1/****************************************************************************** 2** This file is an amalgamation of many separate C source files from SQLite 3** version 3.8.6. By combining all the individual C code files into this 4** single large file, the entire code can be compiled as a single translation 5** unit. This allows many compilers to do optimizations that would not be 6** possible if the files were compiled separately. Performance improvements 7** of 5% or more are commonly seen when SQLite is compiled as a single 8** translation unit. 9** 10** This file is all you need to compile SQLite. To use SQLite in other 11** programs, you need this file and the "sqlite3.h" header file that defines 12** the programming interface to the SQLite library. (If you do not have 13** the "sqlite3.h" header file at hand, you will find a copy embedded within 14** the text of this file. Search for "Begin file sqlite3.h" to find the start 15** of the embedded sqlite3.h header file.) Additional code files may be needed 16** if you want a wrapper to interface SQLite with your choice of programming 17** language. The code for the "sqlite3" command-line shell is also in a 18** separate file. This file contains only code for the core SQLite library. 19*/ 20#define SQLITE_CORE 1 21#define SQLITE_AMALGAMATION 1 22#ifndef SQLITE_PRIVATE 23# define SQLITE_PRIVATE static 24#endif 25#ifndef SQLITE_API 26# define SQLITE_API 27#endif 28/************** Begin file sqliteInt.h ***************************************/ 29/* 30** 2001 September 15 31** 32** The author disclaims copyright to this source code. In place of 33** a legal notice, here is a blessing: 34** 35** May you do good and not evil. 36** May you find forgiveness for yourself and forgive others. 37** May you share freely, never taking more than you give. 38** 39************************************************************************* 40** Internal interface definitions for SQLite. 41** 42*/ 43#ifndef _SQLITEINT_H_ 44#define _SQLITEINT_H_ 45 46/* 47** These #defines should enable >2GB file support on POSIX if the 48** underlying operating system supports it. If the OS lacks 49** large file support, or if the OS is windows, these should be no-ops. 50** 51** Ticket #2739: The _LARGEFILE_SOURCE macro must appear before any 52** system #includes. Hence, this block of code must be the very first 53** code in all source files. 54** 55** Large file support can be disabled using the -DSQLITE_DISABLE_LFS switch 56** on the compiler command line. This is necessary if you are compiling 57** on a recent machine (ex: Red Hat 7.2) but you want your code to work 58** on an older machine (ex: Red Hat 6.0). If you compile on Red Hat 7.2 59** without this option, LFS is enable. But LFS does not exist in the kernel 60** in Red Hat 6.0, so the code won't work. Hence, for maximum binary 61** portability you should omit LFS. 62** 63** The previous paragraph was written in 2005. (This paragraph is written 64** on 2008-11-28.) These days, all Linux kernels support large files, so 65** you should probably leave LFS enabled. But some embedded platforms might 66** lack LFS in which case the SQLITE_DISABLE_LFS macro might still be useful. 67** 68** Similar is true for Mac OS X. LFS is only supported on Mac OS X 9 and later. 69*/ 70#ifndef SQLITE_DISABLE_LFS 71# define _LARGE_FILE 1 72# ifndef _FILE_OFFSET_BITS 73# define _FILE_OFFSET_BITS 64 74# endif 75# define _LARGEFILE_SOURCE 1 76#endif 77 78/* 79** For MinGW, check to see if we can include the header file containing its 80** version information, among other things. Normally, this internal MinGW 81** header file would [only] be included automatically by other MinGW header 82** files; however, the contained version information is now required by this 83** header file to work around binary compatibility issues (see below) and 84** this is the only known way to reliably obtain it. This entire #if block 85** would be completely unnecessary if there was any other way of detecting 86** MinGW via their preprocessor (e.g. if they customized their GCC to define 87** some MinGW-specific macros). When compiling for MinGW, either the 88** _HAVE_MINGW_H or _HAVE__MINGW_H (note the extra underscore) macro must be 89** defined; otherwise, detection of conditions specific to MinGW will be 90** disabled. 91*/ 92#if defined(_HAVE_MINGW_H) 93# include "mingw.h" 94#elif defined(_HAVE__MINGW_H) 95# include "_mingw.h" 96#endif 97 98/* 99** For MinGW version 4.x (and higher), check to see if the _USE_32BIT_TIME_T 100** define is required to maintain binary compatibility with the MSVC runtime 101** library in use (e.g. for Windows XP). 102*/ 103#if !defined(_USE_32BIT_TIME_T) && !defined(_USE_64BIT_TIME_T) && \ 104 defined(_WIN32) && !defined(_WIN64) && \ 105 defined(__MINGW_MAJOR_VERSION) && __MINGW_MAJOR_VERSION >= 4 && \ 106 defined(__MSVCRT__) 107# define _USE_32BIT_TIME_T 108#endif 109 110/* The public SQLite interface. The _FILE_OFFSET_BITS macro must appear 111** first in QNX. Also, the _USE_32BIT_TIME_T macro must appear first for 112** MinGW. 113*/ 114/************** Include sqlite3.h in the middle of sqliteInt.h ***************/ 115/************** Begin file sqlite3.h *****************************************/ 116/* 117** 2001 September 15 118** 119** The author disclaims copyright to this source code. In place of 120** a legal notice, here is a blessing: 121** 122** May you do good and not evil. 123** May you find forgiveness for yourself and forgive others. 124** May you share freely, never taking more than you give. 125** 126************************************************************************* 127** This header file defines the interface that the SQLite library 128** presents to client programs. If a C-function, structure, datatype, 129** or constant definition does not appear in this file, then it is 130** not a published API of SQLite, is subject to change without 131** notice, and should not be referenced by programs that use SQLite. 132** 133** Some of the definitions that are in this file are marked as 134** "experimental". Experimental interfaces are normally new 135** features recently added to SQLite. We do not anticipate changes 136** to experimental interfaces but reserve the right to make minor changes 137** if experience from use "in the wild" suggest such changes are prudent. 138** 139** The official C-language API documentation for SQLite is derived 140** from comments in this file. This file is the authoritative source 141** on how SQLite interfaces are suppose to operate. 142** 143** The name of this file under configuration management is "sqlite.h.in". 144** The makefile makes some minor changes to this file (such as inserting 145** the version number) and changes its name to "sqlite3.h" as 146** part of the build process. 147*/ 148#ifndef _SQLITE3_H_ 149#define _SQLITE3_H_ 150#include <stdarg.h> /* Needed for the definition of va_list */ 151 152/* 153** Make sure we can call this stuff from C++. 154*/ 155#if 0 156extern "C" { 157#endif 158 159 160/* 161** Add the ability to override 'extern' 162*/ 163#ifndef SQLITE_EXTERN 164# define SQLITE_EXTERN extern 165#endif 166 167#ifndef SQLITE_API 168# define SQLITE_API 169#endif 170 171 172/* 173** These no-op macros are used in front of interfaces to mark those 174** interfaces as either deprecated or experimental. New applications 175** should not use deprecated interfaces - they are support for backwards 176** compatibility only. Application writers should be aware that 177** experimental interfaces are subject to change in point releases. 178** 179** These macros used to resolve to various kinds of compiler magic that 180** would generate warning messages when they were used. But that 181** compiler magic ended up generating such a flurry of bug reports 182** that we have taken it all out and gone back to using simple 183** noop macros. 184*/ 185#define SQLITE_DEPRECATED 186#define SQLITE_EXPERIMENTAL 187 188/* 189** Ensure these symbols were not defined by some previous header file. 190*/ 191#ifdef SQLITE_VERSION 192# undef SQLITE_VERSION 193#endif 194#ifdef SQLITE_VERSION_NUMBER 195# undef SQLITE_VERSION_NUMBER 196#endif 197 198/* 199** CAPI3REF: Compile-Time Library Version Numbers 200** 201** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header 202** evaluates to a string literal that is the SQLite version in the 203** format "X.Y.Z" where X is the major version number (always 3 for 204** SQLite3) and Y is the minor version number and Z is the release number.)^ 205** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer 206** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same 207** numbers used in [SQLITE_VERSION].)^ 208** The SQLITE_VERSION_NUMBER for any given release of SQLite will also 209** be larger than the release from which it is derived. Either Y will 210** be held constant and Z will be incremented or else Y will be incremented 211** and Z will be reset to zero. 212** 213** Since version 3.6.18, SQLite source code has been stored in the 214** <a href="http://www.fossil-scm.org/">Fossil configuration management 215** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to 216** a string which identifies a particular check-in of SQLite 217** within its configuration management system. ^The SQLITE_SOURCE_ID 218** string contains the date and time of the check-in (UTC) and an SHA1 219** hash of the entire source tree. 220** 221** See also: [sqlite3_libversion()], 222** [sqlite3_libversion_number()], [sqlite3_sourceid()], 223** [sqlite_version()] and [sqlite_source_id()]. 224*/ 225#define SQLITE_VERSION "3.8.6" 226#define SQLITE_VERSION_NUMBER 3008006 227#define SQLITE_SOURCE_ID "2014-08-15 11:46:33 9491ba7d738528f168657adb43a198238abde19e" 228 229/* 230** CAPI3REF: Run-Time Library Version Numbers 231** KEYWORDS: sqlite3_version, sqlite3_sourceid 232** 233** These interfaces provide the same information as the [SQLITE_VERSION], 234** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros 235** but are associated with the library instead of the header file. ^(Cautious 236** programmers might include assert() statements in their application to 237** verify that values returned by these interfaces match the macros in 238** the header, and thus insure that the application is 239** compiled with matching library and header files. 240** 241** <blockquote><pre> 242** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); 243** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); 244** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); 245** </pre></blockquote>)^ 246** 247** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] 248** macro. ^The sqlite3_libversion() function returns a pointer to the 249** to the sqlite3_version[] string constant. The sqlite3_libversion() 250** function is provided for use in DLLs since DLL users usually do not have 251** direct access to string constants within the DLL. ^The 252** sqlite3_libversion_number() function returns an integer equal to 253** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns 254** a pointer to a string constant whose value is the same as the 255** [SQLITE_SOURCE_ID] C preprocessor macro. 256** 257** See also: [sqlite_version()] and [sqlite_source_id()]. 258*/ 259SQLITE_API const char sqlite3_version[] = SQLITE_VERSION; 260SQLITE_API const char *sqlite3_libversion(void); 261SQLITE_API const char *sqlite3_sourceid(void); 262SQLITE_API int sqlite3_libversion_number(void); 263 264/* 265** CAPI3REF: Run-Time Library Compilation Options Diagnostics 266** 267** ^The sqlite3_compileoption_used() function returns 0 or 1 268** indicating whether the specified option was defined at 269** compile time. ^The SQLITE_ prefix may be omitted from the 270** option name passed to sqlite3_compileoption_used(). 271** 272** ^The sqlite3_compileoption_get() function allows iterating 273** over the list of options that were defined at compile time by 274** returning the N-th compile time option string. ^If N is out of range, 275** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ 276** prefix is omitted from any strings returned by 277** sqlite3_compileoption_get(). 278** 279** ^Support for the diagnostic functions sqlite3_compileoption_used() 280** and sqlite3_compileoption_get() may be omitted by specifying the 281** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. 282** 283** See also: SQL functions [sqlite_compileoption_used()] and 284** [sqlite_compileoption_get()] and the [compile_options pragma]. 285*/ 286#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS 287SQLITE_API int sqlite3_compileoption_used(const char *zOptName); 288SQLITE_API const char *sqlite3_compileoption_get(int N); 289#endif 290 291/* 292** CAPI3REF: Test To See If The Library Is Threadsafe 293** 294** ^The sqlite3_threadsafe() function returns zero if and only if 295** SQLite was compiled with mutexing code omitted due to the 296** [SQLITE_THREADSAFE] compile-time option being set to 0. 297** 298** SQLite can be compiled with or without mutexes. When 299** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes 300** are enabled and SQLite is threadsafe. When the 301** [SQLITE_THREADSAFE] macro is 0, 302** the mutexes are omitted. Without the mutexes, it is not safe 303** to use SQLite concurrently from more than one thread. 304** 305** Enabling mutexes incurs a measurable performance penalty. 306** So if speed is of utmost importance, it makes sense to disable 307** the mutexes. But for maximum safety, mutexes should be enabled. 308** ^The default behavior is for mutexes to be enabled. 309** 310** This interface can be used by an application to make sure that the 311** version of SQLite that it is linking against was compiled with 312** the desired setting of the [SQLITE_THREADSAFE] macro. 313** 314** This interface only reports on the compile-time mutex setting 315** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with 316** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but 317** can be fully or partially disabled using a call to [sqlite3_config()] 318** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], 319** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the 320** sqlite3_threadsafe() function shows only the compile-time setting of 321** thread safety, not any run-time changes to that setting made by 322** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() 323** is unchanged by calls to sqlite3_config().)^ 324** 325** See the [threading mode] documentation for additional information. 326*/ 327SQLITE_API int sqlite3_threadsafe(void); 328 329/* 330** CAPI3REF: Database Connection Handle 331** KEYWORDS: {database connection} {database connections} 332** 333** Each open SQLite database is represented by a pointer to an instance of 334** the opaque structure named "sqlite3". It is useful to think of an sqlite3 335** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and 336** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] 337** and [sqlite3_close_v2()] are its destructors. There are many other 338** interfaces (such as 339** [sqlite3_prepare_v2()], [sqlite3_create_function()], and 340** [sqlite3_busy_timeout()] to name but three) that are methods on an 341** sqlite3 object. 342*/ 343typedef struct sqlite3 sqlite3; 344 345/* 346** CAPI3REF: 64-Bit Integer Types 347** KEYWORDS: sqlite_int64 sqlite_uint64 348** 349** Because there is no cross-platform way to specify 64-bit integer types 350** SQLite includes typedefs for 64-bit signed and unsigned integers. 351** 352** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. 353** The sqlite_int64 and sqlite_uint64 types are supported for backwards 354** compatibility only. 355** 356** ^The sqlite3_int64 and sqlite_int64 types can store integer values 357** between -9223372036854775808 and +9223372036854775807 inclusive. ^The 358** sqlite3_uint64 and sqlite_uint64 types can store integer values 359** between 0 and +18446744073709551615 inclusive. 360*/ 361#ifdef SQLITE_INT64_TYPE 362 typedef SQLITE_INT64_TYPE sqlite_int64; 363 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; 364#elif defined(_MSC_VER) || defined(__BORLANDC__) 365 typedef __int64 sqlite_int64; 366 typedef unsigned __int64 sqlite_uint64; 367#else 368 typedef long long int sqlite_int64; 369 typedef unsigned long long int sqlite_uint64; 370#endif 371typedef sqlite_int64 sqlite3_int64; 372typedef sqlite_uint64 sqlite3_uint64; 373 374/* 375** If compiling for a processor that lacks floating point support, 376** substitute integer for floating-point. 377*/ 378#ifdef SQLITE_OMIT_FLOATING_POINT 379# define double sqlite3_int64 380#endif 381 382/* 383** CAPI3REF: Closing A Database Connection 384** 385** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors 386** for the [sqlite3] object. 387** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if 388** the [sqlite3] object is successfully destroyed and all associated 389** resources are deallocated. 390** 391** ^If the database connection is associated with unfinalized prepared 392** statements or unfinished sqlite3_backup objects then sqlite3_close() 393** will leave the database connection open and return [SQLITE_BUSY]. 394** ^If sqlite3_close_v2() is called with unfinalized prepared statements 395** and/or unfinished sqlite3_backups, then the database connection becomes 396** an unusable "zombie" which will automatically be deallocated when the 397** last prepared statement is finalized or the last sqlite3_backup is 398** finished. The sqlite3_close_v2() interface is intended for use with 399** host languages that are garbage collected, and where the order in which 400** destructors are called is arbitrary. 401** 402** Applications should [sqlite3_finalize | finalize] all [prepared statements], 403** [sqlite3_blob_close | close] all [BLOB handles], and 404** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated 405** with the [sqlite3] object prior to attempting to close the object. ^If 406** sqlite3_close_v2() is called on a [database connection] that still has 407** outstanding [prepared statements], [BLOB handles], and/or 408** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation 409** of resources is deferred until all [prepared statements], [BLOB handles], 410** and [sqlite3_backup] objects are also destroyed. 411** 412** ^If an [sqlite3] object is destroyed while a transaction is open, 413** the transaction is automatically rolled back. 414** 415** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)] 416** must be either a NULL 417** pointer or an [sqlite3] object pointer obtained 418** from [sqlite3_open()], [sqlite3_open16()], or 419** [sqlite3_open_v2()], and not previously closed. 420** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer 421** argument is a harmless no-op. 422*/ 423SQLITE_API int sqlite3_close(sqlite3*); 424SQLITE_API int sqlite3_close_v2(sqlite3*); 425 426/* 427** The type for a callback function. 428** This is legacy and deprecated. It is included for historical 429** compatibility and is not documented. 430*/ 431typedef int (*sqlite3_callback)(void*,int,char**, char**); 432 433/* 434** CAPI3REF: One-Step Query Execution Interface 435** 436** The sqlite3_exec() interface is a convenience wrapper around 437** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], 438** that allows an application to run multiple statements of SQL 439** without having to use a lot of C code. 440** 441** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, 442** semicolon-separate SQL statements passed into its 2nd argument, 443** in the context of the [database connection] passed in as its 1st 444** argument. ^If the callback function of the 3rd argument to 445** sqlite3_exec() is not NULL, then it is invoked for each result row 446** coming out of the evaluated SQL statements. ^The 4th argument to 447** sqlite3_exec() is relayed through to the 1st argument of each 448** callback invocation. ^If the callback pointer to sqlite3_exec() 449** is NULL, then no callback is ever invoked and result rows are 450** ignored. 451** 452** ^If an error occurs while evaluating the SQL statements passed into 453** sqlite3_exec(), then execution of the current statement stops and 454** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() 455** is not NULL then any error message is written into memory obtained 456** from [sqlite3_malloc()] and passed back through the 5th parameter. 457** To avoid memory leaks, the application should invoke [sqlite3_free()] 458** on error message strings returned through the 5th parameter of 459** of sqlite3_exec() after the error message string is no longer needed. 460** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors 461** occur, then sqlite3_exec() sets the pointer in its 5th parameter to 462** NULL before returning. 463** 464** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() 465** routine returns SQLITE_ABORT without invoking the callback again and 466** without running any subsequent SQL statements. 467** 468** ^The 2nd argument to the sqlite3_exec() callback function is the 469** number of columns in the result. ^The 3rd argument to the sqlite3_exec() 470** callback is an array of pointers to strings obtained as if from 471** [sqlite3_column_text()], one for each column. ^If an element of a 472** result row is NULL then the corresponding string pointer for the 473** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the 474** sqlite3_exec() callback is an array of pointers to strings where each 475** entry represents the name of corresponding result column as obtained 476** from [sqlite3_column_name()]. 477** 478** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer 479** to an empty string, or a pointer that contains only whitespace and/or 480** SQL comments, then no SQL statements are evaluated and the database 481** is not changed. 482** 483** Restrictions: 484** 485** <ul> 486** <li> The application must insure that the 1st parameter to sqlite3_exec() 487** is a valid and open [database connection]. 488** <li> The application must not close the [database connection] specified by 489** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. 490** <li> The application must not modify the SQL statement text passed into 491** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. 492** </ul> 493*/ 494SQLITE_API int sqlite3_exec( 495 sqlite3*, /* An open database */ 496 const char *sql, /* SQL to be evaluated */ 497 int (*callback)(void*,int,char**,char**), /* Callback function */ 498 void *, /* 1st argument to callback */ 499 char **errmsg /* Error msg written here */ 500); 501 502/* 503** CAPI3REF: Result Codes 504** KEYWORDS: {result code definitions} 505** 506** Many SQLite functions return an integer result code from the set shown 507** here in order to indicate success or failure. 508** 509** New error codes may be added in future versions of SQLite. 510** 511** See also: [extended result code definitions] 512*/ 513#define SQLITE_OK 0 /* Successful result */ 514/* beginning-of-error-codes */ 515#define SQLITE_ERROR 1 /* SQL error or missing database */ 516#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ 517#define SQLITE_PERM 3 /* Access permission denied */ 518#define SQLITE_ABORT 4 /* Callback routine requested an abort */ 519#define SQLITE_BUSY 5 /* The database file is locked */ 520#define SQLITE_LOCKED 6 /* A table in the database is locked */ 521#define SQLITE_NOMEM 7 /* A malloc() failed */ 522#define SQLITE_READONLY 8 /* Attempt to write a readonly database */ 523#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ 524#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ 525#define SQLITE_CORRUPT 11 /* The database disk image is malformed */ 526#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ 527#define SQLITE_FULL 13 /* Insertion failed because database is full */ 528#define SQLITE_CANTOPEN 14 /* Unable to open the database file */ 529#define SQLITE_PROTOCOL 15 /* Database lock protocol error */ 530#define SQLITE_EMPTY 16 /* Database is empty */ 531#define SQLITE_SCHEMA 17 /* The database schema changed */ 532#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ 533#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ 534#define SQLITE_MISMATCH 20 /* Data type mismatch */ 535#define SQLITE_MISUSE 21 /* Library used incorrectly */ 536#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ 537#define SQLITE_AUTH 23 /* Authorization denied */ 538#define SQLITE_FORMAT 24 /* Auxiliary database format error */ 539#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ 540#define SQLITE_NOTADB 26 /* File opened that is not a database file */ 541#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */ 542#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */ 543#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ 544#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ 545/* end-of-error-codes */ 546 547/* 548** CAPI3REF: Extended Result Codes 549** KEYWORDS: {extended result code definitions} 550** 551** In its default configuration, SQLite API routines return one of 30 integer 552** [result codes]. However, experience has shown that many of 553** these result codes are too coarse-grained. They do not provide as 554** much information about problems as programmers might like. In an effort to 555** address this, newer versions of SQLite (version 3.3.8 and later) include 556** support for additional result codes that provide more detailed information 557** about errors. These [extended result codes] are enabled or disabled 558** on a per database connection basis using the 559** [sqlite3_extended_result_codes()] API. Or, the extended code for 560** the most recent error can be obtained using 561** [sqlite3_extended_errcode()]. 562*/ 563#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) 564#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) 565#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) 566#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) 567#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) 568#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) 569#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) 570#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) 571#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) 572#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) 573#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) 574#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) 575#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) 576#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) 577#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) 578#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) 579#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) 580#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) 581#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) 582#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) 583#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) 584#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) 585#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8)) 586#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8)) 587#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8)) 588#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8)) 589#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) 590#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) 591#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8)) 592#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) 593#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8)) 594#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8)) 595#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8)) 596#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) 597#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) 598#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) 599#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8)) 600#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8)) 601#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8)) 602#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8)) 603#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8)) 604#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8)) 605#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8)) 606#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8)) 607#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8)) 608#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8)) 609#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8)) 610#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8)) 611#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8)) 612#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8)) 613#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8)) 614#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8)) 615 616/* 617** CAPI3REF: Flags For File Open Operations 618** 619** These bit values are intended for use in the 620** 3rd parameter to the [sqlite3_open_v2()] interface and 621** in the 4th parameter to the [sqlite3_vfs.xOpen] method. 