denial of service 3636** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3637** interface to further control untrusted SQL. The size of the database 3638** created by an untrusted script can be contained using the 3639** [max_page_count] [PRAGMA]. 3640** 3641** New run-time limit categories may be added in future releases. 3642*/ 3643int sqlite3_limit(sqlite3*, int id, int newVal); 3644 3645/* 3646** CAPI3REF: Run-Time Limit Categories 3647** KEYWORDS: {limit category} {*limit categories} 3648** 3649** These constants define various performance limits 3650** that can be lowered at run-time using [sqlite3_limit()]. 3651** The synopsis of the meanings of the various limits is shown below. 3652** Additional information is available at [limits | Limits in SQLite]. 3653** 3654** <dl> 3655** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3656** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3657** 3658** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3659** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3660** 3661** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3662** <dd>The maximum number of columns in a table definition or in the 3663** result set of a [SELECT] or the maximum number of columns in an index 3664** or in an ORDER BY or GROUP BY clause.</dd>)^ 3665** 3666** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3667** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3668** 3669** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3670** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3671** 3672** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3673** <dd>The maximum number of instructions in a virtual machine program 3674** used to implement an SQL statement. If [sqlite3_prepare_v2()] or 3675** the equivalent tries to allocate space for more than this many opcodes 3676** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^ 3677** 3678** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3679** <dd>The maximum number of arguments on a function.</dd>)^ 3680** 3681** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3682** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3683** 3684** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3685** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3686** <dd>The maximum length of the pattern argument to the [LIKE] or 3687** [GLOB] operators.</dd>)^ 3688** 3689** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3690** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3691** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3692** 3693** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3694** <dd>The maximum depth of recursion for triggers.</dd>)^ 3695** 3696** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt> 3697** <dd>The maximum number of auxiliary worker threads that a single 3698** [prepared statement] may start.</dd>)^ 3699** </dl> 3700*/ 3701#define SQLITE_LIMIT_LENGTH 0 3702#define SQLITE_LIMIT_SQL_LENGTH 1 3703#define SQLITE_LIMIT_COLUMN 2 3704#define SQLITE_LIMIT_EXPR_DEPTH 3 3705#define SQLITE_LIMIT_COMPOUND_SELECT 4 3706#define SQLITE_LIMIT_VDBE_OP 5 3707#define SQLITE_LIMIT_FUNCTION_ARG 6 3708#define SQLITE_LIMIT_ATTACHED 7 3709#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3710#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3711#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3712#define SQLITE_LIMIT_WORKER_THREADS 11 3713 3714/* 3715** CAPI3REF: Prepare Flags 3716** 3717** These constants define various flags that can be passed into 3718** "prepFlags" parameter of the [sqlite3_prepare_v3()] and 3719** [sqlite3_prepare16_v3()] interfaces. 3720** 3721** New flags may be added in future releases of SQLite. 3722** 3723** <dl> 3724** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt> 3725** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner 3726** that the prepared statement will be retained for a long time and 3727** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()] 3728** and [sqlite3_prepare16_v3()] assume that the prepared statement will 3729** be used just once or at most a few times and then destroyed using 3730** [sqlite3_finalize()] relatively soon. The current implementation acts 3731** on this hint by avoiding the use of [lookaside memory] so as not to 3732** deplete the limited store of lookaside memory. Future versions of 3733** SQLite may act on this hint differently. 3734** 3735** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt> 3736** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used 3737** to be required for any prepared statement that wanted to use the 3738** [sqlite3_normalized_sql()] interface. However, the 3739** [sqlite3_normalized_sql()] interface is now available to all 3740** prepared statements, regardless of whether or not they use this 3741** flag. 3742** 3743** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt> 3744** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler 3745** to return an error (error code SQLITE_ERROR) if the statement uses 3746** any virtual tables. 3747** </dl> 3748*/ 3749#define SQLITE_PREPARE_PERSISTENT 0x01 3750#define SQLITE_PREPARE_NORMALIZE 0x02 3751#define SQLITE_PREPARE_NO_VTAB 0x04 3752 3753/* 3754** CAPI3REF: Compiling An SQL Statement 3755** KEYWORDS: {SQL statement compiler} 3756** METHOD: sqlite3 3757** CONSTRUCTOR: sqlite3_stmt 3758** 3759** To execute an SQL statement, it must first be compiled into a byte-code 3760** program using one of these routines. Or, in other words, these routines 3761** are constructors for the [prepared statement] object. 3762** 3763** The preferred routine to use is [sqlite3_prepare_v2()]. The 3764** [sqlite3_prepare()] interface is legacy and should be avoided. 3765** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used 3766** for special purposes. 3767** 3768** The use of the UTF-8 interfaces is preferred, as SQLite currently 3769** does all parsing using UTF-8. The UTF-16 interfaces are provided 3770** as a convenience. The UTF-16 interfaces work by converting the 3771** input text into UTF-8, then invoking the corresponding UTF-8 interface. 3772** 3773** The first argument, "db", is a [database connection] obtained from a 3774** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3775** [sqlite3_open16()]. The database connection must not have been closed. 3776** 3777** The second argument, "zSql", is the statement to be compiled, encoded 3778** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(), 3779** and sqlite3_prepare_v3() 3780** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(), 3781** and sqlite3_prepare16_v3() use UTF-16. 3782** 3783** ^If the nByte argument is negative, then zSql is read up to the 3784** first zero terminator. ^If nByte is positive, then it is the 3785** number of bytes read from zSql. ^If nByte is zero, then no prepared 3786** statement is generated. 3787** If the caller knows that the supplied string is nul-terminated, then 3788** there is a small performance advantage to passing an nByte parameter that 3789** is the number of bytes in the input string <i>including</i> 3790** the nul-terminator. 3791** 3792** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3793** past the end of the first SQL statement in zSql. These routines only 3794** compile the first statement in zSql, so *pzTail is left pointing to 3795** what remains uncompiled. 3796** 3797** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3798** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3799** to NULL. ^If the input text contains no SQL (if the input is an empty 3800** string or a comment) then *ppStmt is set to NULL. 3801** The calling procedure is responsible for deleting the compiled 3802** SQL statement using [sqlite3_finalize()] after it has finished with it. 3803** ppStmt may not be NULL. 3804** 3805** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3806** otherwise an [error code] is returned. 3807** 3808** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(), 3809** and sqlite3_prepare16_v3() interfaces are recommended for all new programs. 3810** The older interfaces (sqlite3_prepare() and sqlite3_prepare16()) 3811** are retained for backwards compatibility, but their use is discouraged. 3812** ^In the "vX" interfaces, the prepared statement 3813** that is returned (the [sqlite3_stmt] object) contains a copy of the 3814** original SQL text. This causes the [sqlite3_step()] interface to 3815** behave differently in three ways: 3816** 3817** <ol> 3818** <li> 3819** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3820** always used to do, [sqlite3_step()] will automatically recompile the SQL 3821** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3822** retries will occur before sqlite3_step() gives up and returns an error. 3823** </li> 3824** 3825** <li> 3826** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3827** [error codes] or [extended error codes]. ^The legacy behavior was that 3828** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3829** and the application would have to make a second call to [sqlite3_reset()] 3830** in order to find the underlying cause of the problem. With the "v2" prepare 3831** interfaces, the underlying reason for the error is returned immediately. 3832** </li> 3833** 3834** <li> 3835** ^If the specific value bound to a [parameter | host parameter] in the 3836** WHERE clause might influence the choice of query plan for a statement, 3837** then the statement will be automatically recompiled, as if there had been 3838** a schema change, on the first [sqlite3_step()] call following any change 3839** to the [sqlite3_bind_text | bindings] of that [parameter]. 3840** ^The specific value of a WHERE-clause [parameter] might influence the 3841** choice of query plan if the parameter is the left-hand side of a [LIKE] 3842** or [GLOB] operator or if the parameter is compared to an indexed column 3843** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled. 3844** </li> 3845** </ol> 3846** 3847** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having 3848** the extra prepFlags parameter, which is a bit array consisting of zero or 3849** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The 3850** sqlite3_prepare_v2() interface works exactly the same as 3851** sqlite3_prepare_v3() with a zero prepFlags parameter. 3852*/ 3853int sqlite3_prepare( 3854 sqlite3 *db, /* Database handle */ 3855 const char *zSql, /* SQL statement, UTF-8 encoded */ 3856 int nByte, /* Maximum length of zSql in bytes. */ 3857 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3858 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3859); 3860int sqlite3_prepare_v2( 3861 sqlite3 *db, /* Database handle */ 3862 const char *zSql, /* SQL statement, UTF-8 encoded */ 3863 int nByte, /* Maximum length of zSql in bytes. */ 3864 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3865 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3866); 3867int sqlite3_prepare_v3( 3868 sqlite3 *db, /* Database handle */ 3869 const char *zSql, /* SQL statement, UTF-8 encoded */ 3870 int nByte, /* Maximum length of zSql in bytes. */ 3871 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3872 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3873 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3874); 3875int sqlite3_prepare16( 3876 sqlite3 *db, /* Database handle */ 3877 const void *zSql, /* SQL statement, UTF-16 encoded */ 3878 int nByte, /* Maximum length of zSql in bytes. */ 3879 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3880 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3881); 3882int sqlite3_prepare16_v2( 3883 sqlite3 *db, /* Database handle */ 3884 const void *zSql, /* SQL statement, UTF-16 encoded */ 3885 int nByte, /* Maximum length of zSql in bytes. */ 3886 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3887 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3888); 3889int sqlite3_prepare16_v3( 3890 sqlite3 *db, /* Database handle */ 3891 const void *zSql, /* SQL statement, UTF-16 encoded */ 3892 int nByte, /* Maximum length of zSql in bytes. */ 3893 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */ 3894 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3895 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3896); 3897 3898/* 3899** CAPI3REF: Retrieving Statement SQL 3900** METHOD: sqlite3_stmt 3901** 3902** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8 3903** SQL text used to create [prepared statement] P if P was 3904** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], 3905** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 3906** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8 3907** string containing the SQL text of prepared statement P with 3908** [bound parameters] expanded. 3909** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8 3910** string containing the normalized SQL text of prepared statement P. The 3911** semantics used to normalize a SQL statement are unspecified and subject 3912** to change. At a minimum, literal values will be replaced with suitable 3913** placeholders. 3914** 3915** ^(For example, if a prepared statement is created using the SQL 3916** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345 3917** and parameter :xyz is unbound, then sqlite3_sql() will return 3918** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql() 3919** will return "SELECT 2345,NULL".)^ 3920** 3921** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory 3922** is available to hold the result, or if the result would exceed the 3923** the maximum string length determined by the [SQLITE_LIMIT_LENGTH]. 3924** 3925** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of 3926** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time 3927** option causes sqlite3_expanded_sql() to always return NULL. 3928** 3929** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P) 3930** are managed by SQLite and are automatically freed when the prepared 3931** statement is finalized. 3932** ^The string returned by sqlite3_expanded_sql(P), on the other hand, 3933** is obtained from [sqlite3_malloc()] and must be free by the application 3934** by passing it to [sqlite3_free()]. 3935*/ 3936const char *sqlite3_sql(sqlite3_stmt *pStmt); 3937char *sqlite3_expanded_sql(sqlite3_stmt *pStmt); 3938const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt); 3939 3940/* 3941** CAPI3REF: Determine If An SQL Statement Writes The Database 3942** METHOD: sqlite3_stmt 3943** 3944** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3945** and only if the [prepared statement] X makes no direct changes to 3946** the content of the database file. 3947** 3948** Note that [application-defined SQL functions] or 3949** [virtual tables] might change the database indirectly as a side effect. 3950** ^(For example, if an application defines a function "eval()" that 3951** calls [sqlite3_exec()], then the following SQL statement would 3952** change the database file through side-effects: 3953** 3954** <blockquote><pre> 3955** SELECT eval('DELETE FROM t1') FROM t2; 3956** </pre></blockquote> 3957** 3958** But because the [SELECT] statement does not change the database file 3959** directly, sqlite3_stmt_readonly() would still return true.)^ 3960** 3961** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3962** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3963** since the statements themselves do not actually modify the database but 3964** rather they control the timing of when other statements modify the 3965** database. ^The [ATTACH] and [DETACH] statements also cause 3966** sqlite3_stmt_readonly() to return true since, while those statements 3967** change the configuration of a database connection, they do not make 3968** changes to the content of the database files on disk. 3969** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since 3970** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and 3971** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so 3972** sqlite3_stmt_readonly() returns false for those commands. 3973*/ 3974int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3975 3976/* 3977** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement 3978** METHOD: sqlite3_stmt 3979** 3980** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the 3981** prepared statement S is an EXPLAIN statement, or 2 if the 3982** statement S is an EXPLAIN QUERY PLAN. 3983** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is 3984** an ordinary statement or a NULL pointer. 3985*/ 3986int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt); 3987 3988/* 3989** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3990** METHOD: sqlite3_stmt 3991** 3992** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3993** [prepared statement] S has been stepped at least once using 3994** [sqlite3_step(S)] but has neither run to completion (returned 3995** [SQLITE_DONE] from [sqlite3_step(S)]) nor 3996** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3997** interface returns false if S is a NULL pointer. If S is not a 3998** NULL pointer and is not a pointer to a valid [prepared statement] 3999** object, then the behavior is undefined and probably undesirable. 4000** 4001** This interface can be used in combination [sqlite3_next_stmt()] 4002** to locate all prepared statements associated with a database 4003** connection that are in need of being reset. This can be used, 4004** for example, in diagnostic routines to search for prepared 4005** statements that are holding a transaction open. 4006*/ 4007int sqlite3_stmt_busy(sqlite3_stmt*); 4008 4009/* 4010** CAPI3REF: Dynamically Typed Value Object 4011** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 4012** 4013** SQLite uses the sqlite3_value object to represent all values 4014** that can be stored in a database table. SQLite uses dynamic typing 4015** for the values it stores. ^Values stored in sqlite3_value objects 4016** can be integers, floating point values, strings, BLOBs, or NULL. 4017** 4018** An sqlite3_value object may be either "protected" or "unprotected". 4019** Some interfaces require a protected sqlite3_value. Other interfaces 4020** will accept either a protected or an unprotected sqlite3_value. 4021** Every interface that accepts sqlite3_value arguments specifies 4022** whether or not it requires a protected sqlite3_value. The 4023** [sqlite3_value_dup()] interface can be used to construct a new 4024** protected sqlite3_value from an unprotected sqlite3_value. 4025** 4026** The terms "protected" and "unprotected" refer to whether or not 4027** a mutex is held. An internal mutex is held for a protected 4028** sqlite3_value object but no mutex is held for an unprotected 4029** sqlite3_value object. If SQLite is compiled to be single-threaded 4030** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 4031** or if SQLite is run in one of reduced mutex modes 4032** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 4033** then there is no distinction between protected and unprotected 4034** sqlite3_value objects and they can be used interchangeably. However, 4035** for maximum code portability it is recommended that applications 4036** still make the distinction between protected and unprotected 4037** sqlite3_value objects even when not strictly required. 4038** 4039** ^The sqlite3_value objects that are passed as parameters into the 4040** implementation of [application-defined SQL functions] are protected. 4041** ^The sqlite3_value object returned by 4042** [sqlite3_column_value()] is unprotected. 4043** Unprotected sqlite3_value objects may only be used as arguments 4044** to [sqlite3_result_value()], [sqlite3_bind_value()], and 4045** [sqlite3_value_dup()]. 4046** The [sqlite3_value_blob | sqlite3_value_type()] family of 4047** interfaces require protected sqlite3_value objects. 4048*/ 4049typedef struct sqlite3_value sqlite3_value; 4050 4051/* 4052** CAPI3REF: SQL Function Context Object 4053** 4054** The context in which an SQL function executes is stored in an 4055** sqlite3_context object. ^A pointer to an sqlite3_context object 4056** is always first parameter to [application-defined SQL functions]. 4057** The application-defined SQL function implementation will pass this 4058** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 4059** [sqlite3_aggregate_context()], [sqlite3_user_data()], 4060** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 4061** and/or [sqlite3_set_auxdata()]. 4062*/ 4063typedef struct sqlite3_context sqlite3_context; 4064 4065/* 4066** CAPI3REF: Binding Values To Prepared Statements 4067** KEYWORDS: {host parameter} {host parameters} {host parameter name} 4068** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 4069** METHOD: sqlite3_stmt 4070** 4071** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 4072** literals may be replaced by a [parameter] that matches one of following 4073** templates: 4074** 4075** <ul> 4076** <li> ? 4077** <li> ?NNN 4078** <li> :VVV 4079** <li> @VVV 4080** <li> $VVV 4081** </ul> 4082** 4083** In the templates above, NNN represents an integer literal, 4084** and VVV represents an alphanumeric identifier.)^ ^The values of these 4085** parameters (also called "host parameter names" or "SQL parameters") 4086** can be set using the sqlite3_bind_*() routines defined here. 4087** 4088** ^The first argument to the sqlite3_bind_*() routines is always 4089** a pointer to the [sqlite3_stmt] object returned from 4090** [sqlite3_prepare_v2()] or its variants. 4091** 4092** ^The second argument is the index of the SQL parameter to be set. 4093** ^The leftmost SQL parameter has an index of 1. ^When the same named 4094** SQL parameter is used more than once, second and subsequent 4095** occurrences have the same index as the first occurrence. 4096** ^The index for named parameters can be looked up using the 4097** [sqlite3_bind_parameter_index()] API if desired. ^The index 4098** for "?NNN" parameters is the value of NNN. 4099** ^The NNN value must be between 1 and the [sqlite3_limit()] 4100** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 4101** 4102** ^The third argument is the value to bind to the parameter. 4103** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4104** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 4105** is ignored and the end result is the same as sqlite3_bind_null(). 4106** 4107** ^(In those routines that have a fourth argument, its value is the 4108** number of bytes in the parameter. To be clear: the value is the 4109** number of <u>bytes</u> in the value, not the number of characters.)^ 4110** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 4111** is negative, then the length of the string is 4112** the number of bytes up to the first zero terminator. 4113** If the fourth parameter to sqlite3_bind_blob() is negative, then 4114** the behavior is undefined. 4115** If a non-negative fourth parameter is provided to sqlite3_bind_text() 4116** or sqlite3_bind_text16() or sqlite3_bind_text64() then 4117** that parameter must be the byte offset 4118** where the NUL terminator would occur assuming the string were NUL 4119** terminated. If any NUL characters occur at byte offsets less than 4120** the value of the fourth parameter then the resulting string value will 4121** contain embedded NULs. The result of expressions involving strings 4122** with embedded NULs is undefined. 4123** 4124** ^The fifth argument to the BLOB and string binding interfaces 4125** is a destructor used to dispose of the BLOB or 4126** string after SQLite has finished with it. ^The destructor is called 4127** to dispose of the BLOB or string even if the call to the bind API fails, 4128** except the destructor is not called if the third parameter is a NULL 4129** pointer or the fourth parameter is negative. 4130** ^If the fifth argument is 4131** the special value [SQLITE_STATIC], then SQLite assumes that the 4132** information is in static, unmanaged space and does not need to be freed. 4133** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 4134** SQLite makes its own private copy of the data immediately, before 4135** the sqlite3_bind_*() routine returns. 4136** 4137** ^The sixth argument to sqlite3_bind_text64() must be one of 4138** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE] 4139** to specify the encoding of the text in the third parameter. If 4140** the sixth argument to sqlite3_bind_text64() is not one of the 4141** allowed values shown above, or if the text encoding is different 4142** from the encoding specified by the sixth parameter, then the behavior 4143** is undefined. 4144** 4145** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 4146** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 4147** (just an integer to hold its size) while it is being processed. 4148** Zeroblobs are intended to serve as placeholders for BLOBs whose 4149** content is later written using 4150** [sqlite3_blob_open | incremental BLOB I/O] routines. 4151** ^A negative value for the zeroblob results in a zero-length BLOB. 4152** 4153** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in 4154** [prepared statement] S to have an SQL value of NULL, but to also be 4155** associated with the pointer P of type T. ^D is either a NULL pointer or 4156** a pointer to a destructor function for P. ^SQLite will invoke the 4157** destructor D with a single argument of P when it is finished using 4158** P. The T parameter should be a static string, preferably a string 4159** literal. The sqlite3_bind_pointer() routine is part of the 4160** [pointer passing interface] added for SQLite 3.20.0. 4161** 4162** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 4163** for the [prepared statement] or with a prepared statement for which 4164** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 4165** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 4166** routine is passed a [prepared statement] that has been finalized, the 4167** result is undefined and probably harmful. 4168** 4169** ^Bindings are not cleared by the [sqlite3_reset()] routine. 4170** ^Unbound parameters are interpreted as NULL. 4171** 4172** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 4173** [error code] if anything goes wrong. 4174** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB 4175** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or 4176** [SQLITE_MAX_LENGTH]. 4177** ^[SQLITE_RANGE] is returned if the parameter 4178** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 4179** 4180** See also: [sqlite3_bind_parameter_count()], 4181** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 4182*/ 4183int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 4184int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64, 4185 void(*)(void*)); 4186int sqlite3_bind_double(sqlite3_stmt*, int, double); 4187int sqlite3_bind_int(sqlite3_stmt*, int, int); 4188int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 4189int sqlite3_bind_null(sqlite3_stmt*, int); 4190int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*)); 4191int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 4192int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64, 4193 void(*)(void*), unsigned char encoding); 4194int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 4195int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*)); 4196int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 4197int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64); 4198 4199/* 4200** CAPI3REF: Number Of SQL Parameters 4201** METHOD: sqlite3_stmt 4202** 4203** ^This routine can be used to find the number of [SQL parameters] 4204** in a [prepared statement]. SQL parameters are tokens of the 4205** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 4206** placeholders for values that are [sqlite3_bind_blob | bound] 4207** to the parameters at a later time. 4208** 4209** ^(This routine actually returns the index of the largest (rightmost) 4210** parameter. For all forms except ?NNN, this will correspond to the 4211** number of unique parameters. If parameters of the ?NNN form are used, 4212** there may be gaps in the list.)^ 4213** 4214** See also: [sqlite3_bind_blob|sqlite3_bind()], 4215** [sqlite3_bind_parameter_name()], and 4216** [sqlite3_bind_parameter_index()]. 4217*/ 4218int sqlite3_bind_parameter_count(sqlite3_stmt*); 4219 4220/* 4221** CAPI3REF: Name Of A Host Parameter 4222** METHOD: sqlite3_stmt 4223** 4224** ^The sqlite3_bind_parameter_name(P,N) interface returns 4225** the name of the N-th [SQL parameter] in the [prepared statement] P. 4226** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 4227** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 4228** respectively. 4229** In other words, the initial ":" or "$" or "@" or "?" 4230** is included as part of the name.)^ 4231** ^Parameters of the form "?" without a following integer have no name 4232** and are referred to as "nameless" or "anonymous parameters". 4233** 4234** ^The first host parameter has an index of 1, not 0. 4235** 4236** ^If the value N is out of range or if the N-th parameter is 4237** nameless, then NULL is returned. ^The returned string is 4238** always in UTF-8 encoding even if the named parameter was 4239** originally specified as UTF-16 in [sqlite3_prepare16()], 4240** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()]. 4241** 4242** See also: [sqlite3_bind_blob|sqlite3_bind()], 4243** [sqlite3_bind_parameter_count()], and 4244** [sqlite3_bind_parameter_index()]. 4245*/ 4246const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 4247 4248/* 4249** CAPI3REF: Index Of A Parameter With A Given Name 4250** METHOD: sqlite3_stmt 4251** 4252** ^Return the index of an SQL parameter given its name. ^The 4253** index value returned is suitable for use as the second 4254** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 4255** is returned if no matching parameter is found. ^The parameter 4256** name must be given in UTF-8 even if the original statement 4257** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or 4258** [sqlite3_prepare16_v3()]. 4259** 4260** See also: [sqlite3_bind_blob|sqlite3_bind()], 4261** [sqlite3_bind_parameter_count()], and 4262** [sqlite3_bind_parameter_name()]. 4263*/ 4264int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 4265 4266/* 4267** CAPI3REF: Reset All Bindings On A Prepared Statement 4268** METHOD: sqlite3_stmt 4269** 4270** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 4271** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 4272** ^Use this routine to reset all host parameters to NULL. 4273*/ 4274int sqlite3_clear_bindings(sqlite3_stmt*); 4275 4276/* 4277** CAPI3REF: Number Of Columns In A Result Set 4278** METHOD: sqlite3_stmt 4279** 4280** ^Return the number of columns in the result set returned by the 4281** [prepared statement]. ^If this routine returns 0, that means the 4282** [prepared statement] returns no data (for example an [UPDATE]). 4283** ^However, just because this routine returns a positive number does not 4284** mean that one or more rows of data will be returned. ^A SELECT statement 4285** will always have a positive sqlite3_column_count() but depending on the 4286** WHERE clause constraints and the table content, it might return no rows. 4287** 4288** See also: [sqlite3_data_count()] 4289*/ 4290int sqlite3_column_count(sqlite3_stmt *pStmt); 4291 4292/* 4293** CAPI3REF: Column Names In A Result Set 4294** METHOD: sqlite3_stmt 4295** 4296** ^These routines return the name assigned to a particular column 4297** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 4298** interface returns a pointer to a zero-terminated UTF-8 string 4299** and sqlite3_column_name16() returns a pointer to a zero-terminated 4300** UTF-16 string. ^The first parameter is the [prepared statement] 4301** that implements the [SELECT] statement. ^The second parameter is the 4302** column number. ^The leftmost column is number 0. 4303** 4304** ^The returned string pointer is valid until either the [prepared statement] 4305** is destroyed by [sqlite3_finalize()] or until the statement is automatically 4306** reprepared by the first call to [sqlite3_step()] for a particular run 4307** or until the next call to 4308** sqlite3_column_name() or sqlite3_column_name16() on the same column. 4309** 4310** ^If sqlite3_malloc() fails during the processing of either routine 4311** (for example during a conversion from UTF-8 to UTF-16) then a 4312** NULL pointer is returned. 4313** 4314** ^The name of a result column is the value of the "AS" clause for 4315** that column, if there is an AS clause. If there is no AS clause 4316** then the name of the column is unspecified and may change from 4317** one release of SQLite to the next. 4318*/ 4319const char *sqlite3_column_name(sqlite3_stmt*, int N); 4320const void *sqlite3_column_name16(sqlite3_stmt*, int N); 4321 4322/* 4323** CAPI3REF: Source Of Data In A Query Result 4324** METHOD: sqlite3_stmt 4325** 4326** ^These routines provide a means to determine the database, table, and 4327** table column that is the origin of a particular result column in 4328** [SELECT] statement. 4329** ^The name of the database or table or column can be returned as 4330** either a UTF-8 or UTF-16 string. ^The _database_ routines return 4331** the database name, the _table_ routines return the table name, and 4332** the origin_ routines return the column name. 4333** ^The returned string is valid until the [prepared statement] is destroyed 4334** using [sqlite3_finalize()] or until the statement is automatically 4335** reprepared by the first call to [sqlite3_step()] for a particular run 4336** or until the same information is requested 4337** again in a different encoding. 4338** 4339** ^The names returned are the original un-aliased names of the 4340** database, table, and column. 4341** 4342** ^The first argument to these interfaces is a [prepared statement]. 4343** ^These functions return information about the Nth result column returned by 4344** the statement, where N is the second function argument. 4345** ^The left-most column is column 0 for these routines. 4346** 4347** ^If the Nth column returned by the statement is an expression or 4348** subquery and is not a column value, then all of these functions return 4349** NULL. ^These routines might also return NULL if a memory allocation error 4350** occurs. ^Otherwise, they return the name of the attached database, table, 4351** or column that query result column was extracted from. 4352** 4353** ^As with all other SQLite APIs, those whose names end with "16" return 4354** UTF-16 encoded strings and the other functions return UTF-8. 4355** 4356** ^These APIs are only available if the library was compiled with the 4357** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 4358** 4359** If two or more threads call one or more 4360** [sqlite3_column_database_name | column metadata interfaces] 4361** for the same [prepared statement] and result column 4362** at the same time then the results are undefined. 4363*/ 4364const char *sqlite3_column_database_name(sqlite3_stmt*,int); 4365const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 4366const char *sqlite3_column_table_name(sqlite3_stmt*,int); 4367const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 4368const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 4369const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 4370 4371/* 4372** CAPI3REF: Declared Datatype Of A Query Result 4373** METHOD: sqlite3_stmt 4374** 4375** ^(The first parameter is a [prepared statement]. 4376** If this statement is a [SELECT] statement and the Nth column of the 4377** returned result set of that [SELECT] is a table column (not an 4378** expression or subquery) then the declared type of the table 4379** column is returned.)^ ^If the Nth column of the result set is an 4380** expression or subquery, then a NULL pointer is returned. 4381** ^The returned string is always UTF-8 encoded. 4382** 4383** ^(For example, given the database schema: 4384** 4385** CREATE TABLE t1(c1 VARIANT); 4386** 4387** and the following statement to be compiled: 4388** 4389** SELECT c1 + 1, c1 FROM t1; 4390** 4391** this routine would return the string "VARIANT" for the second result 4392** column (i==1), and a NULL pointer for the first result column (i==0).)^ 4393** 4394** ^SQLite uses dynamic run-time typing. ^So just because a column 4395** is declared to contain a particular type does not mean that the 4396** data stored in that column is of the declared type. SQLite is 4397** strongly typed, but the typing is dynamic not static. ^Type 4398** is associated with individual values, not with the containers 4399** used to hold those values. 4400*/ 4401const char *sqlite3_column_decltype(sqlite3_stmt*,int); 4402const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 4403 4404/* 4405** CAPI3REF: Evaluate An SQL Statement 4406** METHOD: sqlite3_stmt 4407** 4408** After a [prepared statement] has been prepared using any of 4409** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()], 4410** or [sqlite3_prepare16_v3()] or one of the legacy 4411** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 4412** must be called one or more times to evaluate the statement. 4413** 4414** The details of the behavior of the sqlite3_step() interface depend 4415** on whether the statement was prepared using the newer "vX" interfaces 4416** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()], 4417** [sqlite3_prepare16_v2()] or the older legacy 4418** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 4419** new "vX" interface is recommended for new applications but the legacy 4420** interface will continue to be supported. 4421** 4422** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 4423** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 4424** ^With the "v2" interface, any of the other [result codes] or 4425** [extended result codes] might be returned as well. 4426** 4427** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 4428** database locks it needs to do its job. ^If the statement is a [COMMIT] 4429** or occurs outside of an explicit transaction, then you can retry the 4430** statement. If the statement is not a [COMMIT] and occurs within an 4431** explicit transaction then you should rollback the transaction before 4432** continuing. 4433** 4434** ^[SQLITE_DONE] means that the statement has finished executing 4435** successfully. sqlite3_step() should not be called again on this virtual 4436** machine without first calling [sqlite3_reset()] to reset the virtual 4437** machine back to its initial state. 4438** 4439** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 4440** is returned each time a new row of data is ready for processing by the 4441** caller. The values may be accessed using the [column access functions]. 4442** sqlite3_step() is called again to retrieve the next row of data. 4443** 4444** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 4445** violation) has occurred. sqlite3_step() should not be called again on 4446** the VM. More information may be found by calling [sqlite3_errmsg()]. 4447** ^With the legacy interface, a more specific error code (for example, 4448** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 4449** can be obtained by calling [sqlite3_reset()] on the 4450** [prepared statement]. ^In the "v2" interface, 4451** the more specific error code is returned directly by sqlite3_step(). 4452** 4453** [SQLITE_MISUSE] means that the this routine was called inappropriately. 4454** Perhaps it was called on a [prepared statement] that has 4455** already been [sqlite3_finalize | finalized] or on one that had 4456** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 4457** be the case that the same database connection is being used by two or 4458** more threads at the same moment in time. 4459** 4460** For all versions of SQLite up to and including 3.6.23.1, a call to 4461** [sqlite3_reset()] was required after sqlite3_step() returned anything 4462** other than [SQLITE_ROW] before any subsequent invocation of 4463** sqlite3_step(). Failure to reset the prepared statement using 4464** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 4465** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1], 4466** sqlite3_step() began 4467** calling [sqlite3_reset()] automatically in this circumstance rather 4468** than returning [SQLITE_MISUSE]. This is not considered a compatibility 4469** break because any application that ever receives an SQLITE_MISUSE error 4470** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 4471** can be used to restore the legacy behavior. 4472** 4473** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 4474** API always returns a generic error code, [SQLITE_ERROR], following any 4475** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 4476** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 4477** specific [error codes] that better describes the error. 4478** We admit that this is a goofy design. The problem has been fixed 4479** with the "v2" interface. If you prepare all of your SQL statements 4480** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()] 4481** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead 4482** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 4483** then the more specific [error codes] are returned directly 4484** by sqlite3_step(). The use of the "vX" interfaces is recommended. 4485*/ 4486int sqlite3_step(sqlite3_stmt*); 4487 4488/* 4489** CAPI3REF: Number of columns in a result set 4490** METHOD: sqlite3_stmt 4491** 4492** ^The sqlite3_data_count(P) interface returns the number of columns in the 4493** current row of the result set of [prepared statement] P. 4494** ^If prepared statement P does not have results ready to return 4495** (via calls to the [sqlite3_column_int | sqlite3_column()] family of 4496** interfaces) then sqlite3_data_count(P) returns 0. 4497** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 4498** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 4499** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 4500** will return non-zero if previous call to [sqlite3_step](P) returned 4501** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 4502** where it always returns zero since each step of that multi-step 4503** pragma returns 0 columns of data. 4504** 4505** See also: [sqlite3_column_count()] 4506*/ 4507int sqlite3_data_count(sqlite3_stmt *pStmt); 4508 4509/* 4510** CAPI3REF: Fundamental Datatypes 4511** KEYWORDS: SQLITE_TEXT 4512** 4513** ^(Every value in SQLite has one of five fundamental datatypes: 4514** 4515** <ul> 4516** <li> 64-bit signed integer 4517** <li> 64-bit IEEE floating point number 4518** <li> string 4519** <li> BLOB 4520** <li> NULL 4521** </ul>)^ 4522** 4523** These constants are codes for each of those types. 4524** 4525** Note that the SQLITE_TEXT constant was also used in SQLite version 2 4526** for a completely different meaning. Software that links against both 4527** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 4528** SQLITE_TEXT. 4529*/ 4530#define SQLITE_INTEGER 1 4531#define SQLITE_FLOAT 2 4532#define SQLITE_BLOB 4 4533#define SQLITE_NULL 5 4534#ifdef SQLITE_TEXT 4535# undef SQLITE_TEXT 4536#else 4537# define SQLITE_TEXT 3 4538#endif 4539#define SQLITE3_TEXT 3 4540 4541/* 4542** CAPI3REF: Result Values From A Query 4543** KEYWORDS: {column access functions} 4544** METHOD: sqlite3_stmt 4545** 4546** <b>Summary:</b> 4547** <blockquote><table border=0 cellpadding=0 cellspacing=0> 4548** <tr><td><b>sqlite3_column_blob</b><td>→<td>BLOB result 4549** <tr><td><b>sqlite3_column_double</b><td>→<td>REAL result 4550** <tr><td><b>sqlite3_column_int</b><td>→<td>32-bit INTEGER result 4551** <tr><td><b>sqlite3_column_int64</b><td>→<td>64-bit INTEGER result 4552** <tr><td><b>sqlite3_column_text</b><td>→<td>UTF-8 TEXT result 4553** <tr><td><b>sqlite3_column_text16</b><td>→<td>UTF-16 TEXT result 4554** <tr><td><b>sqlite3_column_value</b><td>→<td>The result as an 4555** [sqlite3_value|unprotected sqlite3_value] object. 4556** <tr><td> <td> <td> 4557** <tr><td><b>sqlite3_column_bytes</b><td>→<td>Size of a BLOB 4558** or a UTF-8 TEXT result in bytes 4559** <tr><td><b>sqlite3_column_bytes16 </b> 4560** <td>→ <td>Size of UTF-16 4561** TEXT in bytes 4562** <tr><td><b>sqlite3_column_type</b><td>→<td>Default 4563** datatype of the result 4564** </table></blockquote> 4565** 4566** <b>Details:</b> 4567** 4568** ^These routines return information about a single column of the current 4569** result row of a query. ^In every case the first argument is a pointer 4570** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 4571** that was returned from [sqlite3_prepare_v2()] or one of its variants) 4572** and the second argument is the index of the column for which information 4573** should be returned. ^The leftmost column of the result set has the index 0. 4574** ^The number of columns in the result can be determined using 4575** [sqlite3_column_count()]. 4576** 4577** If the SQL statement does not currently point to a valid row, or if the 4578** column index is out of range, the result is undefined. 4579** These routines may only be called when the most recent call to 4580** [sqlite3_step()] has returned [SQLITE_ROW] and neither 4581** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 4582** If any of these routines are called after [sqlite3_reset()] or 4583** [sqlite3_finalize()] or after [sqlite3_step()] has returned 4584** something other than [SQLITE_ROW], the results are undefined. 4585** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 4586** are called from a different thread while any of these routines 4587** are pending, then the results are undefined. 4588** 4589** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16) 4590** each return the value of a result column in a specific data format. If 4591** the result column is not initially in the requested format (for example, 4592** if the query returns an integer but the sqlite3_column_text() interface 4593** is used to extract the value) then an automatic type conversion is performed. 4594** 4595** ^The sqlite3_column_type() routine returns the 4596** [SQLITE_INTEGER | datatype code] for the initial data type 4597** of the result column. ^The returned value is one of [SQLITE_INTEGER], 4598** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. 4599** The return value of sqlite3_column_type() can be used to decide which 4600** of the first six interface should be used to extract the column value. 4601** The value returned by sqlite3_column_type() is only meaningful if no 4602** automatic type conversions have occurred for the value in question. 4603** After a type conversion, the result of calling sqlite3_column_type() 4604** is undefined, though harmless. Future 4605** versions of SQLite may change the behavior of sqlite3_column_type() 4606** following a type conversion. 4607** 4608** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes() 4609** or sqlite3_column_bytes16() interfaces can be used to determine the size 4610** of that BLOB or string. 4611** 4612** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 4613** routine returns the number of bytes in that BLOB or string. 4614** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 4615** the string to UTF-8 and then returns the number of bytes. 4616** ^If the result is a numeric value then sqlite3_column_bytes() uses 4617** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 4618** the number of bytes in that string. 4619** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 4620** 4621** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 4622** routine returns the number of bytes in that BLOB or string. 4623** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 4624** the string to UTF-16 and then returns the number of bytes. 4625** ^If the result is a numeric value then sqlite3_column_bytes16() uses 4626** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 4627** the number of bytes in that string. 4628** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 4629** 4630** ^The values returned by [sqlite3_column_bytes()] and 4631** [sqlite3_column_bytes16()] do not include the zero terminators at the end 4632** of the string. ^For clarity: the values returned by 4633** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 4634** bytes in the string, not the number of characters. 4635** 4636** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 4637** even empty strings, are always zero-terminated. ^The return 4638** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 4639** 4640** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an 4641** [unprotected sqlite3_value] object. In a multithreaded environment, 4642** an unprotected sqlite3_value object may only be used safely with 4643** [sqlite3_bind_value()] and [sqlite3_result_value()]. 4644** If the [unprotected sqlite3_value] object returned by 4645** [sqlite3_column_value()] is used in any other way, including calls 4646** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 4647** or [sqlite3_value_bytes()], the behavior is not threadsafe. 4648** Hence, the sqlite3_column_value() interface 4649** is normally only useful within the implementation of 4650** [application-defined SQL functions] or [virtual tables], not within 4651** top-level application code. 4652** 4653** The these routines may attempt to convert the datatype of the result. 4654** ^For example, if the internal representation is FLOAT and a text result 4655** is requested, [sqlite3_snprintf()] is used internally to perform the 4656** conversion automatically. ^(The following table details the conversions 4657** that are applied: 4658** 4659** <blockquote> 4660** <table border="1"> 4661** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 4662** 4663** <tr><td> NULL <td> INTEGER <td> Result is 0 4664** <tr><td> NULL <td> FLOAT <td> Result is 0.0 4665** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 4666** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 4667** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 4668** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 4669** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 4670** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 4671** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 4672** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 4673** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 4674** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 4675** <tr><td> TEXT <td> BLOB <td> No change 4676** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 4677** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 4678** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 4679** </table> 4680** </blockquote>)^ 4681** 4682** Note that when type conversions occur, pointers returned by prior 4683** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 4684** sqlite3_column_text16() may be invalidated. 4685** Type conversions and pointer invalidations might occur 4686** in the following cases: 4687** 4688** <ul> 4689** <li> The initial content is a BLOB and sqlite3_column_text() or 4690** sqlite3_column_text16() is called. A zero-terminator might 4691** need to be added to the string.</li> 4692** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 4693** sqlite3_column_text16() is called. The content must be converted 4694** to UTF-16.</li> 4695** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 4696** sqlite3_column_text() is called. The content must be converted 4697** to UTF-8.</li> 4698** </ul> 4699** 4700** ^Conversions between UTF-16be and UTF-16le are always done in place and do 4701** not invalidate a prior pointer, though of course the content of the buffer 4702** that the prior pointer references will have been modified. Other kinds 4703** of conversion are done in place when it is possible, but sometimes they 4704** are not possible and in those cases prior pointers are invalidated. 4705** 4706** The safest policy is to invoke these routines 4707** in one of the following ways: 4708** 4709** <ul> 4710** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4711** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4712** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4713** </ul> 4714** 4715** In other words, you should call sqlite3_column_text(), 4716** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4717** into the desired format, then invoke sqlite3_column_bytes() or 4718** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4719** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4720** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4721** with calls to sqlite3_column_bytes(). 4722** 4723** ^The pointers returned are valid until a type conversion occurs as 4724** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4725** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4726** and BLOBs is freed automatically. Do not pass the pointers returned 4727** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4728** [sqlite3_free()]. 4729** 4730** As long as the input parameters are correct, these routines will only 4731** fail if an out-of-memory error occurs during a format conversion. 4732** Only the following subset of interfaces are subject to out-of-memory 4733** errors: 4734** 4735** <ul> 4736** <li> sqlite3_column_blob() 4737** <li> sqlite3_column_text() 4738** <li> sqlite3_column_text16() 4739** <li> sqlite3_column_bytes() 4740** <li> sqlite3_column_bytes16() 4741** </ul> 4742** 4743** If an out-of-memory error occurs, then the return value from these 4744** routines is the same as if the column had contained an SQL NULL value. 4745** Valid SQL NULL returns can be distinguished from out-of-memory errors 4746** by invoking the [sqlite3_errcode()] immediately after the suspect 4747** return value is obtained and before any 4748** other SQLite interface is called on the same [database connection]. 4749*/ 4750const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4751double sqlite3_column_double(sqlite3_stmt*, int iCol); 4752int sqlite3_column_int(sqlite3_stmt*, int iCol); 4753sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4754const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4755const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4756sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4757int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4758int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4759int sqlite3_column_type(sqlite3_stmt*, int iCol); 4760 4761/* 4762** CAPI3REF: Destroy A Prepared Statement Object 4763** DESTRUCTOR: sqlite3_stmt 4764** 4765** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4766** ^If the most recent evaluation of the statement encountered no errors 4767** or if the statement is never been evaluated, then sqlite3_finalize() returns 4768** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4769** sqlite3_finalize(S) returns the appropriate [error code] or 4770** [extended error code]. 4771** 4772** ^The sqlite3_finalize(S) routine can be called at any point during 4773** the life cycle of [prepared statement] S: 4774** before statement S is ever evaluated, after 4775** one or more calls to [sqlite3_reset()], or after any call 4776** to [sqlite3_step()] regardless of whether or not the statement has 4777** completed execution. 4778** 4779** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4780** 4781** The application must finalize every [prepared statement] in order to avoid 4782** resource leaks. It is a grievous error for the application to try to use 4783** a prepared statement after it has been finalized. Any use of a prepared 4784** statement after it has been finalized can result in undefined and 4785** undesirable behavior such as segfaults and heap corruption. 4786*/ 4787int sqlite3_finalize(sqlite3_stmt *pStmt); 4788 4789/* 4790** CAPI3REF: Reset A Prepared Statement Object 4791** METHOD: sqlite3_stmt 4792** 4793** The sqlite3_reset() function is called to reset a [prepared statement] 4794** object back to its initial state, ready to be re-executed. 4795** ^Any SQL statement variables that had values bound to them using 4796** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4797** Use [sqlite3_clear_bindings()] to reset the bindings. 4798** 4799** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4800** back to the beginning of its program. 4801** 4802** ^If the most recent call to [sqlite3_step(S)] for the 4803** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4804** or if [sqlite3_step(S)] has never before been called on S, 4805** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4806** 4807** ^If the most recent call to [sqlite3_step(S)] for the 4808** [prepared statement] S indicated an error, then 4809** [sqlite3_reset(S)] returns an appropriate [error code]. 4810** 4811** ^The [sqlite3_reset(S)] interface does not change the values 4812** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4813*/ 4814int sqlite3_reset(sqlite3_stmt *pStmt); 4815 4816/* 4817** CAPI3REF: Create Or Redefine SQL Functions 4818** KEYWORDS: {function creation routines} 4819** KEYWORDS: {application-defined SQL function} 4820** KEYWORDS: {application-defined SQL functions} 4821** METHOD: sqlite3 4822** 4823** ^These functions (collectively known as "function creation routines") 4824** are used to add SQL functions or aggregates or to redefine the behavior 4825** of existing SQL functions or aggregates. The only differences between 4826** the three "sqlite3_create_function*" routines are the text encoding 4827** expected for the second parameter (the name of the function being 4828** created) and the presence or absence of a destructor callback for 4829** the application data pointer. Function sqlite3_create_window_function() 4830** is similar, but allows the user to supply the extra callback functions 4831** needed by [aggregate window functions]. 4832** 4833** ^The first parameter is the [database connection] to which the SQL 4834** function is to be added. ^If an application uses more than one database 4835** connection then application-defined SQL functions must be added 4836** to each database connection separately. 4837** 4838** ^The second parameter is the name of the SQL function to be created or 4839** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4840** representation, exclusive of the zero-terminator. ^Note that the name 4841** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4842** ^Any attempt to create a function with a longer name 4843** will result in [SQLITE_MISUSE] being returned. 4844** 4845** ^The third parameter (nArg) 4846** is the number of arguments that the SQL function or 4847** aggregate takes. ^If this parameter is -1, then the SQL function or 4848** aggregate may take any number of arguments between 0 and the limit 4849** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4850** parameter is less than -1 or greater than 127 then the behavior is 4851** undefined. 4852** 4853** ^The fourth parameter, eTextRep, specifies what 4854** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4855** its parameters. The application should set this parameter to 4856** [SQLITE_UTF16LE] if the function implementation invokes 4857** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4858** implementation invokes [sqlite3_value_text16be()] on an input, or 4859** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4860** otherwise. ^The same SQL function may be registered multiple times using 4861** different preferred text encodings, with different implementations for 4862** each encoding. 4863** ^When multiple implementations of the same function are available, SQLite 4864** will pick the one that involves the least amount of data conversion. 4865** 4866** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4867** to signal that the function will always return the same result given 4868** the same inputs within a single SQL statement. Most SQL functions are 4869** deterministic. The built-in [random()] SQL function is an example of a 4870** function that is not deterministic. The SQLite query planner is able to 4871** perform additional optimizations on deterministic functions, so use 4872** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4873** 4874** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY] 4875** flag, which if present prevents the function from being invoked from 4876** within VIEWs or TRIGGERs. For security reasons, the [SQLITE_DIRECTONLY] 4877** flag is recommended for any application-defined SQL function that has 4878** side-effects. 4879** 4880** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4881** function can gain access to this pointer using [sqlite3_user_data()].)^ 4882** 4883** ^The sixth, seventh and eighth parameters passed to the three 4884** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are 4885** pointers to C-language functions that implement the SQL function or 4886** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4887** callback only; NULL pointers must be passed as the xStep and xFinal 4888** parameters. ^An aggregate SQL function requires an implementation of xStep 4889** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4890** SQL function or aggregate, pass NULL pointers for all three function 4891** callbacks. 4892** 4893** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue 4894** and xInverse) passed to sqlite3_create_window_function are pointers to 4895** C-language callbacks that implement the new function. xStep and xFinal 4896** must both be non-NULL. xValue and xInverse may either both be NULL, in 4897** which case a regular aggregate function is created, or must both be 4898** non-NULL, in which case the new function may be used as either an aggregate 4899** or aggregate window function. More details regarding the implementation 4900** of aggregate window functions are 4901** [user-defined window functions|available here]. 4902** 4903** ^(If the final parameter to sqlite3_create_function_v2() or 4904** sqlite3_create_window_function() is not NULL, then it is destructor for 4905** the application data pointer. The destructor is invoked when the function 4906** is deleted, either by being overloaded or when the database connection 4907** closes.)^ ^The destructor is also invoked if the call to 4908** sqlite3_create_function_v2() fails. ^When the destructor callback is 4909** invoked, it is passed a single argument which is a copy of the application 4910** data pointer which was the fifth parameter to sqlite3_create_function_v2(). 4911** 4912** ^It is permitted to register multiple implementations of the same 4913** functions with the same name but with either differing numbers of 4914** arguments or differing preferred text encodings. ^SQLite will use 4915** the implementation that most closely matches the way in which the 4916** SQL function is used. ^A function implementation with a non-negative 4917** nArg parameter is a better match than a function implementation with 4918** a negative nArg. ^A function where the preferred text encoding 4919** matches the database encoding is a better 4920** match than a function where the encoding is different. 4921** ^A function where the encoding difference is between UTF16le and UTF16be 4922** is a closer match than a function where the encoding difference is 4923** between UTF8 and UTF16. 4924** 4925** ^Built-in functions may be overloaded by new application-defined functions. 4926** 4927** ^An application-defined function is permitted to call other 4928** SQLite interfaces. However, such calls must not 4929** close the database connection nor finalize or reset the prepared 4930** statement in which the function is running. 4931*/ 4932int sqlite3_create_function( 4933 sqlite3 *db, 4934 const char *zFunctionName, 4935 int nArg, 4936 int eTextRep, 4937 void *pApp, 4938 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4939 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4940 void (*xFinal)(sqlite3_context*) 4941); 4942int sqlite3_create_function16( 4943 sqlite3 *db, 4944 const void *zFunctionName, 4945 int nArg, 4946 int eTextRep, 4947 void *pApp, 4948 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4949 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4950 void (*xFinal)(sqlite3_context*) 4951); 4952int sqlite3_create_function_v2( 4953 sqlite3 *db, 4954 const char *zFunctionName, 4955 int nArg, 4956 int eTextRep, 4957 void *pApp, 4958 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4959 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4960 void (*xFinal)(sqlite3_context*), 4961 void(*xDestroy)(void*) 4962); 4963int sqlite3_create_window_function( 4964 sqlite3 *db, 4965 const char *zFunctionName, 4966 int nArg, 4967 int eTextRep, 4968 void *pApp, 4969 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4970 void (*xFinal)(sqlite3_context*), 4971 void (*xValue)(sqlite3_context*), 4972 void (*xInverse)(sqlite3_context*,int,sqlite3_value**), 4973 void(*xDestroy)(void*) 4974); 4975 4976/* 4977** CAPI3REF: Text Encodings 4978** 4979** These constant define integer codes that represent the various 4980** text encodings supported by SQLite. 4981*/ 4982#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */ 4983#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */ 4984#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */ 4985#define SQLITE_UTF16 4 /* Use native byte order */ 4986#define SQLITE_ANY 5 /* Deprecated */ 4987#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4988 4989/* 4990** CAPI3REF: Function Flags 4991** 4992** These constants may be ORed together with the 4993** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4994** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4995** [sqlite3_create_function_v2()]. 4996** 4997** The SQLITE_DETERMINISTIC flag means that the new function always gives 4998** the same output when the input parameters are the same. The abs() function 4999** is deterministic, for example, but randomblob() is not. Functions must 5000** be deterministic in order to be used in certain contexts such as 5001** [CHECK constraints] or [generated columns]. SQLite might also optimize 5002** deterministic functions by factoring them out of inner loops. 5003** 5004** The SQLITE_DIRECTONLY flag means that the function may only be invoked 5005** from top-level SQL, and cannot be used in VIEWs or TRIGGERs. This is 5006** a security feature which is recommended for all 5007** [application-defined SQL functions] that have side-effects. This flag 5008** prevents an attacker from adding triggers and views to a schema then 5009** tricking a high-privilege application into causing unintended side-effects 5010** while performing ordinary queries. 5011** 5012** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call 5013** [sqlite3_value_subtype()] to inspect the sub-types of its arguments. 5014** Specifying this flag makes no difference for scalar or aggregate user 5015** functions. However, if it is not specified for a user-defined window 5016** function, then any sub-types belonging to arguments passed to the window 5017** function may be discarded before the window function is called (i.e. 5018** sqlite3_value_subtype() will always return 0). 5019*/ 5020#define SQLITE_DETERMINISTIC 0x000000800 5021#define SQLITE_DIRECTONLY 0x000080000 5022#define SQLITE_SUBTYPE 0x000100000 5023 5024/* 5025** CAPI3REF: Deprecated Functions 5026** DEPRECATED 5027** 5028** These functions are [deprecated]. In order to maintain 5029** backwards compatibility with older code, these functions continue 5030** to be supported. However, new applications should avoid 5031** the use of these functions. To encourage programmers to avoid 5032** these functions, we will not explain what they do. 5033*/ 5034#ifndef SQLITE_OMIT_DEPRECATED 5035SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 5036SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 5037SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 5038SQLITE_DEPRECATED int sqlite3_global_recover(void); 5039SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 5040SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 5041 void*,sqlite3_int64); 5042#endif 5043 5044/* 5045** CAPI3REF: Obtaining SQL Values 5046** METHOD: sqlite3_value 5047** 5048** <b>Summary:</b> 5049** <blockquote><table border=0 cellpadding=0 cellspacing=0> 5050** <tr><td><b>sqlite3_value_blob</b><td>→<td>BLOB value 5051** <tr><td><b>sqlite3_value_double</b><td>→<td>REAL value 5052** <tr><td><b>sqlite3_value_int</b><td>→<td>32-bit INTEGER value 5053** <tr><td><b>sqlite3_value_int64</b><td>→<td>64-bit INTEGER value 5054** <tr><td><b>sqlite3_value_pointer</b><td>→<td>Pointer value 5055** <tr><td><b>sqlite3_value_text</b><td>→<td>UTF-8 TEXT value 5056** <tr><td><b>sqlite3_value_text16</b><td>→<td>UTF-16 TEXT value in 5057** the native byteorder 5058** <tr><td><b>sqlite3_value_text16be</b><td>→<td>UTF-16be TEXT value 5059** <tr><td><b>sqlite3_value_text16le</b><td>→<td>UTF-16le TEXT value 5060** <tr><td> <td> <td> 5061** <tr><td><b>sqlite3_value_bytes</b><td>→<td>Size of a BLOB 5062** or a UTF-8 TEXT in bytes 5063** <tr><td><b>sqlite3_value_bytes16 </b> 5064** <td>→ <td>Size of UTF-16 5065** TEXT in bytes 5066** <tr><td><b>sqlite3_value_type</b><td>→<td>Default 5067** datatype of the value 5068** <tr><td><b>sqlite3_value_numeric_type </b> 5069** <td>→ <td>Best numeric datatype of the value 5070** <tr><td><b>sqlite3_value_nochange </b> 5071** <td>→ <td>True if the column is unchanged in an UPDATE 5072** against a virtual table. 5073** <tr><td><b>sqlite3_value_frombind </b> 5074** <td>→ <td>True if value originated from a [bound parameter] 5075** </table></blockquote> 5076** 5077** <b>Details:</b> 5078** 5079** These routines extract type, size, and content information from 5080** [protected sqlite3_value] objects. Protected sqlite3_value objects 5081** are used to pass parameter information into the functions that 5082** implement [application-defined SQL functions] and [virtual tables]. 5083** 5084** These routines work only with [protected sqlite3_value] objects. 5085** Any attempt to use these routines on an [unprotected sqlite3_value] 5086** is not threadsafe. 5087** 5088** ^These routines work just like the corresponding [column access functions] 5089** except that these routines take a single [protected sqlite3_value] object 5090** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 5091** 5092** ^The sqlite3_value_text16() interface extracts a UTF-16 string 5093** in the native byte-order of the host machine. ^The 5094** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 5095** extract UTF-16 strings as big-endian and little-endian respectively. 5096** 5097** ^If [sqlite3_value] object V was initialized 5098** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)] 5099** and if X and Y are strings that compare equal according to strcmp(X,Y), 5100** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise, 5101** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer() 5102** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5103** 5104** ^(The sqlite3_value_type(V) interface returns the 5105** [SQLITE_INTEGER | datatype code] for the initial datatype of the 5106** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER], 5107** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^ 5108** Other interfaces might change the datatype for an sqlite3_value object. 