622*/ 623#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ 624#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ 625#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ 626#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ 627#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ 628#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ 629#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ 630#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */ 631#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ 632#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ 633#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ 634#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ 635#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ 636#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ 637#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ 638#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ 639#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ 640#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ 641#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ 642#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ 643 644/* Reserved: 0x00F00000 */ 645 646/* 647** CAPI3REF: Device Characteristics 648** 649** The xDeviceCharacteristics method of the [sqlite3_io_methods] 650** object returns an integer which is a vector of these 651** bit values expressing I/O characteristics of the mass storage 652** device that holds the file that the [sqlite3_io_methods] 653** refers to. 654** 655** The SQLITE_IOCAP_ATOMIC property means that all writes of 656** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 657** mean that writes of blocks that are nnn bytes in size and 658** are aligned to an address which is an integer multiple of 659** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 660** that when data is appended to a file, the data is appended 661** first then the size of the file is extended, never the other 662** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 663** information is written to disk in the same order as calls 664** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that 665** after reboot following a crash or power loss, the only bytes in a 666** file that were written at the application level might have changed 667** and that adjacent bytes, even bytes within the same sector are 668** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 669** flag indicate that a file cannot be deleted when open. The 670** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on 671** read-only media and cannot be changed even by processes with 672** elevated privileges. 673*/ 674#define SQLITE_IOCAP_ATOMIC 0x00000001 675#define SQLITE_IOCAP_ATOMIC512 0x00000002 676#define SQLITE_IOCAP_ATOMIC1K 0x00000004 677#define SQLITE_IOCAP_ATOMIC2K 0x00000008 678#define SQLITE_IOCAP_ATOMIC4K 0x00000010 679#define SQLITE_IOCAP_ATOMIC8K 0x00000020 680#define SQLITE_IOCAP_ATOMIC16K 0x00000040 681#define SQLITE_IOCAP_ATOMIC32K 0x00000080 682#define SQLITE_IOCAP_ATOMIC64K 0x00000100 683#define SQLITE_IOCAP_SAFE_APPEND 0x00000200 684#define SQLITE_IOCAP_SEQUENTIAL 0x00000400 685#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 686#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000 687#define SQLITE_IOCAP_IMMUTABLE 0x00002000 688 689/* 690** CAPI3REF: File Locking Levels 691** 692** SQLite uses one of these integer values as the second 693** argument to calls it makes to the xLock() and xUnlock() methods 694** of an [sqlite3_io_methods] object. 695*/ 696#define SQLITE_LOCK_NONE 0 697#define SQLITE_LOCK_SHARED 1 698#define SQLITE_LOCK_RESERVED 2 699#define SQLITE_LOCK_PENDING 3 700#define SQLITE_LOCK_EXCLUSIVE 4 701 702/* 703** CAPI3REF: Synchronization Type Flags 704** 705** When SQLite invokes the xSync() method of an 706** [sqlite3_io_methods] object it uses a combination of 707** these integer values as the second argument. 708** 709** When the SQLITE_SYNC_DATAONLY flag is used, it means that the 710** sync operation only needs to flush data to mass storage. Inode 711** information need not be flushed. If the lower four bits of the flag 712** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. 713** If the lower four bits equal SQLITE_SYNC_FULL, that means 714** to use Mac OS X style fullsync instead of fsync(). 715** 716** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags 717** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL 718** settings. The [synchronous pragma] determines when calls to the 719** xSync VFS method occur and applies uniformly across all platforms. 720** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how 721** energetic or rigorous or forceful the sync operations are and 722** only make a difference on Mac OSX for the default SQLite code. 723** (Third-party VFS implementations might also make the distinction 724** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the 725** operating systems natively supported by SQLite, only Mac OSX 726** cares about the difference.) 727*/ 728#define SQLITE_SYNC_NORMAL 0x00002 729#define SQLITE_SYNC_FULL 0x00003 730#define SQLITE_SYNC_DATAONLY 0x00010 731 732/* 733** CAPI3REF: OS Interface Open File Handle 734** 735** An [sqlite3_file] object represents an open file in the 736** [sqlite3_vfs | OS interface layer]. Individual OS interface 737** implementations will 738** want to subclass this object by appending additional fields 739** for their own use. The pMethods entry is a pointer to an 740** [sqlite3_io_methods] object that defines methods for performing 741** I/O operations on the open file. 742*/ 743typedef struct sqlite3_file sqlite3_file; 744struct sqlite3_file { 745 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ 746}; 747 748/* 749** CAPI3REF: OS Interface File Virtual Methods Object 750** 751** Every file opened by the [sqlite3_vfs.xOpen] method populates an 752** [sqlite3_file] object (or, more commonly, a subclass of the 753** [sqlite3_file] object) with a pointer to an instance of this object. 754** This object defines the methods used to perform various operations 755** against the open file represented by the [sqlite3_file] object. 756** 757** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element 758** to a non-NULL pointer, then the sqlite3_io_methods.xClose method 759** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The 760** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] 761** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element 762** to NULL. 763** 764** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or 765** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). 766** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] 767** flag may be ORed in to indicate that only the data of the file 768** and not its inode needs to be synced. 769** 770** The integer values to xLock() and xUnlock() are one of 771** <ul> 772** <li> [SQLITE_LOCK_NONE], 773** <li> [SQLITE_LOCK_SHARED], 774** <li> [SQLITE_LOCK_RESERVED], 775** <li> [SQLITE_LOCK_PENDING], or 776** <li> [SQLITE_LOCK_EXCLUSIVE]. 777** </ul> 778** xLock() increases the lock. xUnlock() decreases the lock. 779** The xCheckReservedLock() method checks whether any database connection, 780** either in this process or in some other process, is holding a RESERVED, 781** PENDING, or EXCLUSIVE lock on the file. It returns true 782** if such a lock exists and false otherwise. 783** 784** The xFileControl() method is a generic interface that allows custom 785** VFS implementations to directly control an open file using the 786** [sqlite3_file_control()] interface. The second "op" argument is an 787** integer opcode. The third argument is a generic pointer intended to 788** point to a structure that may contain arguments or space in which to 789** write return values. Potential uses for xFileControl() might be 790** functions to enable blocking locks with timeouts, to change the 791** locking strategy (for example to use dot-file locks), to inquire 792** about the status of a lock, or to break stale locks. The SQLite 793** core reserves all opcodes less than 100 for its own use. 794** A [file control opcodes | list of opcodes] less than 100 is available. 795** Applications that define a custom xFileControl method should use opcodes 796** greater than 100 to avoid conflicts. VFS implementations should 797** return [SQLITE_NOTFOUND] for file control opcodes that they do not 798** recognize. 799** 800** The xSectorSize() method returns the sector size of the 801** device that underlies the file. The sector size is the 802** minimum write that can be performed without disturbing 803** other bytes in the file. The xDeviceCharacteristics() 804** method returns a bit vector describing behaviors of the 805** underlying device: 806** 807** <ul> 808** <li> [SQLITE_IOCAP_ATOMIC] 809** <li> [SQLITE_IOCAP_ATOMIC512] 810** <li> [SQLITE_IOCAP_ATOMIC1K] 811** <li> [SQLITE_IOCAP_ATOMIC2K] 812** <li> [SQLITE_IOCAP_ATOMIC4K] 813** <li> [SQLITE_IOCAP_ATOMIC8K] 814** <li> [SQLITE_IOCAP_ATOMIC16K] 815** <li> [SQLITE_IOCAP_ATOMIC32K] 816** <li> [SQLITE_IOCAP_ATOMIC64K] 817** <li> [SQLITE_IOCAP_SAFE_APPEND] 818** <li> [SQLITE_IOCAP_SEQUENTIAL] 819** </ul> 820** 821** The SQLITE_IOCAP_ATOMIC property means that all writes of 822** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values 823** mean that writes of blocks that are nnn bytes in size and 824** are aligned to an address which is an integer multiple of 825** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means 826** that when data is appended to a file, the data is appended 827** first then the size of the file is extended, never the other 828** way around. The SQLITE_IOCAP_SEQUENTIAL property means that 829** information is written to disk in the same order as calls 830** to xWrite(). 831** 832** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill 833** in the unread portions of the buffer with zeros. A VFS that 834** fails to zero-fill short reads might seem to work. However, 835** failure to zero-fill short reads will eventually lead to 836** database corruption. 837*/ 838typedef struct sqlite3_io_methods sqlite3_io_methods; 839struct sqlite3_io_methods { 840 int iVersion; 841 int (*xClose)(sqlite3_file*); 842 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); 843 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); 844 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); 845 int (*xSync)(sqlite3_file*, int flags); 846 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); 847 int (*xLock)(sqlite3_file*, int); 848 int (*xUnlock)(sqlite3_file*, int); 849 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); 850 int (*xFileControl)(sqlite3_file*, int op, void *pArg); 851 int (*xSectorSize)(sqlite3_file*); 852 int (*xDeviceCharacteristics)(sqlite3_file*); 853 /* Methods above are valid for version 1 */ 854 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); 855 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); 856 void (*xShmBarrier)(sqlite3_file*); 857 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); 858 /* Methods above are valid for version 2 */ 859 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp); 860 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p); 861 /* Methods above are valid for version 3 */ 862 /* Additional methods may be added in future releases */ 863}; 864 865/* 866** CAPI3REF: Standard File Control Opcodes 867** KEYWORDS: {file control opcodes} {file control opcode} 868** 869** These integer constants are opcodes for the xFileControl method 870** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] 871** interface. 872** 873** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This 874** opcode causes the xFileControl method to write the current state of 875** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], 876** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) 877** into an integer that the pArg argument points to. This capability 878** is used during testing and only needs to be supported when SQLITE_TEST 879** is defined. 880** <ul> 881** <li>[[SQLITE_FCNTL_SIZE_HINT]] 882** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS 883** layer a hint of how large the database file will grow to be during the 884** current transaction. This hint is not guaranteed to be accurate but it 885** is often close. The underlying VFS might choose to preallocate database 886** file space based on this hint in order to help writes to the database 887** file run faster. 888** 889** <li>[[SQLITE_FCNTL_CHUNK_SIZE]] 890** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS 891** extends and truncates the database file in chunks of a size specified 892** by the user. The fourth argument to [sqlite3_file_control()] should 893** point to an integer (type int) containing the new chunk-size to use 894** for the nominated database. Allocating database file space in large 895** chunks (say 1MB at a time), may reduce file-system fragmentation and 896** improve performance on some systems. 897** 898** <li>[[SQLITE_FCNTL_FILE_POINTER]] 899** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer 900** to the [sqlite3_file] object associated with a particular database 901** connection. See the [sqlite3_file_control()] documentation for 902** additional information. 903** 904** <li>[[SQLITE_FCNTL_SYNC_OMITTED]] 905** No longer in use. 906** 907** <li>[[SQLITE_FCNTL_SYNC]] 908** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and 909** sent to the VFS immediately before the xSync method is invoked on a 910** database file descriptor. Or, if the xSync method is not invoked 911** because the user has configured SQLite with 912** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place 913** of the xSync method. In most cases, the pointer argument passed with 914** this file-control is NULL. However, if the database file is being synced 915** as part of a multi-database commit, the argument points to a nul-terminated 916** string containing the transactions master-journal file name. VFSes that 917** do not need this signal should silently ignore this opcode. Applications 918** should not call [sqlite3_file_control()] with this opcode as doing so may 919** disrupt the operation of the specialized VFSes that do require it. 920** 921** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]] 922** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite 923** and sent to the VFS after a transaction has been committed immediately 924** but before the database is unlocked. VFSes that do not need this signal 925** should silently ignore this opcode. Applications should not call 926** [sqlite3_file_control()] with this opcode as doing so may disrupt the 927** operation of the specialized VFSes that do require it. 928** 929** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]] 930** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic 931** retry counts and intervals for certain disk I/O operations for the 932** windows [VFS] in order to provide robustness in the presence of 933** anti-virus programs. By default, the windows VFS will retry file read, 934** file write, and file delete operations up to 10 times, with a delay 935** of 25 milliseconds before the first retry and with the delay increasing 936** by an additional 25 milliseconds with each subsequent retry. This 937** opcode allows these two values (10 retries and 25 milliseconds of delay) 938** to be adjusted. The values are changed for all database connections 939** within the same process. The argument is a pointer to an array of two 940** integers where the first integer i the new retry count and the second 941** integer is the delay. If either integer is negative, then the setting 942** is not changed but instead the prior value of that setting is written 943** into the array entry, allowing the current retry settings to be 944** interrogated. The zDbName parameter is ignored. 945** 946** <li>[[SQLITE_FCNTL_PERSIST_WAL]] 947** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the 948** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary 949** write ahead log and shared memory files used for transaction control 950** are automatically deleted when the latest connection to the database 951** closes. Setting persistent WAL mode causes those files to persist after 952** close. Persisting the files is useful when other processes that do not 953** have write permission on the directory containing the database file want 954** to read the database file, as the WAL and shared memory files must exist 955** in order for the database to be readable. The fourth parameter to 956** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 957** That integer is 0 to disable persistent WAL mode or 1 to enable persistent 958** WAL mode. If the integer is -1, then it is overwritten with the current 959** WAL persistence setting. 960** 961** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]] 962** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the 963** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting 964** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the 965** xDeviceCharacteristics methods. The fourth parameter to 966** [sqlite3_file_control()] for this opcode should be a pointer to an integer. 967** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage 968** mode. If the integer is -1, then it is overwritten with the current 969** zero-damage mode setting. 970** 971** <li>[[SQLITE_FCNTL_OVERWRITE]] 972** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening 973** a write transaction to indicate that, unless it is rolled back for some 974** reason, the entire database file will be overwritten by the current 975** transaction. This is used by VACUUM operations. 976** 977** <li>[[SQLITE_FCNTL_VFSNAME]] 978** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of 979** all [VFSes] in the VFS stack. The names are of all VFS shims and the 980** final bottom-level VFS are written into memory obtained from 981** [sqlite3_malloc()] and the result is stored in the char* variable 982** that the fourth parameter of [sqlite3_file_control()] points to. 983** The caller is responsible for freeing the memory when done. As with 984** all file-control actions, there is no guarantee that this will actually 985** do anything. Callers should initialize the char* variable to a NULL 986** pointer in case this file-control is not implemented. This file-control 987** is intended for diagnostic use only. 988** 989** <li>[[SQLITE_FCNTL_PRAGMA]] 990** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA] 991** file control is sent to the open [sqlite3_file] object corresponding 992** to the database file to which the pragma statement refers. ^The argument 993** to the [SQLITE_FCNTL_PRAGMA] file control is an array of 994** pointers to strings (char**) in which the second element of the array 995** is the name of the pragma and the third element is the argument to the 996** pragma or NULL if the pragma has no argument. ^The handler for an 997** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element 998** of the char** argument point to a string obtained from [sqlite3_mprintf()] 999** or the equivalent and that string will become the result of the pragma or 1000** the error message if the pragma fails. ^If the 1001** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal 1002** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA] 1003** file control returns [SQLITE_OK], then the parser assumes that the 1004** VFS has handled the PRAGMA itself and the parser generates a no-op 1005** prepared statement. ^If the [SQLITE_FCNTL_PRAGMA] file control returns 1006** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means 1007** that the VFS encountered an error while handling the [PRAGMA] and the 1008** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA] 1009** file control occurs at the beginning of pragma statement analysis and so 1010** it is able to override built-in [PRAGMA] statements. 1011** 1012** <li>[[SQLITE_FCNTL_BUSYHANDLER]] 1013** ^The [SQLITE_FCNTL_BUSYHANDLER] 1014** file-control may be invoked by SQLite on the database file handle 1015** shortly after it is opened in order to provide a custom VFS with access 1016** to the connections busy-handler callback. The argument is of type (void **) 1017** - an array of two (void *) values. The first (void *) actually points 1018** to a function of type (int (*)(void *)). In order to invoke the connections 1019** busy-handler, this function should be invoked with the second (void *) in 1020** the array as the only argument. If it returns non-zero, then the operation 1021** should be retried. If it returns zero, the custom VFS should abandon the 1022** current operation. 1023** 1024** <li>[[SQLITE_FCNTL_TEMPFILENAME]] 1025** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control 1026** to have SQLite generate a 1027** temporary filename using the same algorithm that is followed to generate 1028** temporary filenames for TEMP tables and other internal uses. The 1029** argument should be a char** which will be filled with the filename 1030** written into memory obtained from [sqlite3_malloc()]. The caller should 1031** invoke [sqlite3_free()] on the result to avoid a memory leak. 1032** 1033** <li>[[SQLITE_FCNTL_MMAP_SIZE]] 1034** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the 1035** maximum number of bytes that will be used for memory-mapped I/O. 1036** The argument is a pointer to a value of type sqlite3_int64 that 1037** is an advisory maximum number of bytes in the file to memory map. The 1038** pointer is overwritten with the old value. The limit is not changed if 1039** the value originally pointed to is negative, and so the current limit 1040** can be queried by passing in a pointer to a negative number. This 1041** file-control is used internally to implement [PRAGMA mmap_size]. 1042** 1043** <li>[[SQLITE_FCNTL_TRACE]] 1044** The [SQLITE_FCNTL_TRACE] file control provides advisory information 1045** to the VFS about what the higher layers of the SQLite stack are doing. 1046** This file control is used by some VFS activity tracing [shims]. 1047** The argument is a zero-terminated string. Higher layers in the 1048** SQLite stack may generate instances of this file control if 1049** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled. 1050** 1051** <li>[[SQLITE_FCNTL_HAS_MOVED]] 1052** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a 1053** pointer to an integer and it writes a boolean into that integer depending 1054** on whether or not the file has been renamed, moved, or deleted since it 1055** was first opened. 1056** 1057** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]] 1058** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This 1059** opcode causes the xFileControl method to swap the file handle with the one 1060** pointed to by the pArg argument. This capability is used during testing 1061** and only needs to be supported when SQLITE_TEST is defined. 1062** 1063** </ul> 1064*/ 1065#define SQLITE_FCNTL_LOCKSTATE 1 1066#define SQLITE_GET_LOCKPROXYFILE 2 1067#define SQLITE_SET_LOCKPROXYFILE 3 1068#define SQLITE_LAST_ERRNO 4 1069#define SQLITE_FCNTL_SIZE_HINT 5 1070#define SQLITE_FCNTL_CHUNK_SIZE 6 1071#define SQLITE_FCNTL_FILE_POINTER 7 1072#define SQLITE_FCNTL_SYNC_OMITTED 8 1073#define SQLITE_FCNTL_WIN32_AV_RETRY 9 1074#define SQLITE_FCNTL_PERSIST_WAL 10 1075#define SQLITE_FCNTL_OVERWRITE 11 1076#define SQLITE_FCNTL_VFSNAME 12 1077#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13 1078#define SQLITE_FCNTL_PRAGMA 14 1079#define SQLITE_FCNTL_BUSYHANDLER 15 1080#define SQLITE_FCNTL_TEMPFILENAME 16 1081#define SQLITE_FCNTL_MMAP_SIZE 18 1082#define SQLITE_FCNTL_TRACE 19 1083#define SQLITE_FCNTL_HAS_MOVED 20 1084#define SQLITE_FCNTL_SYNC 21 1085#define SQLITE_FCNTL_COMMIT_PHASETWO 22 1086#define SQLITE_FCNTL_WIN32_SET_HANDLE 23 1087 1088/* 1089** CAPI3REF: Mutex Handle 1090** 1091** The mutex module within SQLite defines [sqlite3_mutex] to be an 1092** abstract type for a mutex object. The SQLite core never looks 1093** at the internal representation of an [sqlite3_mutex]. It only 1094** deals with pointers to the [sqlite3_mutex] object. 1095** 1096** Mutexes are created using [sqlite3_mutex_alloc()]. 1097*/ 1098typedef struct sqlite3_mutex sqlite3_mutex; 1099 1100/* 1101** CAPI3REF: OS Interface Object 1102** 1103** An instance of the sqlite3_vfs object defines the interface between 1104** the SQLite core and the underlying operating system. The "vfs" 1105** in the name of the object stands for "virtual file system". See 1106** the [VFS | VFS documentation] for further information. 1107** 1108** The value of the iVersion field is initially 1 but may be larger in 1109** future versions of SQLite. Additional fields may be appended to this 1110** object when the iVersion value is increased. Note that the structure 1111** of the sqlite3_vfs object changes in the transaction between 1112** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not 1113** modified. 1114** 1115** The szOsFile field is the size of the subclassed [sqlite3_file] 1116** structure used by this VFS. mxPathname is the maximum length of 1117** a pathname in this VFS. 1118** 1119** Registered sqlite3_vfs objects are kept on a linked list formed by 1120** the pNext pointer. The [sqlite3_vfs_register()] 1121** and [sqlite3_vfs_unregister()] interfaces manage this list 1122** in a thread-safe way. The [sqlite3_vfs_find()] interface 1123** searches the list. Neither the application code nor the VFS 1124** implementation should use the pNext pointer. 1125** 1126** The pNext field is the only field in the sqlite3_vfs 1127** structure that SQLite will ever modify. SQLite will only access 1128** or modify this field while holding a particular static mutex. 1129** The application should never modify anything within the sqlite3_vfs 1130** object once the object has been registered. 1131** 1132** The zName field holds the name of the VFS module. The name must 1133** be unique across all VFS modules. 1134** 1135** [[sqlite3_vfs.xOpen]] 1136** ^SQLite guarantees that the zFilename parameter to xOpen 1137** is either a NULL pointer or string obtained 1138** from xFullPathname() with an optional suffix added. 1139** ^If a suffix is added to the zFilename parameter, it will 1140** consist of a single "-" character followed by no more than 1141** 11 alphanumeric and/or "-" characters. 1142** ^SQLite further guarantees that 1143** the string will be valid and unchanged until xClose() is 1144** called. Because of the previous sentence, 1145** the [sqlite3_file] can safely store a pointer to the 1146** filename if it needs to remember the filename for some reason. 1147** If the zFilename parameter to xOpen is a NULL pointer then xOpen 1148** must invent its own temporary name for the file. ^Whenever the 1149** xFilename parameter is NULL it will also be the case that the 1150** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. 1151** 1152** The flags argument to xOpen() includes all bits set in 1153** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] 1154** or [sqlite3_open16()] is used, then flags includes at least 1155** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. 1156** If xOpen() opens a file read-only then it sets *pOutFlags to 1157** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. 1158** 1159** ^(SQLite will also add one of the following flags to the xOpen() 1160** call, depending on the object being opened: 1161** 1162** <ul> 1163** <li> [SQLITE_OPEN_MAIN_DB] 1164** <li> [SQLITE_OPEN_MAIN_JOURNAL] 1165** <li> [SQLITE_OPEN_TEMP_DB] 1166** <li> [SQLITE_OPEN_TEMP_JOURNAL] 1167** <li> [SQLITE_OPEN_TRANSIENT_DB] 1168** <li> [SQLITE_OPEN_SUBJOURNAL] 1169** <li> [SQLITE_OPEN_MASTER_JOURNAL] 1170** <li> [SQLITE_OPEN_WAL] 1171** </ul>)^ 1172** 1173** The file I/O implementation can use the object type flags to 1174** change the way it deals with files. For example, an application 1175** that does not care about crash recovery or rollback might make 1176** the open of a journal file a no-op. Writes to this journal would 1177** also be no-ops, and any attempt to read the journal would return 1178** SQLITE_IOERR. Or the implementation might recognize that a database 1179** file will be doing page-aligned sector reads and writes in a random 1180** order and set up its I/O subsystem accordingly. 1181** 1182** SQLite might also add one of the following flags to the xOpen method: 1183** 1184** <ul> 1185** <li> [SQLITE_OPEN_DELETEONCLOSE] 1186** <li> [SQLITE_OPEN_EXCLUSIVE] 1187** </ul> 1188** 1189** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be 1190** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] 1191** will be set for TEMP databases and their journals, transient 1192** databases, and subjournals. 1193** 1194** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction 1195** with the [SQLITE_OPEN_CREATE] flag, which are both directly 1196** analogous to the O_EXCL and O_CREAT flags of the POSIX open() 1197** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the 1198** SQLITE_OPEN_CREATE, is used to indicate that file should always 1199** be created, and that it is an error if it already exists. 1200** It is <i>not</i> used to indicate the file should be opened 1201** for exclusive access. 1202** 1203** ^At least szOsFile bytes of memory are allocated by SQLite 1204** to hold the [sqlite3_file] structure passed as the third 1205** argument to xOpen. The xOpen method does not have to 1206** allocate the structure; it should just fill it in. Note that 1207** the xOpen method must set the sqlite3_file.pMethods to either 1208** a valid [sqlite3_io_methods] object or to NULL. xOpen must do 1209** this even if the open fails. SQLite expects that the sqlite3_file.pMethods 1210** element will be valid after xOpen returns regardless of the success 1211** or failure of the xOpen call. 1212** 1213** [[sqlite3_vfs.xAccess]] 1214** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] 1215** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to 1216** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] 1217** to test whether a file is at least readable. The file can be a 1218** directory. 1219** 1220** ^SQLite will always allocate at least mxPathname+1 bytes for the 1221** output buffer xFullPathname. The exact size of the output buffer 1222** is also passed as a parameter to both methods. If the output buffer 1223** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is 1224** handled as a fatal error by SQLite, vfs implementations should endeavor 1225** to prevent this by setting mxPathname to a sufficiently large value. 1226** 1227** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() 1228** interfaces are not strictly a part of the filesystem, but they are 1229** included in the VFS structure for completeness. 1230** The xRandomness() function attempts to return nBytes bytes 1231** of good-quality randomness into zOut. The return value is 1232** the actual number of bytes of randomness obtained. 1233** The xSleep() method causes the calling thread to sleep for at 1234** least the number of microseconds given. ^The xCurrentTime() 1235** method returns a Julian Day Number for the current date and time as 1236** a floating point value. 1237** ^The xCurrentTimeInt64() method returns, as an integer, the Julian 1238** Day Number multiplied by 86400000 (the number of milliseconds in 1239** a 24-hour day). 1240** ^SQLite will use the xCurrentTimeInt64() method to get the current 1241** date and time if that method is available (if iVersion is 2 or 1242** greater and the function pointer is not NULL) and will fall back 1243** to xCurrentTime() if xCurrentTimeInt64() is unavailable. 1244** 1245** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces 1246** are not used by the SQLite core. These optional interfaces are provided 1247** by some VFSes to facilitate testing of the VFS code. By overriding 1248** system calls with functions under its control, a test program can 1249** simulate faults and error conditions that would otherwise be difficult 1250** or impossible to induce. The set of system calls that can be overridden 1251** varies from one VFS to another, and from one version of the same VFS to the 1252** next. Applications that use these interfaces must be prepared for any 1253** or all of these interfaces to be NULL or for their behavior to change 1254** from one release to the next. Applications must not attempt to access 1255** any of these methods if the iVersion of the VFS is less than 3. 1256*/ 1257typedef struct sqlite3_vfs sqlite3_vfs; 1258typedef void (*sqlite3_syscall_ptr)(void); 1259struct sqlite3_vfs { 1260 int iVersion; /* Structure version number (currently 3) */ 1261 int szOsFile; /* Size of subclassed sqlite3_file */ 1262 int mxPathname; /* Maximum file pathname length */ 1263 sqlite3_vfs *pNext; /* Next registered VFS */ 1264 const char *zName; /* Name of this virtual file system */ 1265 void *pAppData; /* Pointer to application-specific data */ 1266 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, 1267 int flags, int *pOutFlags); 1268 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); 1269 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); 1270 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); 1271 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); 1272 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); 1273 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); 1274 void (*xDlClose)(sqlite3_vfs*, void*); 1275 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); 1276 int (*xSleep)(sqlite3_vfs*, int microseconds); 1277 int (*xCurrentTime)(sqlite3_vfs*, double*); 1278 int (*xGetLastError)(sqlite3_vfs*, int, char *); 1279 /* 1280 ** The methods above are in version 1 of the sqlite_vfs object 1281 ** definition. Those that follow are added in version 2 or later 1282 */ 1283 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); 1284 /* 1285 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. 1286 ** Those below are for version 3 and greater. 1287 */ 1288 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); 1289 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); 1290 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); 1291 /* 1292 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. 1293 ** New fields may be appended in figure versions. The iVersion 1294 ** value will increment whenever this happens. 1295 */ 1296}; 1297 1298/* 1299** CAPI3REF: Flags for the xAccess VFS method 1300** 1301** These integer constants can be used as the third parameter to 1302** the xAccess method of an [sqlite3_vfs] object. They determine 1303** what kind of permissions the xAccess method is looking for. 1304** With SQLITE_ACCESS_EXISTS, the xAccess method 1305** simply checks whether the file exists. 1306** With SQLITE_ACCESS_READWRITE, the xAccess method 1307** checks whether the named directory is both readable and writable 1308** (in other words, if files can be added, removed, and renamed within 1309** the directory). 1310** The SQLITE_ACCESS_READWRITE constant is currently used only by the 1311** [temp_store_directory pragma], though this could change in a future 1312** release of SQLite. 1313** With SQLITE_ACCESS_READ, the xAccess method 1314** checks whether the file is readable. The SQLITE_ACCESS_READ constant is 1315** currently unused, though it might be used in a future release of 1316** SQLite. 1317*/ 1318#define SQLITE_ACCESS_EXISTS 0 1319#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ 1320#define SQLITE_ACCESS_READ 2 /* Unused */ 1321 1322/* 1323** CAPI3REF: Flags for the xShmLock VFS method 1324** 1325** These integer constants define the various locking operations 1326** allowed by the xShmLock method of [sqlite3_io_methods]. The 1327** following are the only legal combinations of flags to the 1328** xShmLock method: 1329** 1330** <ul> 1331** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED 1332** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE 1333** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED 1334** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE 1335** </ul> 1336** 1337** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as 1338** was given no the corresponding lock. 1339** 1340** The xShmLock method can transition between unlocked and SHARED or 1341** between unlocked and EXCLUSIVE. It cannot transition between SHARED 1342** and EXCLUSIVE. 1343*/ 1344#define SQLITE_SHM_UNLOCK 1 1345#define SQLITE_SHM_LOCK 2 1346#define SQLITE_SHM_SHARED 4 1347#define SQLITE_SHM_EXCLUSIVE 8 1348 1349/* 1350** CAPI3REF: Maximum xShmLock index 1351** 1352** The xShmLock method on [sqlite3_io_methods] may use values 1353** between 0 and this upper bound as its "offset" argument. 1354** The SQLite core will never attempt to acquire or release a 1355** lock outside of this range 1356*/ 1357#define SQLITE_SHM_NLOCK 8 1358 1359 1360/* 1361** CAPI3REF: Initialize The SQLite Library 1362** 1363** ^The sqlite3_initialize() routine initializes the 1364** SQLite library. ^The sqlite3_shutdown() routine 1365** deallocates any resources that were allocated by sqlite3_initialize(). 1366** These routines are designed to aid in process initialization and 1367** shutdown on embedded systems. Workstation applications using 1368** SQLite normally do not need to invoke either of these routines. 1369** 1370** A call to sqlite3_initialize() is an "effective" call if it is 1371** the first time sqlite3_initialize() is invoked during the lifetime of 1372** the process, or if it is the first time sqlite3_initialize() is invoked 1373** following a call to sqlite3_shutdown(). ^(Only an effective call 1374** of sqlite3_initialize() does any initialization. All other calls 1375** are harmless no-ops.)^ 1376** 1377** A call to sqlite3_shutdown() is an "effective" call if it is the first 1378** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only 1379** an effective call to sqlite3_shutdown() does any deinitialization. 1380** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ 1381** 1382** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() 1383** is not. The sqlite3_shutdown() interface must only be called from a 1384** single thread. All open [database connections] must be closed and all 1385** other SQLite resources must be deallocated prior to invoking 1386** sqlite3_shutdown(). 1387** 1388** Among other things, ^sqlite3_initialize() will invoke 1389** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() 1390** will invoke sqlite3_os_end(). 1391** 1392** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. 1393** ^If for some reason, sqlite3_initialize() is unable to initialize 1394** the library (perhaps it is unable to allocate a needed resource such 1395** as a mutex) it returns an [error code] other than [SQLITE_OK]. 1396** 1397** ^The sqlite3_initialize() routine is called internally by many other 1398** SQLite interfaces so that an application usually does not need to 1399** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] 1400** calls sqlite3_initialize() so the SQLite library will be automatically 1401** initialized when [sqlite3_open()] is called if it has not be initialized 1402** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] 1403** compile-time option, then the automatic calls to sqlite3_initialize() 1404** are omitted and the application must call sqlite3_initialize() directly 1405** prior to using any other SQLite interface. For maximum portability, 1406** it is recommended that applications always invoke sqlite3_initialize() 1407** directly prior to using any other SQLite interface. Future releases 1408** of SQLite may require this. In other words, the behavior exhibited 1409** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the 1410** default behavior in some future release of SQLite. 1411** 1412** The sqlite3_os_init() routine does operating-system specific 1413** initialization of the SQLite library. The sqlite3_os_end() 1414** routine undoes the effect of sqlite3_os_init(). Typical tasks 1415** performed by these routines include allocation or deallocation 1416** of static resources, initialization of global variables, 1417** setting up a default [sqlite3_vfs] module, or setting up 1418** a default configuration using [sqlite3_config()]. 1419** 1420** The application should never invoke either sqlite3_os_init() 1421** or sqlite3_os_end() directly. The application should only invoke 1422** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() 1423** interface is called automatically by sqlite3_initialize() and 1424** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate 1425** implementations for sqlite3_os_init() and sqlite3_os_end() 1426** are built into SQLite when it is compiled for Unix, Windows, or OS/2. 1427** When [custom builds | built for other platforms] 1428** (using the [SQLITE_OS_OTHER=1] compile-time 1429** option) the application must supply a suitable implementation for 1430** sqlite3_os_init() and sqlite3_os_end(). An application-supplied 1431** implementation of sqlite3_os_init() or sqlite3_os_end() 1432** must return [SQLITE_OK] on success and some other [error code] upon 1433** failure. 1434*/ 1435SQLITE_API int sqlite3_initialize(void); 1436SQLITE_API int sqlite3_shutdown(void); 1437SQLITE_API int sqlite3_os_init(void); 1438SQLITE_API int sqlite3_os_end(void); 1439 1440/* 1441** CAPI3REF: Configuring The SQLite Library 1442** 1443** The sqlite3_config() interface is used to make global configuration 1444** changes to SQLite in order to tune SQLite to the specific needs of 1445** the application. The default configuration is recommended for most 1446** applications and so this routine is usually not necessary. It is 1447** provided to support rare applications with unusual needs. 1448** 1449** The sqlite3_config() interface is not threadsafe. The application 1450** must insure that no other SQLite interfaces are invoked by other 1451** threads while sqlite3_config() is running. Furthermore, sqlite3_config() 1452** may only be invoked prior to library initialization using 1453** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. 1454** ^If sqlite3_config() is called after [sqlite3_initialize()] and before 1455** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. 1456** Note, however, that ^sqlite3_config() can be called as part of the 1457** implementation of an application-defined [sqlite3_os_init()]. 1458** 1459** The first argument to sqlite3_config() is an integer 1460** [configuration option] that determines 1461** what property of SQLite is to be configured. Subsequent arguments 1462** vary depending on the [configuration option] 1463** in the first argument. 1464** 1465** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. 1466** ^If the option is unknown or SQLite is unable to set the option 1467** then this routine returns a non-zero [error code]. 1468*/ 1469SQLITE_API int sqlite3_config(int, ...); 1470 1471/* 1472** CAPI3REF: Configure database connections 1473** 1474** The sqlite3_db_config() interface is used to make configuration 1475** changes to a [database connection]. The interface is similar to 1476** [sqlite3_config()] except that the changes apply to a single 1477** [database connection] (specified in the first argument). 1478** 1479** The second argument to sqlite3_db_config(D,V,...) is the 1480** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code 1481** that indicates what aspect of the [database connection] is being configured. 1482** Subsequent arguments vary depending on the configuration verb. 1483** 1484** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if 1485** the call is considered successful. 1486*/ 1487SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); 1488 1489/* 1490** CAPI3REF: Memory Allocation Routines 1491** 1492** An instance of this object defines the interface between SQLite 1493** and low-level memory allocation routines. 1494** 1495** This object is used in only one place in the SQLite interface. 1496** A pointer to an instance of this object is the argument to 1497** [sqlite3_config()] when the configuration option is 1498** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. 1499** By creating an instance of this object 1500** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) 1501** during configuration, an application can specify an alternative 1502** memory allocation subsystem for SQLite to use for all of its 1503** dynamic memory needs. 1504** 1505** Note that SQLite comes with several [built-in memory allocators] 1506** that are perfectly adequate for the overwhelming majority of applications 1507** and that this object is only useful to a tiny minority of applications 1508** with specialized memory allocation requirements. This object is 1509** also used during testing of SQLite in order to specify an alternative 1510** memory allocator that simulates memory out-of-memory conditions in 1511** order to verify that SQLite recovers gracefully from such 1512** conditions. 1513** 1514** The xMalloc, xRealloc, and xFree methods must work like the 1515** malloc(), realloc() and free() functions from the standard C library. 1516** ^SQLite guarantees that the second argument to 1517** xRealloc is always a value returned by a prior call to xRoundup. 1518** 1519** xSize should return the allocated size of a memory allocation 1520** previously obtained from xMalloc or xRealloc. The allocated size 1521** is always at least as big as the requested size but may be larger. 1522** 1523** The xRoundup method returns what would be the allocated size of 1524** a memory allocation given a particular requested size. Most memory 1525** allocators round up memory allocations at least to the next multiple 1526** of 8. Some allocators round up to a larger multiple or to a power of 2. 1527** Every memory allocation request coming in through [sqlite3_malloc()] 1528** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, 1529** that causes the corresponding memory allocation to fail. 1530** 1531** The xInit method initializes the memory allocator. For example, 1532** it might allocate any require mutexes or initialize internal data 1533** structures. The xShutdown method is invoked (indirectly) by 1534** [sqlite3_shutdown()] and should deallocate any resources acquired 1535** by xInit. The pAppData pointer is used as the only parameter to 1536** xInit and xShutdown. 1537** 1538** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes 1539** the xInit method, so the xInit method need not be threadsafe. The 1540** xShutdown method is only called from [sqlite3_shutdown()] so it does 1541** not need to be threadsafe either. For all other methods, SQLite 1542** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the 1543** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which 1544** it is by default) and so the methods are automatically serialized. 1545** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other 1546** methods must be threadsafe or else make their own arrangements for 1547** serialization. 1548** 1549** SQLite will never invoke xInit() more than once without an intervening 1550** call to xShutdown(). 1551*/ 1552typedef struct sqlite3_mem_methods sqlite3_mem_methods; 1553struct sqlite3_mem_methods { 1554 void *(*xMalloc)(int); /* Memory allocation function */ 1555 void (*xFree)(void*); /* Free a prior allocation */ 1556 void *(*xRealloc)(void*,int); /* Resize an allocation */ 1557 int (*xSize)(void*); /* Return the size of an allocation */ 1558 int (*xRoundup)(int); /* Round up request size to allocation size */ 1559 int (*xInit)(void*); /* Initialize the memory allocator */ 1560 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ 1561 void *pAppData; /* Argument to xInit() and xShutdown() */ 1562}; 1563 1564/* 1565** CAPI3REF: Configuration Options 1566** KEYWORDS: {configuration option} 1567** 1568** These constants are the available integer configuration options that 1569** can be passed as the first argument to the [sqlite3_config()] interface. 1570** 1571** New configuration options may be added in future releases of SQLite. 1572** Existing configuration options might be discontinued. Applications 1573** should check the return code from [sqlite3_config()] to make sure that 1574** the call worked. The [sqlite3_config()] interface will return a 1575** non-zero [error code] if a discontinued or unsupported configuration option 1576** is invoked. 1577** 1578** <dl> 1579** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> 1580** <dd>There are no arguments to this option. ^This option sets the 1581** [threading mode] to Single-thread. In other words, it disables 1582** all mutexing and puts SQLite into a mode where it can only be used 1583** by a single thread. ^If SQLite is compiled with 1584** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1585** it is not possible to change the [threading mode] from its default 1586** value of Single-thread and so [sqlite3_config()] will return 1587** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD 1588** configuration option.</dd> 1589** 1590** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> 1591** <dd>There are no arguments to this option. ^This option sets the 1592** [threading mode] to Multi-thread. In other words, it disables 1593** mutexing on [database connection] and [prepared statement] objects. 1594** The application is responsible for serializing access to 1595** [database connections] and [prepared statements]. But other mutexes 1596** are enabled so that SQLite will be safe to use in a multi-threaded 1597** environment as long as no two threads attempt to use the same 1598** [database connection] at the same time. ^If SQLite is compiled with 1599** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1600** it is not possible to set the Multi-thread [threading mode] and 1601** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1602** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> 1603** 1604** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> 1605** <dd>There are no arguments to this option. ^This option sets the 1606** [threading mode] to Serialized. In other words, this option enables 1607** all mutexes including the recursive 1608** mutexes on [database connection] and [prepared statement] objects. 1609** In this mode (which is the default when SQLite is compiled with 1610** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access 1611** to [database connections] and [prepared statements] so that the 1612** application is free to use the same [database connection] or the 1613** same [prepared statement] in different threads at the same time. 1614** ^If SQLite is compiled with 1615** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1616** it is not possible to set the Serialized [threading mode] and 1617** [sqlite3_config()] will return [SQLITE_ERROR] if called with the 1618** SQLITE_CONFIG_SERIALIZED configuration option.</dd> 1619** 1620** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> 1621** <dd> ^(This option takes a single argument which is a pointer to an 1622** instance of the [sqlite3_mem_methods] structure. The argument specifies 1623** alternative low-level memory allocation routines to be used in place of 1624** the memory allocation routines built into SQLite.)^ ^SQLite makes 1625** its own private copy of the content of the [sqlite3_mem_methods] structure 1626** before the [sqlite3_config()] call returns.</dd> 1627** 1628** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> 1629** <dd> ^(This option takes a single argument which is a pointer to an 1630** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] 1631** structure is filled with the currently defined memory allocation routines.)^ 1632** This option can be used to overload the default memory allocation 1633** routines with a wrapper that simulations memory allocation failure or 1634** tracks memory usage, for example. </dd> 1635** 1636** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> 1637** <dd> ^This option takes single argument of type int, interpreted as a 1638** boolean, which enables or disables the collection of memory allocation 1639** statistics. ^(When memory allocation statistics are disabled, the 1640** following SQLite interfaces become non-operational: 1641** <ul> 1642** <li> [sqlite3_memory_used()] 1643** <li> [sqlite3_memory_highwater()] 1644** <li> [sqlite3_soft_heap_limit64()] 1645** <li> [sqlite3_status()] 1646** </ul>)^ 1647** ^Memory allocation statistics are enabled by default unless SQLite is 1648** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory 1649** allocation statistics are disabled by default. 1650** </dd> 1651** 1652** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> 1653** <dd> ^This option specifies a static memory buffer that SQLite can use for 1654** scratch memory. There are three arguments: A pointer an 8-byte 1655** aligned memory buffer from which the scratch allocations will be 1656** drawn, the size of each scratch allocation (sz), 1657** and the maximum number of scratch allocations (N). The sz 1658** argument must be a multiple of 16. 1659** The first argument must be a pointer to an 8-byte aligned buffer 1660** of at least sz*N bytes of memory. 1661** ^SQLite will use no more than two scratch buffers per thread. So 1662** N should be set to twice the expected maximum number of threads. 1663** ^SQLite will never require a scratch buffer that is more than 6 1664** times the database page size. ^If SQLite needs needs additional 1665** scratch memory beyond what is provided by this configuration option, then 1666** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> 1667** 1668** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> 1669** <dd> ^This option specifies a static memory buffer that SQLite can use for 1670** the database page cache with the default page cache implementation. 1671** This configuration should not be used if an application-define page 1672** cache implementation is loaded using the SQLITE_CONFIG_PCACHE2 option. 1673** There are three arguments to this option: A pointer to 8-byte aligned 1674** memory, the size of each page buffer (sz), and the number of pages (N). 1675** The sz argument should be the size of the largest database page 1676** (a power of two between 512 and 32768) plus a little extra for each 1677** page header. ^The page header size is 20 to 40 bytes depending on 1678** the host architecture. ^It is harmless, apart from the wasted memory, 1679** to make sz a little too large. The first 1680** argument should point to an allocation of at least sz*N bytes of memory. 