5109** For example, if the datatype is initially SQLITE_INTEGER and 5110** sqlite3_value_text(V) is called to extract a text value for that 5111** integer, then subsequent calls to sqlite3_value_type(V) might return 5112** SQLITE_TEXT. Whether or not a persistent internal datatype conversion 5113** occurs is undefined and may change from one release of SQLite to the next. 5114** 5115** ^(The sqlite3_value_numeric_type() interface attempts to apply 5116** numeric affinity to the value. This means that an attempt is 5117** made to convert the value to an integer or floating point. If 5118** such a conversion is possible without loss of information (in other 5119** words, if the value is a string that looks like a number) 5120** then the conversion is performed. Otherwise no conversion occurs. 5121** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 5122** 5123** ^Within the [xUpdate] method of a [virtual table], the 5124** sqlite3_value_nochange(X) interface returns true if and only if 5125** the column corresponding to X is unchanged by the UPDATE operation 5126** that the xUpdate method call was invoked to implement and if 5127** and the prior [xColumn] method call that was invoked to extracted 5128** the value for that column returned without setting a result (probably 5129** because it queried [sqlite3_vtab_nochange()] and found that the column 5130** was unchanging). ^Within an [xUpdate] method, any value for which 5131** sqlite3_value_nochange(X) is true will in all other respects appear 5132** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other 5133** than within an [xUpdate] method call for an UPDATE statement, then 5134** the return value is arbitrary and meaningless. 5135** 5136** ^The sqlite3_value_frombind(X) interface returns non-zero if the 5137** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()] 5138** interfaces. ^If X comes from an SQL literal value, or a table column, 5139** or an expression, then sqlite3_value_frombind(X) returns zero. 5140** 5141** Please pay particular attention to the fact that the pointer returned 5142** from [sqlite3_value_blob()], [sqlite3_value_text()], or 5143** [sqlite3_value_text16()] can be invalidated by a subsequent call to 5144** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 5145** or [sqlite3_value_text16()]. 5146** 5147** These routines must be called from the same thread as 5148** the SQL function that supplied the [sqlite3_value*] parameters. 5149** 5150** As long as the input parameter is correct, these routines can only 5151** fail if an out-of-memory error occurs during a format conversion. 5152** Only the following subset of interfaces are subject to out-of-memory 5153** errors: 5154** 5155** <ul> 5156** <li> sqlite3_value_blob() 5157** <li> sqlite3_value_text() 5158** <li> sqlite3_value_text16() 5159** <li> sqlite3_value_text16le() 5160** <li> sqlite3_value_text16be() 5161** <li> sqlite3_value_bytes() 5162** <li> sqlite3_value_bytes16() 5163** </ul> 5164** 5165** If an out-of-memory error occurs, then the return value from these 5166** routines is the same as if the column had contained an SQL NULL value. 5167** Valid SQL NULL returns can be distinguished from out-of-memory errors 5168** by invoking the [sqlite3_errcode()] immediately after the suspect 5169** return value is obtained and before any 5170** other SQLite interface is called on the same [database connection]. 5171*/ 5172const void *sqlite3_value_blob(sqlite3_value*); 5173double sqlite3_value_double(sqlite3_value*); 5174int sqlite3_value_int(sqlite3_value*); 5175sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 5176void *sqlite3_value_pointer(sqlite3_value*, const char*); 5177const unsigned char *sqlite3_value_text(sqlite3_value*); 5178const void *sqlite3_value_text16(sqlite3_value*); 5179const void *sqlite3_value_text16le(sqlite3_value*); 5180const void *sqlite3_value_text16be(sqlite3_value*); 5181int sqlite3_value_bytes(sqlite3_value*); 5182int sqlite3_value_bytes16(sqlite3_value*); 5183int sqlite3_value_type(sqlite3_value*); 5184int sqlite3_value_numeric_type(sqlite3_value*); 5185int sqlite3_value_nochange(sqlite3_value*); 5186int sqlite3_value_frombind(sqlite3_value*); 5187 5188/* 5189** CAPI3REF: Finding The Subtype Of SQL Values 5190** METHOD: sqlite3_value 5191** 5192** The sqlite3_value_subtype(V) function returns the subtype for 5193** an [application-defined SQL function] argument V. The subtype 5194** information can be used to pass a limited amount of context from 5195** one SQL function to another. Use the [sqlite3_result_subtype()] 5196** routine to set the subtype for the return value of an SQL function. 5197*/ 5198unsigned int sqlite3_value_subtype(sqlite3_value*); 5199 5200/* 5201** CAPI3REF: Copy And Free SQL Values 5202** METHOD: sqlite3_value 5203** 5204** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value] 5205** object D and returns a pointer to that copy. ^The [sqlite3_value] returned 5206** is a [protected sqlite3_value] object even if the input is not. 5207** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a 5208** memory allocation fails. 5209** 5210** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object 5211** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer 5212** then sqlite3_value_free(V) is a harmless no-op. 5213*/ 5214sqlite3_value *sqlite3_value_dup(const sqlite3_value*); 5215void sqlite3_value_free(sqlite3_value*); 5216 5217/* 5218** CAPI3REF: Obtain Aggregate Function Context 5219** METHOD: sqlite3_context 5220** 5221** Implementations of aggregate SQL functions use this 5222** routine to allocate memory for storing their state. 5223** 5224** ^The first time the sqlite3_aggregate_context(C,N) routine is called 5225** for a particular aggregate function, SQLite allocates 5226** N bytes of memory, zeroes out that memory, and returns a pointer 5227** to the new memory. ^On second and subsequent calls to 5228** sqlite3_aggregate_context() for the same aggregate function instance, 5229** the same buffer is returned. Sqlite3_aggregate_context() is normally 5230** called once for each invocation of the xStep callback and then one 5231** last time when the xFinal callback is invoked. ^(When no rows match 5232** an aggregate query, the xStep() callback of the aggregate function 5233** implementation is never called and xFinal() is called exactly once. 5234** In those cases, sqlite3_aggregate_context() might be called for the 5235** first time from within xFinal().)^ 5236** 5237** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 5238** when first called if N is less than or equal to zero or if a memory 5239** allocate error occurs. 5240** 5241** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 5242** determined by the N parameter on first successful call. Changing the 5243** value of N in any subsequents call to sqlite3_aggregate_context() within 5244** the same aggregate function instance will not resize the memory 5245** allocation.)^ Within the xFinal callback, it is customary to set 5246** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 5247** pointless memory allocations occur. 5248** 5249** ^SQLite automatically frees the memory allocated by 5250** sqlite3_aggregate_context() when the aggregate query concludes. 5251** 5252** The first parameter must be a copy of the 5253** [sqlite3_context | SQL function context] that is the first parameter 5254** to the xStep or xFinal callback routine that implements the aggregate 5255** function. 5256** 5257** This routine must be called from the same thread in which 5258** the aggregate SQL function is running. 5259*/ 5260void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 5261 5262/* 5263** CAPI3REF: User Data For Functions 5264** METHOD: sqlite3_context 5265** 5266** ^The sqlite3_user_data() interface returns a copy of 5267** the pointer that was the pUserData parameter (the 5th parameter) 5268** of the [sqlite3_create_function()] 5269** and [sqlite3_create_function16()] routines that originally 5270** registered the application defined function. 5271** 5272** This routine must be called from the same thread in which 5273** the application-defined function is running. 5274*/ 5275void *sqlite3_user_data(sqlite3_context*); 5276 5277/* 5278** CAPI3REF: Database Connection For Functions 5279** METHOD: sqlite3_context 5280** 5281** ^The sqlite3_context_db_handle() interface returns a copy of 5282** the pointer to the [database connection] (the 1st parameter) 5283** of the [sqlite3_create_function()] 5284** and [sqlite3_create_function16()] routines that originally 5285** registered the application defined function. 5286*/ 5287sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 5288 5289/* 5290** CAPI3REF: Function Auxiliary Data 5291** METHOD: sqlite3_context 5292** 5293** These functions may be used by (non-aggregate) SQL functions to 5294** associate metadata with argument values. If the same value is passed to 5295** multiple invocations of the same SQL function during query execution, under 5296** some circumstances the associated metadata may be preserved. An example 5297** of where this might be useful is in a regular-expression matching 5298** function. The compiled version of the regular expression can be stored as 5299** metadata associated with the pattern string. 5300** Then as long as the pattern string remains the same, 5301** the compiled regular expression can be reused on multiple 5302** invocations of the same function. 5303** 5304** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata 5305** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument 5306** value to the application-defined function. ^N is zero for the left-most 5307** function argument. ^If there is no metadata 5308** associated with the function argument, the sqlite3_get_auxdata(C,N) interface 5309** returns a NULL pointer. 5310** 5311** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 5312** argument of the application-defined function. ^Subsequent 5313** calls to sqlite3_get_auxdata(C,N) return P from the most recent 5314** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 5315** NULL if the metadata has been discarded. 5316** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 5317** SQLite will invoke the destructor function X with parameter P exactly 5318** once, when the metadata is discarded. 5319** SQLite is free to discard the metadata at any time, including: <ul> 5320** <li> ^(when the corresponding function parameter changes)^, or 5321** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 5322** SQL statement)^, or 5323** <li> ^(when sqlite3_set_auxdata() is invoked again on the same 5324** parameter)^, or 5325** <li> ^(during the original sqlite3_set_auxdata() call when a memory 5326** allocation error occurs.)^ </ul> 5327** 5328** Note the last bullet in particular. The destructor X in 5329** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 5330** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 5331** should be called near the end of the function implementation and the 5332** function implementation should not make any use of P after 5333** sqlite3_set_auxdata() has been called. 5334** 5335** ^(In practice, metadata is preserved between function calls for 5336** function parameters that are compile-time constants, including literal 5337** values and [parameters] and expressions composed from the same.)^ 5338** 5339** The value of the N parameter to these interfaces should be non-negative. 5340** Future enhancements may make use of negative N values to define new 5341** kinds of function caching behavior. 5342** 5343** These routines must be called from the same thread in which 5344** the SQL function is running. 5345*/ 5346void *sqlite3_get_auxdata(sqlite3_context*, int N); 5347void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 5348 5349 5350/* 5351** CAPI3REF: Constants Defining Special Destructor Behavior 5352** 5353** These are special values for the destructor that is passed in as the 5354** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 5355** argument is SQLITE_STATIC, it means that the content pointer is constant 5356** and will never change. It does not need to be destroyed. ^The 5357** SQLITE_TRANSIENT value means that the content will likely change in 5358** the near future and that SQLite should make its own private copy of 5359** the content before returning. 5360** 5361** The typedef is necessary to work around problems in certain 5362** C++ compilers. 5363*/ 5364typedef void (*sqlite3_destructor_type)(void*); 5365#define SQLITE_STATIC ((sqlite3_destructor_type)0) 5366#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 5367 5368/* 5369** CAPI3REF: Setting The Result Of An SQL Function 5370** METHOD: sqlite3_context 5371** 5372** These routines are used by the xFunc or xFinal callbacks that 5373** implement SQL functions and aggregates. See 5374** [sqlite3_create_function()] and [sqlite3_create_function16()] 5375** for additional information. 5376** 5377** These functions work very much like the [parameter binding] family of 5378** functions used to bind values to host parameters in prepared statements. 5379** Refer to the [SQL parameter] documentation for additional information. 5380** 5381** ^The sqlite3_result_blob() interface sets the result from 5382** an application-defined function to be the BLOB whose content is pointed 5383** to by the second parameter and which is N bytes long where N is the 5384** third parameter. 5385** 5386** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N) 5387** interfaces set the result of the application-defined function to be 5388** a BLOB containing all zero bytes and N bytes in size. 5389** 5390** ^The sqlite3_result_double() interface sets the result from 5391** an application-defined function to be a floating point value specified 5392** by its 2nd argument. 5393** 5394** ^The sqlite3_result_error() and sqlite3_result_error16() functions 5395** cause the implemented SQL function to throw an exception. 5396** ^SQLite uses the string pointed to by the 5397** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 5398** as the text of an error message. ^SQLite interprets the error 5399** message string from sqlite3_result_error() as UTF-8. ^SQLite 5400** interprets the string from sqlite3_result_error16() as UTF-16 in native 5401** byte order. ^If the third parameter to sqlite3_result_error() 5402** or sqlite3_result_error16() is negative then SQLite takes as the error 5403** message all text up through the first zero character. 5404** ^If the third parameter to sqlite3_result_error() or 5405** sqlite3_result_error16() is non-negative then SQLite takes that many 5406** bytes (not characters) from the 2nd parameter as the error message. 5407** ^The sqlite3_result_error() and sqlite3_result_error16() 5408** routines make a private copy of the error message text before 5409** they return. Hence, the calling function can deallocate or 5410** modify the text after they return without harm. 5411** ^The sqlite3_result_error_code() function changes the error code 5412** returned by SQLite as a result of an error in a function. ^By default, 5413** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 5414** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 5415** 5416** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 5417** error indicating that a string or BLOB is too long to represent. 5418** 5419** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 5420** error indicating that a memory allocation failed. 5421** 5422** ^The sqlite3_result_int() interface sets the return value 5423** of the application-defined function to be the 32-bit signed integer 5424** value given in the 2nd argument. 5425** ^The sqlite3_result_int64() interface sets the return value 5426** of the application-defined function to be the 64-bit signed integer 5427** value given in the 2nd argument. 5428** 5429** ^The sqlite3_result_null() interface sets the return value 5430** of the application-defined function to be NULL. 5431** 5432** ^The sqlite3_result_text(), sqlite3_result_text16(), 5433** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 5434** set the return value of the application-defined function to be 5435** a text string which is represented as UTF-8, UTF-16 native byte order, 5436** UTF-16 little endian, or UTF-16 big endian, respectively. 5437** ^The sqlite3_result_text64() interface sets the return value of an 5438** application-defined function to be a text string in an encoding 5439** specified by the fifth (and last) parameter, which must be one 5440** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]. 5441** ^SQLite takes the text result from the application from 5442** the 2nd parameter of the sqlite3_result_text* interfaces. 5443** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5444** is negative, then SQLite takes result text from the 2nd parameter 5445** through the first zero character. 5446** ^If the 3rd parameter to the sqlite3_result_text* interfaces 5447** is non-negative, then as many bytes (not characters) of the text 5448** pointed to by the 2nd parameter are taken as the application-defined 5449** function result. If the 3rd parameter is non-negative, then it 5450** must be the byte offset into the string where the NUL terminator would 5451** appear if the string where NUL terminated. If any NUL characters occur 5452** in the string at a byte offset that is less than the value of the 3rd 5453** parameter, then the resulting string will contain embedded NULs and the 5454** result of expressions operating on strings with embedded NULs is undefined. 5455** ^If the 4th parameter to the sqlite3_result_text* interfaces 5456** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 5457** function as the destructor on the text or BLOB result when it has 5458** finished using that result. 5459** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 5460** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 5461** assumes that the text or BLOB result is in constant space and does not 5462** copy the content of the parameter nor call a destructor on the content 5463** when it has finished using that result. 5464** ^If the 4th parameter to the sqlite3_result_text* interfaces 5465** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 5466** then SQLite makes a copy of the result into space obtained 5467** from [sqlite3_malloc()] before it returns. 5468** 5469** ^The sqlite3_result_value() interface sets the result of 5470** the application-defined function to be a copy of the 5471** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 5472** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 5473** so that the [sqlite3_value] specified in the parameter may change or 5474** be deallocated after sqlite3_result_value() returns without harm. 5475** ^A [protected sqlite3_value] object may always be used where an 5476** [unprotected sqlite3_value] object is required, so either 5477** kind of [sqlite3_value] object can be used with this interface. 5478** 5479** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an 5480** SQL NULL value, just like [sqlite3_result_null(C)], except that it 5481** also associates the host-language pointer P or type T with that 5482** NULL value such that the pointer can be retrieved within an 5483** [application-defined SQL function] using [sqlite3_value_pointer()]. 5484** ^If the D parameter is not NULL, then it is a pointer to a destructor 5485** for the P parameter. ^SQLite invokes D with P as its only argument 5486** when SQLite is finished with P. The T parameter should be a static 5487** string and preferably a string literal. The sqlite3_result_pointer() 5488** routine is part of the [pointer passing interface] added for SQLite 3.20.0. 5489** 5490** If these routines are called from within the different thread 5491** than the one containing the application-defined function that received 5492** the [sqlite3_context] pointer, the results are undefined. 5493*/ 5494void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 5495void sqlite3_result_blob64(sqlite3_context*,const void*, 5496 sqlite3_uint64,void(*)(void*)); 5497void sqlite3_result_double(sqlite3_context*, double); 5498void sqlite3_result_error(sqlite3_context*, const char*, int); 5499void sqlite3_result_error16(sqlite3_context*, const void*, int); 5500void sqlite3_result_error_toobig(sqlite3_context*); 5501void sqlite3_result_error_nomem(sqlite3_context*); 5502void sqlite3_result_error_code(sqlite3_context*, int); 5503void sqlite3_result_int(sqlite3_context*, int); 5504void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 5505void sqlite3_result_null(sqlite3_context*); 5506void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 5507void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64, 5508 void(*)(void*), unsigned char encoding); 5509void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 5510void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 5511void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 5512void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 5513void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*)); 5514void sqlite3_result_zeroblob(sqlite3_context*, int n); 5515int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n); 5516 5517 5518/* 5519** CAPI3REF: Setting The Subtype Of An SQL Function 5520** METHOD: sqlite3_context 5521** 5522** The sqlite3_result_subtype(C,T) function causes the subtype of 5523** the result from the [application-defined SQL function] with 5524** [sqlite3_context] C to be the value T. Only the lower 8 bits 5525** of the subtype T are preserved in current versions of SQLite; 5526** higher order bits are discarded. 5527** The number of subtype bytes preserved by SQLite might increase 5528** in future releases of SQLite. 5529*/ 5530void sqlite3_result_subtype(sqlite3_context*,unsigned int); 5531 5532/* 5533** CAPI3REF: Define New Collating Sequences 5534** METHOD: sqlite3 5535** 5536** ^These functions add, remove, or modify a [collation] associated 5537** with the [database connection] specified as the first argument. 5538** 5539** ^The name of the collation is a UTF-8 string 5540** for sqlite3_create_collation() and sqlite3_create_collation_v2() 5541** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 5542** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 5543** considered to be the same name. 5544** 5545** ^(The third argument (eTextRep) must be one of the constants: 5546** <ul> 5547** <li> [SQLITE_UTF8], 5548** <li> [SQLITE_UTF16LE], 5549** <li> [SQLITE_UTF16BE], 5550** <li> [SQLITE_UTF16], or 5551** <li> [SQLITE_UTF16_ALIGNED]. 5552** </ul>)^ 5553** ^The eTextRep argument determines the encoding of strings passed 5554** to the collating function callback, xCallback. 5555** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 5556** force strings to be UTF16 with native byte order. 5557** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 5558** on an even byte address. 5559** 5560** ^The fourth argument, pArg, is an application data pointer that is passed 5561** through as the first argument to the collating function callback. 5562** 5563** ^The fifth argument, xCallback, is a pointer to the collating function. 5564** ^Multiple collating functions can be registered using the same name but 5565** with different eTextRep parameters and SQLite will use whichever 5566** function requires the least amount of data transformation. 5567** ^If the xCallback argument is NULL then the collating function is 5568** deleted. ^When all collating functions having the same name are deleted, 5569** that collation is no longer usable. 5570** 5571** ^The collating function callback is invoked with a copy of the pArg 5572** application data pointer and with two strings in the encoding specified 5573** by the eTextRep argument. The collating function must return an 5574** integer that is negative, zero, or positive 5575** if the first string is less than, equal to, or greater than the second, 5576** respectively. A collating function must always return the same answer 5577** given the same inputs. If two or more collating functions are registered 5578** to the same collation name (using different eTextRep values) then all 5579** must give an equivalent answer when invoked with equivalent strings. 5580** The collating function must obey the following properties for all 5581** strings A, B, and C: 5582** 5583** <ol> 5584** <li> If A==B then B==A. 5585** <li> If A==B and B==C then A==C. 5586** <li> If A<B THEN B>A. 5587** <li> If A<B and B<C then A<C. 5588** </ol> 5589** 5590** If a collating function fails any of the above constraints and that 5591** collating function is registered and used, then the behavior of SQLite 5592** is undefined. 5593** 5594** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 5595** with the addition that the xDestroy callback is invoked on pArg when 5596** the collating function is deleted. 5597** ^Collating functions are deleted when they are overridden by later 5598** calls to the collation creation functions or when the 5599** [database connection] is closed using [sqlite3_close()]. 5600** 5601** ^The xDestroy callback is <u>not</u> called if the 5602** sqlite3_create_collation_v2() function fails. Applications that invoke 5603** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 5604** check the return code and dispose of the application data pointer 5605** themselves rather than expecting SQLite to deal with it for them. 5606** This is different from every other SQLite interface. The inconsistency 5607** is unfortunate but cannot be changed without breaking backwards 5608** compatibility. 5609** 5610** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 5611*/ 5612int sqlite3_create_collation( 5613 sqlite3*, 5614 const char *zName, 5615 int eTextRep, 5616 void *pArg, 5617 int(*xCompare)(void*,int,const void*,int,const void*) 5618); 5619int sqlite3_create_collation_v2( 5620 sqlite3*, 5621 const char *zName, 5622 int eTextRep, 5623 void *pArg, 5624 int(*xCompare)(void*,int,const void*,int,const void*), 5625 void(*xDestroy)(void*) 5626); 5627int sqlite3_create_collation16( 5628 sqlite3*, 5629 const void *zName, 5630 int eTextRep, 5631 void *pArg, 5632 int(*xCompare)(void*,int,const void*,int,const void*) 5633); 5634 5635/* 5636** CAPI3REF: Collation Needed Callbacks 5637** METHOD: sqlite3 5638** 5639** ^To avoid having to register all collation sequences before a database 5640** can be used, a single callback function may be registered with the 5641** [database connection] to be invoked whenever an undefined collation 5642** sequence is required. 5643** 5644** ^If the function is registered using the sqlite3_collation_needed() API, 5645** then it is passed the names of undefined collation sequences as strings 5646** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 5647** the names are passed as UTF-16 in machine native byte order. 5648** ^A call to either function replaces the existing collation-needed callback. 5649** 5650** ^(When the callback is invoked, the first argument passed is a copy 5651** of the second argument to sqlite3_collation_needed() or 5652** sqlite3_collation_needed16(). The second argument is the database 5653** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 5654** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 5655** sequence function required. The fourth parameter is the name of the 5656** required collation sequence.)^ 5657** 5658** The callback function should register the desired collation using 5659** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 5660** [sqlite3_create_collation_v2()]. 5661*/ 5662int sqlite3_collation_needed( 5663 sqlite3*, 5664 void*, 5665 void(*)(void*,sqlite3*,int eTextRep,const char*) 5666); 5667int sqlite3_collation_needed16( 5668 sqlite3*, 5669 void*, 5670 void(*)(void*,sqlite3*,int eTextRep,const void*) 5671); 5672 5673#ifdef SQLITE_HAS_CODEC 5674/* 5675** Specify the key for an encrypted database. This routine should be 5676** called right after sqlite3_open(). 5677** 5678** The code to implement this API is not available in the public release 5679** of SQLite. 5680*/ 5681int sqlite3_key( 5682 sqlite3 *db, /* Database to be rekeyed */ 5683 const void *pKey, int nKey /* The key */ 5684); 5685int sqlite3_key_v2( 5686 sqlite3 *db, /* Database to be rekeyed */ 5687 const char *zDbName, /* Name of the database */ 5688 const void *pKey, int nKey /* The key */ 5689); 5690 5691/* 5692** Change the key on an open database. If the current database is not 5693** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 5694** database is decrypted. 5695** 5696** The code to implement this API is not available in the public release 5697** of SQLite. 5698*/ 5699int sqlite3_rekey( 5700 sqlite3 *db, /* Database to be rekeyed */ 5701 const void *pKey, int nKey /* The new key */ 5702); 5703int sqlite3_rekey_v2( 5704 sqlite3 *db, /* Database to be rekeyed */ 5705 const char *zDbName, /* Name of the database */ 5706 const void *pKey, int nKey /* The new key */ 5707); 5708 5709/* 5710** Specify the activation key for a SEE database. Unless 5711** activated, none of the SEE routines will work. 5712*/ 5713void sqlite3_activate_see( 5714 const char *zPassPhrase /* Activation phrase */ 5715); 5716#endif 5717 5718#ifdef SQLITE_ENABLE_CEROD 5719/* 5720** Specify the activation key for a CEROD database. Unless 5721** activated, none of the CEROD routines will work. 5722*/ 5723void sqlite3_activate_cerod( 5724 const char *zPassPhrase /* Activation phrase */ 5725); 5726#endif 5727 5728/* 5729** CAPI3REF: Suspend Execution For A Short Time 5730** 5731** The sqlite3_sleep() function causes the current thread to suspend execution 5732** for at least a number of milliseconds specified in its parameter. 5733** 5734** If the operating system does not support sleep requests with 5735** millisecond time resolution, then the time will be rounded up to 5736** the nearest second. The number of milliseconds of sleep actually 5737** requested from the operating system is returned. 5738** 5739** ^SQLite implements this interface by calling the xSleep() 5740** method of the default [sqlite3_vfs] object. If the xSleep() method 5741** of the default VFS is not implemented correctly, or not implemented at 5742** all, then the behavior of sqlite3_sleep() may deviate from the description 5743** in the previous paragraphs. 5744*/ 5745int sqlite3_sleep(int); 5746 5747/* 5748** CAPI3REF: Name Of The Folder Holding Temporary Files 5749** 5750** ^(If this global variable is made to point to a string which is 5751** the name of a folder (a.k.a. directory), then all temporary files 5752** created by SQLite when using a built-in [sqlite3_vfs | VFS] 5753** will be placed in that directory.)^ ^If this variable 5754** is a NULL pointer, then SQLite performs a search for an appropriate 5755** temporary file directory. 5756** 5757** Applications are strongly discouraged from using this global variable. 5758** It is required to set a temporary folder on Windows Runtime (WinRT). 5759** But for all other platforms, it is highly recommended that applications 5760** neither read nor write this variable. This global variable is a relic 5761** that exists for backwards compatibility of legacy applications and should 5762** be avoided in new projects. 5763** 5764** It is not safe to read or modify this variable in more than one 5765** thread at a time. It is not safe to read or modify this variable 5766** if a [database connection] is being used at the same time in a separate 5767** thread. 5768** It is intended that this variable be set once 5769** as part of process initialization and before any SQLite interface 5770** routines have been called and that this variable remain unchanged 5771** thereafter. 5772** 5773** ^The [temp_store_directory pragma] may modify this variable and cause 5774** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5775** the [temp_store_directory pragma] always assumes that any string 5776** that this variable points to is held in memory obtained from 5777** [sqlite3_malloc] and the pragma may attempt to free that memory 5778** using [sqlite3_free]. 5779** Hence, if this variable is modified directly, either it should be 5780** made NULL or made to point to memory obtained from [sqlite3_malloc] 5781** or else the use of the [temp_store_directory pragma] should be avoided. 5782** Except when requested by the [temp_store_directory pragma], SQLite 5783** does not free the memory that sqlite3_temp_directory points to. If 5784** the application wants that memory to be freed, it must do 5785** so itself, taking care to only do so after all [database connection] 5786** objects have been destroyed. 5787** 5788** <b>Note to Windows Runtime users:</b> The temporary directory must be set 5789** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 5790** features that require the use of temporary files may fail. Here is an 5791** example of how to do this using C++ with the Windows Runtime: 5792** 5793** <blockquote><pre> 5794** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 5795** TemporaryFolder->Path->Data(); 5796** char zPathBuf[MAX_PATH + 1]; 5797** memset(zPathBuf, 0, sizeof(zPathBuf)); 5798** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 5799** NULL, NULL); 5800** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 5801** </pre></blockquote> 5802*/ 5803SQLITE_EXTERN char *sqlite3_temp_directory; 5804 5805/* 5806** CAPI3REF: Name Of The Folder Holding Database Files 5807** 5808** ^(If this global variable is made to point to a string which is 5809** the name of a folder (a.k.a. directory), then all database files 5810** specified with a relative pathname and created or accessed by 5811** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 5812** to be relative to that directory.)^ ^If this variable is a NULL 5813** pointer, then SQLite assumes that all database files specified 5814** with a relative pathname are relative to the current directory 5815** for the process. Only the windows VFS makes use of this global 5816** variable; it is ignored by the unix VFS. 5817** 5818** Changing the value of this variable while a database connection is 5819** open can result in a corrupt database. 5820** 5821** It is not safe to read or modify this variable in more than one 5822** thread at a time. It is not safe to read or modify this variable 5823** if a [database connection] is being used at the same time in a separate 5824** thread. 5825** It is intended that this variable be set once 5826** as part of process initialization and before any SQLite interface 5827** routines have been called and that this variable remain unchanged 5828** thereafter. 5829** 5830** ^The [data_store_directory pragma] may modify this variable and cause 5831** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 5832** the [data_store_directory pragma] always assumes that any string 5833** that this variable points to is held in memory obtained from 5834** [sqlite3_malloc] and the pragma may attempt to free that memory 5835** using [sqlite3_free]. 5836** Hence, if this variable is modified directly, either it should be 5837** made NULL or made to point to memory obtained from [sqlite3_malloc] 5838** or else the use of the [data_store_directory pragma] should be avoided. 5839*/ 5840SQLITE_EXTERN char *sqlite3_data_directory; 5841 5842/* 5843** CAPI3REF: Win32 Specific Interface 5844** 5845** These interfaces are available only on Windows. The 5846** [sqlite3_win32_set_directory] interface is used to set the value associated 5847** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to 5848** zValue, depending on the value of the type parameter. The zValue parameter 5849** should be NULL to cause the previous value to be freed via [sqlite3_free]; 5850** a non-NULL value will be copied into memory obtained from [sqlite3_malloc] 5851** prior to being used. The [sqlite3_win32_set_directory] interface returns 5852** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported, 5853** or [SQLITE_NOMEM] if memory could not be allocated. The value of the 5854** [sqlite3_data_directory] variable is intended to act as a replacement for 5855** the current directory on the sub-platforms of Win32 where that concept is 5856** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and 5857** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the 5858** sqlite3_win32_set_directory interface except the string parameter must be 5859** UTF-8 or UTF-16, respectively. 5860*/ 5861int sqlite3_win32_set_directory( 5862 unsigned long type, /* Identifier for directory being set or reset */ 5863 void *zValue /* New value for directory being set or reset */ 5864); 5865int sqlite3_win32_set_directory8(unsigned long type, const char *zValue); 5866int sqlite3_win32_set_directory16(unsigned long type, const void *zValue); 5867 5868/* 5869** CAPI3REF: Win32 Directory Types 5870** 5871** These macros are only available on Windows. They define the allowed values 5872** for the type argument to the [sqlite3_win32_set_directory] interface. 5873*/ 5874#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1 5875#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2 5876 5877/* 5878** CAPI3REF: Test For Auto-Commit Mode 5879** KEYWORDS: {autocommit mode} 5880** METHOD: sqlite3 5881** 5882** ^The sqlite3_get_autocommit() interface returns non-zero or 5883** zero if the given database connection is or is not in autocommit mode, 5884** respectively. ^Autocommit mode is on by default. 5885** ^Autocommit mode is disabled by a [BEGIN] statement. 5886** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 5887** 5888** If certain kinds of errors occur on a statement within a multi-statement 5889** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 5890** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 5891** transaction might be rolled back automatically. The only way to 5892** find out whether SQLite automatically rolled back the transaction after 5893** an error is to use this function. 5894** 5895** If another thread changes the autocommit status of the database 5896** connection while this routine is running, then the return value 5897** is undefined. 5898*/ 5899int sqlite3_get_autocommit(sqlite3*); 5900 5901/* 5902** CAPI3REF: Find The Database Handle Of A Prepared Statement 5903** METHOD: sqlite3_stmt 5904** 5905** ^The sqlite3_db_handle interface returns the [database connection] handle 5906** to which a [prepared statement] belongs. ^The [database connection] 5907** returned by sqlite3_db_handle is the same [database connection] 5908** that was the first argument 5909** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 5910** create the statement in the first place. 5911*/ 5912sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 5913 5914/* 5915** CAPI3REF: Return The Filename For A Database Connection 5916** METHOD: sqlite3 5917** 5918** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename 5919** associated with database N of connection D. 5920** ^If there is no attached database N on the database 5921** connection D, or if database N is a temporary or in-memory database, then 5922** this function will return either a NULL pointer or an empty string. 5923** 5924** ^The string value returned by this routine is owned and managed by 5925** the database connection. ^The value will be valid until the database N 5926** is [DETACH]-ed or until the database connection closes. 5927** 5928** ^The filename returned by this function is the output of the 5929** xFullPathname method of the [VFS]. ^In other words, the filename 5930** will be an absolute pathname, even if the filename used 5931** to open the database originally was a URI or relative pathname. 5932*/ 5933const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 5934 5935/* 5936** CAPI3REF: Determine if a database is read-only 5937** METHOD: sqlite3 5938** 5939** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 5940** of connection D is read-only, 0 if it is read/write, or -1 if N is not 5941** the name of a database on connection D. 5942*/ 5943int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 5944 5945/* 5946** CAPI3REF: Find the next prepared statement 5947** METHOD: sqlite3 5948** 5949** ^This interface returns a pointer to the next [prepared statement] after 5950** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 5951** then this interface returns a pointer to the first prepared statement 5952** associated with the database connection pDb. ^If no prepared statement 5953** satisfies the conditions of this routine, it returns NULL. 5954** 5955** The [database connection] pointer D in a call to 5956** [sqlite3_next_stmt(D,S)] must refer to an open database 5957** connection and in particular must not be a NULL pointer. 5958*/ 5959sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 5960 5961/* 5962** CAPI3REF: Commit And Rollback Notification Callbacks 5963** METHOD: sqlite3 5964** 5965** ^The sqlite3_commit_hook() interface registers a callback 5966** function to be invoked whenever a transaction is [COMMIT | committed]. 5967** ^Any callback set by a previous call to sqlite3_commit_hook() 5968** for the same database connection is overridden. 5969** ^The sqlite3_rollback_hook() interface registers a callback 5970** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 5971** ^Any callback set by a previous call to sqlite3_rollback_hook() 5972** for the same database connection is overridden. 5973** ^The pArg argument is passed through to the callback. 5974** ^If the callback on a commit hook function returns non-zero, 5975** then the commit is converted into a rollback. 5976** 5977** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 5978** return the P argument from the previous call of the same function 5979** on the same [database connection] D, or NULL for 5980** the first call for each function on D. 5981** 5982** The commit and rollback hook callbacks are not reentrant. 5983** The callback implementation must not do anything that will modify 5984** the database connection that invoked the callback. Any actions 5985** to modify the database connection must be deferred until after the 5986** completion of the [sqlite3_step()] call that triggered the commit 5987** or rollback hook in the first place. 5988** Note that running any other SQL statements, including SELECT statements, 5989** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 5990** the database connections for the meaning of "modify" in this paragraph. 5991** 5992** ^Registering a NULL function disables the callback. 5993** 5994** ^When the commit hook callback routine returns zero, the [COMMIT] 5995** operation is allowed to continue normally. ^If the commit hook 5996** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5997** ^The rollback hook is invoked on a rollback that results from a commit 5998** hook returning non-zero, just as it would be with any other rollback. 5999** 6000** ^For the purposes of this API, a transaction is said to have been 6001** rolled back if an explicit "ROLLBACK" statement is executed, or 6002** an error or constraint causes an implicit rollback to occur. 6003** ^The rollback callback is not invoked if a transaction is 6004** automatically rolled back because the database connection is closed. 6005** 6006** See also the [sqlite3_update_hook()] interface. 6007*/ 6008void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 6009void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 6010 6011/* 6012** CAPI3REF: Data Change Notification Callbacks 6013** METHOD: sqlite3 6014** 6015** ^The sqlite3_update_hook() interface registers a callback function 6016** with the [database connection] identified by the first argument 6017** to be invoked whenever a row is updated, inserted or deleted in 6018** a [rowid table]. 6019** ^Any callback set by a previous call to this function 6020** for the same database connection is overridden. 6021** 6022** ^The second argument is a pointer to the function to invoke when a 6023** row is updated, inserted or deleted in a rowid table. 6024** ^The first argument to the callback is a copy of the third argument 6025** to sqlite3_update_hook(). 6026** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 6027** or [SQLITE_UPDATE], depending on the operation that caused the callback 6028** to be invoked. 6029** ^The third and fourth arguments to the callback contain pointers to the 6030** database and table name containing the affected row. 6031** ^The final callback parameter is the [rowid] of the row. 6032** ^In the case of an update, this is the [rowid] after the update takes place. 6033** 6034** ^(The update hook is not invoked when internal system tables are 6035** modified (i.e. sqlite_master and sqlite_sequence).)^ 6036** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 6037** 6038** ^In the current implementation, the update hook 6039** is not invoked when conflicting rows are deleted because of an 6040** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 6041** invoked when rows are deleted using the [truncate optimization]. 6042** The exceptions defined in this paragraph might change in a future 6043** release of SQLite. 6044** 6045** The update hook implementation must not do anything that will modify 6046** the database connection that invoked the update hook. Any actions 6047** to modify the database connection must be deferred until after the 6048** completion of the [sqlite3_step()] call that triggered the update hook. 6049** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 6050** database connections for the meaning of "modify" in this paragraph. 6051** 6052** ^The sqlite3_update_hook(D,C,P) function 6053** returns the P argument from the previous call 6054** on the same [database connection] D, or NULL for 6055** the first call on D. 6056** 6057** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()], 6058** and [sqlite3_preupdate_hook()] interfaces. 6059*/ 6060void *sqlite3_update_hook( 6061 sqlite3*, 6062 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 6063 void* 6064); 6065 6066/* 6067** CAPI3REF: Enable Or Disable Shared Pager Cache 6068** 6069** ^(This routine enables or disables the sharing of the database cache 6070** and schema data structures between [database connection | connections] 6071** to the same database. Sharing is enabled if the argument is true 6072** and disabled if the argument is false.)^ 6073** 6074** ^Cache sharing is enabled and disabled for an entire process. 6075** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]). 6076** In prior versions of SQLite, 6077** sharing was enabled or disabled for each thread separately. 6078** 6079** ^(The cache sharing mode set by this interface effects all subsequent 6080** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 6081** Existing database connections continue to use the sharing mode 6082** that was in effect at the time they were opened.)^ 6083** 6084** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 6085** successfully. An [error code] is returned otherwise.)^ 6086** 6087** ^Shared cache is disabled by default. It is recommended that it stay 6088** that way. In other words, do not use this routine. This interface 6089** continues to be provided for historical compatibility, but its use is 6090** discouraged. Any use of shared cache is discouraged. If shared cache 6091** must be used, it is recommended that shared cache only be enabled for 6092** individual database connections using the [sqlite3_open_v2()] interface 6093** with the [SQLITE_OPEN_SHAREDCACHE] flag. 6094** 6095** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0 6096** and will always return SQLITE_MISUSE. On those systems, 6097** shared cache mode should be enabled per-database connection via 6098** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE]. 6099** 6100** This interface is threadsafe on processors where writing a 6101** 32-bit integer is atomic. 6102** 6103** See Also: [SQLite Shared-Cache Mode] 6104*/ 6105int sqlite3_enable_shared_cache(int); 6106 6107/* 6108** CAPI3REF: Attempt To Free Heap Memory 6109** 6110** ^The sqlite3_release_memory() interface attempts to free N bytes 6111** of heap memory by deallocating non-essential memory allocations 6112** held by the database library. Memory used to cache database 6113** pages to improve performance is an example of non-essential memory. 6114** ^sqlite3_release_memory() returns the number of bytes actually freed, 6115** which might be more or less than the amount requested. 6116** ^The sqlite3_release_memory() routine is a no-op returning zero 6117** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 6118** 6119** See also: [sqlite3_db_release_memory()] 6120*/ 6121int sqlite3_release_memory(int); 6122 6123/* 6124** CAPI3REF: Free Memory Used By A Database Connection 6125** METHOD: sqlite3 6126** 6127** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 6128** memory as possible from database connection D. Unlike the 6129** [sqlite3_release_memory()] interface, this interface is in effect even 6130** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 6131** omitted. 6132** 6133** See also: [sqlite3_release_memory()] 6134*/ 6135int sqlite3_db_release_memory(sqlite3*); 6136 6137/* 6138** CAPI3REF: Impose A Limit On Heap Size 6139** 6140** These interfaces impose limits on the amount of heap memory that will be 6141** by all database connections within a single process. 6142** 6143** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 6144** soft limit on the amount of heap memory that may be allocated by SQLite. 6145** ^SQLite strives to keep heap memory utilization below the soft heap 6146** limit by reducing the number of pages held in the page cache 6147** as heap memory usages approaches the limit. 6148** ^The soft heap limit is "soft" because even though SQLite strives to stay 6149** below the limit, it will exceed the limit rather than generate 6150** an [SQLITE_NOMEM] error. In other words, the soft heap limit 6151** is advisory only. 6152** 6153** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of 6154** N bytes on the amount of memory that will be allocated. ^The 6155** sqlite3_hard_heap_limit64(N) interface is similar to 6156** sqlite3_soft_heap_limit64(N) except that memory allocations will fail 6157** when the hard heap limit is reached. 6158** 6159** ^The return value from both sqlite3_soft_heap_limit64() and 6160** sqlite3_hard_heap_limit64() is the size of 6161** the heap limit prior to the call, or negative in the case of an 6162** error. ^If the argument N is negative 6163** then no change is made to the heap limit. Hence, the current 6164** size of heap limits can be determined by invoking 6165** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1). 6166** 6167** ^Setting the heap limits to zero disables the heap limiter mechanism. 6168** 6169** ^The soft heap limit may not be greater than the hard heap limit. 6170** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N) 6171** is invoked with a value of N that is greater than the hard heap limit, 6172** the the soft heap limit is set to the value of the hard heap limit. 6173** ^The soft heap limit is automatically enabled whenever the hard heap 6174** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and 6175** the soft heap limit is outside the range of 1..N, then the soft heap 6176** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the 6177** hard heap limit is enabled makes the soft heap limit equal to the 6178** hard heap limit. 6179** 6180** The memory allocation limits can also be adjusted using 6181** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit]. 6182** 6183** ^(The heap limits are not enforced in the current implementation 6184** if one or more of following conditions are true: 6185** 6186** <ul> 6187** <li> The limit value is set to zero. 6188** <li> Memory accounting is disabled using a combination of the 6189** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 6190** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 6191** <li> An alternative page cache implementation is specified using 6192** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 6193** <li> The page cache allocates from its own memory pool supplied 6194** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 6195** from the heap. 6196** </ul>)^ 6197** 6198** The circumstances under which SQLite will enforce the heap limits may 6199** changes in future releases of SQLite. 6200*/ 6201sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 6202sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N); 6203 6204/* 6205** CAPI3REF: Deprecated Soft Heap Limit Interface 6206** DEPRECATED 6207** 6208** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 6209** interface. This routine is provided for historical compatibility 6210** only. All new applications should use the 6211** [sqlite3_soft_heap_limit64()] interface rather than this one. 6212*/ 6213SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 6214 6215 6216/* 6217** CAPI3REF: Extract Metadata About A Column Of A Table 6218** METHOD: sqlite3 6219** 6220** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns 6221** information about column C of table T in database D 6222** on [database connection] X.)^ ^The sqlite3_table_column_metadata() 6223** interface returns SQLITE_OK and fills in the non-NULL pointers in 6224** the final five arguments with appropriate values if the specified 6225** column exists. ^The sqlite3_table_column_metadata() interface returns 6226** SQLITE_ERROR if the specified column does not exist. 6227** ^If the column-name parameter to sqlite3_table_column_metadata() is a 6228** NULL pointer, then this routine simply checks for the existence of the 6229** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it 6230** does not. If the table name parameter T in a call to 6231** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is 6232** undefined behavior. 6233** 6234** ^The column is identified by the second, third and fourth parameters to 6235** this function. ^(The second parameter is either the name of the database 6236** (i.e. "main", "temp", or an attached database) containing the specified 6237** table or NULL.)^ ^If it is NULL, then all attached databases are searched 6238** for the table using the same algorithm used by the database engine to 6239** resolve unqualified table references. 6240** 6241** ^The third and fourth parameters to this function are the table and column 6242** name of the desired column, respectively. 6243** 6244** ^Metadata is returned by writing to the memory locations passed as the 5th 6245** and subsequent parameters to this function. ^Any of these arguments may be 6246** NULL, in which case the corresponding element of metadata is omitted. 6247** 6248** ^(<blockquote> 6249** <table border="1"> 6250** <tr><th> Parameter <th> Output<br>Type <th> Description 6251** 6252** <tr><td> 5th <td> const char* <td> Data type 6253** <tr><td> 6th <td> const char* <td> Name of default collation sequence 6254** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 6255** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 6256** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 6257** </table> 6258** </blockquote>)^ 6259** 6260** ^The memory pointed to by the character pointers returned for the 6261** declaration type and collation sequence is valid until the next 6262** call to any SQLite API function. 6263** 6264** ^If the specified table is actually a view, an [error code] is returned. 6265** 6266** ^If the specified column is "rowid", "oid" or "_rowid_" and the table 6267** is not a [WITHOUT ROWID] table and an 6268** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 6269** parameters are set for the explicitly declared column. ^(If there is no 6270** [INTEGER PRIMARY KEY] column, then the outputs 6271** for the [rowid] are set as follows: 6272** 6273** <pre> 6274** data type: "INTEGER" 6275** collation sequence: "BINARY" 6276** not null: 0 6277** primary key: 1 6278** auto increment: 0 6279** </pre>)^ 6280** 6281** ^This function causes all database schemas to be read from disk and 6282** parsed, if that has not already been done, and returns an error if 6283** any errors are encountered while loading the schema. 6284*/ 6285int sqlite3_table_column_metadata( 6286 sqlite3 *db, /* Connection handle */ 6287 const char *zDbName, /* Database name or NULL */ 6288 const char *zTableName, /* Table name */ 6289 const char *zColumnName, /* Column name */ 6290 char const **pzDataType, /* OUTPUT: Declared data type */ 6291 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 6292 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 6293 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 6294 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 6295); 6296 6297/* 6298** CAPI3REF: Load An Extension 6299** METHOD: sqlite3 6300** 6301** ^This interface loads an SQLite extension library from the named file. 6302** 6303** ^The sqlite3_load_extension() interface attempts to load an 6304** [SQLite extension] library contained in the file zFile. If 6305** the file cannot be loaded directly, attempts are made to load 6306** with various operating-system specific extensions added. 6307** So for example, if "samplelib" cannot be loaded, then names like 6308** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 6309** be tried also. 6310** 6311** ^The entry point is zProc. 6312** ^(zProc may be 0, in which case SQLite will try to come up with an 6313** entry point name on its own. It first tries "sqlite3_extension_init". 6314** If that does not work, it constructs a name "sqlite3_X_init" where the 6315** X is consists of the lower-case equivalent of all ASCII alphabetic 6316** characters in the filename from the last "/" to the first following 6317** "." and omitting any initial "lib".)^ 6318** ^The sqlite3_load_extension() interface returns 6319** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 6320** ^If an error occurs and pzErrMsg is not 0, then the 6321** [sqlite3_load_extension()] interface shall attempt to 6322** fill *pzErrMsg with error message text stored in memory 6323** obtained from [sqlite3_malloc()]. The calling function 6324** should free this memory by calling [sqlite3_free()]. 6325** 6326** ^Extension loading must be enabled using 6327** [sqlite3_enable_load_extension()] or 6328** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL) 6329** prior to calling this API, 6330** otherwise an error will be returned. 6331** 6332** <b>Security warning:</b> It is recommended that the 6333** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this 6334** interface. The use of the [sqlite3_enable_load_extension()] interface 6335** should be avoided. This will keep the SQL function [load_extension()] 6336** disabled and prevent SQL injections from giving attackers 6337** access to extension loading capabilities. 6338** 6339** See also the [load_extension() SQL function]. 6340*/ 6341int sqlite3_load_extension( 6342 sqlite3 *db, /* Load the extension into this database connection */ 6343 const char *zFile, /* Name of the shared library containing extension */ 6344 const char *zProc, /* Entry point. Derived from zFile if 0 */ 6345 char **pzErrMsg /* Put error message here if not 0 */ 6346); 6347 6348/* 6349** CAPI3REF: Enable Or Disable Extension Loading 6350** METHOD: sqlite3 6351** 6352** ^So as not to open security holes in older applications that are 6353** unprepared to deal with [extension loading], and as a means of disabling 6354** [extension loading] while evaluating user-entered SQL, the following API 6355** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 6356** 6357** ^Extension loading is off by default. 6358** ^Call the sqlite3_enable_load_extension() routine with onoff==1 6359** to turn extension loading on and call it with onoff==0 to turn 6360** it back off again. 6361** 6362** ^This interface enables or disables both the C-API 6363** [sqlite3_load_extension()] and the SQL function [load_extension()]. 6364** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..) 6365** to enable or disable only the C-API.)^ 6366** 6367** <b>Security warning:</b> It is recommended that extension loading 6368** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method 6369** rather than this interface, so the [load_extension()] SQL function 6370** remains disabled. This will prevent SQL injections from giving attackers 6371** access to extension loading capabilities. 6372*/ 6373int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 6374 6375/* 6376** CAPI3REF: Automatically Load Statically Linked Extensions 6377** 6378** ^This interface causes the xEntryPoint() function to be invoked for 6379** each new [database connection] that is created. The idea here is that 6380** xEntryPoint() is the entry point for a statically linked [SQLite extension] 6381** that is to be automatically loaded into all new database connections. 6382** 6383** ^(Even though the function prototype shows that xEntryPoint() takes 6384** no arguments and returns void, SQLite invokes xEntryPoint() with three 6385** arguments and expects an integer result as if the signature of the 6386** entry point where as follows: 6387** 6388** <blockquote><pre> 6389** int xEntryPoint( 6390** sqlite3 *db, 6391** const char **pzErrMsg, 6392** const struct sqlite3_api_routines *pThunk 6393** ); 6394** </pre></blockquote>)^ 6395** 6396** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 6397** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 6398** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 6399** is NULL before calling the xEntryPoint(). ^SQLite will invoke 6400** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 6401** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 6402** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 6403** 6404** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 6405** on the list of automatic extensions is a harmless no-op. ^No entry point 6406** will be called more than once for each database connection that is opened. 6407** 6408** See also: [sqlite3_reset_auto_extension()] 6409** and [sqlite3_cancel_auto_extension()] 6410*/ 6411int sqlite3_auto_extension(void(*xEntryPoint)(void)); 6412 6413/* 6414** CAPI3REF: Cancel Automatic Extension Loading 6415** 6416** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 6417** initialization routine X that was registered using a prior call to 6418** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 6419** routine returns 1 if initialization routine X was successfully 6420** unregistered and it returns 0 if X was not on the list of initialization 6421** routines. 6422*/ 6423int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void)); 6424 6425/* 6426** CAPI3REF: Reset Automatic Extension Loading 6427** 6428** ^This interface disables all automatic extensions previously 6429** registered using [sqlite3_auto_extension()]. 6430*/ 6431void sqlite3_reset_auto_extension(void); 6432 6433/* 6434** The interface to the virtual-table mechanism is currently considered 6435** to be experimental. The interface might change in incompatible ways. 6436** If this is a problem for you, do not use the interface at this time. 6437** 6438** When the virtual-table mechanism stabilizes, we will declare the 6439** interface fixed, support it indefinitely, and remove this comment. 6440*/ 6441 6442/* 6443** Structures used by the virtual table interface 6444*/ 6445typedef struct sqlite3_vtab sqlite3_vtab; 6446typedef struct sqlite3_index_info sqlite3_index_info; 6447typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 6448typedef struct sqlite3_module sqlite3_module; 6449 6450/* 6451** CAPI3REF: Virtual Table Object 6452** KEYWORDS: sqlite3_module {virtual table module} 6453** 6454** This structure, sometimes called a "virtual table module", 6455** defines the implementation of a [virtual table]. 6456** This structure consists mostly of methods for the module. 6457** 6458** ^A virtual table module is created by filling in a persistent 6459** instance of this structure and passing a pointer to that instance 6460** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 6461** ^The registration remains valid until it is replaced by a different 6462** module or until the [database connection] closes. The content 6463** of this structure must not change while it is registered with 6464** any database connection. 6465*/ 6466struct sqlite3_module { 6467 int iVersion; 6468 int (*xCreate)(sqlite3*, void *pAux, 6469 int argc, const char *const*argv, 6470 sqlite3_vtab **ppVTab, char**); 6471 int (*xConnect)(sqlite3*, void *pAux, 6472 int argc, const char *const*argv, 6473 sqlite3_vtab **ppVTab, char**); 6474 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 6475 int (*xDisconnect)(sqlite3_vtab *pVTab); 6476 int (*xDestroy)(sqlite3_vtab *pVTab); 6477 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 6478 int (*xClose)(sqlite3_vtab_cursor*); 6479 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 6480 int argc, sqlite3_value **argv); 6481 int (*xNext)(sqlite3_vtab_cursor*); 6482 int (*xEof)(sqlite3_vtab_cursor*); 6483 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 6484 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 6485 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 6486 int (*xBegin)(sqlite3_vtab *pVTab); 6487 int (*xSync)(sqlite3_vtab *pVTab); 6488 int (*xCommit)(sqlite3_vtab *pVTab); 6489 int (*xRollback)(sqlite3_vtab *pVTab); 6490 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 6491 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 6492 void **ppArg); 6493 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 6494 /* The methods above are in version 1 of the sqlite_module object. Those 6495 ** below are for version 2 and greater. */ 6496 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 6497 int (*xRelease)(sqlite3_vtab *pVTab, int); 6498 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 6499 /* The methods above are in versions 1 and 2 of the sqlite_module object. 6500 ** Those below are for version 3 and greater. */ 6501 int (*xShadowName)(const char*); 6502}; 6503 6504/* 6505** CAPI3REF: Virtual Table Indexing Information 6506** KEYWORDS: sqlite3_index_info 6507** 6508** The sqlite3_index_info structure and its substructures is used as part 6509** of the [virtual table] interface to 6510** pass information into and receive the reply from the [xBestIndex] 6511** method of a [virtual table module]. The fields under **Inputs** are the 6512** inputs to xBestIndex and are read-only. xBestIndex inserts its 6513** results into the **Outputs** fields. 6514** 6515** ^(The aConstraint[] array records WHERE clause constraints of the form: 6516** 6517** <blockquote>column OP expr</blockquote> 6518** 6519** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 6520** stored in aConstraint[].op using one of the 6521** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 6522** ^(The index of the column is stored in 6523** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 6524** expr on the right-hand side can be evaluated (and thus the constraint 6525** is usable) and false if it cannot.)^ 6526** 6527** ^The optimizer automatically inverts terms of the form "expr OP column" 6528** and makes other simplifications to the WHERE clause in an attempt to 6529** get as many WHERE clause terms into the form shown above as possible. 6530** ^The aConstraint[] array only reports WHERE clause terms that are 6531** relevant to the particular virtual table being queried. 6532** 6533** ^Information about the ORDER BY clause is stored in aOrderBy[]. 6534** ^Each term of aOrderBy records a column of the ORDER BY clause. 6535** 6536** The colUsed field indicates which columns of the virtual table may be 6537** required by the current scan. Virtual table columns are numbered from 6538** zero in the order in which they appear within the CREATE TABLE statement 6539** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62), 6540** the corresponding bit is set within the colUsed mask if the column may be 6541** required by SQLite. If the table has at least 64 columns and any column 6542** to the right of the first 63 is required, then bit 63 of colUsed is also 6543** set. In other words, column iCol may be required if the expression 6544** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to 6545** non-zero. 6546** 6547** The [xBestIndex] method must fill aConstraintUsage[] with information 6548** about what parameters to pass to xFilter. ^If argvIndex>0 then 6549** the right-hand side of the corresponding aConstraint[] is evaluated 6550** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 6551** is true, then the constraint is assumed to be fully handled by the 6552** virtual table and might not be checked again by the byte code.)^ ^(The 6553** aConstraintUsage[].omit flag is an optimization hint. When the omit flag 6554** is left in its default setting of false, the constraint will always be 6555** checked separately in byte code. If the omit flag is change to true, then 6556** the constraint may or may not be checked in byte code. In other words, 6557** when the omit flag is true there is no guarantee that the constraint will 6558** not be checked again using byte code.)^ 6559** 6560** ^The idxNum and idxPtr values are recorded and passed into the 6561** [xFilter] method. 6562** ^[sqlite3_free()] is used to free idxPtr if and only if 6563** needToFreeIdxPtr is true. 6564** 6565** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 6566** the correct order to satisfy the ORDER BY clause so that no separate 6567** sorting step is required. 6568** 6569** ^The estimatedCost value is an estimate of the cost of a particular 6570** strategy. A cost of N indicates that the cost of the strategy is similar 6571** to a linear scan of an SQLite table with N rows. A cost of log(N) 6572** indicates that the expense of the operation is similar to that of a 6573** binary search on a unique indexed field of an SQLite table with N rows. 6574** 6575** ^The estimatedRows value is an estimate of the number of rows that 6576** will be returned by the strategy. 6577** 6578** The xBestIndex method may optionally populate the idxFlags field with a 6579** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag - 6580** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite 6581** assumes that the strategy may visit at most one row. 6582** 6583** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then 6584** SQLite also assumes that if a call to the xUpdate() method is made as 6585** part of the same statement to delete or update a virtual table row and the 6586** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback 6587** any database changes. In other words, if the xUpdate() returns 6588** SQLITE_CONSTRAINT, the database contents must be exactly as they were 6589** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not 6590** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by 6591** the xUpdate method are automatically rolled back by SQLite. 6592** 6593** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 6594** structure for SQLite [version 3.8.2] ([dateof:3.8.2]). 