1681** ^SQLite will use the memory provided by the first argument to satisfy its 1682** memory needs for the first N pages that it adds to cache. ^If additional 1683** page cache memory is needed beyond what is provided by this option, then 1684** SQLite goes to [sqlite3_malloc()] for the additional storage space. 1685** The pointer in the first argument must 1686** be aligned to an 8-byte boundary or subsequent behavior of SQLite 1687** will be undefined.</dd> 1688** 1689** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> 1690** <dd> ^This option specifies a static memory buffer that SQLite will use 1691** for all of its dynamic memory allocation needs beyond those provided 1692** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. 1693** There are three arguments: An 8-byte aligned pointer to the memory, 1694** the number of bytes in the memory buffer, and the minimum allocation size. 1695** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts 1696** to using its default memory allocator (the system malloc() implementation), 1697** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the 1698** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or 1699** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory 1700** allocator is engaged to handle all of SQLites memory allocation needs. 1701** The first pointer (the memory pointer) must be aligned to an 8-byte 1702** boundary or subsequent behavior of SQLite will be undefined. 1703** The minimum allocation size is capped at 2**12. Reasonable values 1704** for the minimum allocation size are 2**5 through 2**8.</dd> 1705** 1706** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> 1707** <dd> ^(This option takes a single argument which is a pointer to an 1708** instance of the [sqlite3_mutex_methods] structure. The argument specifies 1709** alternative low-level mutex routines to be used in place 1710** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the 1711** content of the [sqlite3_mutex_methods] structure before the call to 1712** [sqlite3_config()] returns. ^If SQLite is compiled with 1713** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1714** the entire mutexing subsystem is omitted from the build and hence calls to 1715** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will 1716** return [SQLITE_ERROR].</dd> 1717** 1718** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> 1719** <dd> ^(This option takes a single argument which is a pointer to an 1720** instance of the [sqlite3_mutex_methods] structure. The 1721** [sqlite3_mutex_methods] 1722** structure is filled with the currently defined mutex routines.)^ 1723** This option can be used to overload the default mutex allocation 1724** routines with a wrapper used to track mutex usage for performance 1725** profiling or testing, for example. ^If SQLite is compiled with 1726** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then 1727** the entire mutexing subsystem is omitted from the build and hence calls to 1728** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will 1729** return [SQLITE_ERROR].</dd> 1730** 1731** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> 1732** <dd> ^(This option takes two arguments that determine the default 1733** memory allocation for the lookaside memory allocator on each 1734** [database connection]. The first argument is the 1735** size of each lookaside buffer slot and the second is the number of 1736** slots allocated to each database connection.)^ ^(This option sets the 1737** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] 1738** verb to [sqlite3_db_config()] can be used to change the lookaside 1739** configuration on individual connections.)^ </dd> 1740** 1741** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt> 1742** <dd> ^(This option takes a single argument which is a pointer to 1743** an [sqlite3_pcache_methods2] object. This object specifies the interface 1744** to a custom page cache implementation.)^ ^SQLite makes a copy of the 1745** object and uses it for page cache memory allocations.</dd> 1746** 1747** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt> 1748** <dd> ^(This option takes a single argument which is a pointer to an 1749** [sqlite3_pcache_methods2] object. SQLite copies of the current 1750** page cache implementation into that object.)^ </dd> 1751** 1752** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> 1753** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite 1754** global [error log]. 1755** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a 1756** function with a call signature of void(*)(void*,int,const char*), 1757** and a pointer to void. ^If the function pointer is not NULL, it is 1758** invoked by [sqlite3_log()] to process each logging event. ^If the 1759** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. 1760** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is 1761** passed through as the first parameter to the application-defined logger 1762** function whenever that function is invoked. ^The second parameter to 1763** the logger function is a copy of the first parameter to the corresponding 1764** [sqlite3_log()] call and is intended to be a [result code] or an 1765** [extended result code]. ^The third parameter passed to the logger is 1766** log message after formatting via [sqlite3_snprintf()]. 1767** The SQLite logging interface is not reentrant; the logger function 1768** supplied by the application must not invoke any SQLite interface. 1769** In a multi-threaded application, the application-defined logger 1770** function must be threadsafe. </dd> 1771** 1772** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI 1773** <dd>^(This option takes a single argument of type int. If non-zero, then 1774** URI handling is globally enabled. If the parameter is zero, then URI handling 1775** is globally disabled.)^ ^If URI handling is globally enabled, all filenames 1776** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or 1777** specified as part of [ATTACH] commands are interpreted as URIs, regardless 1778** of whether or not the [SQLITE_OPEN_URI] flag is set when the database 1779** connection is opened. ^If it is globally disabled, filenames are 1780** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the 1781** database connection is opened. ^(By default, URI handling is globally 1782** disabled. The default value may be changed by compiling with the 1783** [SQLITE_USE_URI] symbol defined.)^ 1784** 1785** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN 1786** <dd>^This option takes a single integer argument which is interpreted as 1787** a boolean in order to enable or disable the use of covering indices for 1788** full table scans in the query optimizer. ^The default setting is determined 1789** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on" 1790** if that compile-time option is omitted. 1791** The ability to disable the use of covering indices for full table scans 1792** is because some incorrectly coded legacy applications might malfunction 1793** when the optimization is enabled. Providing the ability to 1794** disable the optimization allows the older, buggy application code to work 1795** without change even with newer versions of SQLite. 1796** 1797** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]] 1798** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE 1799** <dd> These options are obsolete and should not be used by new code. 1800** They are retained for backwards compatibility but are now no-ops. 1801** </dd> 1802** 1803** [[SQLITE_CONFIG_SQLLOG]] 1804** <dt>SQLITE_CONFIG_SQLLOG 1805** <dd>This option is only available if sqlite is compiled with the 1806** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should 1807** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int). 1808** The second should be of type (void*). The callback is invoked by the library 1809** in three separate circumstances, identified by the value passed as the 1810** fourth parameter. If the fourth parameter is 0, then the database connection 1811** passed as the second argument has just been opened. The third argument 1812** points to a buffer containing the name of the main database file. If the 1813** fourth parameter is 1, then the SQL statement that the third parameter 1814** points to has just been executed. Or, if the fourth parameter is 2, then 1815** the connection being passed as the second parameter is being closed. The 1816** third parameter is passed NULL In this case. An example of using this 1817** configuration option can be seen in the "test_sqllog.c" source file in 1818** the canonical SQLite source tree.</dd> 1819** 1820** [[SQLITE_CONFIG_MMAP_SIZE]] 1821** <dt>SQLITE_CONFIG_MMAP_SIZE 1822** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values 1823** that are the default mmap size limit (the default setting for 1824** [PRAGMA mmap_size]) and the maximum allowed mmap size limit. 1825** ^The default setting can be overridden by each database connection using 1826** either the [PRAGMA mmap_size] command, or by using the 1827** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size 1828** cannot be changed at run-time. Nor may the maximum allowed mmap size 1829** exceed the compile-time maximum mmap size set by the 1830** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^ 1831** ^If either argument to this option is negative, then that argument is 1832** changed to its compile-time default. 1833** 1834** [[SQLITE_CONFIG_WIN32_HEAPSIZE]] 1835** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE 1836** <dd>^This option is only available if SQLite is compiled for Windows 1837** with the [SQLITE_WIN32_MALLOC] pre-processor macro defined. 1838** SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value 1839** that specifies the maximum size of the created heap. 1840** </dl> 1841*/ 1842#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ 1843#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ 1844#define SQLITE_CONFIG_SERIALIZED 3 /* nil */ 1845#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ 1846#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ 1847#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ 1848#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ 1849#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ 1850#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ 1851#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ 1852#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ 1853/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ 1854#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ 1855#define SQLITE_CONFIG_PCACHE 14 /* no-op */ 1856#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */ 1857#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ 1858#define SQLITE_CONFIG_URI 17 /* int */ 1859#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */ 1860#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */ 1861#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */ 1862#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */ 1863#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */ 1864#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */ 1865 1866/* 1867** CAPI3REF: Database Connection Configuration Options 1868** 1869** These constants are the available integer configuration options that 1870** can be passed as the second argument to the [sqlite3_db_config()] interface. 1871** 1872** New configuration options may be added in future releases of SQLite. 1873** Existing configuration options might be discontinued. Applications 1874** should check the return code from [sqlite3_db_config()] to make sure that 1875** the call worked. ^The [sqlite3_db_config()] interface will return a 1876** non-zero [error code] if a discontinued or unsupported configuration option 1877** is invoked. 1878** 1879** <dl> 1880** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> 1881** <dd> ^This option takes three additional arguments that determine the 1882** [lookaside memory allocator] configuration for the [database connection]. 1883** ^The first argument (the third parameter to [sqlite3_db_config()] is a 1884** pointer to a memory buffer to use for lookaside memory. 1885** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb 1886** may be NULL in which case SQLite will allocate the 1887** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the 1888** size of each lookaside buffer slot. ^The third argument is the number of 1889** slots. The size of the buffer in the first argument must be greater than 1890** or equal to the product of the second and third arguments. The buffer 1891** must be aligned to an 8-byte boundary. ^If the second argument to 1892** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally 1893** rounded down to the next smaller multiple of 8. ^(The lookaside memory 1894** configuration for a database connection can only be changed when that 1895** connection is not currently using lookaside memory, or in other words 1896** when the "current value" returned by 1897** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. 1898** Any attempt to change the lookaside memory configuration when lookaside 1899** memory is in use leaves the configuration unchanged and returns 1900** [SQLITE_BUSY].)^</dd> 1901** 1902** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> 1903** <dd> ^This option is used to enable or disable the enforcement of 1904** [foreign key constraints]. There should be two additional arguments. 1905** The first argument is an integer which is 0 to disable FK enforcement, 1906** positive to enable FK enforcement or negative to leave FK enforcement 1907** unchanged. The second parameter is a pointer to an integer into which 1908** is written 0 or 1 to indicate whether FK enforcement is off or on 1909** following this call. The second parameter may be a NULL pointer, in 1910** which case the FK enforcement setting is not reported back. </dd> 1911** 1912** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> 1913** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. 1914** There should be two additional arguments. 1915** The first argument is an integer which is 0 to disable triggers, 1916** positive to enable triggers or negative to leave the setting unchanged. 1917** The second parameter is a pointer to an integer into which 1918** is written 0 or 1 to indicate whether triggers are disabled or enabled 1919** following this call. The second parameter may be a NULL pointer, in 1920** which case the trigger setting is not reported back. </dd> 1921** 1922** </dl> 1923*/ 1924#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ 1925#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ 1926#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ 1927 1928 1929/* 1930** CAPI3REF: Enable Or Disable Extended Result Codes 1931** 1932** ^The sqlite3_extended_result_codes() routine enables or disables the 1933** [extended result codes] feature of SQLite. ^The extended result 1934** codes are disabled by default for historical compatibility. 1935*/ 1936SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); 1937 1938/* 1939** CAPI3REF: Last Insert Rowid 1940** 1941** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables) 1942** has a unique 64-bit signed 1943** integer key called the [ROWID | "rowid"]. ^The rowid is always available 1944** as an undeclared column named ROWID, OID, or _ROWID_ as long as those 1945** names are not also used by explicitly declared columns. ^If 1946** the table has a column of type [INTEGER PRIMARY KEY] then that column 1947** is another alias for the rowid. 1948** 1949** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the 1950** most recent successful [INSERT] into a rowid table or [virtual table] 1951** on database connection D. 1952** ^Inserts into [WITHOUT ROWID] tables are not recorded. 1953** ^If no successful [INSERT]s into rowid tables 1954** have ever occurred on the database connection D, 1955** then sqlite3_last_insert_rowid(D) returns zero. 1956** 1957** ^(If an [INSERT] occurs within a trigger or within a [virtual table] 1958** method, then this routine will return the [rowid] of the inserted 1959** row as long as the trigger or virtual table method is running. 1960** But once the trigger or virtual table method ends, the value returned 1961** by this routine reverts to what it was before the trigger or virtual 1962** table method began.)^ 1963** 1964** ^An [INSERT] that fails due to a constraint violation is not a 1965** successful [INSERT] and does not change the value returned by this 1966** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, 1967** and INSERT OR ABORT make no changes to the return value of this 1968** routine when their insertion fails. ^(When INSERT OR REPLACE 1969** encounters a constraint violation, it does not fail. The 1970** INSERT continues to completion after deleting rows that caused 1971** the constraint problem so INSERT OR REPLACE will always change 1972** the return value of this interface.)^ 1973** 1974** ^For the purposes of this routine, an [INSERT] is considered to 1975** be successful even if it is subsequently rolled back. 1976** 1977** This function is accessible to SQL statements via the 1978** [last_insert_rowid() SQL function]. 1979** 1980** If a separate thread performs a new [INSERT] on the same 1981** database connection while the [sqlite3_last_insert_rowid()] 1982** function is running and thus changes the last insert [rowid], 1983** then the value returned by [sqlite3_last_insert_rowid()] is 1984** unpredictable and might not equal either the old or the new 1985** last insert [rowid]. 1986*/ 1987SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); 1988 1989/* 1990** CAPI3REF: Count The Number Of Rows Modified 1991** 1992** ^This function returns the number of database rows that were changed 1993** or inserted or deleted by the most recently completed SQL statement 1994** on the [database connection] specified by the first parameter. 1995** ^(Only changes that are directly specified by the [INSERT], [UPDATE], 1996** or [DELETE] statement are counted. Auxiliary changes caused by 1997** triggers or [foreign key actions] are not counted.)^ Use the 1998** [sqlite3_total_changes()] function to find the total number of changes 1999** including changes caused by triggers and foreign key actions. 2000** 2001** ^Changes to a view that are simulated by an [INSTEAD OF trigger] 2002** are not counted. Only real table changes are counted. 2003** 2004** ^(A "row change" is a change to a single row of a single table 2005** caused by an INSERT, DELETE, or UPDATE statement. Rows that 2006** are changed as side effects of [REPLACE] constraint resolution, 2007** rollback, ABORT processing, [DROP TABLE], or by any other 2008** mechanisms do not count as direct row changes.)^ 2009** 2010** A "trigger context" is a scope of execution that begins and 2011** ends with the script of a [CREATE TRIGGER | trigger]. 2012** Most SQL statements are 2013** evaluated outside of any trigger. This is the "top level" 2014** trigger context. If a trigger fires from the top level, a 2015** new trigger context is entered for the duration of that one 2016** trigger. Subtriggers create subcontexts for their duration. 2017** 2018** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does 2019** not create a new trigger context. 2020** 2021** ^This function returns the number of direct row changes in the 2022** most recent INSERT, UPDATE, or DELETE statement within the same 2023** trigger context. 2024** 2025** ^Thus, when called from the top level, this function returns the 2026** number of changes in the most recent INSERT, UPDATE, or DELETE 2027** that also occurred at the top level. ^(Within the body of a trigger, 2028** the sqlite3_changes() interface can be called to find the number of 2029** changes in the most recently completed INSERT, UPDATE, or DELETE 2030** statement within the body of the same trigger. 2031** However, the number returned does not include changes 2032** caused by subtriggers since those have their own context.)^ 2033** 2034** See also the [sqlite3_total_changes()] interface, the 2035** [count_changes pragma], and the [changes() SQL function]. 2036** 2037** If a separate thread makes changes on the same database connection 2038** while [sqlite3_changes()] is running then the value returned 2039** is unpredictable and not meaningful. 2040*/ 2041SQLITE_API int sqlite3_changes(sqlite3*); 2042 2043/* 2044** CAPI3REF: Total Number Of Rows Modified 2045** 2046** ^This function returns the number of row changes caused by [INSERT], 2047** [UPDATE] or [DELETE] statements since the [database connection] was opened. 2048** ^(The count returned by sqlite3_total_changes() includes all changes 2049** from all [CREATE TRIGGER | trigger] contexts and changes made by 2050** [foreign key actions]. However, 2051** the count does not include changes used to implement [REPLACE] constraints, 2052** do rollbacks or ABORT processing, or [DROP TABLE] processing. The 2053** count does not include rows of views that fire an [INSTEAD OF trigger], 2054** though if the INSTEAD OF trigger makes changes of its own, those changes 2055** are counted.)^ 2056** ^The sqlite3_total_changes() function counts the changes as soon as 2057** the statement that makes them is completed (when the statement handle 2058** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). 2059** 2060** See also the [sqlite3_changes()] interface, the 2061** [count_changes pragma], and the [total_changes() SQL function]. 2062** 2063** If a separate thread makes changes on the same database connection 2064** while [sqlite3_total_changes()] is running then the value 2065** returned is unpredictable and not meaningful. 2066*/ 2067SQLITE_API int sqlite3_total_changes(sqlite3*); 2068 2069/* 2070** CAPI3REF: Interrupt A Long-Running Query 2071** 2072** ^This function causes any pending database operation to abort and 2073** return at its earliest opportunity. This routine is typically 2074** called in response to a user action such as pressing "Cancel" 2075** or Ctrl-C where the user wants a long query operation to halt 2076** immediately. 2077** 2078** ^It is safe to call this routine from a thread different from the 2079** thread that is currently running the database operation. But it 2080** is not safe to call this routine with a [database connection] that 2081** is closed or might close before sqlite3_interrupt() returns. 2082** 2083** ^If an SQL operation is very nearly finished at the time when 2084** sqlite3_interrupt() is called, then it might not have an opportunity 2085** to be interrupted and might continue to completion. 2086** 2087** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. 2088** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE 2089** that is inside an explicit transaction, then the entire transaction 2090** will be rolled back automatically. 2091** 2092** ^The sqlite3_interrupt(D) call is in effect until all currently running 2093** SQL statements on [database connection] D complete. ^Any new SQL statements 2094** that are started after the sqlite3_interrupt() call and before the 2095** running statements reaches zero are interrupted as if they had been 2096** running prior to the sqlite3_interrupt() call. ^New SQL statements 2097** that are started after the running statement count reaches zero are 2098** not effected by the sqlite3_interrupt(). 2099** ^A call to sqlite3_interrupt(D) that occurs when there are no running 2100** SQL statements is a no-op and has no effect on SQL statements 2101** that are started after the sqlite3_interrupt() call returns. 2102** 2103** If the database connection closes while [sqlite3_interrupt()] 2104** is running then bad things will likely happen. 2105*/ 2106SQLITE_API void sqlite3_interrupt(sqlite3*); 2107 2108/* 2109** CAPI3REF: Determine If An SQL Statement Is Complete 2110** 2111** These routines are useful during command-line input to determine if the 2112** currently entered text seems to form a complete SQL statement or 2113** if additional input is needed before sending the text into 2114** SQLite for parsing. ^These routines return 1 if the input string 2115** appears to be a complete SQL statement. ^A statement is judged to be 2116** complete if it ends with a semicolon token and is not a prefix of a 2117** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within 2118** string literals or quoted identifier names or comments are not 2119** independent tokens (they are part of the token in which they are 2120** embedded) and thus do not count as a statement terminator. ^Whitespace 2121** and comments that follow the final semicolon are ignored. 2122** 2123** ^These routines return 0 if the statement is incomplete. ^If a 2124** memory allocation fails, then SQLITE_NOMEM is returned. 2125** 2126** ^These routines do not parse the SQL statements thus 2127** will not detect syntactically incorrect SQL. 2128** 2129** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior 2130** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked 2131** automatically by sqlite3_complete16(). If that initialization fails, 2132** then the return value from sqlite3_complete16() will be non-zero 2133** regardless of whether or not the input SQL is complete.)^ 2134** 2135** The input to [sqlite3_complete()] must be a zero-terminated 2136** UTF-8 string. 2137** 2138** The input to [sqlite3_complete16()] must be a zero-terminated 2139** UTF-16 string in native byte order. 2140*/ 2141SQLITE_API int sqlite3_complete(const char *sql); 2142SQLITE_API int sqlite3_complete16(const void *sql); 2143 2144/* 2145** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors 2146** 2147** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X 2148** that might be invoked with argument P whenever 2149** an attempt is made to access a database table associated with 2150** [database connection] D when another thread 2151** or process has the table locked. 2152** The sqlite3_busy_handler() interface is used to implement 2153** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout]. 2154** 2155** ^If the busy callback is NULL, then [SQLITE_BUSY] 2156** is returned immediately upon encountering the lock. ^If the busy callback 2157** is not NULL, then the callback might be invoked with two arguments. 2158** 2159** ^The first argument to the busy handler is a copy of the void* pointer which 2160** is the third argument to sqlite3_busy_handler(). ^The second argument to 2161** the busy handler callback is the number of times that the busy handler has 2162** been invoked for the same locking event. ^If the 2163** busy callback returns 0, then no additional attempts are made to 2164** access the database and [SQLITE_BUSY] is returned 2165** to the application. 2166** ^If the callback returns non-zero, then another attempt 2167** is made to access the database and the cycle repeats. 2168** 2169** The presence of a busy handler does not guarantee that it will be invoked 2170** when there is lock contention. ^If SQLite determines that invoking the busy 2171** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] 2172** to the application instead of invoking the 2173** busy handler. 2174** Consider a scenario where one process is holding a read lock that 2175** it is trying to promote to a reserved lock and 2176** a second process is holding a reserved lock that it is trying 2177** to promote to an exclusive lock. The first process cannot proceed 2178** because it is blocked by the second and the second process cannot 2179** proceed because it is blocked by the first. If both processes 2180** invoke the busy handlers, neither will make any progress. Therefore, 2181** SQLite returns [SQLITE_BUSY] for the first process, hoping that this 2182** will induce the first process to release its read lock and allow 2183** the second process to proceed. 