6595** If a virtual table extension is 6596** used with an SQLite version earlier than 3.8.2, the results of attempting 6597** to read or write the estimatedRows field are undefined (but are likely 6598** to include crashing the application). The estimatedRows field should 6599** therefore only be used if [sqlite3_libversion_number()] returns a 6600** value greater than or equal to 3008002. Similarly, the idxFlags field 6601** was added for [version 3.9.0] ([dateof:3.9.0]). 6602** It may therefore only be used if 6603** sqlite3_libversion_number() returns a value greater than or equal to 6604** 3009000. 6605*/ 6606struct sqlite3_index_info { 6607 /* Inputs */ 6608 int nConstraint; /* Number of entries in aConstraint */ 6609 struct sqlite3_index_constraint { 6610 int iColumn; /* Column constrained. -1 for ROWID */ 6611 unsigned char op; /* Constraint operator */ 6612 unsigned char usable; /* True if this constraint is usable */ 6613 int iTermOffset; /* Used internally - xBestIndex should ignore */ 6614 } *aConstraint; /* Table of WHERE clause constraints */ 6615 int nOrderBy; /* Number of terms in the ORDER BY clause */ 6616 struct sqlite3_index_orderby { 6617 int iColumn; /* Column number */ 6618 unsigned char desc; /* True for DESC. False for ASC. */ 6619 } *aOrderBy; /* The ORDER BY clause */ 6620 /* Outputs */ 6621 struct sqlite3_index_constraint_usage { 6622 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 6623 unsigned char omit; /* Do not code a test for this constraint */ 6624 } *aConstraintUsage; 6625 int idxNum; /* Number used to identify the index */ 6626 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 6627 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 6628 int orderByConsumed; /* True if output is already ordered */ 6629 double estimatedCost; /* Estimated cost of using this index */ 6630 /* Fields below are only available in SQLite 3.8.2 and later */ 6631 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 6632 /* Fields below are only available in SQLite 3.9.0 and later */ 6633 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */ 6634 /* Fields below are only available in SQLite 3.10.0 and later */ 6635 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */ 6636}; 6637 6638/* 6639** CAPI3REF: Virtual Table Scan Flags 6640** 6641** Virtual table implementations are allowed to set the 6642** [sqlite3_index_info].idxFlags field to some combination of 6643** these bits. 6644*/ 6645#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */ 6646 6647/* 6648** CAPI3REF: Virtual Table Constraint Operator Codes 6649** 6650** These macros define the allowed values for the 6651** [sqlite3_index_info].aConstraint[].op field. Each value represents 6652** an operator that is part of a constraint term in the wHERE clause of 6653** a query that uses a [virtual table]. 6654*/ 6655#define SQLITE_INDEX_CONSTRAINT_EQ 2 6656#define SQLITE_INDEX_CONSTRAINT_GT 4 6657#define SQLITE_INDEX_CONSTRAINT_LE 8 6658#define SQLITE_INDEX_CONSTRAINT_LT 16 6659#define SQLITE_INDEX_CONSTRAINT_GE 32 6660#define SQLITE_INDEX_CONSTRAINT_MATCH 64 6661#define SQLITE_INDEX_CONSTRAINT_LIKE 65 6662#define SQLITE_INDEX_CONSTRAINT_GLOB 66 6663#define SQLITE_INDEX_CONSTRAINT_REGEXP 67 6664#define SQLITE_INDEX_CONSTRAINT_NE 68 6665#define SQLITE_INDEX_CONSTRAINT_ISNOT 69 6666#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70 6667#define SQLITE_INDEX_CONSTRAINT_ISNULL 71 6668#define SQLITE_INDEX_CONSTRAINT_IS 72 6669#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150 6670 6671/* 6672** CAPI3REF: Register A Virtual Table Implementation 6673** METHOD: sqlite3 6674** 6675** ^These routines are used to register a new [virtual table module] name. 6676** ^Module names must be registered before 6677** creating a new [virtual table] using the module and before using a 6678** preexisting [virtual table] for the module. 6679** 6680** ^The module name is registered on the [database connection] specified 6681** by the first parameter. ^The name of the module is given by the 6682** second parameter. ^The third parameter is a pointer to 6683** the implementation of the [virtual table module]. ^The fourth 6684** parameter is an arbitrary client data pointer that is passed through 6685** into the [xCreate] and [xConnect] methods of the virtual table module 6686** when a new virtual table is be being created or reinitialized. 6687** 6688** ^The sqlite3_create_module_v2() interface has a fifth parameter which 6689** is a pointer to a destructor for the pClientData. ^SQLite will 6690** invoke the destructor function (if it is not NULL) when SQLite 6691** no longer needs the pClientData pointer. ^The destructor will also 6692** be invoked if the call to sqlite3_create_module_v2() fails. 6693** ^The sqlite3_create_module() 6694** interface is equivalent to sqlite3_create_module_v2() with a NULL 6695** destructor. 6696** 6697** ^If the third parameter (the pointer to the sqlite3_module object) is 6698** NULL then no new module is create and any existing modules with the 6699** same name are dropped. 6700** 6701** See also: [sqlite3_drop_modules()] 6702*/ 6703int sqlite3_create_module( 6704 sqlite3 *db, /* SQLite connection to register module with */ 6705 const char *zName, /* Name of the module */ 6706 const sqlite3_module *p, /* Methods for the module */ 6707 void *pClientData /* Client data for xCreate/xConnect */ 6708); 6709int sqlite3_create_module_v2( 6710 sqlite3 *db, /* SQLite connection to register module with */ 6711 const char *zName, /* Name of the module */ 6712 const sqlite3_module *p, /* Methods for the module */ 6713 void *pClientData, /* Client data for xCreate/xConnect */ 6714 void(*xDestroy)(void*) /* Module destructor function */ 6715); 6716 6717/* 6718** CAPI3REF: Remove Unnecessary Virtual Table Implementations 6719** METHOD: sqlite3 6720** 6721** ^The sqlite3_drop_modules(D,L) interface removes all virtual 6722** table modules from database connection D except those named on list L. 6723** The L parameter must be either NULL or a pointer to an array of pointers 6724** to strings where the array is terminated by a single NULL pointer. 6725** ^If the L parameter is NULL, then all virtual table modules are removed. 6726** 6727** See also: [sqlite3_create_module()] 6728*/ 6729int sqlite3_drop_modules( 6730 sqlite3 *db, /* Remove modules from this connection */ 6731 const char **azKeep /* Except, do not remove the ones named here */ 6732); 6733 6734/* 6735** CAPI3REF: Virtual Table Instance Object 6736** KEYWORDS: sqlite3_vtab 6737** 6738** Every [virtual table module] implementation uses a subclass 6739** of this object to describe a particular instance 6740** of the [virtual table]. Each subclass will 6741** be tailored to the specific needs of the module implementation. 6742** The purpose of this superclass is to define certain fields that are 6743** common to all module implementations. 6744** 6745** ^Virtual tables methods can set an error message by assigning a 6746** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 6747** take care that any prior string is freed by a call to [sqlite3_free()] 6748** prior to assigning a new string to zErrMsg. ^After the error message 6749** is delivered up to the client application, the string will be automatically 6750** freed by sqlite3_free() and the zErrMsg field will be zeroed. 6751*/ 6752struct sqlite3_vtab { 6753 const sqlite3_module *pModule; /* The module for this virtual table */ 6754 int nRef; /* Number of open cursors */ 6755 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 6756 /* Virtual table implementations will typically add additional fields */ 6757}; 6758 6759/* 6760** CAPI3REF: Virtual Table Cursor Object 6761** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 6762** 6763** Every [virtual table module] implementation uses a subclass of the 6764** following structure to describe cursors that point into the 6765** [virtual table] and are used 6766** to loop through the virtual table. Cursors are created using the 6767** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 6768** by the [sqlite3_module.xClose | xClose] method. Cursors are used 6769** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 6770** of the module. Each module implementation will define 6771** the content of a cursor structure to suit its own needs. 6772** 6773** This superclass exists in order to define fields of the cursor that 6774** are common to all implementations. 6775*/ 6776struct sqlite3_vtab_cursor { 6777 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 6778 /* Virtual table implementations will typically add additional fields */ 6779}; 6780 6781/* 6782** CAPI3REF: Declare The Schema Of A Virtual Table 6783** 6784** ^The [xCreate] and [xConnect] methods of a 6785** [virtual table module] call this interface 6786** to declare the format (the names and datatypes of the columns) of 6787** the virtual tables they implement. 6788*/ 6789int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 6790 6791/* 6792** CAPI3REF: Overload A Function For A Virtual Table 6793** METHOD: sqlite3 6794** 6795** ^(Virtual tables can provide alternative implementations of functions 6796** using the [xFindFunction] method of the [virtual table module]. 6797** But global versions of those functions 6798** must exist in order to be overloaded.)^ 6799** 6800** ^(This API makes sure a global version of a function with a particular 6801** name and number of parameters exists. If no such function exists 6802** before this API is called, a new function is created.)^ ^The implementation 6803** of the new function always causes an exception to be thrown. So 6804** the new function is not good for anything by itself. Its only 6805** purpose is to be a placeholder function that can be overloaded 6806** by a [virtual table]. 6807*/ 6808int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 6809 6810/* 6811** The interface to the virtual-table mechanism defined above (back up 6812** to a comment remarkably similar to this one) is currently considered 6813** to be experimental. The interface might change in incompatible ways. 6814** If this is a problem for you, do not use the interface at this time. 6815** 6816** When the virtual-table mechanism stabilizes, we will declare the 6817** interface fixed, support it indefinitely, and remove this comment. 6818*/ 6819 6820/* 6821** CAPI3REF: A Handle To An Open BLOB 6822** KEYWORDS: {BLOB handle} {BLOB handles} 6823** 6824** An instance of this object represents an open BLOB on which 6825** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 6826** ^Objects of this type are created by [sqlite3_blob_open()] 6827** and destroyed by [sqlite3_blob_close()]. 6828** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 6829** can be used to read or write small subsections of the BLOB. 6830** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 6831*/ 6832typedef struct sqlite3_blob sqlite3_blob; 6833 6834/* 6835** CAPI3REF: Open A BLOB For Incremental I/O 6836** METHOD: sqlite3 6837** CONSTRUCTOR: sqlite3_blob 6838** 6839** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 6840** in row iRow, column zColumn, table zTable in database zDb; 6841** in other words, the same BLOB that would be selected by: 6842** 6843** <pre> 6844** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 6845** </pre>)^ 6846** 6847** ^(Parameter zDb is not the filename that contains the database, but 6848** rather the symbolic name of the database. For attached databases, this is 6849** the name that appears after the AS keyword in the [ATTACH] statement. 6850** For the main database file, the database name is "main". For TEMP 6851** tables, the database name is "temp".)^ 6852** 6853** ^If the flags parameter is non-zero, then the BLOB is opened for read 6854** and write access. ^If the flags parameter is zero, the BLOB is opened for 6855** read-only access. 6856** 6857** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored 6858** in *ppBlob. Otherwise an [error code] is returned and, unless the error 6859** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided 6860** the API is not misused, it is always safe to call [sqlite3_blob_close()] 6861** on *ppBlob after this function it returns. 6862** 6863** This function fails with SQLITE_ERROR if any of the following are true: 6864** <ul> 6865** <li> ^(Database zDb does not exist)^, 6866** <li> ^(Table zTable does not exist within database zDb)^, 6867** <li> ^(Table zTable is a WITHOUT ROWID table)^, 6868** <li> ^(Column zColumn does not exist)^, 6869** <li> ^(Row iRow is not present in the table)^, 6870** <li> ^(The specified column of row iRow contains a value that is not 6871** a TEXT or BLOB value)^, 6872** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE 6873** constraint and the blob is being opened for read/write access)^, 6874** <li> ^([foreign key constraints | Foreign key constraints] are enabled, 6875** column zColumn is part of a [child key] definition and the blob is 6876** being opened for read/write access)^. 6877** </ul> 6878** 6879** ^Unless it returns SQLITE_MISUSE, this function sets the 6880** [database connection] error code and message accessible via 6881** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 6882** 6883** A BLOB referenced by sqlite3_blob_open() may be read using the 6884** [sqlite3_blob_read()] interface and modified by using 6885** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a 6886** different row of the same table using the [sqlite3_blob_reopen()] 6887** interface. However, the column, table, or database of a [BLOB handle] 6888** cannot be changed after the [BLOB handle] is opened. 6889** 6890** ^(If the row that a BLOB handle points to is modified by an 6891** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 6892** then the BLOB handle is marked as "expired". 6893** This is true if any column of the row is changed, even a column 6894** other than the one the BLOB handle is open on.)^ 6895** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 6896** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 6897** ^(Changes written into a BLOB prior to the BLOB expiring are not 6898** rolled back by the expiration of the BLOB. Such changes will eventually 6899** commit if the transaction continues to completion.)^ 6900** 6901** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 6902** the opened blob. ^The size of a blob may not be changed by this 6903** interface. Use the [UPDATE] SQL command to change the size of a 6904** blob. 6905** 6906** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 6907** and the built-in [zeroblob] SQL function may be used to create a 6908** zero-filled blob to read or write using the incremental-blob interface. 6909** 6910** To avoid a resource leak, every open [BLOB handle] should eventually 6911** be released by a call to [sqlite3_blob_close()]. 6912** 6913** See also: [sqlite3_blob_close()], 6914** [sqlite3_blob_reopen()], [sqlite3_blob_read()], 6915** [sqlite3_blob_bytes()], [sqlite3_blob_write()]. 6916*/ 6917int sqlite3_blob_open( 6918 sqlite3*, 6919 const char *zDb, 6920 const char *zTable, 6921 const char *zColumn, 6922 sqlite3_int64 iRow, 6923 int flags, 6924 sqlite3_blob **ppBlob 6925); 6926 6927/* 6928** CAPI3REF: Move a BLOB Handle to a New Row 6929** METHOD: sqlite3_blob 6930** 6931** ^This function is used to move an existing [BLOB handle] so that it points 6932** to a different row of the same database table. ^The new row is identified 6933** by the rowid value passed as the second argument. Only the row can be 6934** changed. ^The database, table and column on which the blob handle is open 6935** remain the same. Moving an existing [BLOB handle] to a new row is 6936** faster than closing the existing handle and opening a new one. 6937** 6938** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 6939** it must exist and there must be either a blob or text value stored in 6940** the nominated column.)^ ^If the new row is not present in the table, or if 6941** it does not contain a blob or text value, or if another error occurs, an 6942** SQLite error code is returned and the blob handle is considered aborted. 6943** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 6944** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 6945** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 6946** always returns zero. 6947** 6948** ^This function sets the database handle error code and message. 6949*/ 6950int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 6951 6952/* 6953** CAPI3REF: Close A BLOB Handle 6954** DESTRUCTOR: sqlite3_blob 6955** 6956** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed 6957** unconditionally. Even if this routine returns an error code, the 6958** handle is still closed.)^ 6959** 6960** ^If the blob handle being closed was opened for read-write access, and if 6961** the database is in auto-commit mode and there are no other open read-write 6962** blob handles or active write statements, the current transaction is 6963** committed. ^If an error occurs while committing the transaction, an error 6964** code is returned and the transaction rolled back. 6965** 6966** Calling this function with an argument that is not a NULL pointer or an 6967** open blob handle results in undefined behaviour. ^Calling this routine 6968** with a null pointer (such as would be returned by a failed call to 6969** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function 6970** is passed a valid open blob handle, the values returned by the 6971** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning. 6972*/ 6973int sqlite3_blob_close(sqlite3_blob *); 6974 6975/* 6976** CAPI3REF: Return The Size Of An Open BLOB 6977** METHOD: sqlite3_blob 6978** 6979** ^Returns the size in bytes of the BLOB accessible via the 6980** successfully opened [BLOB handle] in its only argument. ^The 6981** incremental blob I/O routines can only read or overwriting existing 6982** blob content; they cannot change the size of a blob. 6983** 6984** This routine only works on a [BLOB handle] which has been created 6985** by a prior successful call to [sqlite3_blob_open()] and which has not 6986** been closed by [sqlite3_blob_close()]. Passing any other pointer in 6987** to this routine results in undefined and probably undesirable behavior. 6988*/ 6989int sqlite3_blob_bytes(sqlite3_blob *); 6990 6991/* 6992** CAPI3REF: Read Data From A BLOB Incrementally 6993** METHOD: sqlite3_blob 6994** 6995** ^(This function is used to read data from an open [BLOB handle] into a 6996** caller-supplied buffer. N bytes of data are copied into buffer Z 6997** from the open BLOB, starting at offset iOffset.)^ 6998** 6999** ^If offset iOffset is less than N bytes from the end of the BLOB, 7000** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 7001** less than zero, [SQLITE_ERROR] is returned and no data is read. 7002** ^The size of the blob (and hence the maximum value of N+iOffset) 7003** can be determined using the [sqlite3_blob_bytes()] interface. 7004** 7005** ^An attempt to read from an expired [BLOB handle] fails with an 7006** error code of [SQLITE_ABORT]. 7007** 7008** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 7009** Otherwise, an [error code] or an [extended error code] is returned.)^ 7010** 7011** This routine only works on a [BLOB handle] which has been created 7012** by a prior successful call to [sqlite3_blob_open()] and which has not 7013** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7014** to this routine results in undefined and probably undesirable behavior. 7015** 7016** See also: [sqlite3_blob_write()]. 7017*/ 7018int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 7019 7020/* 7021** CAPI3REF: Write Data Into A BLOB Incrementally 7022** METHOD: sqlite3_blob 7023** 7024** ^(This function is used to write data into an open [BLOB handle] from a 7025** caller-supplied buffer. N bytes of data are copied from the buffer Z 7026** into the open BLOB, starting at offset iOffset.)^ 7027** 7028** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 7029** Otherwise, an [error code] or an [extended error code] is returned.)^ 7030** ^Unless SQLITE_MISUSE is returned, this function sets the 7031** [database connection] error code and message accessible via 7032** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions. 7033** 7034** ^If the [BLOB handle] passed as the first argument was not opened for 7035** writing (the flags parameter to [sqlite3_blob_open()] was zero), 7036** this function returns [SQLITE_READONLY]. 7037** 7038** This function may only modify the contents of the BLOB; it is 7039** not possible to increase the size of a BLOB using this API. 7040** ^If offset iOffset is less than N bytes from the end of the BLOB, 7041** [SQLITE_ERROR] is returned and no data is written. The size of the 7042** BLOB (and hence the maximum value of N+iOffset) can be determined 7043** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less 7044** than zero [SQLITE_ERROR] is returned and no data is written. 7045** 7046** ^An attempt to write to an expired [BLOB handle] fails with an 7047** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 7048** before the [BLOB handle] expired are not rolled back by the 7049** expiration of the handle, though of course those changes might 7050** have been overwritten by the statement that expired the BLOB handle 7051** or by other independent statements. 7052** 7053** This routine only works on a [BLOB handle] which has been created 7054** by a prior successful call to [sqlite3_blob_open()] and which has not 7055** been closed by [sqlite3_blob_close()]. Passing any other pointer in 7056** to this routine results in undefined and probably undesirable behavior. 7057** 7058** See also: [sqlite3_blob_read()]. 7059*/ 7060int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 7061 7062/* 7063** CAPI3REF: Virtual File System Objects 7064** 7065** A virtual filesystem (VFS) is an [sqlite3_vfs] object 7066** that SQLite uses to interact 7067** with the underlying operating system. Most SQLite builds come with a 7068** single default VFS that is appropriate for the host computer. 7069** New VFSes can be registered and existing VFSes can be unregistered. 7070** The following interfaces are provided. 7071** 7072** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 7073** ^Names are case sensitive. 7074** ^Names are zero-terminated UTF-8 strings. 7075** ^If there is no match, a NULL pointer is returned. 7076** ^If zVfsName is NULL then the default VFS is returned. 7077** 7078** ^New VFSes are registered with sqlite3_vfs_register(). 7079** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 7080** ^The same VFS can be registered multiple times without injury. 7081** ^To make an existing VFS into the default VFS, register it again 7082** with the makeDflt flag set. If two different VFSes with the 7083** same name are registered, the behavior is undefined. If a 7084** VFS is registered with a name that is NULL or an empty string, 7085** then the behavior is undefined. 7086** 7087** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 7088** ^(If the default VFS is unregistered, another VFS is chosen as 7089** the default. The choice for the new VFS is arbitrary.)^ 7090*/ 7091sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 7092int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 7093int sqlite3_vfs_unregister(sqlite3_vfs*); 7094 7095/* 7096** CAPI3REF: Mutexes 7097** 7098** The SQLite core uses these routines for thread 7099** synchronization. Though they are intended for internal 7100** use by SQLite, code that links against SQLite is 7101** permitted to use any of these routines. 7102** 7103** The SQLite source code contains multiple implementations 7104** of these mutex routines. An appropriate implementation 7105** is selected automatically at compile-time. The following 7106** implementations are available in the SQLite core: 7107** 7108** <ul> 7109** <li> SQLITE_MUTEX_PTHREADS 7110** <li> SQLITE_MUTEX_W32 7111** <li> SQLITE_MUTEX_NOOP 7112** </ul> 7113** 7114** The SQLITE_MUTEX_NOOP implementation is a set of routines 7115** that does no real locking and is appropriate for use in 7116** a single-threaded application. The SQLITE_MUTEX_PTHREADS and 7117** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 7118** and Windows. 7119** 7120** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 7121** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 7122** implementation is included with the library. In this case the 7123** application must supply a custom mutex implementation using the 7124** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 7125** before calling sqlite3_initialize() or any other public sqlite3_ 7126** function that calls sqlite3_initialize(). 7127** 7128** ^The sqlite3_mutex_alloc() routine allocates a new 7129** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc() 7130** routine returns NULL if it is unable to allocate the requested 7131** mutex. The argument to sqlite3_mutex_alloc() must one of these 7132** integer constants: 7133** 7134** <ul> 7135** <li> SQLITE_MUTEX_FAST 7136** <li> SQLITE_MUTEX_RECURSIVE 7137** <li> SQLITE_MUTEX_STATIC_MASTER 7138** <li> SQLITE_MUTEX_STATIC_MEM 7139** <li> SQLITE_MUTEX_STATIC_OPEN 7140** <li> SQLITE_MUTEX_STATIC_PRNG 7141** <li> SQLITE_MUTEX_STATIC_LRU 7142** <li> SQLITE_MUTEX_STATIC_PMEM 7143** <li> SQLITE_MUTEX_STATIC_APP1 7144** <li> SQLITE_MUTEX_STATIC_APP2 7145** <li> SQLITE_MUTEX_STATIC_APP3 7146** <li> SQLITE_MUTEX_STATIC_VFS1 7147** <li> SQLITE_MUTEX_STATIC_VFS2 7148** <li> SQLITE_MUTEX_STATIC_VFS3 7149** </ul> 7150** 7151** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 7152** cause sqlite3_mutex_alloc() to create 7153** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 7154** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 7155** The mutex implementation does not need to make a distinction 7156** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 7157** not want to. SQLite will only request a recursive mutex in 7158** cases where it really needs one. If a faster non-recursive mutex 7159** implementation is available on the host platform, the mutex subsystem 7160** might return such a mutex in response to SQLITE_MUTEX_FAST. 7161** 7162** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 7163** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 7164** a pointer to a static preexisting mutex. ^Nine static mutexes are 7165** used by the current version of SQLite. Future versions of SQLite 7166** may add additional static mutexes. Static mutexes are for internal 7167** use by SQLite only. Applications that use SQLite mutexes should 7168** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 7169** SQLITE_MUTEX_RECURSIVE. 7170** 7171** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 7172** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 7173** returns a different mutex on every call. ^For the static 7174** mutex types, the same mutex is returned on every call that has 7175** the same type number. 7176** 7177** ^The sqlite3_mutex_free() routine deallocates a previously 7178** allocated dynamic mutex. Attempting to deallocate a static 7179** mutex results in undefined behavior. 7180** 7181** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 7182** to enter a mutex. ^If another thread is already within the mutex, 7183** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 7184** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 7185** upon successful entry. ^(Mutexes created using 7186** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 7187** In such cases, the 7188** mutex must be exited an equal number of times before another thread 7189** can enter.)^ If the same thread tries to enter any mutex other 7190** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined. 7191** 7192** ^(Some systems (for example, Windows 95) do not support the operation 7193** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 7194** will always return SQLITE_BUSY. The SQLite core only ever uses 7195** sqlite3_mutex_try() as an optimization so this is acceptable 7196** behavior.)^ 7197** 7198** ^The sqlite3_mutex_leave() routine exits a mutex that was 7199** previously entered by the same thread. The behavior 7200** is undefined if the mutex is not currently entered by the 7201** calling thread or is not currently allocated. 7202** 7203** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 7204** sqlite3_mutex_leave() is a NULL pointer, then all three routines 7205** behave as no-ops. 7206** 7207** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 7208*/ 7209sqlite3_mutex *sqlite3_mutex_alloc(int); 7210void sqlite3_mutex_free(sqlite3_mutex*); 7211void sqlite3_mutex_enter(sqlite3_mutex*); 7212int sqlite3_mutex_try(sqlite3_mutex*); 7213void sqlite3_mutex_leave(sqlite3_mutex*); 7214 7215/* 7216** CAPI3REF: Mutex Methods Object 7217** 7218** An instance of this structure defines the low-level routines 7219** used to allocate and use mutexes. 7220** 7221** Usually, the default mutex implementations provided by SQLite are 7222** sufficient, however the application has the option of substituting a custom 7223** implementation for specialized deployments or systems for which SQLite 7224** does not provide a suitable implementation. In this case, the application 7225** creates and populates an instance of this structure to pass 7226** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 7227** Additionally, an instance of this structure can be used as an 7228** output variable when querying the system for the current mutex 7229** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 7230** 7231** ^The xMutexInit method defined by this structure is invoked as 7232** part of system initialization by the sqlite3_initialize() function. 7233** ^The xMutexInit routine is called by SQLite exactly once for each 7234** effective call to [sqlite3_initialize()]. 7235** 7236** ^The xMutexEnd method defined by this structure is invoked as 7237** part of system shutdown by the sqlite3_shutdown() function. The 7238** implementation of this method is expected to release all outstanding 7239** resources obtained by the mutex methods implementation, especially 7240** those obtained by the xMutexInit method. ^The xMutexEnd() 7241** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 7242** 7243** ^(The remaining seven methods defined by this structure (xMutexAlloc, 7244** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 7245** xMutexNotheld) implement the following interfaces (respectively): 7246** 7247** <ul> 7248** <li> [sqlite3_mutex_alloc()] </li> 7249** <li> [sqlite3_mutex_free()] </li> 7250** <li> [sqlite3_mutex_enter()] </li> 7251** <li> [sqlite3_mutex_try()] </li> 7252** <li> [sqlite3_mutex_leave()] </li> 7253** <li> [sqlite3_mutex_held()] </li> 7254** <li> [sqlite3_mutex_notheld()] </li> 7255** </ul>)^ 7256** 7257** The only difference is that the public sqlite3_XXX functions enumerated 7258** above silently ignore any invocations that pass a NULL pointer instead 7259** of a valid mutex handle. The implementations of the methods defined 7260** by this structure are not required to handle this case. The results 7261** of passing a NULL pointer instead of a valid mutex handle are undefined 7262** (i.e. it is acceptable to provide an implementation that segfaults if 7263** it is passed a NULL pointer). 7264** 7265** The xMutexInit() method must be threadsafe. It must be harmless to 7266** invoke xMutexInit() multiple times within the same process and without 7267** intervening calls to xMutexEnd(). Second and subsequent calls to 7268** xMutexInit() must be no-ops. 7269** 7270** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 7271** and its associates). Similarly, xMutexAlloc() must not use SQLite memory 7272** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 7273** memory allocation for a fast or recursive mutex. 7274** 7275** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 7276** called, but only if the prior call to xMutexInit returned SQLITE_OK. 7277** If xMutexInit fails in any way, it is expected to clean up after itself 7278** prior to returning. 7279*/ 7280typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 7281struct sqlite3_mutex_methods { 7282 int (*xMutexInit)(void); 7283 int (*xMutexEnd)(void); 7284 sqlite3_mutex *(*xMutexAlloc)(int); 7285 void (*xMutexFree)(sqlite3_mutex *); 7286 void (*xMutexEnter)(sqlite3_mutex *); 7287 int (*xMutexTry)(sqlite3_mutex *); 7288 void (*xMutexLeave)(sqlite3_mutex *); 7289 int (*xMutexHeld)(sqlite3_mutex *); 7290 int (*xMutexNotheld)(sqlite3_mutex *); 7291}; 7292 7293/* 7294** CAPI3REF: Mutex Verification Routines 7295** 7296** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 7297** are intended for use inside assert() statements. The SQLite core 7298** never uses these routines except inside an assert() and applications 7299** are advised to follow the lead of the core. The SQLite core only 7300** provides implementations for these routines when it is compiled 7301** with the SQLITE_DEBUG flag. External mutex implementations 7302** are only required to provide these routines if SQLITE_DEBUG is 7303** defined and if NDEBUG is not defined. 7304** 7305** These routines should return true if the mutex in their argument 7306** is held or not held, respectively, by the calling thread. 7307** 7308** The implementation is not required to provide versions of these 7309** routines that actually work. If the implementation does not provide working 7310** versions of these routines, it should at least provide stubs that always 7311** return true so that one does not get spurious assertion failures. 7312** 7313** If the argument to sqlite3_mutex_held() is a NULL pointer then 7314** the routine should return 1. This seems counter-intuitive since 7315** clearly the mutex cannot be held if it does not exist. But 7316** the reason the mutex does not exist is because the build is not 7317** using mutexes. And we do not want the assert() containing the 7318** call to sqlite3_mutex_held() to fail, so a non-zero return is 7319** the appropriate thing to do. The sqlite3_mutex_notheld() 7320** interface should also return 1 when given a NULL pointer. 7321*/ 7322#ifndef NDEBUG 7323int sqlite3_mutex_held(sqlite3_mutex*); 7324int sqlite3_mutex_notheld(sqlite3_mutex*); 7325#endif 7326 7327/* 7328** CAPI3REF: Mutex Types 7329** 7330** The [sqlite3_mutex_alloc()] interface takes a single argument 7331** which is one of these integer constants. 7332** 7333** The set of static mutexes may change from one SQLite release to the 7334** next. Applications that override the built-in mutex logic must be 7335** prepared to accommodate additional static mutexes. 7336*/ 7337#define SQLITE_MUTEX_FAST 0 7338#define SQLITE_MUTEX_RECURSIVE 1 7339#define SQLITE_MUTEX_STATIC_MASTER 2 7340#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 7341#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 7342#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 7343#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */ 7344#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 7345#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 7346#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 7347#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 7348#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 7349#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 7350#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */ 7351#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */ 7352#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */ 7353 7354/* 7355** CAPI3REF: Retrieve the mutex for a database connection 7356** METHOD: sqlite3 7357** 7358** ^This interface returns a pointer the [sqlite3_mutex] object that 7359** serializes access to the [database connection] given in the argument 7360** when the [threading mode] is Serialized. 7361** ^If the [threading mode] is Single-thread or Multi-thread then this 7362** routine returns a NULL pointer. 7363*/ 7364sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 7365 7366/* 7367** CAPI3REF: Low-Level Control Of Database Files 7368** METHOD: sqlite3 7369** KEYWORDS: {file control} 7370** 7371** ^The [sqlite3_file_control()] interface makes a direct call to the 7372** xFileControl method for the [sqlite3_io_methods] object associated 7373** with a particular database identified by the second argument. ^The 7374** name of the database is "main" for the main database or "temp" for the 7375** TEMP database, or the name that appears after the AS keyword for 7376** databases that are added using the [ATTACH] SQL command. 7377** ^A NULL pointer can be used in place of "main" to refer to the 7378** main database file. 7379** ^The third and fourth parameters to this routine 7380** are passed directly through to the second and third parameters of 7381** the xFileControl method. ^The return value of the xFileControl 7382** method becomes the return value of this routine. 7383** 7384** A few opcodes for [sqlite3_file_control()] are handled directly 7385** by the SQLite core and never invoke the 7386** sqlite3_io_methods.xFileControl method. 7387** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes 7388** a pointer to the underlying [sqlite3_file] object to be written into 7389** the space pointed to by the 4th parameter. The 7390** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns 7391** the [sqlite3_file] object associated with the journal file instead of 7392** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns 7393** a pointer to the underlying [sqlite3_vfs] object for the file. 7394** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter 7395** from the pager. 7396** 7397** ^If the second parameter (zDbName) does not match the name of any 7398** open database file, then SQLITE_ERROR is returned. ^This error 7399** code is not remembered and will not be recalled by [sqlite3_errcode()] 7400** or [sqlite3_errmsg()]. The underlying xFileControl method might 7401** also return SQLITE_ERROR. There is no way to distinguish between 7402** an incorrect zDbName and an SQLITE_ERROR return from the underlying 7403** xFileControl method. 7404** 7405** See also: [file control opcodes] 7406*/ 7407int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 7408 7409/* 7410** CAPI3REF: Testing Interface 7411** 7412** ^The sqlite3_test_control() interface is used to read out internal 7413** state of SQLite and to inject faults into SQLite for testing 7414** purposes. ^The first parameter is an operation code that determines 7415** the number, meaning, and operation of all subsequent parameters. 7416** 7417** This interface is not for use by applications. It exists solely 7418** for verifying the correct operation of the SQLite library. Depending 7419** on how the SQLite library is compiled, this interface might not exist. 7420** 7421** The details of the operation codes, their meanings, the parameters 7422** they take, and what they do are all subject to change without notice. 7423** Unlike most of the SQLite API, this function is not guaranteed to 7424** operate consistently from one release to the next. 7425*/ 7426int sqlite3_test_control(int op, ...); 7427 7428/* 7429** CAPI3REF: Testing Interface Operation Codes 7430** 7431** These constants are the valid operation code parameters used 7432** as the first argument to [sqlite3_test_control()]. 7433** 7434** These parameters and their meanings are subject to change 7435** without notice. These values are for testing purposes only. 7436** Applications should not use any of these parameters or the 7437** [sqlite3_test_control()] interface. 7438*/ 7439#define SQLITE_TESTCTRL_FIRST 5 7440#define SQLITE_TESTCTRL_PRNG_SAVE 5 7441#define SQLITE_TESTCTRL_PRNG_RESTORE 6 7442#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */ 7443#define SQLITE_TESTCTRL_BITVEC_TEST 8 7444#define SQLITE_TESTCTRL_FAULT_INSTALL 9 7445#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 7446#define SQLITE_TESTCTRL_PENDING_BYTE 11 7447#define SQLITE_TESTCTRL_ASSERT 12 7448#define SQLITE_TESTCTRL_ALWAYS 13 7449#define SQLITE_TESTCTRL_RESERVE 14 7450#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 7451#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */ 7452#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */ 7453#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17 7454#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 7455#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */ 7456#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19 7457#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 7458#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 7459#define SQLITE_TESTCTRL_BYTEORDER 22 7460#define SQLITE_TESTCTRL_ISINIT 23 7461#define SQLITE_TESTCTRL_SORTER_MMAP 24 7462#define SQLITE_TESTCTRL_IMPOSTER 25 7463#define SQLITE_TESTCTRL_PARSER_COVERAGE 26 7464#define SQLITE_TESTCTRL_RESULT_INTREAL 27 7465#define SQLITE_TESTCTRL_PRNG_SEED 28 7466#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29 7467#define SQLITE_TESTCTRL_LAST 29 /* Largest TESTCTRL */ 7468 7469/* 7470** CAPI3REF: SQL Keyword Checking 7471** 7472** These routines provide access to the set of SQL language keywords 7473** recognized by SQLite. Applications can uses these routines to determine 7474** whether or not a specific identifier needs to be escaped (for example, 7475** by enclosing in double-quotes) so as not to confuse the parser. 7476** 7477** The sqlite3_keyword_count() interface returns the number of distinct 7478** keywords understood by SQLite. 7479** 7480** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and 7481** makes *Z point to that keyword expressed as UTF8 and writes the number 7482** of bytes in the keyword into *L. The string that *Z points to is not 7483** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns 7484** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z 7485** or L are NULL or invalid pointers then calls to 7486** sqlite3_keyword_name(N,Z,L) result in undefined behavior. 7487** 7488** The sqlite3_keyword_check(Z,L) interface checks to see whether or not 7489** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero 7490** if it is and zero if not. 7491** 7492** The parser used by SQLite is forgiving. It is often possible to use 7493** a keyword as an identifier as long as such use does not result in a 7494** parsing ambiguity. For example, the statement 7495** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and 7496** creates a new table named "BEGIN" with three columns named 7497** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid 7498** using keywords as identifiers. Common techniques used to avoid keyword 7499** name collisions include: 7500** <ul> 7501** <li> Put all identifier names inside double-quotes. This is the official 7502** SQL way to escape identifier names. 7503** <li> Put identifier names inside [...]. This is not standard SQL, 7504** but it is what SQL Server does and so lots of programmers use this 7505** technique. 7506** <li> Begin every identifier with the letter "Z" as no SQL keywords start 7507** with "Z". 7508** <li> Include a digit somewhere in every identifier name. 7509** </ul> 7510** 7511** Note that the number of keywords understood by SQLite can depend on 7512** compile-time options. For example, "VACUUM" is not a keyword if 7513** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also, 7514** new keywords may be added to future releases of SQLite. 7515*/ 7516int sqlite3_keyword_count(void); 7517int sqlite3_keyword_name(int,const char**,int*); 7518int sqlite3_keyword_check(const char*,int); 7519 7520/* 7521** CAPI3REF: Dynamic String Object 7522** KEYWORDS: {dynamic string} 7523** 7524** An instance of the sqlite3_str object contains a dynamically-sized 7525** string under construction. 7526** 7527** The lifecycle of an sqlite3_str object is as follows: 7528** <ol> 7529** <li> ^The sqlite3_str object is created using [sqlite3_str_new()]. 7530** <li> ^Text is appended to the sqlite3_str object using various 7531** methods, such as [sqlite3_str_appendf()]. 7532** <li> ^The sqlite3_str object is destroyed and the string it created 7533** is returned using the [sqlite3_str_finish()] interface. 7534** </ol> 7535*/ 7536typedef struct sqlite3_str sqlite3_str; 7537 7538/* 7539** CAPI3REF: Create A New Dynamic String Object 7540** CONSTRUCTOR: sqlite3_str 7541** 7542** ^The [sqlite3_str_new(D)] interface allocates and initializes 7543** a new [sqlite3_str] object. To avoid memory leaks, the object returned by 7544** [sqlite3_str_new()] must be freed by a subsequent call to 7545** [sqlite3_str_finish(X)]. 7546** 7547** ^The [sqlite3_str_new(D)] interface always returns a pointer to a 7548** valid [sqlite3_str] object, though in the event of an out-of-memory 7549** error the returned object might be a special singleton that will 7550** silently reject new text, always return SQLITE_NOMEM from 7551** [sqlite3_str_errcode()], always return 0 for 7552** [sqlite3_str_length()], and always return NULL from 7553** [sqlite3_str_finish(X)]. It is always safe to use the value 7554** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter 7555** to any of the other [sqlite3_str] methods. 7556** 7557** The D parameter to [sqlite3_str_new(D)] may be NULL. If the 7558** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum 7559** length of the string contained in the [sqlite3_str] object will be 7560** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead 7561** of [SQLITE_MAX_LENGTH]. 7562*/ 7563sqlite3_str *sqlite3_str_new(sqlite3*); 7564 7565/* 7566** CAPI3REF: Finalize A Dynamic String 7567** DESTRUCTOR: sqlite3_str 7568** 7569** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X 7570** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()] 7571** that contains the constructed string. The calling application should 7572** pass the returned value to [sqlite3_free()] to avoid a memory leak. 7573** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any 7574** errors were encountered during construction of the string. ^The 7575** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the 7576** string in [sqlite3_str] object X is zero bytes long. 7577*/ 7578char *sqlite3_str_finish(sqlite3_str*); 7579 7580/* 7581** CAPI3REF: Add Content To A Dynamic String 7582** METHOD: sqlite3_str 7583** 7584** These interfaces add content to an sqlite3_str object previously obtained 7585** from [sqlite3_str_new()]. 7586** 7587** ^The [sqlite3_str_appendf(X,F,...)] and 7588** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf] 7589** functionality of SQLite to append formatted text onto the end of 7590** [sqlite3_str] object X. 7591** 7592** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S 7593** onto the end of the [sqlite3_str] object X. N must be non-negative. 7594** S must contain at least N non-zero bytes of content. To append a 7595** zero-terminated string in its entirety, use the [sqlite3_str_appendall()] 7596** method instead. 7597** 7598** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of 7599** zero-terminated string S onto the end of [sqlite3_str] object X. 7600** 7601** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the 7602** single-byte character C onto the end of [sqlite3_str] object X. 7603** ^This method can be used, for example, to add whitespace indentation. 7604** 7605** ^The [sqlite3_str_reset(X)] method resets the string under construction 7606** inside [sqlite3_str] object X back to zero bytes in length. 7607** 7608** These methods do not return a result code. ^If an error occurs, that fact 7609** is recorded in the [sqlite3_str] object and can be recovered by a 7610** subsequent call to [sqlite3_str_errcode(X)]. 7611*/ 7612void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...); 7613void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list); 7614void sqlite3_str_append(sqlite3_str*, const char *zIn, int N); 7615void sqlite3_str_appendall(sqlite3_str*, const char *zIn); 7616void sqlite3_str_appendchar(sqlite3_str*, int N, char C); 7617void sqlite3_str_reset(sqlite3_str*); 7618 7619/* 7620** CAPI3REF: Status Of A Dynamic String 7621** METHOD: sqlite3_str 7622** 7623** These interfaces return the current status of an [sqlite3_str] object. 7624** 7625** ^If any prior errors have occurred while constructing the dynamic string 7626** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return 7627** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns 7628** [SQLITE_NOMEM] following any out-of-memory error, or 7629** [SQLITE_TOOBIG] if the size of the dynamic string exceeds 7630** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors. 7631** 7632** ^The [sqlite3_str_length(X)] method returns the current length, in bytes, 7633** of the dynamic string under construction in [sqlite3_str] object X. 7634** ^The length returned by [sqlite3_str_length(X)] does not include the 7635** zero-termination byte. 7636** 7637** ^The [sqlite3_str_value(X)] method returns a pointer to the current 7638** content of the dynamic string under construction in X. The value 7639** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X 7640** and might be freed or altered by any subsequent method on the same 7641** [sqlite3_str] object. Applications must not used the pointer returned 7642** [sqlite3_str_value(X)] after any subsequent method call on the same 7643** object. ^Applications may change the content of the string returned 7644** by [sqlite3_str_value(X)] as long as they do not write into any bytes 7645** outside the range of 0 to [sqlite3_str_length(X)] and do not read or 7646** write any byte after any subsequent sqlite3_str method call. 7647*/ 7648int sqlite3_str_errcode(sqlite3_str*); 7649int sqlite3_str_length(sqlite3_str*); 7650char *sqlite3_str_value(sqlite3_str*); 7651 7652/* 7653** CAPI3REF: SQLite Runtime Status 7654** 7655** ^These interfaces are used to retrieve runtime status information 7656** about the performance of SQLite, and optionally to reset various 7657** highwater marks. ^The first argument is an integer code for 7658** the specific parameter to measure. ^(Recognized integer codes 7659** are of the form [status parameters | SQLITE_STATUS_...].)^ 7660** ^The current value of the parameter is returned into *pCurrent. 7661** ^The highest recorded value is returned in *pHighwater. ^If the 7662** resetFlag is true, then the highest record value is reset after 7663** *pHighwater is written. ^(Some parameters do not record the highest 7664** value. For those parameters 7665** nothing is written into *pHighwater and the resetFlag is ignored.)^ 7666** ^(Other parameters record only the highwater mark and not the current 7667** value. For these latter parameters nothing is written into *pCurrent.)^ 7668** 7669** ^The sqlite3_status() and sqlite3_status64() routines return 7670** SQLITE_OK on success and a non-zero [error code] on failure. 7671** 7672** If either the current value or the highwater mark is too large to 7673** be represented by a 32-bit integer, then the values returned by 7674** sqlite3_status() are undefined. 7675** 7676** See also: [sqlite3_db_status()] 7677*/ 7678int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 7679int sqlite3_status64( 7680 int op, 7681 sqlite3_int64 *pCurrent, 7682 sqlite3_int64 *pHighwater, 7683 int resetFlag 7684); 7685 7686 7687/* 7688** CAPI3REF: Status Parameters 7689** KEYWORDS: {status parameters} 7690** 7691** These integer constants designate various run-time status parameters 7692** that can be returned by [sqlite3_status()]. 7693** 7694** <dl> 7695** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 7696** <dd>This parameter is the current amount of memory checked out 7697** using [sqlite3_malloc()], either directly or indirectly. The 7698** figure includes calls made to [sqlite3_malloc()] by the application 7699** and internal memory usage by the SQLite library. Auxiliary page-cache 7700** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 7701** this parameter. The amount returned is the sum of the allocation 7702** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 7703** 7704** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 7705** <dd>This parameter records the largest memory allocation request 7706** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 7707** internal equivalents). Only the value returned in the 7708** *pHighwater parameter to [sqlite3_status()] is of interest. 7709** The value written into the *pCurrent parameter is undefined.</dd>)^ 7710** 7711** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 7712** <dd>This parameter records the number of separate memory allocations 7713** currently checked out.</dd>)^ 7714** 7715** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 7716** <dd>This parameter returns the number of pages used out of the 7717** [pagecache memory allocator] that was configured using 7718** [SQLITE_CONFIG_PAGECACHE]. The 7719** value returned is in pages, not in bytes.</dd>)^ 7720** 7721** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 7722** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 7723** <dd>This parameter returns the number of bytes of page cache 7724** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 7725** buffer and where forced to overflow to [sqlite3_malloc()]. The 7726** returned value includes allocations that overflowed because they 7727** where too large (they were larger than the "sz" parameter to 7728** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 7729** no space was left in the page cache.</dd>)^ 7730** 7731** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 7732** <dd>This parameter records the largest memory allocation request 7733** handed to the [pagecache memory allocator]. Only the value returned in the 7734** *pHighwater parameter to [sqlite3_status()] is of interest. 7735** The value written into the *pCurrent parameter is undefined.</dd>)^ 7736** 7737** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt> 7738** <dd>No longer used.</dd> 7739** 7740** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 7741** <dd>No longer used.</dd> 7742** 7743** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 7744** <dd>No longer used.</dd> 7745** 7746** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 7747** <dd>The *pHighwater parameter records the deepest parser stack. 7748** The *pCurrent value is undefined. The *pHighwater value is only 7749** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 7750** </dl> 7751** 7752** New status parameters may be added from time to time. 7753*/ 7754#define SQLITE_STATUS_MEMORY_USED 0 7755#define SQLITE_STATUS_PAGECACHE_USED 1 7756#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 7757#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */ 7758#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */ 7759#define SQLITE_STATUS_MALLOC_SIZE 5 7760#define SQLITE_STATUS_PARSER_STACK 6 7761#define SQLITE_STATUS_PAGECACHE_SIZE 7 7762#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */ 7763#define SQLITE_STATUS_MALLOC_COUNT 9 7764 7765/* 7766** CAPI3REF: Database Connection Status 7767** METHOD: sqlite3 7768** 7769** ^This interface is used to retrieve runtime status information 7770** about a single [database connection]. ^The first argument is the 7771** database connection object to be interrogated. ^The second argument 7772** is an integer constant, taken from the set of 7773** [SQLITE_DBSTATUS options], that 7774** determines the parameter to interrogate. The set of 7775** [SQLITE_DBSTATUS options] is likely 7776** to grow in future releases of SQLite. 7777** 7778** ^The current value of the requested parameter is written into *pCur 7779** and the highest instantaneous value is written into *pHiwtr. ^If 7780** the resetFlg is true, then the highest instantaneous value is 7781** reset back down to the current value. 7782** 7783** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 7784** non-zero [error code] on failure. 7785** 7786** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 7787*/ 7788int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 7789 7790/* 7791** CAPI3REF: Status Parameters for database connections 7792** KEYWORDS: {SQLITE_DBSTATUS options} 7793** 7794** These constants are the available integer "verbs" that can be passed as 7795** the second argument to the [sqlite3_db_status()] interface. 7796** 7797** New verbs may be added in future releases of SQLite. Existing verbs 7798** might be discontinued. Applications should check the return code from 7799** [sqlite3_db_status()] to make sure that the call worked. 7800** The [sqlite3_db_status()] interface will return a non-zero error code 7801** if a discontinued or unsupported verb is invoked. 7802** 7803** <dl> 7804** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 7805** <dd>This parameter returns the number of lookaside memory slots currently 7806** checked out.</dd>)^ 7807** 7808** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 7809** <dd>This parameter returns the number of malloc attempts that were 7810** satisfied using lookaside memory. Only the high-water value is meaningful; 7811** the current value is always zero.)^ 7812** 7813** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 7814** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 7815** <dd>This parameter returns the number malloc attempts that might have 7816** been satisfied using lookaside memory but failed due to the amount of 7817** memory requested being larger than the lookaside slot size. 7818** Only the high-water value is meaningful; 7819** the current value is always zero.)^ 7820** 7821** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 7822** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 7823** <dd>This parameter returns the number malloc attempts that might have 7824** been satisfied using lookaside memory but failed due to all lookaside 7825** memory already being in use. 7826** Only the high-water value is meaningful; 7827** the current value is always zero.)^ 7828** 7829** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 7830** <dd>This parameter returns the approximate number of bytes of heap 7831** memory used by all pager caches associated with the database connection.)^ 7832** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 7833** 7834** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]] 7835** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt> 7836** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a 7837** pager cache is shared between two or more connections the bytes of heap 7838** memory used by that pager cache is divided evenly between the attached 7839** connections.)^ In other words, if none of the pager caches associated 7840** with the database connection are shared, this request returns the same 7841** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are 7842** shared, the value returned by this call will be smaller than that returned 7843** by DBSTATUS_CACHE_USED. ^The highwater mark associated with 7844** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0. 7845** 7846** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 7847** <dd>This parameter returns the approximate number of bytes of heap 7848** memory used to store the schema for all databases associated 7849** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 7850** ^The full amount of memory used by the schemas is reported, even if the 7851** schema memory is shared with other database connections due to 7852** [shared cache mode] being enabled. 7853** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 7854** 7855** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 7856** <dd>This parameter returns the approximate number of bytes of heap 7857** and lookaside memory used by all prepared statements associated with 7858** the database connection.)^ 7859** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 7860** </dd> 7861** 7862** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 7863** <dd>This parameter returns the number of pager cache hits that have 7864** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 7865** is always 0. 7866** </dd> 7867** 7868** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 7869** <dd>This parameter returns the number of pager cache misses that have 7870** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 7871** is always 0. 7872** </dd> 7873** 7874** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 7875** <dd>This parameter returns the number of dirty cache entries that have 7876** been written to disk. Specifically, the number of pages written to the 7877** wal file in wal mode databases, or the number of pages written to the 7878** database file in rollback mode databases. Any pages written as part of 7879** transaction rollback or database recovery operations are not included. 7880** If an IO or other error occurs while writing a page to disk, the effect 7881** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 7882** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 7883** </dd> 7884** 7885** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt> 7886** <dd>This parameter returns the number of dirty cache entries that have 7887** been written to disk in the middle of a transaction due to the page 7888** cache overflowing. Transactions are more efficient if they are written 7889** to disk all at once. When pages spill mid-transaction, that introduces 7890** additional overhead. This parameter can be used help identify 7891** inefficiencies that can be resolved by increasing the cache size. 7892** </dd> 7893** 7894** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 7895** <dd>This parameter returns zero for the current value if and only if 7896** all foreign key constraints (deferred or immediate) have been 7897** resolved.)^ ^The highwater mark is always 0. 7898** </dd> 7899** </dl> 7900*/ 7901#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 7902#define SQLITE_DBSTATUS_CACHE_USED 1 7903#define SQLITE_DBSTATUS_SCHEMA_USED 2 7904#define SQLITE_DBSTATUS_STMT_USED 3 7905#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 7906#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 7907#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 7908#define SQLITE_DBSTATUS_CACHE_HIT 7 7909#define SQLITE_DBSTATUS_CACHE_MISS 8 7910#define SQLITE_DBSTATUS_CACHE_WRITE 9 7911#define SQLITE_DBSTATUS_DEFERRED_FKS 10 7912#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11 7913#define SQLITE_DBSTATUS_CACHE_SPILL 12 7914#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */ 7915 7916 7917/* 7918** CAPI3REF: Prepared Statement Status 7919** METHOD: sqlite3_stmt 7920** 7921** ^(Each prepared statement maintains various 7922** [SQLITE_STMTSTATUS counters] that measure the number 7923** of times it has performed specific operations.)^ These counters can 7924** be used to monitor the performance characteristics of the prepared 7925** statements. For example, if the number of table steps greatly exceeds 7926** the number of table searches or result rows, that would tend to indicate 7927** that the prepared statement is using a full table scan rather than 7928** an index. 7929** 7930** ^(This interface is used to retrieve and reset counter values from 7931** a [prepared statement]. The first argument is the prepared statement 7932** object to be interrogated. The second argument 7933** is an integer code for a specific [SQLITE_STMTSTATUS counter] 7934** to be interrogated.)^ 7935** ^The current value of the requested counter is returned. 7936** ^If the resetFlg is true, then the counter is reset to zero after this 7937** interface call returns. 7938** 7939** See also: [sqlite3_status()] and [sqlite3_db_status()]. 7940*/ 7941int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 7942 7943/* 7944** CAPI3REF: Status Parameters for prepared statements 7945** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 7946** 7947** These preprocessor macros define integer codes that name counter 7948** values associated with the [sqlite3_stmt_status()] interface. 7949** The meanings of the various counters are as follows: 7950** 7951** <dl> 7952** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 7953** <dd>^This is the number of times that SQLite has stepped forward in 7954** a table as part of a full table scan. Large numbers for this counter 7955** may indicate opportunities for performance improvement through 7956** careful use of indices.</dd> 7957** 7958** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 7959** <dd>^This is the number of sort operations that have occurred. 7960** A non-zero value in this counter may indicate an opportunity to 7961** improvement performance through careful use of indices.</dd> 7962** 7963** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 7964** <dd>^This is the number of rows inserted into transient indices that 7965** were created automatically in order to help joins run faster. 7966** A non-zero value in this counter may indicate an opportunity to 7967** improvement performance by adding permanent indices that do not 7968** need to be reinitialized each time the statement is run.</dd> 7969** 7970** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 7971** <dd>^This is the number of virtual machine operations executed 7972** by the prepared statement if that number is less than or equal 7973** to 2147483647. The number of virtual machine operations can be 7974** used as a proxy for the total work done by the prepared statement. 7975** If the number of virtual machine operations exceeds 2147483647 7976** then the value returned by this statement status code is undefined. 7977** 7978** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt> 7979** <dd>^This is the number of times that the prepare statement has been 7980** automatically regenerated due to schema changes or changes to 7981** [bound parameters] that might affect the query plan. 7982** 7983** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt> 7984** <dd>^This is the number of times that the prepared statement has 7985** been run. A single "run" for the purposes of this counter is one 7986** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()]. 7987** The counter is incremented on the first [sqlite3_step()] call of each 7988** cycle. 7989** 7990** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt> 7991** <dd>^This is the approximate number of bytes of heap memory 7992** used to store the prepared statement. ^This value is not actually 7993** a counter, and so the resetFlg parameter to sqlite3_stmt_status() 7994** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED. 7995** </dd> 7996** </dl> 7997*/ 7998#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 7999#define SQLITE_STMTSTATUS_SORT 2 8000#define SQLITE_STMTSTATUS_AUTOINDEX 3 8001#define SQLITE_STMTSTATUS_VM_STEP 4 8002#define SQLITE_STMTSTATUS_REPREPARE 5 8003#define SQLITE_STMTSTATUS_RUN 6 8004#define SQLITE_STMTSTATUS_MEMUSED 99 8005 8006/* 8007** CAPI3REF: Custom Page Cache Object 8008** 8009** The sqlite3_pcache type is opaque. It is implemented by 8010** the pluggable module. The SQLite core has no knowledge of 8011** its size or internal structure and never deals with the 8012** sqlite3_pcache object except by holding and passing pointers 8013** to the object. 8014** 8015** See [sqlite3_pcache_methods2] for additional information. 8016*/ 8017typedef struct sqlite3_pcache sqlite3_pcache; 8018 8019/* 8020** CAPI3REF: Custom Page Cache Object 8021** 8022** The sqlite3_pcache_page object represents a single page in the 8023** page cache. The page cache will allocate instances of this 8024** object. Various methods of the page cache use pointers to instances 8025** of this object as parameters or as their return value. 8026** 8027** See [sqlite3_pcache_methods2] for additional information. 8028*/ 8029typedef struct sqlite3_pcache_page sqlite3_pcache_page; 8030struct sqlite3_pcache_page { 8031 void *pBuf; /* The content of the page */ 8032 void *pExtra; /* Extra information associated with the page */ 8033}; 8034 8035/* 8036** CAPI3REF: Application Defined Page Cache. 8037** KEYWORDS: {page cache} 8038** 8039** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 8040** register an alternative page cache implementation by passing in an 8041** instance of the sqlite3_pcache_methods2 structure.)^ 8042** In many applications, most of the heap memory allocated by 8043** SQLite is used for the page cache. 8044** By implementing a 8045** custom page cache using this API, an application can better control 8046** the amount of memory consumed by SQLite, the way in which 8047** that memory is allocated and released, and the policies used to 8048** determine exactly which parts of a database file are cached and for 8049** how long. 8050** 8051** The alternative page cache mechanism is an 8052** extreme measure that is only needed by the most demanding applications. 8053** The built-in page cache is recommended for most uses. 8054** 8055** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 8056** internal buffer by SQLite within the call to [sqlite3_config]. Hence 8057** the application may discard the parameter after the call to 8058** [sqlite3_config()] returns.)^ 8059** 8060** [[the xInit() page cache method]] 8061** ^(The xInit() method is called once for each effective 8062** call to [sqlite3_initialize()])^ 8063** (usually only once during the lifetime of the process). ^(The xInit() 8064** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 8065** The intent of the xInit() method is to set up global data structures 8066** required by the custom page cache implementation. 8067** ^(If the xInit() method is NULL, then the 8068** built-in default page cache is used instead of the application defined 8069** page cache.)^ 8070** 8071** [[the xShutdown() page cache method]] 8072** ^The xShutdown() method is called by [sqlite3_shutdown()]. 8073** It can be used to clean up 8074** any outstanding resources before process shutdown, if required. 8075** ^The xShutdown() method may be NULL. 8076** 8077** ^SQLite automatically serializes calls to the xInit method, 8078** so the xInit method need not be threadsafe. ^The 8079** xShutdown method is only called from [sqlite3_shutdown()] so it does 8080** not need to be threadsafe either. All other methods must be threadsafe 8081** in multithreaded applications. 8082** 8083** ^SQLite will never invoke xInit() more than once without an intervening 8084** call to xShutdown(). 8085** 8086** [[the xCreate() page cache methods]] 8087** ^SQLite invokes the xCreate() method to construct a new cache instance. 8088** SQLite will typically create one cache instance for each open database file, 8089** though this is not guaranteed. ^The 8090** first parameter, szPage, is the size in bytes of the pages that must 8091** be allocated by the cache. ^szPage will always a power of two. ^The 8092** second parameter szExtra is a number of bytes of extra storage 8093** associated with each page cache entry. ^The szExtra parameter will 8094** a number less than 250. SQLite will use the 8095** extra szExtra bytes on each page to store metadata about the underlying 8096** database page on disk. The value passed into szExtra depends 8097** on the SQLite version, the target platform, and how SQLite was compiled. 