2184** 2185** ^The default busy callback is NULL. 2186** 2187** ^(There can only be a single busy handler defined for each 2188** [database connection]. Setting a new busy handler clears any 2189** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] 2190** or evaluating [PRAGMA busy_timeout=N] will change the 2191** busy handler and thus clear any previously set busy handler. 2192** 2193** The busy callback should not take any actions which modify the 2194** database connection that invoked the busy handler. In other words, 2195** the busy handler is not reentrant. Any such actions 2196** result in undefined behavior. 2197** 2198** A busy handler must not close the database connection 2199** or [prepared statement] that invoked the busy handler. 2200*/ 2201SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); 2202 2203/* 2204** CAPI3REF: Set A Busy Timeout 2205** 2206** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps 2207** for a specified amount of time when a table is locked. ^The handler 2208** will sleep multiple times until at least "ms" milliseconds of sleeping 2209** have accumulated. ^After at least "ms" milliseconds of sleeping, 2210** the handler returns 0 which causes [sqlite3_step()] to return 2211** [SQLITE_BUSY]. 2212** 2213** ^Calling this routine with an argument less than or equal to zero 2214** turns off all busy handlers. 2215** 2216** ^(There can only be a single busy handler for a particular 2217** [database connection] any any given moment. If another busy handler 2218** was defined (using [sqlite3_busy_handler()]) prior to calling 2219** this routine, that other busy handler is cleared.)^ 2220** 2221** See also: [PRAGMA busy_timeout] 2222*/ 2223SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); 2224 2225/* 2226** CAPI3REF: Convenience Routines For Running Queries 2227** 2228** This is a legacy interface that is preserved for backwards compatibility. 2229** Use of this interface is not recommended. 2230** 2231** Definition: A <b>result table</b> is memory data structure created by the 2232** [sqlite3_get_table()] interface. A result table records the 2233** complete query results from one or more queries. 2234** 2235** The table conceptually has a number of rows and columns. But 2236** these numbers are not part of the result table itself. These 2237** numbers are obtained separately. Let N be the number of rows 2238** and M be the number of columns. 2239** 2240** A result table is an array of pointers to zero-terminated UTF-8 strings. 2241** There are (N+1)*M elements in the array. The first M pointers point 2242** to zero-terminated strings that contain the names of the columns. 2243** The remaining entries all point to query results. NULL values result 2244** in NULL pointers. All other values are in their UTF-8 zero-terminated 2245** string representation as returned by [sqlite3_column_text()]. 2246** 2247** A result table might consist of one or more memory allocations. 2248** It is not safe to pass a result table directly to [sqlite3_free()]. 2249** A result table should be deallocated using [sqlite3_free_table()]. 2250** 2251** ^(As an example of the result table format, suppose a query result 2252** is as follows: 2253** 2254** <blockquote><pre> 2255** Name | Age 2256** ----------------------- 2257** Alice | 43 2258** Bob | 28 2259** Cindy | 21 2260** </pre></blockquote> 2261** 2262** There are two column (M==2) and three rows (N==3). Thus the 2263** result table has 8 entries. Suppose the result table is stored 2264** in an array names azResult. Then azResult holds this content: 2265** 2266** <blockquote><pre> 2267** azResult[0] = "Name"; 2268** azResult[1] = "Age"; 2269** azResult[2] = "Alice"; 2270** azResult[3] = "43"; 2271** azResult[4] = "Bob"; 2272** azResult[5] = "28"; 2273** azResult[6] = "Cindy"; 2274** azResult[7] = "21"; 2275** </pre></blockquote>)^ 2276** 2277** ^The sqlite3_get_table() function evaluates one or more 2278** semicolon-separated SQL statements in the zero-terminated UTF-8 2279** string of its 2nd parameter and returns a result table to the 2280** pointer given in its 3rd parameter. 2281** 2282** After the application has finished with the result from sqlite3_get_table(), 2283** it must pass the result table pointer to sqlite3_free_table() in order to 2284** release the memory that was malloced. Because of the way the 2285** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling 2286** function must not try to call [sqlite3_free()] directly. Only 2287** [sqlite3_free_table()] is able to release the memory properly and safely. 2288** 2289** The sqlite3_get_table() interface is implemented as a wrapper around 2290** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access 2291** to any internal data structures of SQLite. It uses only the public 2292** interface defined here. As a consequence, errors that occur in the 2293** wrapper layer outside of the internal [sqlite3_exec()] call are not 2294** reflected in subsequent calls to [sqlite3_errcode()] or 2295** [sqlite3_errmsg()]. 2296*/ 2297SQLITE_API int sqlite3_get_table( 2298 sqlite3 *db, /* An open database */ 2299 const char *zSql, /* SQL to be evaluated */ 2300 char ***pazResult, /* Results of the query */ 2301 int *pnRow, /* Number of result rows written here */ 2302 int *pnColumn, /* Number of result columns written here */ 2303 char **pzErrmsg /* Error msg written here */ 2304); 2305SQLITE_API void sqlite3_free_table(char **result); 2306 2307/* 2308** CAPI3REF: Formatted String Printing Functions 2309** 2310** These routines are work-alikes of the "printf()" family of functions 2311** from the standard C library. 2312** 2313** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their 2314** results into memory obtained from [sqlite3_malloc()]. 2315** The strings returned by these two routines should be 2316** released by [sqlite3_free()]. ^Both routines return a 2317** NULL pointer if [sqlite3_malloc()] is unable to allocate enough 2318** memory to hold the resulting string. 2319** 2320** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from 2321** the standard C library. The result is written into the 2322** buffer supplied as the second parameter whose size is given by 2323** the first parameter. Note that the order of the 2324** first two parameters is reversed from snprintf().)^ This is an 2325** historical accident that cannot be fixed without breaking 2326** backwards compatibility. ^(Note also that sqlite3_snprintf() 2327** returns a pointer to its buffer instead of the number of 2328** characters actually written into the buffer.)^ We admit that 2329** the number of characters written would be a more useful return 2330** value but we cannot change the implementation of sqlite3_snprintf() 2331** now without breaking compatibility. 2332** 2333** ^As long as the buffer size is greater than zero, sqlite3_snprintf() 2334** guarantees that the buffer is always zero-terminated. ^The first 2335** parameter "n" is the total size of the buffer, including space for 2336** the zero terminator. So the longest string that can be completely 2337** written will be n-1 characters. 2338** 2339** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). 2340** 2341** These routines all implement some additional formatting 2342** options that are useful for constructing SQL statements. 2343** All of the usual printf() formatting options apply. In addition, there 2344** is are "%q", "%Q", and "%z" options. 2345** 2346** ^(The %q option works like %s in that it substitutes a nul-terminated 2347** string from the argument list. But %q also doubles every '\'' character. 2348** %q is designed for use inside a string literal.)^ By doubling each '\'' 2349** character it escapes that character and allows it to be inserted into 2350** the string. 2351** 2352** For example, assume the string variable zText contains text as follows: 2353** 2354** <blockquote><pre> 2355** char *zText = "It's a happy day!"; 2356** </pre></blockquote> 2357** 2358** One can use this text in an SQL statement as follows: 2359** 2360** <blockquote><pre> 2361** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); 2362** sqlite3_exec(db, zSQL, 0, 0, 0); 2363** sqlite3_free(zSQL); 2364** </pre></blockquote> 2365** 2366** Because the %q format string is used, the '\'' character in zText 2367** is escaped and the SQL generated is as follows: 2368** 2369** <blockquote><pre> 2370** INSERT INTO table1 VALUES('It''s a happy day!') 2371** </pre></blockquote> 2372** 2373** This is correct. Had we used %s instead of %q, the generated SQL 2374** would have looked like this: 2375** 2376** <blockquote><pre> 2377** INSERT INTO table1 VALUES('It's a happy day!'); 2378** </pre></blockquote> 2379** 2380** This second example is an SQL syntax error. As a general rule you should 2381** always use %q instead of %s when inserting text into a string literal. 2382** 2383** ^(The %Q option works like %q except it also adds single quotes around 2384** the outside of the total string. Additionally, if the parameter in the 2385** argument list is a NULL pointer, %Q substitutes the text "NULL" (without 2386** single quotes).)^ So, for example, one could say: 2387** 2388** <blockquote><pre> 2389** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); 2390** sqlite3_exec(db, zSQL, 0, 0, 0); 2391** sqlite3_free(zSQL); 2392** </pre></blockquote> 2393** 2394** The code above will render a correct SQL statement in the zSQL 2395** variable even if the zText variable is a NULL pointer. 2396** 2397** ^(The "%z" formatting option works like "%s" but with the 2398** addition that after the string has been read and copied into 2399** the result, [sqlite3_free()] is called on the input string.)^ 2400*/ 2401SQLITE_API char *sqlite3_mprintf(const char*,...); 2402SQLITE_API char *sqlite3_vmprintf(const char*, va_list); 2403SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); 2404SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); 2405 2406/* 2407** CAPI3REF: Memory Allocation Subsystem 2408** 2409** The SQLite core uses these three routines for all of its own 2410** internal memory allocation needs. "Core" in the previous sentence 2411** does not include operating-system specific VFS implementation. The 2412** Windows VFS uses native malloc() and free() for some operations. 2413** 2414** ^The sqlite3_malloc() routine returns a pointer to a block 2415** of memory at least N bytes in length, where N is the parameter. 2416** ^If sqlite3_malloc() is unable to obtain sufficient free 2417** memory, it returns a NULL pointer. ^If the parameter N to 2418** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns 2419** a NULL pointer. 2420** 2421** ^Calling sqlite3_free() with a pointer previously returned 2422** by sqlite3_malloc() or sqlite3_realloc() releases that memory so 2423** that it might be reused. ^The sqlite3_free() routine is 2424** a no-op if is called with a NULL pointer. Passing a NULL pointer 2425** to sqlite3_free() is harmless. After being freed, memory 2426** should neither be read nor written. Even reading previously freed 2427** memory might result in a segmentation fault or other severe error. 2428** Memory corruption, a segmentation fault, or other severe error 2429** might result if sqlite3_free() is called with a non-NULL pointer that 2430** was not obtained from sqlite3_malloc() or sqlite3_realloc(). 2431** 2432** ^(The sqlite3_realloc() interface attempts to resize a 2433** prior memory allocation to be at least N bytes, where N is the 2434** second parameter. The memory allocation to be resized is the first 2435** parameter.)^ ^ If the first parameter to sqlite3_realloc() 2436** is a NULL pointer then its behavior is identical to calling 2437** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). 2438** ^If the second parameter to sqlite3_realloc() is zero or 2439** negative then the behavior is exactly the same as calling 2440** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). 2441** ^sqlite3_realloc() returns a pointer to a memory allocation 2442** of at least N bytes in size or NULL if sufficient memory is unavailable. 2443** ^If M is the size of the prior allocation, then min(N,M) bytes 2444** of the prior allocation are copied into the beginning of buffer returned 2445** by sqlite3_realloc() and the prior allocation is freed. 2446** ^If sqlite3_realloc() returns NULL, then the prior allocation 2447** is not freed. 2448** 2449** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() 2450** is always aligned to at least an 8 byte boundary, or to a 2451** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time 2452** option is used. 2453** 2454** In SQLite version 3.5.0 and 3.5.1, it was possible to define 2455** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in 2456** implementation of these routines to be omitted. That capability 2457** is no longer provided. Only built-in memory allocators can be used. 2458** 2459** Prior to SQLite version 3.7.10, the Windows OS interface layer called 2460** the system malloc() and free() directly when converting 2461** filenames between the UTF-8 encoding used by SQLite 2462** and whatever filename encoding is used by the particular Windows 2463** installation. Memory allocation errors were detected, but 2464** they were reported back as [SQLITE_CANTOPEN] or 2465** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. 2466** 2467** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] 2468** must be either NULL or else pointers obtained from a prior 2469** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have 2470** not yet been released. 2471** 2472** The application must not read or write any part of 2473** a block of memory after it has been released using 2474** [sqlite3_free()] or [sqlite3_realloc()]. 2475*/ 2476SQLITE_API void *sqlite3_malloc(int); 2477SQLITE_API void *sqlite3_realloc(void*, int); 2478SQLITE_API void sqlite3_free(void*); 2479 2480/* 2481** CAPI3REF: Memory Allocator Statistics 2482** 2483** SQLite provides these two interfaces for reporting on the status 2484** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] 2485** routines, which form the built-in memory allocation subsystem. 2486** 2487** ^The [sqlite3_memory_used()] routine returns the number of bytes 2488** of memory currently outstanding (malloced but not freed). 2489** ^The [sqlite3_memory_highwater()] routine returns the maximum 2490** value of [sqlite3_memory_used()] since the high-water mark 2491** was last reset. ^The values returned by [sqlite3_memory_used()] and 2492** [sqlite3_memory_highwater()] include any overhead 2493** added by SQLite in its implementation of [sqlite3_malloc()], 2494** but not overhead added by the any underlying system library 2495** routines that [sqlite3_malloc()] may call. 2496** 2497** ^The memory high-water mark is reset to the current value of 2498** [sqlite3_memory_used()] if and only if the parameter to 2499** [sqlite3_memory_highwater()] is true. ^The value returned 2500** by [sqlite3_memory_highwater(1)] is the high-water mark 2501** prior to the reset. 2502*/ 2503SQLITE_API sqlite3_int64 sqlite3_memory_used(void); 2504SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); 2505 2506/* 2507** CAPI3REF: Pseudo-Random Number Generator 2508** 2509** SQLite contains a high-quality pseudo-random number generator (PRNG) used to 2510** select random [ROWID | ROWIDs] when inserting new records into a table that 2511** already uses the largest possible [ROWID]. The PRNG is also used for 2512** the build-in random() and randomblob() SQL functions. This interface allows 2513** applications to access the same PRNG for other purposes. 2514** 2515** ^A call to this routine stores N bytes of randomness into buffer P. 2516** ^If N is less than one, then P can be a NULL pointer. 2517** 2518** ^If this routine has not been previously called or if the previous 2519** call had N less than one, then the PRNG is seeded using randomness 2520** obtained from the xRandomness method of the default [sqlite3_vfs] object. 2521** ^If the previous call to this routine had an N of 1 or more then 2522** the pseudo-randomness is generated 2523** internally and without recourse to the [sqlite3_vfs] xRandomness 2524** method. 2525*/ 2526SQLITE_API void sqlite3_randomness(int N, void *P); 2527 2528/* 2529** CAPI3REF: Compile-Time Authorization Callbacks 2530** 2531** ^This routine registers an authorizer callback with a particular 2532** [database connection], supplied in the first argument. 2533** ^The authorizer callback is invoked as SQL statements are being compiled 2534** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], 2535** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various 2536** points during the compilation process, as logic is being created 2537** to perform various actions, the authorizer callback is invoked to 2538** see if those actions are allowed. ^The authorizer callback should 2539** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the 2540** specific action but allow the SQL statement to continue to be 2541** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be 2542** rejected with an error. ^If the authorizer callback returns 2543** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] 2544** then the [sqlite3_prepare_v2()] or equivalent call that triggered 2545** the authorizer will fail with an error message. 2546** 2547** When the callback returns [SQLITE_OK], that means the operation 2548** requested is ok. ^When the callback returns [SQLITE_DENY], the 2549** [sqlite3_prepare_v2()] or equivalent call that triggered the 2550** authorizer will fail with an error message explaining that 2551** access is denied. 2552** 2553** ^The first parameter to the authorizer callback is a copy of the third 2554** parameter to the sqlite3_set_authorizer() interface. ^The second parameter 2555** to the callback is an integer [SQLITE_COPY | action code] that specifies 2556** the particular action to be authorized. ^The third through sixth parameters 2557** to the callback are zero-terminated strings that contain additional 2558** details about the action to be authorized. 2559** 2560** ^If the action code is [SQLITE_READ] 2561** and the callback returns [SQLITE_IGNORE] then the 2562** [prepared statement] statement is constructed to substitute 2563** a NULL value in place of the table column that would have 2564** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] 2565** return can be used to deny an untrusted user access to individual 2566** columns of a table. 2567** ^If the action code is [SQLITE_DELETE] and the callback returns 2568** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the 2569** [truncate optimization] is disabled and all rows are deleted individually. 2570** 2571** An authorizer is used when [sqlite3_prepare | preparing] 2572** SQL statements from an untrusted source, to ensure that the SQL statements 2573** do not try to access data they are not allowed to see, or that they do not 2574** try to execute malicious statements that damage the database. For 2575** example, an application may allow a user to enter arbitrary 2576** SQL queries for evaluation by a database. But the application does 2577** not want the user to be able to make arbitrary changes to the 2578** database. An authorizer could then be put in place while the 2579** user-entered SQL is being [sqlite3_prepare | prepared] that 2580** disallows everything except [SELECT] statements. 2581** 2582** Applications that need to process SQL from untrusted sources 2583** might also consider lowering resource limits using [sqlite3_limit()] 2584** and limiting database size using the [max_page_count] [PRAGMA] 2585** in addition to using an authorizer. 2586** 2587** ^(Only a single authorizer can be in place on a database connection 2588** at a time. Each call to sqlite3_set_authorizer overrides the 2589** previous call.)^ ^Disable the authorizer by installing a NULL callback. 2590** The authorizer is disabled by default. 2591** 2592** The authorizer callback must not do anything that will modify 2593** the database connection that invoked the authorizer callback. 2594** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2595** database connections for the meaning of "modify" in this paragraph. 2596** 2597** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the 2598** statement might be re-prepared during [sqlite3_step()] due to a 2599** schema change. Hence, the application should ensure that the 2600** correct authorizer callback remains in place during the [sqlite3_step()]. 2601** 2602** ^Note that the authorizer callback is invoked only during 2603** [sqlite3_prepare()] or its variants. Authorization is not 2604** performed during statement evaluation in [sqlite3_step()], unless 2605** as stated in the previous paragraph, sqlite3_step() invokes 2606** sqlite3_prepare_v2() to reprepare a statement after a schema change. 2607*/ 2608SQLITE_API int sqlite3_set_authorizer( 2609 sqlite3*, 2610 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), 2611 void *pUserData 2612); 2613 2614/* 2615** CAPI3REF: Authorizer Return Codes 2616** 2617** The [sqlite3_set_authorizer | authorizer callback function] must 2618** return either [SQLITE_OK] or one of these two constants in order 2619** to signal SQLite whether or not the action is permitted. See the 2620** [sqlite3_set_authorizer | authorizer documentation] for additional 2621** information. 2622** 2623** Note that SQLITE_IGNORE is also used as a [conflict resolution mode] 2624** returned from the [sqlite3_vtab_on_conflict()] interface. 2625*/ 2626#define SQLITE_DENY 1 /* Abort the SQL statement with an error */ 2627#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ 2628 2629/* 2630** CAPI3REF: Authorizer Action Codes 2631** 2632** The [sqlite3_set_authorizer()] interface registers a callback function 2633** that is invoked to authorize certain SQL statement actions. The 2634** second parameter to the callback is an integer code that specifies 2635** what action is being authorized. These are the integer action codes that 2636** the authorizer callback may be passed. 2637** 2638** These action code values signify what kind of operation is to be 2639** authorized. The 3rd and 4th parameters to the authorization 2640** callback function will be parameters or NULL depending on which of these 2641** codes is used as the second parameter. ^(The 5th parameter to the 2642** authorizer callback is the name of the database ("main", "temp", 2643** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback 2644** is the name of the inner-most trigger or view that is responsible for 2645** the access attempt or NULL if this access attempt is directly from 2646** top-level SQL code. 2647*/ 2648/******************************************* 3rd ************ 4th ***********/ 2649#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ 2650#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ 2651#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ 2652#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ 2653#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ 2654#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ 2655#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ 2656#define SQLITE_CREATE_VIEW 8 /* View Name NULL */ 2657#define SQLITE_DELETE 9 /* Table Name NULL */ 2658#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ 2659#define SQLITE_DROP_TABLE 11 /* Table Name NULL */ 2660#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ 2661#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ 2662#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ 2663#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ 2664#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ 2665#define SQLITE_DROP_VIEW 17 /* View Name NULL */ 2666#define SQLITE_INSERT 18 /* Table Name NULL */ 2667#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ 2668#define SQLITE_READ 20 /* Table Name Column Name */ 2669#define SQLITE_SELECT 21 /* NULL NULL */ 2670#define SQLITE_TRANSACTION 22 /* Operation NULL */ 2671#define SQLITE_UPDATE 23 /* Table Name Column Name */ 2672#define SQLITE_ATTACH 24 /* Filename NULL */ 2673#define SQLITE_DETACH 25 /* Database Name NULL */ 2674#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ 2675#define SQLITE_REINDEX 27 /* Index Name NULL */ 2676#define SQLITE_ANALYZE 28 /* Table Name NULL */ 2677#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ 2678#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ 2679#define SQLITE_FUNCTION 31 /* NULL Function Name */ 2680#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ 2681#define SQLITE_COPY 0 /* No longer used */ 2682#define SQLITE_RECURSIVE 33 /* NULL NULL */ 2683 2684/* 2685** CAPI3REF: Tracing And Profiling Functions 2686** 2687** These routines register callback functions that can be used for 2688** tracing and profiling the execution of SQL statements. 2689** 2690** ^The callback function registered by sqlite3_trace() is invoked at 2691** various times when an SQL statement is being run by [sqlite3_step()]. 2692** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the 2693** SQL statement text as the statement first begins executing. 2694** ^(Additional sqlite3_trace() callbacks might occur 2695** as each triggered subprogram is entered. The callbacks for triggers 2696** contain a UTF-8 SQL comment that identifies the trigger.)^ 2697** 2698** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit 2699** the length of [bound parameter] expansion in the output of sqlite3_trace(). 2700** 2701** ^The callback function registered by sqlite3_profile() is invoked 2702** as each SQL statement finishes. ^The profile callback contains 2703** the original statement text and an estimate of wall-clock time 2704** of how long that statement took to run. ^The profile callback 2705** time is in units of nanoseconds, however the current implementation 2706** is only capable of millisecond resolution so the six least significant 2707** digits in the time are meaningless. Future versions of SQLite 2708** might provide greater resolution on the profiler callback. The 2709** sqlite3_profile() function is considered experimental and is 2710** subject to change in future versions of SQLite. 2711*/ 2712SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); 2713SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, 2714 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); 2715 2716/* 2717** CAPI3REF: Query Progress Callbacks 2718** 2719** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback 2720** function X to be invoked periodically during long running calls to 2721** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for 2722** database connection D. An example use for this 2723** interface is to keep a GUI updated during a large query. 2724** 2725** ^The parameter P is passed through as the only parameter to the 2726** callback function X. ^The parameter N is the approximate number of 2727** [virtual machine instructions] that are evaluated between successive 2728** invocations of the callback X. ^If N is less than one then the progress 2729** handler is disabled. 2730** 2731** ^Only a single progress handler may be defined at one time per 2732** [database connection]; setting a new progress handler cancels the 2733** old one. ^Setting parameter X to NULL disables the progress handler. 2734** ^The progress handler is also disabled by setting N to a value less 2735** than 1. 2736** 2737** ^If the progress callback returns non-zero, the operation is 2738** interrupted. This feature can be used to implement a 2739** "Cancel" button on a GUI progress dialog box. 2740** 2741** The progress handler callback must not do anything that will modify 2742** the database connection that invoked the progress handler. 2743** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 2744** database connections for the meaning of "modify" in this paragraph. 2745** 2746*/ 2747SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); 2748 2749/* 2750** CAPI3REF: Opening A New Database Connection 2751** 2752** ^These routines open an SQLite database file as specified by the 2753** filename argument. ^The filename argument is interpreted as UTF-8 for 2754** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte 2755** order for sqlite3_open16(). ^(A [database connection] handle is usually 2756** returned in *ppDb, even if an error occurs. The only exception is that 2757** if SQLite is unable to allocate memory to hold the [sqlite3] object, 2758** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] 2759** object.)^ ^(If the database is opened (and/or created) successfully, then 2760** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The 2761** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain 2762** an English language description of the error following a failure of any 2763** of the sqlite3_open() routines. 2764** 2765** ^The default encoding for the database will be UTF-8 if 2766** sqlite3_open() or sqlite3_open_v2() is called and 2767** UTF-16 in the native byte order if sqlite3_open16() is used. 2768** 2769** Whether or not an error occurs when it is opened, resources 2770** associated with the [database connection] handle should be released by 2771** passing it to [sqlite3_close()] when it is no longer required. 2772** 2773** The sqlite3_open_v2() interface works like sqlite3_open() 2774** except that it accepts two additional parameters for additional control 2775** over the new database connection. ^(The flags parameter to 2776** sqlite3_open_v2() can take one of 2777** the following three values, optionally combined with the 2778** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], 2779** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ 2780** 2781** <dl> 2782** ^(<dt>[SQLITE_OPEN_READONLY]</dt> 2783** <dd>The database is opened in read-only mode. If the database does not 2784** already exist, an error is returned.</dd>)^ 2785** 2786** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> 2787** <dd>The database is opened for reading and writing if possible, or reading 2788** only if the file is write protected by the operating system. In either 2789** case the database must already exist, otherwise an error is returned.</dd>)^ 2790** 2791** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> 2792** <dd>The database is opened for reading and writing, and is created if 2793** it does not already exist. This is the behavior that is always used for 2794** sqlite3_open() and sqlite3_open16().</dd>)^ 2795** </dl> 2796** 2797** If the 3rd parameter to sqlite3_open_v2() is not one of the 2798** combinations shown above optionally combined with other 2799** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] 2800** then the behavior is undefined. 2801** 2802** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection 2803** opens in the multi-thread [threading mode] as long as the single-thread 2804** mode has not been set at compile-time or start-time. ^If the 2805** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens 2806** in the serialized [threading mode] unless single-thread was 2807** previously selected at compile-time or start-time. 2808** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be 2809** eligible to use [shared cache mode], regardless of whether or not shared 2810** cache is enabled using [sqlite3_enable_shared_cache()]. ^The 2811** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not 2812** participate in [shared cache mode] even if it is enabled. 2813** 2814** ^The fourth parameter to sqlite3_open_v2() is the name of the 2815** [sqlite3_vfs] object that defines the operating system interface that 2816** the new database connection should use. ^If the fourth parameter is 2817** a NULL pointer then the default [sqlite3_vfs] object is used. 2818** 2819** ^If the filename is ":memory:", then a private, temporary in-memory database 2820** is created for the connection. ^This in-memory database will vanish when 2821** the database connection is closed. Future versions of SQLite might 2822** make use of additional special filenames that begin with the ":" character. 2823** It is recommended that when a database filename actually does begin with 2824** a ":" character you should prefix the filename with a pathname such as 2825** "./" to avoid ambiguity. 2826** 2827** ^If the filename is an empty string, then a private, temporary 2828** on-disk database will be created. ^This private database will be 2829** automatically deleted as soon as the database connection is closed. 2830** 2831** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> 2832** 2833** ^If [URI filename] interpretation is enabled, and the filename argument 2834** begins with "file:", then the filename is interpreted as a URI. ^URI 2835** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is 2836** set in the fourth argument to sqlite3_open_v2(), or if it has 2837** been enabled globally using the [SQLITE_CONFIG_URI] option with the 2838** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. 2839** As of SQLite version 3.7.7, URI filename interpretation is turned off 2840** by default, but future releases of SQLite might enable URI filename 2841** interpretation by default. See "[URI filenames]" for additional 2842** information. 2843** 2844** URI filenames are parsed according to RFC 3986. ^If the URI contains an 2845** authority, then it must be either an empty string or the string 2846** "localhost". ^If the authority is not an empty string or "localhost", an 2847** error is returned to the caller. ^The fragment component of a URI, if 2848** present, is ignored. 2849** 2850** ^SQLite uses the path component of the URI as the name of the disk file 2851** which contains the database. ^If the path begins with a '/' character, 2852** then it is interpreted as an absolute path. ^If the path does not begin 2853** with a '/' (meaning that the authority section is omitted from the URI) 2854** then the path is interpreted as a relative path. 2855** ^On windows, the first component of an absolute path 2856** is a drive specification (e.g. "C:"). 2857** 2858** [[core URI query parameters]] 2859** The query component of a URI may contain parameters that are interpreted 2860** either by SQLite itself, or by a [VFS | custom VFS implementation]. 2861** SQLite interprets the following three query parameters: 2862** 2863** <ul> 2864** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of 2865** a VFS object that provides the operating system interface that should 2866** be used to access the database file on disk. ^If this option is set to 2867** an empty string the default VFS object is used. ^Specifying an unknown 2868** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is 2869** present, then the VFS specified by the option takes precedence over 2870** the value passed as the fourth parameter to sqlite3_open_v2(). 2871** 2872** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw", 2873** "rwc", or "memory". Attempting to set it to any other value is 2874** an error)^. 2875** ^If "ro" is specified, then the database is opened for read-only 2876** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the 2877** third argument to sqlite3_open_v2(). ^If the mode option is set to 2878** "rw", then the database is opened for read-write (but not create) 2879** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had 2880** been set. ^Value "rwc" is equivalent to setting both 2881** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is 2882** set to "memory" then a pure [in-memory database] that never reads 2883** or writes from disk is used. ^It is an error to specify a value for 2884** the mode parameter that is less restrictive than that specified by 2885** the flags passed in the third parameter to sqlite3_open_v2(). 2886** 2887** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or 2888** "private". ^Setting it to "shared" is equivalent to setting the 2889** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to 2890** sqlite3_open_v2(). ^Setting the cache parameter to "private" is 2891** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. 2892** ^If sqlite3_open_v2() is used and the "cache" parameter is present in 2893** a URI filename, its value overrides any behavior requested by setting 2894** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. 2895** 2896** <li> <b>psow</b>: ^The psow parameter may be "true" (or "on" or "yes" or 2897** "1") or "false" (or "off" or "no" or "0") to indicate that the 2898** [powersafe overwrite] property does or does not apply to the 2899** storage media on which the database file resides. ^The psow query 2900** parameter only works for the built-in unix and Windows VFSes. 2901** 2902** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter 2903** which if set disables file locking in rollback journal modes. This 2904** is useful for accessing a database on a filesystem that does not 2905** support locking. Caution: Database corruption might result if two 2906** or more processes write to the same database and any one of those 2907** processes uses nolock=1. 2908** 2909** <li> <b>immutable</b>: ^The immutable parameter is a boolean query 2910** parameter that indicates that the database file is stored on 2911** read-only media. ^When immutable is set, SQLite assumes that the 2912** database file cannot be changed, even by a process with higher 2913** privilege, and so the database is opened read-only and all locking 2914** and change detection is disabled. Caution: Setting the immutable 2915** property on a database file that does in fact change can result 2916** in incorrect query results and/or [SQLITE_CORRUPT] errors. 2917** See also: [SQLITE_IOCAP_IMMUTABLE]. 2918** 2919** </ul> 2920** 2921** ^Specifying an unknown parameter in the query component of a URI is not an 2922** error. Future versions of SQLite might understand additional query 2923** parameters. See "[query parameters with special meaning to SQLite]" for 2924** additional information. 2925** 2926** [[URI filename examples]] <h3>URI filename examples</h3> 2927** 2928** <table border="1" align=center cellpadding=5> 2929** <tr><th> URI filenames <th> Results 2930** <tr><td> file:data.db <td> 2931** Open the file "data.db" in the current directory. 2932** <tr><td> file:/home/fred/data.db<br> 2933** file:///home/fred/data.db <br> 2934** file://localhost/home/fred/data.db <br> <td> 2935** Open the database file "/home/fred/data.db". 2936** <tr><td> file://darkstar/home/fred/data.db <td> 2937** An error. "darkstar" is not a recognized authority. 2938** <tr><td style="white-space:nowrap"> 2939** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db 2940** <td> Windows only: Open the file "data.db" on fred's desktop on drive 2941** C:. Note that the %20 escaping in this example is not strictly 2942** necessary - space characters can be used literally 2943** in URI filenames. 2944** <tr><td> file:data.db?mode=ro&cache=private <td> 2945** Open file "data.db" in the current directory for read-only access. 2946** Regardless of whether or not shared-cache mode is enabled by 2947** default, use a private cache. 2948** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td> 2949** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile" 2950** that uses dot-files in place of posix advisory locking. 2951** <tr><td> file:data.db?mode=readonly <td> 2952** An error. "readonly" is not a valid option for the "mode" parameter. 2953** </table> 2954** 2955** ^URI hexadecimal escape sequences (%HH) are supported within the path and 2956** query components of a URI. A hexadecimal escape sequence consists of a 2957** percent sign - "%" - followed by exactly two hexadecimal digits 2958** specifying an octet value. ^Before the path or query components of a 2959** URI filename are interpreted, they are encoded using UTF-8 and all 2960** hexadecimal escape sequences replaced by a single byte containing the 2961** corresponding octet. If this process generates an invalid UTF-8 encoding, 2962** the results are undefined. 2963** 2964** <b>Note to Windows users:</b> The encoding used for the filename argument 2965** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever 2966** codepage is currently defined. Filenames containing international 2967** characters must be converted to UTF-8 prior to passing them into 2968** sqlite3_open() or sqlite3_open_v2(). 2969** 2970** <b>Note to Windows Runtime users:</b> The temporary directory must be set 2971** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various 2972** features that require the use of temporary files may fail. 2973** 2974** See also: [sqlite3_temp_directory] 2975*/ 2976SQLITE_API int sqlite3_open( 2977 const char *filename, /* Database filename (UTF-8) */ 2978 sqlite3 **ppDb /* OUT: SQLite db handle */ 2979); 2980SQLITE_API int sqlite3_open16( 2981 const void *filename, /* Database filename (UTF-16) */ 2982 sqlite3 **ppDb /* OUT: SQLite db handle */ 2983); 2984SQLITE_API int sqlite3_open_v2( 2985 const char *filename, /* Database filename (UTF-8) */ 2986 sqlite3 **ppDb, /* OUT: SQLite db handle */ 2987 int flags, /* Flags */ 2988 const char *zVfs /* Name of VFS module to use */ 2989); 2990 2991/* 2992** CAPI3REF: Obtain Values For URI Parameters 2993** 2994** These are utility routines, useful to VFS implementations, that check 2995** to see if a database file was a URI that contained a specific query 2996** parameter, and if so obtains the value of that query parameter. 2997** 2998** If F is the database filename pointer passed into the xOpen() method of 2999** a VFS implementation when the flags parameter to xOpen() has one or 3000** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and 3001** P is the name of the query parameter, then 3002** sqlite3_uri_parameter(F,P) returns the value of the P 3003** parameter if it exists or a NULL pointer if P does not appear as a 3004** query parameter on F. If P is a query parameter of F 3005** has no explicit value, then sqlite3_uri_parameter(F,P) returns 3006** a pointer to an empty string. 3007** 3008** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean 3009** parameter and returns true (1) or false (0) according to the value 3010** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the 3011** value of query parameter P is one of "yes", "true", or "on" in any 3012** case or if the value begins with a non-zero number. The 3013** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of 3014** query parameter P is one of "no", "false", or "off" in any case or 3015** if the value begins with a numeric zero. If P is not a query 3016** parameter on F or if the value of P is does not match any of the 3017** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0). 3018** 3019** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a 3020** 64-bit signed integer and returns that integer, or D if P does not 3021** exist. If the value of P is something other than an integer, then 3022** zero is returned. 3023** 3024** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and 3025** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and 3026** is not a database file pathname pointer that SQLite passed into the xOpen 3027** VFS method, then the behavior of this routine is undefined and probably 3028** undesirable. 3029*/ 3030SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); 3031SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault); 3032SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64); 3033 3034 3035/* 3036** CAPI3REF: Error Codes And Messages 3037** 3038** ^The sqlite3_errcode() interface returns the numeric [result code] or 3039** [extended result code] for the most recent failed sqlite3_* API call 3040** associated with a [database connection]. If a prior API call failed 3041** but the most recent API call succeeded, the return value from 3042** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() 3043** interface is the same except that it always returns the 3044** [extended result code] even when extended result codes are 3045** disabled. 3046** 3047** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language 3048** text that describes the error, as either UTF-8 or UTF-16 respectively. 3049** ^(Memory to hold the error message string is managed internally. 3050** The application does not need to worry about freeing the result. 3051** However, the error string might be overwritten or deallocated by 3052** subsequent calls to other SQLite interface functions.)^ 3053** 3054** ^The sqlite3_errstr() interface returns the English-language text 3055** that describes the [result code], as UTF-8. 3056** ^(Memory to hold the error message string is managed internally 3057** and must not be freed by the application)^. 3058** 3059** When the serialized [threading mode] is in use, it might be the 3060** case that a second error occurs on a separate thread in between 3061** the time of the first error and the call to these interfaces. 3062** When that happens, the second error will be reported since these 3063** interfaces always report the most recent result. To avoid 3064** this, each thread can obtain exclusive use of the [database connection] D 3065** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning 3066** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after 3067** all calls to the interfaces listed here are completed. 3068** 3069** If an interface fails with SQLITE_MISUSE, that means the interface 3070** was invoked incorrectly by the application. In that case, the 3071** error code and message may or may not be set. 3072*/ 3073SQLITE_API int sqlite3_errcode(sqlite3 *db); 3074SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); 3075SQLITE_API const char *sqlite3_errmsg(sqlite3*); 3076SQLITE_API const void *sqlite3_errmsg16(sqlite3*); 3077SQLITE_API const char *sqlite3_errstr(int); 3078 3079/* 3080** CAPI3REF: SQL Statement Object 3081** KEYWORDS: {prepared statement} {prepared statements} 3082** 3083** An instance of this object represents a single SQL statement. 3084** This object is variously known as a "prepared statement" or a 3085** "compiled SQL statement" or simply as a "statement". 3086** 3087** The life of a statement object goes something like this: 3088** 3089** <ol> 3090** <li> Create the object using [sqlite3_prepare_v2()] or a related 3091** function. 3092** <li> Bind values to [host parameters] using the sqlite3_bind_*() 3093** interfaces. 3094** <li> Run the SQL by calling [sqlite3_step()] one or more times. 3095** <li> Reset the statement using [sqlite3_reset()] then go back 3096** to step 2. Do this zero or more times. 3097** <li> Destroy the object using [sqlite3_finalize()]. 3098** </ol> 3099** 3100** Refer to documentation on individual methods above for additional 3101** information. 3102*/ 3103typedef struct sqlite3_stmt sqlite3_stmt; 3104 3105/* 3106** CAPI3REF: Run-time Limits 3107** 3108** ^(This interface allows the size of various constructs to be limited 3109** on a connection by connection basis. The first parameter is the 3110** [database connection] whose limit is to be set or queried. The 3111** second parameter is one of the [limit categories] that define a 3112** class of constructs to be size limited. The third parameter is the 3113** new limit for that construct.)^ 3114** 3115** ^If the new limit is a negative number, the limit is unchanged. 3116** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a 3117** [limits | hard upper bound] 3118** set at compile-time by a C preprocessor macro called 3119** [limits | SQLITE_MAX_<i>NAME</i>]. 3120** (The "_LIMIT_" in the name is changed to "_MAX_".))^ 3121** ^Attempts to increase a limit above its hard upper bound are 3122** silently truncated to the hard upper bound. 3123** 3124** ^Regardless of whether or not the limit was changed, the 3125** [sqlite3_limit()] interface returns the prior value of the limit. 3126** ^Hence, to find the current value of a limit without changing it, 3127** simply invoke this interface with the third parameter set to -1. 3128** 3129** Run-time limits are intended for use in applications that manage 3130** both their own internal database and also databases that are controlled 3131** by untrusted external sources. An example application might be a 3132** web browser that has its own databases for storing history and 3133** separate databases controlled by JavaScript applications downloaded 3134** off the Internet. The internal databases can be given the 3135** large, default limits. Databases managed by external sources can 3136** be given much smaller limits designed to prevent a denial of service 3137** attack. Developers might also want to use the [sqlite3_set_authorizer()] 3138** interface to further control untrusted SQL. The size of the database 3139** created by an untrusted script can be contained using the 3140** [max_page_count] [PRAGMA]. 3141** 3142** New run-time limit categories may be added in future releases. 3143*/ 3144SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); 3145 3146/* 3147** CAPI3REF: Run-Time Limit Categories 3148** KEYWORDS: {limit category} {*limit categories} 3149** 3150** These constants define various performance limits 3151** that can be lowered at run-time using [sqlite3_limit()]. 3152** The synopsis of the meanings of the various limits is shown below. 3153** Additional information is available at [limits | Limits in SQLite]. 3154** 3155** <dl> 3156** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> 3157** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ 3158** 3159** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> 3160** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ 3161** 3162** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> 3163** <dd>The maximum number of columns in a table definition or in the 3164** result set of a [SELECT] or the maximum number of columns in an index 3165** or in an ORDER BY or GROUP BY clause.</dd>)^ 3166** 3167** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> 3168** <dd>The maximum depth of the parse tree on any expression.</dd>)^ 3169** 3170** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> 3171** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ 3172** 3173** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> 3174** <dd>The maximum number of instructions in a virtual machine program 3175** used to implement an SQL statement. This limit is not currently 3176** enforced, though that might be added in some future release of 3177** SQLite.</dd>)^ 3178** 3179** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> 3180** <dd>The maximum number of arguments on a function.</dd>)^ 3181** 3182** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> 3183** <dd>The maximum number of [ATTACH | attached databases].)^</dd> 3184** 3185** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] 3186** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> 3187** <dd>The maximum length of the pattern argument to the [LIKE] or 3188** [GLOB] operators.</dd>)^ 3189** 3190** [[SQLITE_LIMIT_VARIABLE_NUMBER]] 3191** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> 3192** <dd>The maximum index number of any [parameter] in an SQL statement.)^ 3193** 3194** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> 3195** <dd>The maximum depth of recursion for triggers.</dd>)^ 3196** </dl> 3197*/ 3198#define SQLITE_LIMIT_LENGTH 0 3199#define SQLITE_LIMIT_SQL_LENGTH 1 3200#define SQLITE_LIMIT_COLUMN 2 3201#define SQLITE_LIMIT_EXPR_DEPTH 3 3202#define SQLITE_LIMIT_COMPOUND_SELECT 4 3203#define SQLITE_LIMIT_VDBE_OP 5 3204#define SQLITE_LIMIT_FUNCTION_ARG 6 3205#define SQLITE_LIMIT_ATTACHED 7 3206#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 3207#define SQLITE_LIMIT_VARIABLE_NUMBER 9 3208#define SQLITE_LIMIT_TRIGGER_DEPTH 10 3209 3210/* 3211** CAPI3REF: Compiling An SQL Statement 3212** KEYWORDS: {SQL statement compiler} 3213** 3214** To execute an SQL query, it must first be compiled into a byte-code 3215** program using one of these routines. 3216** 3217** The first argument, "db", is a [database connection] obtained from a 3218** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or 3219** [sqlite3_open16()]. The database connection must not have been closed. 3220** 3221** The second argument, "zSql", is the statement to be compiled, encoded 3222** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() 3223** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() 3224** use UTF-16. 3225** 3226** ^If the nByte argument is less than zero, then zSql is read up to the 3227** first zero terminator. ^If nByte is non-negative, then it is the maximum 3228** number of bytes read from zSql. ^When nByte is non-negative, the 3229** zSql string ends at either the first '\000' or '\u0000' character or 3230** the nByte-th byte, whichever comes first. If the caller knows 3231** that the supplied string is nul-terminated, then there is a small 3232** performance advantage to be gained by passing an nByte parameter that 3233** is equal to the number of bytes in the input string <i>including</i> 3234** the nul-terminator bytes as this saves SQLite from having to 3235** make a copy of the input string. 3236** 3237** ^If pzTail is not NULL then *pzTail is made to point to the first byte 3238** past the end of the first SQL statement in zSql. These routines only 3239** compile the first statement in zSql, so *pzTail is left pointing to 3240** what remains uncompiled. 3241** 3242** ^*ppStmt is left pointing to a compiled [prepared statement] that can be 3243** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set 3244** to NULL. ^If the input text contains no SQL (if the input is an empty 3245** string or a comment) then *ppStmt is set to NULL. 3246** The calling procedure is responsible for deleting the compiled 3247** SQL statement using [sqlite3_finalize()] after it has finished with it. 3248** ppStmt may not be NULL. 3249** 3250** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; 3251** otherwise an [error code] is returned. 3252** 3253** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are 3254** recommended for all new programs. The two older interfaces are retained 3255** for backwards compatibility, but their use is discouraged. 3256** ^In the "v2" interfaces, the prepared statement 3257** that is returned (the [sqlite3_stmt] object) contains a copy of the 3258** original SQL text. This causes the [sqlite3_step()] interface to 3259** behave differently in three ways: 3260** 3261** <ol> 3262** <li> 3263** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it 3264** always used to do, [sqlite3_step()] will automatically recompile the SQL 3265** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY] 3266** retries will occur before sqlite3_step() gives up and returns an error. 3267** </li> 3268** 3269** <li> 3270** ^When an error occurs, [sqlite3_step()] will return one of the detailed 3271** [error codes] or [extended error codes]. ^The legacy behavior was that 3272** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code 3273** and the application would have to make a second call to [sqlite3_reset()] 3274** in order to find the underlying cause of the problem. With the "v2" prepare 3275** interfaces, the underlying reason for the error is returned immediately. 