8098** ^The third argument to xCreate(), bPurgeable, is true if the cache being 8099** created will be used to cache database pages of a file stored on disk, or 8100** false if it is used for an in-memory database. The cache implementation 8101** does not have to do anything special based with the value of bPurgeable; 8102** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 8103** never invoke xUnpin() except to deliberately delete a page. 8104** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 8105** false will always have the "discard" flag set to true. 8106** ^Hence, a cache created with bPurgeable false will 8107** never contain any unpinned pages. 8108** 8109** [[the xCachesize() page cache method]] 8110** ^(The xCachesize() method may be called at any time by SQLite to set the 8111** suggested maximum cache-size (number of pages stored by) the cache 8112** instance passed as the first argument. This is the value configured using 8113** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 8114** parameter, the implementation is not required to do anything with this 8115** value; it is advisory only. 8116** 8117** [[the xPagecount() page cache methods]] 8118** The xPagecount() method must return the number of pages currently 8119** stored in the cache, both pinned and unpinned. 8120** 8121** [[the xFetch() page cache methods]] 8122** The xFetch() method locates a page in the cache and returns a pointer to 8123** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 8124** The pBuf element of the returned sqlite3_pcache_page object will be a 8125** pointer to a buffer of szPage bytes used to store the content of a 8126** single database page. The pExtra element of sqlite3_pcache_page will be 8127** a pointer to the szExtra bytes of extra storage that SQLite has requested 8128** for each entry in the page cache. 8129** 8130** The page to be fetched is determined by the key. ^The minimum key value 8131** is 1. After it has been retrieved using xFetch, the page is considered 8132** to be "pinned". 8133** 8134** If the requested page is already in the page cache, then the page cache 8135** implementation must return a pointer to the page buffer with its content 8136** intact. If the requested page is not already in the cache, then the 8137** cache implementation should use the value of the createFlag 8138** parameter to help it determined what action to take: 8139** 8140** <table border=1 width=85% align=center> 8141** <tr><th> createFlag <th> Behavior when page is not already in cache 8142** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 8143** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 8144** Otherwise return NULL. 8145** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 8146** NULL if allocating a new page is effectively impossible. 8147** </table> 8148** 8149** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 8150** will only use a createFlag of 2 after a prior call with a createFlag of 1 8151** failed.)^ In between the xFetch() calls, SQLite may 8152** attempt to unpin one or more cache pages by spilling the content of 8153** pinned pages to disk and synching the operating system disk cache. 8154** 8155** [[the xUnpin() page cache method]] 8156** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 8157** as its second argument. If the third parameter, discard, is non-zero, 8158** then the page must be evicted from the cache. 8159** ^If the discard parameter is 8160** zero, then the page may be discarded or retained at the discretion of 8161** page cache implementation. ^The page cache implementation 8162** may choose to evict unpinned pages at any time. 8163** 8164** The cache must not perform any reference counting. A single 8165** call to xUnpin() unpins the page regardless of the number of prior calls 8166** to xFetch(). 8167** 8168** [[the xRekey() page cache methods]] 8169** The xRekey() method is used to change the key value associated with the 8170** page passed as the second argument. If the cache 8171** previously contains an entry associated with newKey, it must be 8172** discarded. ^Any prior cache entry associated with newKey is guaranteed not 8173** to be pinned. 8174** 8175** When SQLite calls the xTruncate() method, the cache must discard all 8176** existing cache entries with page numbers (keys) greater than or equal 8177** to the value of the iLimit parameter passed to xTruncate(). If any 8178** of these pages are pinned, they are implicitly unpinned, meaning that 8179** they can be safely discarded. 8180** 8181** [[the xDestroy() page cache method]] 8182** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 8183** All resources associated with the specified cache should be freed. ^After 8184** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 8185** handle invalid, and will not use it with any other sqlite3_pcache_methods2 8186** functions. 8187** 8188** [[the xShrink() page cache method]] 8189** ^SQLite invokes the xShrink() method when it wants the page cache to 8190** free up as much of heap memory as possible. The page cache implementation 8191** is not obligated to free any memory, but well-behaved implementations should 8192** do their best. 8193*/ 8194typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 8195struct sqlite3_pcache_methods2 { 8196 int iVersion; 8197 void *pArg; 8198 int (*xInit)(void*); 8199 void (*xShutdown)(void*); 8200 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 8201 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8202 int (*xPagecount)(sqlite3_pcache*); 8203 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8204 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 8205 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 8206 unsigned oldKey, unsigned newKey); 8207 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8208 void (*xDestroy)(sqlite3_pcache*); 8209 void (*xShrink)(sqlite3_pcache*); 8210}; 8211 8212/* 8213** This is the obsolete pcache_methods object that has now been replaced 8214** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 8215** retained in the header file for backwards compatibility only. 8216*/ 8217typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 8218struct sqlite3_pcache_methods { 8219 void *pArg; 8220 int (*xInit)(void*); 8221 void (*xShutdown)(void*); 8222 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 8223 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 8224 int (*xPagecount)(sqlite3_pcache*); 8225 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 8226 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 8227 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 8228 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 8229 void (*xDestroy)(sqlite3_pcache*); 8230}; 8231 8232 8233/* 8234** CAPI3REF: Online Backup Object 8235** 8236** The sqlite3_backup object records state information about an ongoing 8237** online backup operation. ^The sqlite3_backup object is created by 8238** a call to [sqlite3_backup_init()] and is destroyed by a call to 8239** [sqlite3_backup_finish()]. 8240** 8241** See Also: [Using the SQLite Online Backup API] 8242*/ 8243typedef struct sqlite3_backup sqlite3_backup; 8244 8245/* 8246** CAPI3REF: Online Backup API. 8247** 8248** The backup API copies the content of one database into another. 8249** It is useful either for creating backups of databases or 8250** for copying in-memory databases to or from persistent files. 8251** 8252** See Also: [Using the SQLite Online Backup API] 8253** 8254** ^SQLite holds a write transaction open on the destination database file 8255** for the duration of the backup operation. 8256** ^The source database is read-locked only while it is being read; 8257** it is not locked continuously for the entire backup operation. 8258** ^Thus, the backup may be performed on a live source database without 8259** preventing other database connections from 8260** reading or writing to the source database while the backup is underway. 8261** 8262** ^(To perform a backup operation: 8263** <ol> 8264** <li><b>sqlite3_backup_init()</b> is called once to initialize the 8265** backup, 8266** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 8267** the data between the two databases, and finally 8268** <li><b>sqlite3_backup_finish()</b> is called to release all resources 8269** associated with the backup operation. 8270** </ol>)^ 8271** There should be exactly one call to sqlite3_backup_finish() for each 8272** successful call to sqlite3_backup_init(). 8273** 8274** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 8275** 8276** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 8277** [database connection] associated with the destination database 8278** and the database name, respectively. 8279** ^The database name is "main" for the main database, "temp" for the 8280** temporary database, or the name specified after the AS keyword in 8281** an [ATTACH] statement for an attached database. 8282** ^The S and M arguments passed to 8283** sqlite3_backup_init(D,N,S,M) identify the [database connection] 8284** and database name of the source database, respectively. 8285** ^The source and destination [database connections] (parameters S and D) 8286** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 8287** an error. 8288** 8289** ^A call to sqlite3_backup_init() will fail, returning NULL, if 8290** there is already a read or read-write transaction open on the 8291** destination database. 8292** 8293** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 8294** returned and an error code and error message are stored in the 8295** destination [database connection] D. 8296** ^The error code and message for the failed call to sqlite3_backup_init() 8297** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 8298** [sqlite3_errmsg16()] functions. 8299** ^A successful call to sqlite3_backup_init() returns a pointer to an 8300** [sqlite3_backup] object. 8301** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 8302** sqlite3_backup_finish() functions to perform the specified backup 8303** operation. 8304** 8305** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 8306** 8307** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 8308** the source and destination databases specified by [sqlite3_backup] object B. 8309** ^If N is negative, all remaining source pages are copied. 8310** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 8311** are still more pages to be copied, then the function returns [SQLITE_OK]. 8312** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 8313** from source to destination, then it returns [SQLITE_DONE]. 8314** ^If an error occurs while running sqlite3_backup_step(B,N), 8315** then an [error code] is returned. ^As well as [SQLITE_OK] and 8316** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 8317** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 8318** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 8319** 8320** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 8321** <ol> 8322** <li> the destination database was opened read-only, or 8323** <li> the destination database is using write-ahead-log journaling 8324** and the destination and source page sizes differ, or 8325** <li> the destination database is an in-memory database and the 8326** destination and source page sizes differ. 8327** </ol>)^ 8328** 8329** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 8330** the [sqlite3_busy_handler | busy-handler function] 8331** is invoked (if one is specified). ^If the 8332** busy-handler returns non-zero before the lock is available, then 8333** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 8334** sqlite3_backup_step() can be retried later. ^If the source 8335** [database connection] 8336** is being used to write to the source database when sqlite3_backup_step() 8337** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 8338** case the call to sqlite3_backup_step() can be retried later on. ^(If 8339** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 8340** [SQLITE_READONLY] is returned, then 8341** there is no point in retrying the call to sqlite3_backup_step(). These 8342** errors are considered fatal.)^ The application must accept 8343** that the backup operation has failed and pass the backup operation handle 8344** to the sqlite3_backup_finish() to release associated resources. 8345** 8346** ^The first call to sqlite3_backup_step() obtains an exclusive lock 8347** on the destination file. ^The exclusive lock is not released until either 8348** sqlite3_backup_finish() is called or the backup operation is complete 8349** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 8350** sqlite3_backup_step() obtains a [shared lock] on the source database that 8351** lasts for the duration of the sqlite3_backup_step() call. 8352** ^Because the source database is not locked between calls to 8353** sqlite3_backup_step(), the source database may be modified mid-way 8354** through the backup process. ^If the source database is modified by an 8355** external process or via a database connection other than the one being 8356** used by the backup operation, then the backup will be automatically 8357** restarted by the next call to sqlite3_backup_step(). ^If the source 8358** database is modified by the using the same database connection as is used 8359** by the backup operation, then the backup database is automatically 8360** updated at the same time. 8361** 8362** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 8363** 8364** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 8365** application wishes to abandon the backup operation, the application 8366** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 8367** ^The sqlite3_backup_finish() interfaces releases all 8368** resources associated with the [sqlite3_backup] object. 8369** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 8370** active write-transaction on the destination database is rolled back. 8371** The [sqlite3_backup] object is invalid 8372** and may not be used following a call to sqlite3_backup_finish(). 8373** 8374** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 8375** sqlite3_backup_step() errors occurred, regardless or whether or not 8376** sqlite3_backup_step() completed. 8377** ^If an out-of-memory condition or IO error occurred during any prior 8378** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 8379** sqlite3_backup_finish() returns the corresponding [error code]. 8380** 8381** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 8382** is not a permanent error and does not affect the return value of 8383** sqlite3_backup_finish(). 8384** 8385** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]] 8386** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 8387** 8388** ^The sqlite3_backup_remaining() routine returns the number of pages still 8389** to be backed up at the conclusion of the most recent sqlite3_backup_step(). 8390** ^The sqlite3_backup_pagecount() routine returns the total number of pages 8391** in the source database at the conclusion of the most recent 8392** sqlite3_backup_step(). 8393** ^(The values returned by these functions are only updated by 8394** sqlite3_backup_step(). If the source database is modified in a way that 8395** changes the size of the source database or the number of pages remaining, 8396** those changes are not reflected in the output of sqlite3_backup_pagecount() 8397** and sqlite3_backup_remaining() until after the next 8398** sqlite3_backup_step().)^ 8399** 8400** <b>Concurrent Usage of Database Handles</b> 8401** 8402** ^The source [database connection] may be used by the application for other 8403** purposes while a backup operation is underway or being initialized. 8404** ^If SQLite is compiled and configured to support threadsafe database 8405** connections, then the source database connection may be used concurrently 8406** from within other threads. 8407** 8408** However, the application must guarantee that the destination 8409** [database connection] is not passed to any other API (by any thread) after 8410** sqlite3_backup_init() is called and before the corresponding call to 8411** sqlite3_backup_finish(). SQLite does not currently check to see 8412** if the application incorrectly accesses the destination [database connection] 8413** and so no error code is reported, but the operations may malfunction 8414** nevertheless. Use of the destination database connection while a 8415** backup is in progress might also also cause a mutex deadlock. 8416** 8417** If running in [shared cache mode], the application must 8418** guarantee that the shared cache used by the destination database 8419** is not accessed while the backup is running. In practice this means 8420** that the application must guarantee that the disk file being 8421** backed up to is not accessed by any connection within the process, 8422** not just the specific connection that was passed to sqlite3_backup_init(). 8423** 8424** The [sqlite3_backup] object itself is partially threadsafe. Multiple 8425** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 8426** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 8427** APIs are not strictly speaking threadsafe. If they are invoked at the 8428** same time as another thread is invoking sqlite3_backup_step() it is 8429** possible that they return invalid values. 8430*/ 8431sqlite3_backup *sqlite3_backup_init( 8432 sqlite3 *pDest, /* Destination database handle */ 8433 const char *zDestName, /* Destination database name */ 8434 sqlite3 *pSource, /* Source database handle */ 8435 const char *zSourceName /* Source database name */ 8436); 8437int sqlite3_backup_step(sqlite3_backup *p, int nPage); 8438int sqlite3_backup_finish(sqlite3_backup *p); 8439int sqlite3_backup_remaining(sqlite3_backup *p); 8440int sqlite3_backup_pagecount(sqlite3_backup *p); 8441 8442/* 8443** CAPI3REF: Unlock Notification 8444** METHOD: sqlite3 8445** 8446** ^When running in shared-cache mode, a database operation may fail with 8447** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 8448** individual tables within the shared-cache cannot be obtained. See 8449** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 8450** ^This API may be used to register a callback that SQLite will invoke 8451** when the connection currently holding the required lock relinquishes it. 8452** ^This API is only available if the library was compiled with the 8453** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 8454** 8455** See Also: [Using the SQLite Unlock Notification Feature]. 8456** 8457** ^Shared-cache locks are released when a database connection concludes 8458** its current transaction, either by committing it or rolling it back. 8459** 8460** ^When a connection (known as the blocked connection) fails to obtain a 8461** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 8462** identity of the database connection (the blocking connection) that 8463** has locked the required resource is stored internally. ^After an 8464** application receives an SQLITE_LOCKED error, it may call the 8465** sqlite3_unlock_notify() method with the blocked connection handle as 8466** the first argument to register for a callback that will be invoked 8467** when the blocking connections current transaction is concluded. ^The 8468** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 8469** call that concludes the blocking connection's transaction. 8470** 8471** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 8472** there is a chance that the blocking connection will have already 8473** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 8474** If this happens, then the specified callback is invoked immediately, 8475** from within the call to sqlite3_unlock_notify().)^ 8476** 8477** ^If the blocked connection is attempting to obtain a write-lock on a 8478** shared-cache table, and more than one other connection currently holds 8479** a read-lock on the same table, then SQLite arbitrarily selects one of 8480** the other connections to use as the blocking connection. 8481** 8482** ^(There may be at most one unlock-notify callback registered by a 8483** blocked connection. If sqlite3_unlock_notify() is called when the 8484** blocked connection already has a registered unlock-notify callback, 8485** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 8486** called with a NULL pointer as its second argument, then any existing 8487** unlock-notify callback is canceled. ^The blocked connections 8488** unlock-notify callback may also be canceled by closing the blocked 8489** connection using [sqlite3_close()]. 8490** 8491** The unlock-notify callback is not reentrant. If an application invokes 8492** any sqlite3_xxx API functions from within an unlock-notify callback, a 8493** crash or deadlock may be the result. 8494** 8495** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 8496** returns SQLITE_OK. 8497** 8498** <b>Callback Invocation Details</b> 8499** 8500** When an unlock-notify callback is registered, the application provides a 8501** single void* pointer that is passed to the callback when it is invoked. 8502** However, the signature of the callback function allows SQLite to pass 8503** it an array of void* context pointers. The first argument passed to 8504** an unlock-notify callback is a pointer to an array of void* pointers, 8505** and the second is the number of entries in the array. 8506** 8507** When a blocking connection's transaction is concluded, there may be 8508** more than one blocked connection that has registered for an unlock-notify 8509** callback. ^If two or more such blocked connections have specified the 8510** same callback function, then instead of invoking the callback function 8511** multiple times, it is invoked once with the set of void* context pointers 8512** specified by the blocked connections bundled together into an array. 8513** This gives the application an opportunity to prioritize any actions 8514** related to the set of unblocked database connections. 8515** 8516** <b>Deadlock Detection</b> 8517** 8518** Assuming that after registering for an unlock-notify callback a 8519** database waits for the callback to be issued before taking any further 8520** action (a reasonable assumption), then using this API may cause the 8521** application to deadlock. For example, if connection X is waiting for 8522** connection Y's transaction to be concluded, and similarly connection 8523** Y is waiting on connection X's transaction, then neither connection 8524** will proceed and the system may remain deadlocked indefinitely. 8525** 8526** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 8527** detection. ^If a given call to sqlite3_unlock_notify() would put the 8528** system in a deadlocked state, then SQLITE_LOCKED is returned and no 8529** unlock-notify callback is registered. The system is said to be in 8530** a deadlocked state if connection A has registered for an unlock-notify 8531** callback on the conclusion of connection B's transaction, and connection 8532** B has itself registered for an unlock-notify callback when connection 8533** A's transaction is concluded. ^Indirect deadlock is also detected, so 8534** the system is also considered to be deadlocked if connection B has 8535** registered for an unlock-notify callback on the conclusion of connection 8536** C's transaction, where connection C is waiting on connection A. ^Any 8537** number of levels of indirection are allowed. 8538** 8539** <b>The "DROP TABLE" Exception</b> 8540** 8541** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 8542** always appropriate to call sqlite3_unlock_notify(). There is however, 8543** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 8544** SQLite checks if there are any currently executing SELECT statements 8545** that belong to the same connection. If there are, SQLITE_LOCKED is 8546** returned. In this case there is no "blocking connection", so invoking 8547** sqlite3_unlock_notify() results in the unlock-notify callback being 8548** invoked immediately. If the application then re-attempts the "DROP TABLE" 8549** or "DROP INDEX" query, an infinite loop might be the result. 8550** 8551** One way around this problem is to check the extended error code returned 8552** by an sqlite3_step() call. ^(If there is a blocking connection, then the 8553** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 8554** the special "DROP TABLE/INDEX" case, the extended error code is just 8555** SQLITE_LOCKED.)^ 8556*/ 8557int sqlite3_unlock_notify( 8558 sqlite3 *pBlocked, /* Waiting connection */ 8559 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 8560 void *pNotifyArg /* Argument to pass to xNotify */ 8561); 8562 8563 8564/* 8565** CAPI3REF: String Comparison 8566** 8567** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 8568** and extensions to compare the contents of two buffers containing UTF-8 8569** strings in a case-independent fashion, using the same definition of "case 8570** independence" that SQLite uses internally when comparing identifiers. 8571*/ 8572int sqlite3_stricmp(const char *, const char *); 8573int sqlite3_strnicmp(const char *, const char *, int); 8574 8575/* 8576** CAPI3REF: String Globbing 8577* 8578** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if 8579** string X matches the [GLOB] pattern P. 8580** ^The definition of [GLOB] pattern matching used in 8581** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 8582** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function 8583** is case sensitive. 8584** 8585** Note that this routine returns zero on a match and non-zero if the strings 8586** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8587** 8588** See also: [sqlite3_strlike()]. 8589*/ 8590int sqlite3_strglob(const char *zGlob, const char *zStr); 8591 8592/* 8593** CAPI3REF: String LIKE Matching 8594* 8595** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if 8596** string X matches the [LIKE] pattern P with escape character E. 8597** ^The definition of [LIKE] pattern matching used in 8598** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E" 8599** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without 8600** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0. 8601** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case 8602** insensitive - equivalent upper and lower case ASCII characters match 8603** one another. 8604** 8605** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though 8606** only ASCII characters are case folded. 8607** 8608** Note that this routine returns zero on a match and non-zero if the strings 8609** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 8610** 8611** See also: [sqlite3_strglob()]. 8612*/ 8613int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc); 8614 8615/* 8616** CAPI3REF: Error Logging Interface 8617** 8618** ^The [sqlite3_log()] interface writes a message into the [error log] 8619** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 8620** ^If logging is enabled, the zFormat string and subsequent arguments are 8621** used with [sqlite3_snprintf()] to generate the final output string. 8622** 8623** The sqlite3_log() interface is intended for use by extensions such as 8624** virtual tables, collating functions, and SQL functions. While there is 8625** nothing to prevent an application from calling sqlite3_log(), doing so 8626** is considered bad form. 8627** 8628** The zFormat string must not be NULL. 8629** 8630** To avoid deadlocks and other threading problems, the sqlite3_log() routine 8631** will not use dynamically allocated memory. The log message is stored in 8632** a fixed-length buffer on the stack. If the log message is longer than 8633** a few hundred characters, it will be truncated to the length of the 8634** buffer. 8635*/ 8636void sqlite3_log(int iErrCode, const char *zFormat, ...); 8637 8638/* 8639** CAPI3REF: Write-Ahead Log Commit Hook 8640** METHOD: sqlite3 8641** 8642** ^The [sqlite3_wal_hook()] function is used to register a callback that 8643** is invoked each time data is committed to a database in wal mode. 8644** 8645** ^(The callback is invoked by SQLite after the commit has taken place and 8646** the associated write-lock on the database released)^, so the implementation 8647** may read, write or [checkpoint] the database as required. 8648** 8649** ^The first parameter passed to the callback function when it is invoked 8650** is a copy of the third parameter passed to sqlite3_wal_hook() when 8651** registering the callback. ^The second is a copy of the database handle. 8652** ^The third parameter is the name of the database that was written to - 8653** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 8654** is the number of pages currently in the write-ahead log file, 8655** including those that were just committed. 8656** 8657** The callback function should normally return [SQLITE_OK]. ^If an error 8658** code is returned, that error will propagate back up through the 8659** SQLite code base to cause the statement that provoked the callback 8660** to report an error, though the commit will have still occurred. If the 8661** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 8662** that does not correspond to any valid SQLite error code, the results 8663** are undefined. 8664** 8665** A single database handle may have at most a single write-ahead log callback 8666** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 8667** previously registered write-ahead log callback. ^Note that the 8668** [sqlite3_wal_autocheckpoint()] interface and the 8669** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 8670** overwrite any prior [sqlite3_wal_hook()] settings. 8671*/ 8672void *sqlite3_wal_hook( 8673 sqlite3*, 8674 int(*)(void *,sqlite3*,const char*,int), 8675 void* 8676); 8677 8678/* 8679** CAPI3REF: Configure an auto-checkpoint 8680** METHOD: sqlite3 8681** 8682** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 8683** [sqlite3_wal_hook()] that causes any database on [database connection] D 8684** to automatically [checkpoint] 8685** after committing a transaction if there are N or 8686** more frames in the [write-ahead log] file. ^Passing zero or 8687** a negative value as the nFrame parameter disables automatic 8688** checkpoints entirely. 8689** 8690** ^The callback registered by this function replaces any existing callback 8691** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 8692** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 8693** configured by this function. 8694** 8695** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 8696** from SQL. 8697** 8698** ^Checkpoints initiated by this mechanism are 8699** [sqlite3_wal_checkpoint_v2|PASSIVE]. 8700** 8701** ^Every new [database connection] defaults to having the auto-checkpoint 8702** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 8703** pages. The use of this interface 8704** is only necessary if the default setting is found to be suboptimal 8705** for a particular application. 8706*/ 8707int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 8708 8709/* 8710** CAPI3REF: Checkpoint a database 8711** METHOD: sqlite3 8712** 8713** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to 8714** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^ 8715** 8716** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the 8717** [write-ahead log] for database X on [database connection] D to be 8718** transferred into the database file and for the write-ahead log to 8719** be reset. See the [checkpointing] documentation for addition 8720** information. 8721** 8722** This interface used to be the only way to cause a checkpoint to 8723** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()] 8724** interface was added. This interface is retained for backwards 8725** compatibility and as a convenience for applications that need to manually 8726** start a callback but which do not need the full power (and corresponding 8727** complication) of [sqlite3_wal_checkpoint_v2()]. 8728*/ 8729int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 8730 8731/* 8732** CAPI3REF: Checkpoint a database 8733** METHOD: sqlite3 8734** 8735** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint 8736** operation on database X of [database connection] D in mode M. Status 8737** information is written back into integers pointed to by L and C.)^ 8738** ^(The M parameter must be a valid [checkpoint mode]:)^ 8739** 8740** <dl> 8741** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 8742** ^Checkpoint as many frames as possible without waiting for any database 8743** readers or writers to finish, then sync the database file if all frames 8744** in the log were checkpointed. ^The [busy-handler callback] 8745** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode. 8746** ^On the other hand, passive mode might leave the checkpoint unfinished 8747** if there are concurrent readers or writers. 8748** 8749** <dt>SQLITE_CHECKPOINT_FULL<dd> 8750** ^This mode blocks (it invokes the 8751** [sqlite3_busy_handler|busy-handler callback]) until there is no 8752** database writer and all readers are reading from the most recent database 8753** snapshot. ^It then checkpoints all frames in the log file and syncs the 8754** database file. ^This mode blocks new database writers while it is pending, 8755** but new database readers are allowed to continue unimpeded. 8756** 8757** <dt>SQLITE_CHECKPOINT_RESTART<dd> 8758** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition 8759** that after checkpointing the log file it blocks (calls the 8760** [busy-handler callback]) 8761** until all readers are reading from the database file only. ^This ensures 8762** that the next writer will restart the log file from the beginning. 8763** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new 8764** database writer attempts while it is pending, but does not impede readers. 8765** 8766** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd> 8767** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the 8768** addition that it also truncates the log file to zero bytes just prior 8769** to a successful return. 8770** </dl> 8771** 8772** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in 8773** the log file or to -1 if the checkpoint could not run because 8774** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not 8775** NULL,then *pnCkpt is set to the total number of checkpointed frames in the 8776** log file (including any that were already checkpointed before the function 8777** was called) or to -1 if the checkpoint could not run due to an error or 8778** because the database is not in WAL mode. ^Note that upon successful 8779** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been 8780** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero. 8781** 8782** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If 8783** any other process is running a checkpoint operation at the same time, the 8784** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a 8785** busy-handler configured, it will not be invoked in this case. 8786** 8787** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the 8788** exclusive "writer" lock on the database file. ^If the writer lock cannot be 8789** obtained immediately, and a busy-handler is configured, it is invoked and 8790** the writer lock retried until either the busy-handler returns 0 or the lock 8791** is successfully obtained. ^The busy-handler is also invoked while waiting for 8792** database readers as described above. ^If the busy-handler returns 0 before 8793** the writer lock is obtained or while waiting for database readers, the 8794** checkpoint operation proceeds from that point in the same way as 8795** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 8796** without blocking any further. ^SQLITE_BUSY is returned in this case. 8797** 8798** ^If parameter zDb is NULL or points to a zero length string, then the 8799** specified operation is attempted on all WAL databases [attached] to 8800** [database connection] db. In this case the 8801** values written to output parameters *pnLog and *pnCkpt are undefined. ^If 8802** an SQLITE_BUSY error is encountered when processing one or more of the 8803** attached WAL databases, the operation is still attempted on any remaining 8804** attached databases and SQLITE_BUSY is returned at the end. ^If any other 8805** error occurs while processing an attached database, processing is abandoned 8806** and the error code is returned to the caller immediately. ^If no error 8807** (SQLITE_BUSY or otherwise) is encountered while processing the attached 8808** databases, SQLITE_OK is returned. 8809** 8810** ^If database zDb is the name of an attached database that is not in WAL 8811** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If 8812** zDb is not NULL (or a zero length string) and is not the name of any 8813** attached database, SQLITE_ERROR is returned to the caller. 8814** 8815** ^Unless it returns SQLITE_MISUSE, 8816** the sqlite3_wal_checkpoint_v2() interface 8817** sets the error information that is queried by 8818** [sqlite3_errcode()] and [sqlite3_errmsg()]. 8819** 8820** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface 8821** from SQL. 8822*/ 8823int sqlite3_wal_checkpoint_v2( 8824 sqlite3 *db, /* Database handle */ 8825 const char *zDb, /* Name of attached database (or NULL) */ 8826 int eMode, /* SQLITE_CHECKPOINT_* value */ 8827 int *pnLog, /* OUT: Size of WAL log in frames */ 8828 int *pnCkpt /* OUT: Total number of frames checkpointed */ 8829); 8830 8831/* 8832** CAPI3REF: Checkpoint Mode Values 8833** KEYWORDS: {checkpoint mode} 8834** 8835** These constants define all valid values for the "checkpoint mode" passed 8836** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface. 8837** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the 8838** meaning of each of these checkpoint modes. 8839*/ 8840#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */ 8841#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */ 8842#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */ 8843#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */ 8844 8845/* 8846** CAPI3REF: Virtual Table Interface Configuration 8847** 8848** This function may be called by either the [xConnect] or [xCreate] method 8849** of a [virtual table] implementation to configure 8850** various facets of the virtual table interface. 8851** 8852** If this interface is invoked outside the context of an xConnect or 8853** xCreate virtual table method then the behavior is undefined. 8854** 8855** At present, there is only one option that may be configured using 8856** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 8857** may be added in the future. 8858*/ 8859int sqlite3_vtab_config(sqlite3*, int op, ...); 8860 8861/* 8862** CAPI3REF: Virtual Table Configuration Options 8863** 8864** These macros define the various options to the 8865** [sqlite3_vtab_config()] interface that [virtual table] implementations 8866** can use to customize and optimize their behavior. 8867** 8868** <dl> 8869** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]] 8870** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 8871** <dd>Calls of the form 8872** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 8873** where X is an integer. If X is zero, then the [virtual table] whose 8874** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 8875** support constraints. In this configuration (which is the default) if 8876** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 8877** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 8878** specified as part of the users SQL statement, regardless of the actual 8879** ON CONFLICT mode specified. 8880** 8881** If X is non-zero, then the virtual table implementation guarantees 8882** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 8883** any modifications to internal or persistent data structures have been made. 8884** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 8885** is able to roll back a statement or database transaction, and abandon 8886** or continue processing the current SQL statement as appropriate. 8887** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 8888** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 8889** had been ABORT. 8890** 8891** Virtual table implementations that are required to handle OR REPLACE 8892** must do so within the [xUpdate] method. If a call to the 8893** [sqlite3_vtab_on_conflict()] function indicates that the current ON 8894** CONFLICT policy is REPLACE, the virtual table implementation should 8895** silently replace the appropriate rows within the xUpdate callback and 8896** return SQLITE_OK. Or, if this is not possible, it may return 8897** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 8898** constraint handling. 8899** </dl> 8900*/ 8901#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 8902 8903/* 8904** CAPI3REF: Determine The Virtual Table Conflict Policy 8905** 8906** This function may only be called from within a call to the [xUpdate] method 8907** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 8908** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 8909** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 8910** of the SQL statement that triggered the call to the [xUpdate] method of the 8911** [virtual table]. 8912*/ 8913int sqlite3_vtab_on_conflict(sqlite3 *); 8914 8915/* 8916** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE 8917** 8918** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn] 8919** method of a [virtual table], then it returns true if and only if the 8920** column is being fetched as part of an UPDATE operation during which the 8921** column value will not change. Applications might use this to substitute 8922** a return value that is less expensive to compute and that the corresponding 8923** [xUpdate] method understands as a "no-change" value. 8924** 8925** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that 8926** the column is not changed by the UPDATE statement, then the xColumn 8927** method can optionally return without setting a result, without calling 8928** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces]. 8929** In that case, [sqlite3_value_nochange(X)] will return true for the 8930** same column in the [xUpdate] method. 8931*/ 8932int sqlite3_vtab_nochange(sqlite3_context*); 8933 8934/* 8935** CAPI3REF: Determine The Collation For a Virtual Table Constraint 8936** 8937** This function may only be called from within a call to the [xBestIndex] 8938** method of a [virtual table]. 8939** 8940** The first argument must be the sqlite3_index_info object that is the 8941** first parameter to the xBestIndex() method. The second argument must be 8942** an index into the aConstraint[] array belonging to the sqlite3_index_info 8943** structure passed to xBestIndex. This function returns a pointer to a buffer 8944** containing the name of the collation sequence for the corresponding 8945** constraint. 8946*/ 8947SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int); 8948 8949/* 8950** CAPI3REF: Conflict resolution modes 8951** KEYWORDS: {conflict resolution mode} 8952** 8953** These constants are returned by [sqlite3_vtab_on_conflict()] to 8954** inform a [virtual table] implementation what the [ON CONFLICT] mode 8955** is for the SQL statement being evaluated. 8956** 8957** Note that the [SQLITE_IGNORE] constant is also used as a potential 8958** return value from the [sqlite3_set_authorizer()] callback and that 8959** [SQLITE_ABORT] is also a [result code]. 8960*/ 8961#define SQLITE_ROLLBACK 1 8962/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 8963#define SQLITE_FAIL 3 8964/* #define SQLITE_ABORT 4 // Also an error code */ 8965#define SQLITE_REPLACE 5 8966 8967/* 8968** CAPI3REF: Prepared Statement Scan Status Opcodes 8969** KEYWORDS: {scanstatus options} 8970** 8971** The following constants can be used for the T parameter to the 8972** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a 8973** different metric for sqlite3_stmt_scanstatus() to return. 8974** 8975** When the value returned to V is a string, space to hold that string is 8976** managed by the prepared statement S and will be automatically freed when 8977** S is finalized. 8978** 8979** <dl> 8980** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> 8981** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be 8982** set to the total number of times that the X-th loop has run.</dd> 8983** 8984** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> 8985** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set 8986** to the total number of rows examined by all iterations of the X-th loop.</dd> 8987** 8988** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> 8989** <dd>^The "double" variable pointed to by the V parameter will be set to the 8990** query planner's estimate for the average number of rows output from each 8991** iteration of the X-th loop. If the query planner's estimates was accurate, 8992** then this value will approximate the quotient NVISIT/NLOOP and the 8993** product of this value for all prior loops with the same SELECTID will 8994** be the NLOOP value for the current loop. 8995** 8996** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> 8997** <dd>^The "const char *" variable pointed to by the V parameter will be set 8998** to a zero-terminated UTF-8 string containing the name of the index or table 8999** used for the X-th loop. 9000** 9001** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> 9002** <dd>^The "const char *" variable pointed to by the V parameter will be set 9003** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] 9004** description for the X-th loop. 9005** 9006** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt> 9007** <dd>^The "int" variable pointed to by the V parameter will be set to the 9008** "select-id" for the X-th loop. The select-id identifies which query or 9009** subquery the loop is part of. The main query has a select-id of zero. 9010** The select-id is the same value as is output in the first column 9011** of an [EXPLAIN QUERY PLAN] query. 9012** </dl> 9013*/ 9014#define SQLITE_SCANSTAT_NLOOP 0 9015#define SQLITE_SCANSTAT_NVISIT 1 9016#define SQLITE_SCANSTAT_EST 2 9017#define SQLITE_SCANSTAT_NAME 3 9018#define SQLITE_SCANSTAT_EXPLAIN 4 9019#define SQLITE_SCANSTAT_SELECTID 5 9020 9021/* 9022** CAPI3REF: Prepared Statement Scan Status 9023** METHOD: sqlite3_stmt 9024** 9025** This interface returns information about the predicted and measured 9026** performance for pStmt. Advanced applications can use this 9027** interface to compare the predicted and the measured performance and 9028** issue warnings and/or rerun [ANALYZE] if discrepancies are found. 9029** 9030** Since this interface is expected to be rarely used, it is only 9031** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS] 9032** compile-time option. 9033** 9034** The "iScanStatusOp" parameter determines which status information to return. 9035** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior 9036** of this interface is undefined. 9037** ^The requested measurement is written into a variable pointed to by 9038** the "pOut" parameter. 9039** Parameter "idx" identifies the specific loop to retrieve statistics for. 9040** Loops are numbered starting from zero. ^If idx is out of range - less than 9041** zero or greater than or equal to the total number of loops used to implement 9042** the statement - a non-zero value is returned and the variable that pOut 9043** points to is unchanged. 9044** 9045** ^Statistics might not be available for all loops in all statements. ^In cases 9046** where there exist loops with no available statistics, this function behaves 9047** as if the loop did not exist - it returns non-zero and leave the variable 9048** that pOut points to unchanged. 9049** 9050** See also: [sqlite3_stmt_scanstatus_reset()] 9051*/ 9052int sqlite3_stmt_scanstatus( 9053 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ 9054 int idx, /* Index of loop to report on */ 9055 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ 9056 void *pOut /* Result written here */ 9057); 9058 9059/* 9060** CAPI3REF: Zero Scan-Status Counters 9061** METHOD: sqlite3_stmt 9062** 9063** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. 9064** 9065** This API is only available if the library is built with pre-processor 9066** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. 9067*/ 9068void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); 9069 9070/* 9071** CAPI3REF: Flush caches to disk mid-transaction 9072** 9073** ^If a write-transaction is open on [database connection] D when the 9074** [sqlite3_db_cacheflush(D)] interface invoked, any dirty 9075** pages in the pager-cache that are not currently in use are written out 9076** to disk. A dirty page may be in use if a database cursor created by an 9077** active SQL statement is reading from it, or if it is page 1 of a database 9078** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)] 9079** interface flushes caches for all schemas - "main", "temp", and 9080** any [attached] databases. 9081** 9082** ^If this function needs to obtain extra database locks before dirty pages 9083** can be flushed to disk, it does so. ^If those locks cannot be obtained 9084** immediately and there is a busy-handler callback configured, it is invoked 9085** in the usual manner. ^If the required lock still cannot be obtained, then 9086** the database is skipped and an attempt made to flush any dirty pages 9087** belonging to the next (if any) database. ^If any databases are skipped 9088** because locks cannot be obtained, but no other error occurs, this 9089** function returns SQLITE_BUSY. 9090** 9091** ^If any other error occurs while flushing dirty pages to disk (for 9092** example an IO error or out-of-memory condition), then processing is 9093** abandoned and an SQLite [error code] is returned to the caller immediately. 9094** 9095** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK. 9096** 9097** ^This function does not set the database handle error code or message 9098** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions. 9099*/ 9100int sqlite3_db_cacheflush(sqlite3*); 9101 9102/* 9103** CAPI3REF: The pre-update hook. 9104** 9105** ^These interfaces are only available if SQLite is compiled using the 9106** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option. 9107** 9108** ^The [sqlite3_preupdate_hook()] interface registers a callback function 9109** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation 9110** on a database table. 9111** ^At most one preupdate hook may be registered at a time on a single 9112** [database connection]; each call to [sqlite3_preupdate_hook()] overrides 9113** the previous setting. 9114** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()] 9115** with a NULL pointer as the second parameter. 9116** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as 9117** the first parameter to callbacks. 9118** 9119** ^The preupdate hook only fires for changes to real database tables; the 9120** preupdate hook is not invoked for changes to [virtual tables] or to 9121** system tables like sqlite_master or sqlite_stat1. 9122** 9123** ^The second parameter to the preupdate callback is a pointer to 9124** the [database connection] that registered the preupdate hook. 9125** ^The third parameter to the preupdate callback is one of the constants 9126** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the 9127** kind of update operation that is about to occur. 9128** ^(The fourth parameter to the preupdate callback is the name of the 9129** database within the database connection that is being modified. This 9130** will be "main" for the main database or "temp" for TEMP tables or 9131** the name given after the AS keyword in the [ATTACH] statement for attached 9132** databases.)^ 9133** ^The fifth parameter to the preupdate callback is the name of the 9134** table that is being modified. 9135** 9136** For an UPDATE or DELETE operation on a [rowid table], the sixth 9137** parameter passed to the preupdate callback is the initial [rowid] of the 9138** row being modified or deleted. For an INSERT operation on a rowid table, 9139** or any operation on a WITHOUT ROWID table, the value of the sixth 9140** parameter is undefined. For an INSERT or UPDATE on a rowid table the 9141** seventh parameter is the final rowid value of the row being inserted 9142** or updated. The value of the seventh parameter passed to the callback 9143** function is not defined for operations on WITHOUT ROWID tables, or for 9144** INSERT operations on rowid tables. 9145** 9146** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()], 9147** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces 9148** provide additional information about a preupdate event. These routines 9149** may only be called from within a preupdate callback. Invoking any of 9150** these routines from outside of a preupdate callback or with a 9151** [database connection] pointer that is different from the one supplied 9152** to the preupdate callback results in undefined and probably undesirable 9153** behavior. 9154** 9155** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns 9156** in the row that is being inserted, updated, or deleted. 9157** 9158** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to 9159** a [protected sqlite3_value] that contains the value of the Nth column of 9160** the table row before it is updated. The N parameter must be between 0 9161** and one less than the number of columns or the behavior will be 9162** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE 9163** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the 9164** behavior is undefined. The [sqlite3_value] that P points to 9165** will be destroyed when the preupdate callback returns. 9166** 9167** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to 9168** a [protected sqlite3_value] that contains the value of the Nth column of 9169** the table row after it is updated. The N parameter must be between 0 9170** and one less than the number of columns or the behavior will be 9171** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE 9172** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the 9173** behavior is undefined. The [sqlite3_value] that P points to 9174** will be destroyed when the preupdate callback returns. 9175** 9176** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate 9177** callback was invoked as a result of a direct insert, update, or delete 9178** operation; or 1 for inserts, updates, or deletes invoked by top-level 9179** triggers; or 2 for changes resulting from triggers called by top-level 9180** triggers; and so forth. 9181** 9182** See also: [sqlite3_update_hook()] 9183*/ 9184#if defined(SQLITE_ENABLE_PREUPDATE_HOOK) 9185void *sqlite3_preupdate_hook( 9186 sqlite3 *db, 9187 void(*xPreUpdate)( 9188 void *pCtx, /* Copy of third arg to preupdate_hook() */ 9189 sqlite3 *db, /* Database handle */ 9190 int op, /* SQLITE_UPDATE, DELETE or INSERT */ 9191 char const *zDb, /* Database name */ 9192 char const *zName, /* Table name */ 9193 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */ 9194 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */ 9195 ), 9196 void* 9197); 9198int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **); 9199int sqlite3_preupdate_count(sqlite3 *); 9200int sqlite3_preupdate_depth(sqlite3 *); 9201int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **); 9202#endif 9203 9204/* 9205** CAPI3REF: Low-level system error code 9206** 9207** ^Attempt to return the underlying operating system error code or error 9208** number that caused the most recent I/O error or failure to open a file. 9209** The return value is OS-dependent. For example, on unix systems, after 9210** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be 9211** called to get back the underlying "errno" that caused the problem, such 9212** as ENOSPC, EAUTH, EISDIR, and so forth. 9213*/ 9214int sqlite3_system_errno(sqlite3*); 9215 9216/* 9217** CAPI3REF: Database Snapshot 9218** KEYWORDS: {snapshot} {sqlite3_snapshot} 9219** 9220** An instance of the snapshot object records the state of a [WAL mode] 9221** database for some specific point in history. 9222** 9223** In [WAL mode], multiple [database connections] that are open on the 9224** same database file can each be reading a different historical version 9225** of the database file. When a [database connection] begins a read 9226** transaction, that connection sees an unchanging copy of the database 9227** as it existed for the point in time when the transaction first started. 9228** Subsequent changes to the database from other connections are not seen 9229** by the reader until a new read transaction is started. 9230** 9231** The sqlite3_snapshot object records state information about an historical 9232** version of the database file so that it is possible to later open a new read 9233** transaction that sees that historical version of the database rather than 9234** the most recent version. 9235*/ 9236typedef struct sqlite3_snapshot { 9237 unsigned char hidden[48]; 9238} sqlite3_snapshot; 9239 9240/* 9241** CAPI3REF: Record A Database Snapshot 9242** CONSTRUCTOR: sqlite3_snapshot 9243** 9244** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a 9245** new [sqlite3_snapshot] object that records the current state of 9246** schema S in database connection D. ^On success, the 9247** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly 9248** created [sqlite3_snapshot] object into *P and returns SQLITE_OK. 9249** If there is not already a read-transaction open on schema S when 9250** this function is called, one is opened automatically. 9251** 9252** The following must be true for this function to succeed. If any of 9253** the following statements are false when sqlite3_snapshot_get() is 9254** called, SQLITE_ERROR is returned. The final value of *P is undefined 9255** in this case. 9256** 9257** <ul> 9258** <li> The database handle must not be in [autocommit mode]. 9259** 9260** <li> Schema S of [database connection] D must be a [WAL mode] database. 9261** 9262** <li> There must not be a write transaction open on schema S of database 9263** connection D. 9264** 9265** <li> One or more transactions must have been written to the current wal 9266** file since it was created on disk (by any connection). This means 9267** that a snapshot cannot be taken on a wal mode database with no wal 9268** file immediately after it is first opened. At least one transaction 9269** must be written to it first. 9270** </ul> 9271** 9272** This function may also return SQLITE_NOMEM. If it is called with the 9273** database handle in autocommit mode but fails for some other reason, 9274** whether or not a read transaction is opened on schema S is undefined. 9275** 9276** The [sqlite3_snapshot] object returned from a successful call to 9277** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()] 9278** to avoid a memory leak. 9279** 9280** The [sqlite3_snapshot_get()] interface is only available when the 9281** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9282*/ 9283SQLITE_EXPERIMENTAL int sqlite3_snapshot_get( 9284 sqlite3 *db, 9285 const char *zSchema, 9286 sqlite3_snapshot **ppSnapshot 9287); 9288 9289/* 9290** CAPI3REF: Start a read transaction on an historical snapshot 9291** METHOD: sqlite3_snapshot 9292** 9293** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read 9294** transaction or upgrades an existing one for schema S of 9295** [database connection] D such that the read transaction refers to 9296** historical [snapshot] P, rather than the most recent change to the 9297** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK 9298** on success or an appropriate [error code] if it fails. 9299** 9300** ^In order to succeed, the database connection must not be in 9301** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there 9302** is already a read transaction open on schema S, then the database handle 9303** must have no active statements (SELECT statements that have been passed 9304** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()). 9305** SQLITE_ERROR is returned if either of these conditions is violated, or 9306** if schema S does not exist, or if the snapshot object is invalid. 9307** 9308** ^A call to sqlite3_snapshot_open() will fail to open if the specified 9309** snapshot has been overwritten by a [checkpoint]. In this case 9310** SQLITE_ERROR_SNAPSHOT is returned. 9311** 9312** If there is already a read transaction open when this function is 9313** invoked, then the same read transaction remains open (on the same 9314** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT 9315** is returned. If another error code - for example SQLITE_PROTOCOL or an 9316** SQLITE_IOERR error code - is returned, then the final state of the 9317** read transaction is undefined. If SQLITE_OK is returned, then the 9318** read transaction is now open on database snapshot P. 9319** 9320** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the 9321** database connection D does not know that the database file for 9322** schema S is in [WAL mode]. A database connection might not know 9323** that the database file is in [WAL mode] if there has been no prior 9324** I/O on that database connection, or if the database entered [WAL mode] 9325** after the most recent I/O on the database connection.)^ 9326** (Hint: Run "[PRAGMA application_id]" against a newly opened 9327** database connection in order to make it ready to use snapshots.) 9328** 9329** The [sqlite3_snapshot_open()] interface is only available when the 9330** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9331*/ 9332SQLITE_EXPERIMENTAL int sqlite3_snapshot_open( 9333 sqlite3 *db, 9334 const char *zSchema, 9335 sqlite3_snapshot *pSnapshot 9336); 9337 9338/* 9339** CAPI3REF: Destroy a snapshot 9340** DESTRUCTOR: sqlite3_snapshot 9341** 9342** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P. 9343** The application must eventually free every [sqlite3_snapshot] object 9344** using this routine to avoid a memory leak. 9345** 9346** The [sqlite3_snapshot_free()] interface is only available when the 9347** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used. 9348*/ 9349SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*); 9350 9351/* 9352** CAPI3REF: Compare the ages of two snapshot handles. 9353** METHOD: sqlite3_snapshot 9354** 9355** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages 9356** of two valid snapshot handles. 9357** 9358** If the two snapshot handles are not associated with the same database 9359** file, the result of the comparison is undefined. 9360** 9361** Additionally, the result of the comparison is only valid if both of the 9362** snapshot handles were obtained by calling sqlite3_snapshot_get() since the 9363** last time the wal file was deleted. The wal file is deleted when the 9364** database is changed back to rollback mode or when the number of database 9365** clients drops to zero. If either snapshot handle was obtained before the 9366** wal file was last deleted, the value returned by this function 9367** is undefined. 9368** 9369** Otherwise, this API returns a negative value if P1 refers to an older 9370** snapshot than P2, zero if the two handles refer to the same database 9371** snapshot, and a positive value if P1 is a newer snapshot than P2. 9372** 9373** This interface is only available if SQLite is compiled with the 9374** [SQLITE_ENABLE_SNAPSHOT] option. 9375*/ 9376SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp( 9377 sqlite3_snapshot *p1, 9378 sqlite3_snapshot *p2 9379); 9380 9381/* 9382** CAPI3REF: Recover snapshots from a wal file 9383** METHOD: sqlite3_snapshot 9384** 9385** If a [WAL file] remains on disk after all database connections close 9386** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control] 9387** or because the last process to have the database opened exited without 9388** calling [sqlite3_close()]) and a new connection is subsequently opened 9389** on that database and [WAL file], the [sqlite3_snapshot_open()] interface 9390** will only be able to open the last transaction added to the WAL file 9391** even though the WAL file contains other valid transactions. 9392** 9393** This function attempts to scan the WAL file associated with database zDb 9394** of database handle db and make all valid snapshots available to 9395** sqlite3_snapshot_open(). It is an error if there is already a read 9396** transaction open on the database, or if the database is not a WAL mode 9397** database. 9398** 9399** SQLITE_OK is returned if successful, or an SQLite error code otherwise. 9400** 9401** This interface is only available if SQLite is compiled with the 9402** [SQLITE_ENABLE_SNAPSHOT] option. 9403*/ 9404SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb); 9405 9406/* 9407** CAPI3REF: Serialize a database 9408** 9409** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory 9410** that is a serialization of the S database on [database connection] D. 9411** If P is not a NULL pointer, then the size of the database in bytes 9412** is written into *P. 9413** 9414** For an ordinary on-disk database file, the serialization is just a 9415** copy of the disk file. For an in-memory database or a "TEMP" database, 9416** the serialization is the same sequence of bytes which would be written 9417** to disk if that database where backed up to disk. 9418** 9419** The usual case is that sqlite3_serialize() copies the serialization of 9420** the database into memory obtained from [sqlite3_malloc64()] and returns 9421** a pointer to that memory. The caller is responsible for freeing the 9422** returned value to avoid a memory leak. However, if the F argument 9423** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations 9424** are made, and the sqlite3_serialize() function will return a pointer 9425** to the contiguous memory representation of the database that SQLite 9426** is currently using for that database, or NULL if the no such contiguous 9427** memory representation of the database exists. A contiguous memory 9428** representation of the database will usually only exist if there has 9429** been a prior call to [sqlite3_deserialize(D,S,...)] with the same 9430** values of D and S. 9431** The size of the database is written into *P even if the 9432** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy 9433** of the database exists. 9434** 9435** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the 9436** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory 9437** allocation error occurs. 9438** 9439** This interface is only available if SQLite is compiled with the 9440** [SQLITE_ENABLE_DESERIALIZE] option. 9441*/ 9442unsigned char *sqlite3_serialize( 9443 sqlite3 *db, /* The database connection */ 9444 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */ 9445 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */ 9446 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */ 9447); 9448 9449/* 9450** CAPI3REF: Flags for sqlite3_serialize 9451** 9452** Zero or more of the following constants can be OR-ed together for 9453** the F argument to [sqlite3_serialize(D,S,P,F)]. 9454** 9455** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return 9456** a pointer to contiguous in-memory database that it is currently using, 9457** without making a copy of the database. If SQLite is not currently using 9458** a contiguous in-memory database, then this option causes 9459** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be 9460** using a contiguous in-memory database if it has been initialized by a 9461** prior call to [sqlite3_deserialize()]. 9462*/ 9463#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */ 9464 9465/* 9466** CAPI3REF: Deserialize a database 9467** 9468** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the 9469** [database connection] D to disconnect from database S and then 9470** reopen S as an in-memory database based on the serialization contained 9471** in P. The serialized database P is N bytes in size. M is the size of 9472** the buffer P, which might be larger than N. If M is larger than N, and 9473** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is 9474** permitted to add content to the in-memory database as long as the total 9475** size does not exceed M bytes. 9476** 9477** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will 9478** invoke sqlite3_free() on the serialization buffer when the database 9479** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then 9480** SQLite will try to increase the buffer size using sqlite3_realloc64() 9481** if writes on the database cause it to grow larger than M bytes. 9482** 9483** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the 9484** database is currently in a read transaction or is involved in a backup 9485** operation. 9486** 9487** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the 9488** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then 9489** [sqlite3_free()] is invoked on argument P prior to returning. 9490** 9491** This interface is only available if SQLite is compiled with the 9492** [SQLITE_ENABLE_DESERIALIZE] option. 9493*/ 9494int sqlite3_deserialize( 9495 sqlite3 *db, /* The database connection */ 9496 const char *zSchema, /* Which DB to reopen with the deserialization */ 9497 unsigned char *pData, /* The serialized database content */ 9498 sqlite3_int64 szDb, /* Number bytes in the deserialization */ 9499 sqlite3_int64 szBuf, /* Total size of buffer pData[] */ 9500 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */ 9501); 9502 9503/* 9504** CAPI3REF: Flags for sqlite3_deserialize() 9505** 9506** The following are allowed values for 6th argument (the F argument) to 9507** the [sqlite3_deserialize(D,S,P,N,M,F)] interface. 9508** 9509** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization 9510** in the P argument is held in memory obtained from [sqlite3_malloc64()] 9511** and that SQLite should take ownership of this memory and automatically 9512** free it when it has finished using it. Without this flag, the caller 9513** is responsible for freeing any dynamically allocated memory. 9514** 9515** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to 9516** grow the size of the database using calls to [sqlite3_realloc64()]. This 9517** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used. 9518** Without this flag, the deserialized database cannot increase in size beyond 9519** the number of bytes specified by the M parameter. 9520** 9521** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database 9522** should be treated as read-only. 9523*/ 9524#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */ 9525#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */ 9526#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */ 9527 9528/* 9529** Undo the hack that converts floating point types to integer for 9530** builds on processors without floating point support. 9531*/ 9532#ifdef SQLITE_OMIT_FLOATING_POINT 9533# undef double 9534#endif 9535 9536#ifdef __cplusplus 9537} /* End of the 'extern "C"' block */ 9538#endif 9539#endif /* SQLITE3_H */ 9540