3276** </li> 3277** 3278** <li> 3279** ^If the specific value bound to [parameter | host parameter] in the 3280** WHERE clause might influence the choice of query plan for a statement, 3281** then the statement will be automatically recompiled, as if there had been 3282** a schema change, on the first [sqlite3_step()] call following any change 3283** to the [sqlite3_bind_text | bindings] of that [parameter]. 3284** ^The specific value of WHERE-clause [parameter] might influence the 3285** choice of query plan if the parameter is the left-hand side of a [LIKE] 3286** or [GLOB] operator or if the parameter is compared to an indexed column 3287** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled. 3288** </li> 3289** </ol> 3290*/ 3291SQLITE_API int sqlite3_prepare( 3292 sqlite3 *db, /* Database handle */ 3293 const char *zSql, /* SQL statement, UTF-8 encoded */ 3294 int nByte, /* Maximum length of zSql in bytes. */ 3295 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3296 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3297); 3298SQLITE_API int sqlite3_prepare_v2( 3299 sqlite3 *db, /* Database handle */ 3300 const char *zSql, /* SQL statement, UTF-8 encoded */ 3301 int nByte, /* Maximum length of zSql in bytes. */ 3302 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3303 const char **pzTail /* OUT: Pointer to unused portion of zSql */ 3304); 3305SQLITE_API int sqlite3_prepare16( 3306 sqlite3 *db, /* Database handle */ 3307 const void *zSql, /* SQL statement, UTF-16 encoded */ 3308 int nByte, /* Maximum length of zSql in bytes. */ 3309 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3310 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3311); 3312SQLITE_API int sqlite3_prepare16_v2( 3313 sqlite3 *db, /* Database handle */ 3314 const void *zSql, /* SQL statement, UTF-16 encoded */ 3315 int nByte, /* Maximum length of zSql in bytes. */ 3316 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ 3317 const void **pzTail /* OUT: Pointer to unused portion of zSql */ 3318); 3319 3320/* 3321** CAPI3REF: Retrieving Statement SQL 3322** 3323** ^This interface can be used to retrieve a saved copy of the original 3324** SQL text used to create a [prepared statement] if that statement was 3325** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. 3326*/ 3327SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); 3328 3329/* 3330** CAPI3REF: Determine If An SQL Statement Writes The Database 3331** 3332** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if 3333** and only if the [prepared statement] X makes no direct changes to 3334** the content of the database file. 3335** 3336** Note that [application-defined SQL functions] or 3337** [virtual tables] might change the database indirectly as a side effect. 3338** ^(For example, if an application defines a function "eval()" that 3339** calls [sqlite3_exec()], then the following SQL statement would 3340** change the database file through side-effects: 3341** 3342** <blockquote><pre> 3343** SELECT eval('DELETE FROM t1') FROM t2; 3344** </pre></blockquote> 3345** 3346** But because the [SELECT] statement does not change the database file 3347** directly, sqlite3_stmt_readonly() would still return true.)^ 3348** 3349** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], 3350** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, 3351** since the statements themselves do not actually modify the database but 3352** rather they control the timing of when other statements modify the 3353** database. ^The [ATTACH] and [DETACH] statements also cause 3354** sqlite3_stmt_readonly() to return true since, while those statements 3355** change the configuration of a database connection, they do not make 3356** changes to the content of the database files on disk. 3357*/ 3358SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); 3359 3360/* 3361** CAPI3REF: Determine If A Prepared Statement Has Been Reset 3362** 3363** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the 3364** [prepared statement] S has been stepped at least once using 3365** [sqlite3_step(S)] but has not run to completion and/or has not 3366** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S) 3367** interface returns false if S is a NULL pointer. If S is not a 3368** NULL pointer and is not a pointer to a valid [prepared statement] 3369** object, then the behavior is undefined and probably undesirable. 3370** 3371** This interface can be used in combination [sqlite3_next_stmt()] 3372** to locate all prepared statements associated with a database 3373** connection that are in need of being reset. This can be used, 3374** for example, in diagnostic routines to search for prepared 3375** statements that are holding a transaction open. 3376*/ 3377SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*); 3378 3379/* 3380** CAPI3REF: Dynamically Typed Value Object 3381** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} 3382** 3383** SQLite uses the sqlite3_value object to represent all values 3384** that can be stored in a database table. SQLite uses dynamic typing 3385** for the values it stores. ^Values stored in sqlite3_value objects 3386** can be integers, floating point values, strings, BLOBs, or NULL. 3387** 3388** An sqlite3_value object may be either "protected" or "unprotected". 3389** Some interfaces require a protected sqlite3_value. Other interfaces 3390** will accept either a protected or an unprotected sqlite3_value. 3391** Every interface that accepts sqlite3_value arguments specifies 3392** whether or not it requires a protected sqlite3_value. 3393** 3394** The terms "protected" and "unprotected" refer to whether or not 3395** a mutex is held. An internal mutex is held for a protected 3396** sqlite3_value object but no mutex is held for an unprotected 3397** sqlite3_value object. If SQLite is compiled to be single-threaded 3398** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) 3399** or if SQLite is run in one of reduced mutex modes 3400** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] 3401** then there is no distinction between protected and unprotected 3402** sqlite3_value objects and they can be used interchangeably. However, 3403** for maximum code portability it is recommended that applications 3404** still make the distinction between protected and unprotected 3405** sqlite3_value objects even when not strictly required. 3406** 3407** ^The sqlite3_value objects that are passed as parameters into the 3408** implementation of [application-defined SQL functions] are protected. 3409** ^The sqlite3_value object returned by 3410** [sqlite3_column_value()] is unprotected. 3411** Unprotected sqlite3_value objects may only be used with 3412** [sqlite3_result_value()] and [sqlite3_bind_value()]. 3413** The [sqlite3_value_blob | sqlite3_value_type()] family of 3414** interfaces require protected sqlite3_value objects. 3415*/ 3416typedef struct Mem sqlite3_value; 3417 3418/* 3419** CAPI3REF: SQL Function Context Object 3420** 3421** The context in which an SQL function executes is stored in an 3422** sqlite3_context object. ^A pointer to an sqlite3_context object 3423** is always first parameter to [application-defined SQL functions]. 3424** The application-defined SQL function implementation will pass this 3425** pointer through into calls to [sqlite3_result_int | sqlite3_result()], 3426** [sqlite3_aggregate_context()], [sqlite3_user_data()], 3427** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], 3428** and/or [sqlite3_set_auxdata()]. 3429*/ 3430typedef struct sqlite3_context sqlite3_context; 3431 3432/* 3433** CAPI3REF: Binding Values To Prepared Statements 3434** KEYWORDS: {host parameter} {host parameters} {host parameter name} 3435** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} 3436** 3437** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, 3438** literals may be replaced by a [parameter] that matches one of following 3439** templates: 3440** 3441** <ul> 3442** <li> ? 3443** <li> ?NNN 3444** <li> :VVV 3445** <li> @VVV 3446** <li> $VVV 3447** </ul> 3448** 3449** In the templates above, NNN represents an integer literal, 3450** and VVV represents an alphanumeric identifier.)^ ^The values of these 3451** parameters (also called "host parameter names" or "SQL parameters") 3452** can be set using the sqlite3_bind_*() routines defined here. 3453** 3454** ^The first argument to the sqlite3_bind_*() routines is always 3455** a pointer to the [sqlite3_stmt] object returned from 3456** [sqlite3_prepare_v2()] or its variants. 3457** 3458** ^The second argument is the index of the SQL parameter to be set. 3459** ^The leftmost SQL parameter has an index of 1. ^When the same named 3460** SQL parameter is used more than once, second and subsequent 3461** occurrences have the same index as the first occurrence. 3462** ^The index for named parameters can be looked up using the 3463** [sqlite3_bind_parameter_index()] API if desired. ^The index 3464** for "?NNN" parameters is the value of NNN. 3465** ^The NNN value must be between 1 and the [sqlite3_limit()] 3466** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). 3467** 3468** ^The third argument is the value to bind to the parameter. 3469** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3470** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter 3471** is ignored and the end result is the same as sqlite3_bind_null(). 3472** 3473** ^(In those routines that have a fourth argument, its value is the 3474** number of bytes in the parameter. To be clear: the value is the 3475** number of <u>bytes</u> in the value, not the number of characters.)^ 3476** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16() 3477** is negative, then the length of the string is 3478** the number of bytes up to the first zero terminator. 3479** If the fourth parameter to sqlite3_bind_blob() is negative, then 3480** the behavior is undefined. 3481** If a non-negative fourth parameter is provided to sqlite3_bind_text() 3482** or sqlite3_bind_text16() then that parameter must be the byte offset 3483** where the NUL terminator would occur assuming the string were NUL 3484** terminated. If any NUL characters occur at byte offsets less than 3485** the value of the fourth parameter then the resulting string value will 3486** contain embedded NULs. The result of expressions involving strings 3487** with embedded NULs is undefined. 3488** 3489** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and 3490** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or 3491** string after SQLite has finished with it. ^The destructor is called 3492** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), 3493** sqlite3_bind_text(), or sqlite3_bind_text16() fails. 3494** ^If the fifth argument is 3495** the special value [SQLITE_STATIC], then SQLite assumes that the 3496** information is in static, unmanaged space and does not need to be freed. 3497** ^If the fifth argument has the value [SQLITE_TRANSIENT], then 3498** SQLite makes its own private copy of the data immediately, before 3499** the sqlite3_bind_*() routine returns. 3500** 3501** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that 3502** is filled with zeroes. ^A zeroblob uses a fixed amount of memory 3503** (just an integer to hold its size) while it is being processed. 3504** Zeroblobs are intended to serve as placeholders for BLOBs whose 3505** content is later written using 3506** [sqlite3_blob_open | incremental BLOB I/O] routines. 3507** ^A negative value for the zeroblob results in a zero-length BLOB. 3508** 3509** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer 3510** for the [prepared statement] or with a prepared statement for which 3511** [sqlite3_step()] has been called more recently than [sqlite3_reset()], 3512** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() 3513** routine is passed a [prepared statement] that has been finalized, the 3514** result is undefined and probably harmful. 3515** 3516** ^Bindings are not cleared by the [sqlite3_reset()] routine. 3517** ^Unbound parameters are interpreted as NULL. 3518** 3519** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an 3520** [error code] if anything goes wrong. 3521** ^[SQLITE_RANGE] is returned if the parameter 3522** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. 3523** 3524** See also: [sqlite3_bind_parameter_count()], 3525** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. 3526*/ 3527SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); 3528SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); 3529SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); 3530SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); 3531SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); 3532SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); 3533SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); 3534SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); 3535SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); 3536 3537/* 3538** CAPI3REF: Number Of SQL Parameters 3539** 3540** ^This routine can be used to find the number of [SQL parameters] 3541** in a [prepared statement]. SQL parameters are tokens of the 3542** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as 3543** placeholders for values that are [sqlite3_bind_blob | bound] 3544** to the parameters at a later time. 3545** 3546** ^(This routine actually returns the index of the largest (rightmost) 3547** parameter. For all forms except ?NNN, this will correspond to the 3548** number of unique parameters. If parameters of the ?NNN form are used, 3549** there may be gaps in the list.)^ 3550** 3551** See also: [sqlite3_bind_blob|sqlite3_bind()], 3552** [sqlite3_bind_parameter_name()], and 3553** [sqlite3_bind_parameter_index()]. 3554*/ 3555SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); 3556 3557/* 3558** CAPI3REF: Name Of A Host Parameter 3559** 3560** ^The sqlite3_bind_parameter_name(P,N) interface returns 3561** the name of the N-th [SQL parameter] in the [prepared statement] P. 3562** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" 3563** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" 3564** respectively. 3565** In other words, the initial ":" or "$" or "@" or "?" 3566** is included as part of the name.)^ 3567** ^Parameters of the form "?" without a following integer have no name 3568** and are referred to as "nameless" or "anonymous parameters". 3569** 3570** ^The first host parameter has an index of 1, not 0. 3571** 3572** ^If the value N is out of range or if the N-th parameter is 3573** nameless, then NULL is returned. ^The returned string is 3574** always in UTF-8 encoding even if the named parameter was 3575** originally specified as UTF-16 in [sqlite3_prepare16()] or 3576** [sqlite3_prepare16_v2()]. 3577** 3578** See also: [sqlite3_bind_blob|sqlite3_bind()], 3579** [sqlite3_bind_parameter_count()], and 3580** [sqlite3_bind_parameter_index()]. 3581*/ 3582SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); 3583 3584/* 3585** CAPI3REF: Index Of A Parameter With A Given Name 3586** 3587** ^Return the index of an SQL parameter given its name. ^The 3588** index value returned is suitable for use as the second 3589** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero 3590** is returned if no matching parameter is found. ^The parameter 3591** name must be given in UTF-8 even if the original statement 3592** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. 3593** 3594** See also: [sqlite3_bind_blob|sqlite3_bind()], 3595** [sqlite3_bind_parameter_count()], and 3596** [sqlite3_bind_parameter_index()]. 3597*/ 3598SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); 3599 3600/* 3601** CAPI3REF: Reset All Bindings On A Prepared Statement 3602** 3603** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset 3604** the [sqlite3_bind_blob | bindings] on a [prepared statement]. 3605** ^Use this routine to reset all host parameters to NULL. 3606*/ 3607SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); 3608 3609/* 3610** CAPI3REF: Number Of Columns In A Result Set 3611** 3612** ^Return the number of columns in the result set returned by the 3613** [prepared statement]. ^This routine returns 0 if pStmt is an SQL 3614** statement that does not return data (for example an [UPDATE]). 3615** 3616** See also: [sqlite3_data_count()] 3617*/ 3618SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); 3619 3620/* 3621** CAPI3REF: Column Names In A Result Set 3622** 3623** ^These routines return the name assigned to a particular column 3624** in the result set of a [SELECT] statement. ^The sqlite3_column_name() 3625** interface returns a pointer to a zero-terminated UTF-8 string 3626** and sqlite3_column_name16() returns a pointer to a zero-terminated 3627** UTF-16 string. ^The first parameter is the [prepared statement] 3628** that implements the [SELECT] statement. ^The second parameter is the 3629** column number. ^The leftmost column is number 0. 3630** 3631** ^The returned string pointer is valid until either the [prepared statement] 3632** is destroyed by [sqlite3_finalize()] or until the statement is automatically 3633** reprepared by the first call to [sqlite3_step()] for a particular run 3634** or until the next call to 3635** sqlite3_column_name() or sqlite3_column_name16() on the same column. 3636** 3637** ^If sqlite3_malloc() fails during the processing of either routine 3638** (for example during a conversion from UTF-8 to UTF-16) then a 3639** NULL pointer is returned. 3640** 3641** ^The name of a result column is the value of the "AS" clause for 3642** that column, if there is an AS clause. If there is no AS clause 3643** then the name of the column is unspecified and may change from 3644** one release of SQLite to the next. 3645*/ 3646SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); 3647SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); 3648 3649/* 3650** CAPI3REF: Source Of Data In A Query Result 3651** 3652** ^These routines provide a means to determine the database, table, and 3653** table column that is the origin of a particular result column in 3654** [SELECT] statement. 3655** ^The name of the database or table or column can be returned as 3656** either a UTF-8 or UTF-16 string. ^The _database_ routines return 3657** the database name, the _table_ routines return the table name, and 3658** the origin_ routines return the column name. 3659** ^The returned string is valid until the [prepared statement] is destroyed 3660** using [sqlite3_finalize()] or until the statement is automatically 3661** reprepared by the first call to [sqlite3_step()] for a particular run 3662** or until the same information is requested 3663** again in a different encoding. 3664** 3665** ^The names returned are the original un-aliased names of the 3666** database, table, and column. 3667** 3668** ^The first argument to these interfaces is a [prepared statement]. 3669** ^These functions return information about the Nth result column returned by 3670** the statement, where N is the second function argument. 3671** ^The left-most column is column 0 for these routines. 3672** 3673** ^If the Nth column returned by the statement is an expression or 3674** subquery and is not a column value, then all of these functions return 3675** NULL. ^These routine might also return NULL if a memory allocation error 3676** occurs. ^Otherwise, they return the name of the attached database, table, 3677** or column that query result column was extracted from. 3678** 3679** ^As with all other SQLite APIs, those whose names end with "16" return 3680** UTF-16 encoded strings and the other functions return UTF-8. 3681** 3682** ^These APIs are only available if the library was compiled with the 3683** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. 3684** 3685** If two or more threads call one or more of these routines against the same 3686** prepared statement and column at the same time then the results are 3687** undefined. 3688** 3689** If two or more threads call one or more 3690** [sqlite3_column_database_name | column metadata interfaces] 3691** for the same [prepared statement] and result column 3692** at the same time then the results are undefined. 3693*/ 3694SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); 3695SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); 3696SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); 3697SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); 3698SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); 3699SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); 3700 3701/* 3702** CAPI3REF: Declared Datatype Of A Query Result 3703** 3704** ^(The first parameter is a [prepared statement]. 3705** If this statement is a [SELECT] statement and the Nth column of the 3706** returned result set of that [SELECT] is a table column (not an 3707** expression or subquery) then the declared type of the table 3708** column is returned.)^ ^If the Nth column of the result set is an 3709** expression or subquery, then a NULL pointer is returned. 3710** ^The returned string is always UTF-8 encoded. 3711** 3712** ^(For example, given the database schema: 3713** 3714** CREATE TABLE t1(c1 VARIANT); 3715** 3716** and the following statement to be compiled: 3717** 3718** SELECT c1 + 1, c1 FROM t1; 3719** 3720** this routine would return the string "VARIANT" for the second result 3721** column (i==1), and a NULL pointer for the first result column (i==0).)^ 3722** 3723** ^SQLite uses dynamic run-time typing. ^So just because a column 3724** is declared to contain a particular type does not mean that the 3725** data stored in that column is of the declared type. SQLite is 3726** strongly typed, but the typing is dynamic not static. ^Type 3727** is associated with individual values, not with the containers 3728** used to hold those values. 3729*/ 3730SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); 3731SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); 3732 3733/* 3734** CAPI3REF: Evaluate An SQL Statement 3735** 3736** After a [prepared statement] has been prepared using either 3737** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy 3738** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function 3739** must be called one or more times to evaluate the statement. 3740** 3741** The details of the behavior of the sqlite3_step() interface depend 3742** on whether the statement was prepared using the newer "v2" interface 3743** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy 3744** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the 3745** new "v2" interface is recommended for new applications but the legacy 3746** interface will continue to be supported. 3747** 3748** ^In the legacy interface, the return value will be either [SQLITE_BUSY], 3749** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. 3750** ^With the "v2" interface, any of the other [result codes] or 3751** [extended result codes] might be returned as well. 3752** 3753** ^[SQLITE_BUSY] means that the database engine was unable to acquire the 3754** database locks it needs to do its job. ^If the statement is a [COMMIT] 3755** or occurs outside of an explicit transaction, then you can retry the 3756** statement. If the statement is not a [COMMIT] and occurs within an 3757** explicit transaction then you should rollback the transaction before 3758** continuing. 3759** 3760** ^[SQLITE_DONE] means that the statement has finished executing 3761** successfully. sqlite3_step() should not be called again on this virtual 3762** machine without first calling [sqlite3_reset()] to reset the virtual 3763** machine back to its initial state. 3764** 3765** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] 3766** is returned each time a new row of data is ready for processing by the 3767** caller. The values may be accessed using the [column access functions]. 3768** sqlite3_step() is called again to retrieve the next row of data. 3769** 3770** ^[SQLITE_ERROR] means that a run-time error (such as a constraint 3771** violation) has occurred. sqlite3_step() should not be called again on 3772** the VM. More information may be found by calling [sqlite3_errmsg()]. 3773** ^With the legacy interface, a more specific error code (for example, 3774** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) 3775** can be obtained by calling [sqlite3_reset()] on the 3776** [prepared statement]. ^In the "v2" interface, 3777** the more specific error code is returned directly by sqlite3_step(). 3778** 3779** [SQLITE_MISUSE] means that the this routine was called inappropriately. 3780** Perhaps it was called on a [prepared statement] that has 3781** already been [sqlite3_finalize | finalized] or on one that had 3782** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could 3783** be the case that the same database connection is being used by two or 3784** more threads at the same moment in time. 3785** 3786** For all versions of SQLite up to and including 3.6.23.1, a call to 3787** [sqlite3_reset()] was required after sqlite3_step() returned anything 3788** other than [SQLITE_ROW] before any subsequent invocation of 3789** sqlite3_step(). Failure to reset the prepared statement using 3790** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from 3791** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began 3792** calling [sqlite3_reset()] automatically in this circumstance rather 3793** than returning [SQLITE_MISUSE]. This is not considered a compatibility 3794** break because any application that ever receives an SQLITE_MISUSE error 3795** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option 3796** can be used to restore the legacy behavior. 3797** 3798** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() 3799** API always returns a generic error code, [SQLITE_ERROR], following any 3800** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call 3801** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the 3802** specific [error codes] that better describes the error. 3803** We admit that this is a goofy design. The problem has been fixed 3804** with the "v2" interface. If you prepare all of your SQL statements 3805** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead 3806** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, 3807** then the more specific [error codes] are returned directly 3808** by sqlite3_step(). The use of the "v2" interface is recommended. 3809*/ 3810SQLITE_API int sqlite3_step(sqlite3_stmt*); 3811 3812/* 3813** CAPI3REF: Number of columns in a result set 3814** 3815** ^The sqlite3_data_count(P) interface returns the number of columns in the 3816** current row of the result set of [prepared statement] P. 3817** ^If prepared statement P does not have results ready to return 3818** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of 3819** interfaces) then sqlite3_data_count(P) returns 0. 3820** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. 3821** ^The sqlite3_data_count(P) routine returns 0 if the previous call to 3822** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P) 3823** will return non-zero if previous call to [sqlite3_step](P) returned 3824** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum] 3825** where it always returns zero since each step of that multi-step 3826** pragma returns 0 columns of data. 3827** 3828** See also: [sqlite3_column_count()] 3829*/ 3830SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); 3831 3832/* 3833** CAPI3REF: Fundamental Datatypes 3834** KEYWORDS: SQLITE_TEXT 3835** 3836** ^(Every value in SQLite has one of five fundamental datatypes: 3837** 3838** <ul> 3839** <li> 64-bit signed integer 3840** <li> 64-bit IEEE floating point number 3841** <li> string 3842** <li> BLOB 3843** <li> NULL 3844** </ul>)^ 3845** 3846** These constants are codes for each of those types. 3847** 3848** Note that the SQLITE_TEXT constant was also used in SQLite version 2 3849** for a completely different meaning. Software that links against both 3850** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not 3851** SQLITE_TEXT. 3852*/ 3853#define SQLITE_INTEGER 1 3854#define SQLITE_FLOAT 2 3855#define SQLITE_BLOB 4 3856#define SQLITE_NULL 5 3857#ifdef SQLITE_TEXT 3858# undef SQLITE_TEXT 3859#else 3860# define SQLITE_TEXT 3 3861#endif 3862#define SQLITE3_TEXT 3 3863 3864/* 3865** CAPI3REF: Result Values From A Query 3866** KEYWORDS: {column access functions} 3867** 3868** These routines form the "result set" interface. 3869** 3870** ^These routines return information about a single column of the current 3871** result row of a query. ^In every case the first argument is a pointer 3872** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] 3873** that was returned from [sqlite3_prepare_v2()] or one of its variants) 3874** and the second argument is the index of the column for which information 3875** should be returned. ^The leftmost column of the result set has the index 0. 3876** ^The number of columns in the result can be determined using 3877** [sqlite3_column_count()]. 3878** 3879** If the SQL statement does not currently point to a valid row, or if the 3880** column index is out of range, the result is undefined. 3881** These routines may only be called when the most recent call to 3882** [sqlite3_step()] has returned [SQLITE_ROW] and neither 3883** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. 3884** If any of these routines are called after [sqlite3_reset()] or 3885** [sqlite3_finalize()] or after [sqlite3_step()] has returned 3886** something other than [SQLITE_ROW], the results are undefined. 3887** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] 3888** are called from a different thread while any of these routines 3889** are pending, then the results are undefined. 3890** 3891** ^The sqlite3_column_type() routine returns the 3892** [SQLITE_INTEGER | datatype code] for the initial data type 3893** of the result column. ^The returned value is one of [SQLITE_INTEGER], 3894** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value 3895** returned by sqlite3_column_type() is only meaningful if no type 3896** conversions have occurred as described below. After a type conversion, 3897** the value returned by sqlite3_column_type() is undefined. Future 3898** versions of SQLite may change the behavior of sqlite3_column_type() 3899** following a type conversion. 3900** 3901** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() 3902** routine returns the number of bytes in that BLOB or string. 3903** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts 3904** the string to UTF-8 and then returns the number of bytes. 3905** ^If the result is a numeric value then sqlite3_column_bytes() uses 3906** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns 3907** the number of bytes in that string. 3908** ^If the result is NULL, then sqlite3_column_bytes() returns zero. 3909** 3910** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() 3911** routine returns the number of bytes in that BLOB or string. 3912** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts 3913** the string to UTF-16 and then returns the number of bytes. 3914** ^If the result is a numeric value then sqlite3_column_bytes16() uses 3915** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns 3916** the number of bytes in that string. 3917** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. 3918** 3919** ^The values returned by [sqlite3_column_bytes()] and 3920** [sqlite3_column_bytes16()] do not include the zero terminators at the end 3921** of the string. ^For clarity: the values returned by 3922** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of 3923** bytes in the string, not the number of characters. 3924** 3925** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), 3926** even empty strings, are always zero-terminated. ^The return 3927** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. 3928** 3929** ^The object returned by [sqlite3_column_value()] is an 3930** [unprotected sqlite3_value] object. An unprotected sqlite3_value object 3931** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. 3932** If the [unprotected sqlite3_value] object returned by 3933** [sqlite3_column_value()] is used in any other way, including calls 3934** to routines like [sqlite3_value_int()], [sqlite3_value_text()], 3935** or [sqlite3_value_bytes()], then the behavior is undefined. 3936** 3937** These routines attempt to convert the value where appropriate. ^For 3938** example, if the internal representation is FLOAT and a text result 3939** is requested, [sqlite3_snprintf()] is used internally to perform the 3940** conversion automatically. ^(The following table details the conversions 3941** that are applied: 3942** 3943** <blockquote> 3944** <table border="1"> 3945** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion 3946** 3947** <tr><td> NULL <td> INTEGER <td> Result is 0 3948** <tr><td> NULL <td> FLOAT <td> Result is 0.0 3949** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer 3950** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer 3951** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float 3952** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer 3953** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT 3954** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER 3955** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float 3956** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB 3957** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER 3958** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL 3959** <tr><td> TEXT <td> BLOB <td> No change 3960** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER 3961** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL 3962** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed 3963** </table> 3964** </blockquote>)^ 3965** 3966** The table above makes reference to standard C library functions atoi() 3967** and atof(). SQLite does not really use these functions. It has its 3968** own equivalent internal routines. The atoi() and atof() names are 3969** used in the table for brevity and because they are familiar to most 3970** C programmers. 3971** 3972** Note that when type conversions occur, pointers returned by prior 3973** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or 3974** sqlite3_column_text16() may be invalidated. 3975** Type conversions and pointer invalidations might occur 3976** in the following cases: 3977** 3978** <ul> 3979** <li> The initial content is a BLOB and sqlite3_column_text() or 3980** sqlite3_column_text16() is called. A zero-terminator might 3981** need to be added to the string.</li> 3982** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or 3983** sqlite3_column_text16() is called. The content must be converted 3984** to UTF-16.</li> 3985** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or 3986** sqlite3_column_text() is called. The content must be converted 3987** to UTF-8.</li> 3988** </ul> 3989** 3990** ^Conversions between UTF-16be and UTF-16le are always done in place and do 3991** not invalidate a prior pointer, though of course the content of the buffer 3992** that the prior pointer references will have been modified. Other kinds 3993** of conversion are done in place when it is possible, but sometimes they 3994** are not possible and in those cases prior pointers are invalidated. 3995** 3996** The safest and easiest to remember policy is to invoke these routines 3997** in one of the following ways: 3998** 3999** <ul> 4000** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> 4001** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> 4002** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> 4003** </ul> 4004** 4005** In other words, you should call sqlite3_column_text(), 4006** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result 4007** into the desired format, then invoke sqlite3_column_bytes() or 4008** sqlite3_column_bytes16() to find the size of the result. Do not mix calls 4009** to sqlite3_column_text() or sqlite3_column_blob() with calls to 4010** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() 4011** with calls to sqlite3_column_bytes(). 4012** 4013** ^The pointers returned are valid until a type conversion occurs as 4014** described above, or until [sqlite3_step()] or [sqlite3_reset()] or 4015** [sqlite3_finalize()] is called. ^The memory space used to hold strings 4016** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned 4017** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into 4018** [sqlite3_free()]. 4019** 4020** ^(If a memory allocation error occurs during the evaluation of any 4021** of these routines, a default value is returned. The default value 4022** is either the integer 0, the floating point number 0.0, or a NULL 4023** pointer. Subsequent calls to [sqlite3_errcode()] will return 4024** [SQLITE_NOMEM].)^ 4025*/ 4026SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); 4027SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); 4028SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); 4029SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); 4030SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); 4031SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); 4032SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); 4033SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); 4034SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); 4035SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); 4036 4037/* 4038** CAPI3REF: Destroy A Prepared Statement Object 4039** 4040** ^The sqlite3_finalize() function is called to delete a [prepared statement]. 4041** ^If the most recent evaluation of the statement encountered no errors 4042** or if the statement is never been evaluated, then sqlite3_finalize() returns 4043** SQLITE_OK. ^If the most recent evaluation of statement S failed, then 4044** sqlite3_finalize(S) returns the appropriate [error code] or 4045** [extended error code]. 4046** 4047** ^The sqlite3_finalize(S) routine can be called at any point during 4048** the life cycle of [prepared statement] S: 4049** before statement S is ever evaluated, after 4050** one or more calls to [sqlite3_reset()], or after any call 4051** to [sqlite3_step()] regardless of whether or not the statement has 4052** completed execution. 4053** 4054** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. 4055** 4056** The application must finalize every [prepared statement] in order to avoid 4057** resource leaks. It is a grievous error for the application to try to use 4058** a prepared statement after it has been finalized. Any use of a prepared 4059** statement after it has been finalized can result in undefined and 4060** undesirable behavior such as segfaults and heap corruption. 4061*/ 4062SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); 4063 4064/* 4065** CAPI3REF: Reset A Prepared Statement Object 4066** 4067** The sqlite3_reset() function is called to reset a [prepared statement] 4068** object back to its initial state, ready to be re-executed. 4069** ^Any SQL statement variables that had values bound to them using 4070** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. 4071** Use [sqlite3_clear_bindings()] to reset the bindings. 4072** 4073** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S 4074** back to the beginning of its program. 4075** 4076** ^If the most recent call to [sqlite3_step(S)] for the 4077** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], 4078** or if [sqlite3_step(S)] has never before been called on S, 4079** then [sqlite3_reset(S)] returns [SQLITE_OK]. 4080** 4081** ^If the most recent call to [sqlite3_step(S)] for the 4082** [prepared statement] S indicated an error, then 4083** [sqlite3_reset(S)] returns an appropriate [error code]. 4084** 4085** ^The [sqlite3_reset(S)] interface does not change the values 4086** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. 4087*/ 4088SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); 4089 4090/* 4091** CAPI3REF: Create Or Redefine SQL Functions 4092** KEYWORDS: {function creation routines} 4093** KEYWORDS: {application-defined SQL function} 4094** KEYWORDS: {application-defined SQL functions} 4095** 4096** ^These functions (collectively known as "function creation routines") 4097** are used to add SQL functions or aggregates or to redefine the behavior 4098** of existing SQL functions or aggregates. The only differences between 4099** these routines are the text encoding expected for 4100** the second parameter (the name of the function being created) 4101** and the presence or absence of a destructor callback for 4102** the application data pointer. 4103** 4104** ^The first parameter is the [database connection] to which the SQL 4105** function is to be added. ^If an application uses more than one database 4106** connection then application-defined SQL functions must be added 4107** to each database connection separately. 4108** 4109** ^The second parameter is the name of the SQL function to be created or 4110** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 4111** representation, exclusive of the zero-terminator. ^Note that the name 4112** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. 4113** ^Any attempt to create a function with a longer name 4114** will result in [SQLITE_MISUSE] being returned. 4115** 4116** ^The third parameter (nArg) 4117** is the number of arguments that the SQL function or 4118** aggregate takes. ^If this parameter is -1, then the SQL function or 4119** aggregate may take any number of arguments between 0 and the limit 4120** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third 4121** parameter is less than -1 or greater than 127 then the behavior is 4122** undefined. 4123** 4124** ^The fourth parameter, eTextRep, specifies what 4125** [SQLITE_UTF8 | text encoding] this SQL function prefers for 4126** its parameters. The application should set this parameter to 4127** [SQLITE_UTF16LE] if the function implementation invokes 4128** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the 4129** implementation invokes [sqlite3_value_text16be()] on an input, or 4130** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8] 4131** otherwise. ^The same SQL function may be registered multiple times using 4132** different preferred text encodings, with different implementations for 4133** each encoding. 4134** ^When multiple implementations of the same function are available, SQLite 4135** will pick the one that involves the least amount of data conversion. 4136** 4137** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC] 4138** to signal that the function will always return the same result given 4139** the same inputs within a single SQL statement. Most SQL functions are 4140** deterministic. The built-in [random()] SQL function is an example of a 4141** function that is not deterministic. The SQLite query planner is able to 4142** perform additional optimizations on deterministic functions, so use 4143** of the [SQLITE_DETERMINISTIC] flag is recommended where possible. 4144** 4145** ^(The fifth parameter is an arbitrary pointer. The implementation of the 4146** function can gain access to this pointer using [sqlite3_user_data()].)^ 4147** 4148** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are 4149** pointers to C-language functions that implement the SQL function or 4150** aggregate. ^A scalar SQL function requires an implementation of the xFunc 4151** callback only; NULL pointers must be passed as the xStep and xFinal 4152** parameters. ^An aggregate SQL function requires an implementation of xStep 4153** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing 4154** SQL function or aggregate, pass NULL pointers for all three function 4155** callbacks. 4156** 4157** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, 4158** then it is destructor for the application data pointer. 4159** The destructor is invoked when the function is deleted, either by being 4160** overloaded or when the database connection closes.)^ 4161** ^The destructor is also invoked if the call to 4162** sqlite3_create_function_v2() fails. 4163** ^When the destructor callback of the tenth parameter is invoked, it 4164** is passed a single argument which is a copy of the application data 4165** pointer which was the fifth parameter to sqlite3_create_function_v2(). 4166** 4167** ^It is permitted to register multiple implementations of the same 4168** functions with the same name but with either differing numbers of 4169** arguments or differing preferred text encodings. ^SQLite will use 4170** the implementation that most closely matches the way in which the 4171** SQL function is used. ^A function implementation with a non-negative 4172** nArg parameter is a better match than a function implementation with 4173** a negative nArg. ^A function where the preferred text encoding 4174** matches the database encoding is a better 4175** match than a function where the encoding is different. 4176** ^A function where the encoding difference is between UTF16le and UTF16be 4177** is a closer match than a function where the encoding difference is 4178** between UTF8 and UTF16. 4179** 4180** ^Built-in functions may be overloaded by new application-defined functions. 4181** 4182** ^An application-defined function is permitted to call other 4183** SQLite interfaces. However, such calls must not 4184** close the database connection nor finalize or reset the prepared 4185** statement in which the function is running. 4186*/ 4187SQLITE_API int sqlite3_create_function( 4188 sqlite3 *db, 4189 const char *zFunctionName, 4190 int nArg, 4191 int eTextRep, 4192 void *pApp, 4193 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4194 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4195 void (*xFinal)(sqlite3_context*) 4196); 4197SQLITE_API int sqlite3_create_function16( 4198 sqlite3 *db, 4199 const void *zFunctionName, 4200 int nArg, 4201 int eTextRep, 4202 void *pApp, 4203 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4204 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4205 void (*xFinal)(sqlite3_context*) 4206); 4207SQLITE_API int sqlite3_create_function_v2( 4208 sqlite3 *db, 4209 const char *zFunctionName, 4210 int nArg, 4211 int eTextRep, 4212 void *pApp, 4213 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), 4214 void (*xStep)(sqlite3_context*,int,sqlite3_value**), 4215 void (*xFinal)(sqlite3_context*), 4216 void(*xDestroy)(void*) 4217); 4218 4219/* 4220** CAPI3REF: Text Encodings 4221** 4222** These constant define integer codes that represent the various 4223** text encodings supported by SQLite. 4224*/ 4225#define SQLITE_UTF8 1 4226#define SQLITE_UTF16LE 2 4227#define SQLITE_UTF16BE 3 4228#define SQLITE_UTF16 4 /* Use native byte order */ 4229#define SQLITE_ANY 5 /* Deprecated */ 4230#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ 4231 4232/* 4233** CAPI3REF: Function Flags 4234** 4235** These constants may be ORed together with the 4236** [SQLITE_UTF8 | preferred text encoding] as the fourth argument 4237** to [sqlite3_create_function()], [sqlite3_create_function16()], or 4238** [sqlite3_create_function_v2()]. 4239*/ 4240#define SQLITE_DETERMINISTIC 0x800 4241 4242/* 4243** CAPI3REF: Deprecated Functions 4244** DEPRECATED 4245** 4246** These functions are [deprecated]. In order to maintain 4247** backwards compatibility with older code, these functions continue 4248** to be supported. However, new applications should avoid 4249** the use of these functions. To help encourage people to avoid 4250** using these functions, we are not going to tell you what they do. 4251*/ 4252#ifndef SQLITE_OMIT_DEPRECATED 4253SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); 4254SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); 4255SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); 4256SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); 4257SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); 4258SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int), 4259 void*,sqlite3_int64); 4260#endif 4261 4262/* 4263** CAPI3REF: Obtaining SQL Function Parameter Values 4264** 4265** The C-language implementation of SQL functions and aggregates uses 4266** this set of interface routines to access the parameter values on 4267** the function or aggregate. 4268** 4269** The xFunc (for scalar functions) or xStep (for aggregates) parameters 4270** to [sqlite3_create_function()] and [sqlite3_create_function16()] 4271** define callbacks that implement the SQL functions and aggregates. 4272** The 3rd parameter to these callbacks is an array of pointers to 4273** [protected sqlite3_value] objects. There is one [sqlite3_value] object for 4274** each parameter to the SQL function. These routines are used to 4275** extract values from the [sqlite3_value] objects. 4276** 4277** These routines work only with [protected sqlite3_value] objects. 4278** Any attempt to use these routines on an [unprotected sqlite3_value] 4279** object results in undefined behavior. 4280** 4281** ^These routines work just like the corresponding [column access functions] 4282** except that these routines take a single [protected sqlite3_value] object 4283** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. 4284** 4285** ^The sqlite3_value_text16() interface extracts a UTF-16 string 4286** in the native byte-order of the host machine. ^The 4287** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces 4288** extract UTF-16 strings as big-endian and little-endian respectively. 4289** 4290** ^(The sqlite3_value_numeric_type() interface attempts to apply 4291** numeric affinity to the value. This means that an attempt is 4292** made to convert the value to an integer or floating point. If 4293** such a conversion is possible without loss of information (in other 4294** words, if the value is a string that looks like a number) 4295** then the conversion is performed. Otherwise no conversion occurs. 4296** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ 4297** 4298** Please pay particular attention to the fact that the pointer returned 4299** from [sqlite3_value_blob()], [sqlite3_value_text()], or 4300** [sqlite3_value_text16()] can be invalidated by a subsequent call to 4301** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], 4302** or [sqlite3_value_text16()]. 4303** 4304** These routines must be called from the same thread as 4305** the SQL function that supplied the [sqlite3_value*] parameters. 4306*/ 4307SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); 4308SQLITE_API int sqlite3_value_bytes(sqlite3_value*); 4309SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); 4310SQLITE_API double sqlite3_value_double(sqlite3_value*); 4311SQLITE_API int sqlite3_value_int(sqlite3_value*); 4312SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); 4313SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); 4314SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); 4315SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); 4316SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); 4317SQLITE_API int sqlite3_value_type(sqlite3_value*); 4318SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); 4319 4320/* 4321** CAPI3REF: Obtain Aggregate Function Context 4322** 4323** Implementations of aggregate SQL functions use this 4324** routine to allocate memory for storing their state. 4325** 4326** ^The first time the sqlite3_aggregate_context(C,N) routine is called 4327** for a particular aggregate function, SQLite 4328** allocates N of memory, zeroes out that memory, and returns a pointer 4329** to the new memory. ^On second and subsequent calls to 4330** sqlite3_aggregate_context() for the same aggregate function instance, 4331** the same buffer is returned. Sqlite3_aggregate_context() is normally 4332** called once for each invocation of the xStep callback and then one 4333** last time when the xFinal callback is invoked. ^(When no rows match 4334** an aggregate query, the xStep() callback of the aggregate function 4335** implementation is never called and xFinal() is called exactly once. 4336** In those cases, sqlite3_aggregate_context() might be called for the 4337** first time from within xFinal().)^ 4338** 4339** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer 4340** when first called if N is less than or equal to zero or if a memory 4341** allocate error occurs. 4342** 4343** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is 4344** determined by the N parameter on first successful call. Changing the 4345** value of N in subsequent call to sqlite3_aggregate_context() within 4346** the same aggregate function instance will not resize the memory 4347** allocation.)^ Within the xFinal callback, it is customary to set 4348** N=0 in calls to sqlite3_aggregate_context(C,N) so that no 4349** pointless memory allocations occur. 4350** 4351** ^SQLite automatically frees the memory allocated by 4352** sqlite3_aggregate_context() when the aggregate query concludes. 4353** 4354** The first parameter must be a copy of the 4355** [sqlite3_context | SQL function context] that is the first parameter 4356** to the xStep or xFinal callback routine that implements the aggregate 4357** function. 4358** 4359** This routine must be called from the same thread in which 4360** the aggregate SQL function is running. 4361*/ 4362SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); 4363 4364/* 4365** CAPI3REF: User Data For Functions 4366** 4367** ^The sqlite3_user_data() interface returns a copy of 4368** the pointer that was the pUserData parameter (the 5th parameter) 4369** of the [sqlite3_create_function()] 4370** and [sqlite3_create_function16()] routines that originally 4371** registered the application defined function. 4372** 4373** This routine must be called from the same thread in which 4374** the application-defined function is running. 4375*/ 4376SQLITE_API void *sqlite3_user_data(sqlite3_context*); 4377 4378/* 4379** CAPI3REF: Database Connection For Functions 4380** 4381** ^The sqlite3_context_db_handle() interface returns a copy of 4382** the pointer to the [database connection] (the 1st parameter) 4383** of the [sqlite3_create_function()] 4384** and [sqlite3_create_function16()] routines that originally 4385** registered the application defined function. 4386*/ 4387SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); 4388 4389/* 4390** CAPI3REF: Function Auxiliary Data 4391** 4392** These functions may be used by (non-aggregate) SQL functions to 4393** associate metadata with argument values. If the same value is passed to 4394** multiple invocations of the same SQL function during query execution, under 4395** some circumstances the associated metadata may be preserved. An example 4396** of where this might be useful is in a regular-expression matching 4397** function. The compiled version of the regular expression can be stored as 4398** metadata associated with the pattern string. 4399** Then as long as the pattern string remains the same, 4400** the compiled regular expression can be reused on multiple 4401** invocations of the same function. 4402** 4403** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata 4404** associated by the sqlite3_set_auxdata() function with the Nth argument 4405** value to the application-defined function. ^If there is no metadata 4406** associated with the function argument, this sqlite3_get_auxdata() interface 4407** returns a NULL pointer. 4408** 4409** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th 4410** argument of the application-defined function. ^Subsequent 4411** calls to sqlite3_get_auxdata(C,N) return P from the most recent 4412** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or 4413** NULL if the metadata has been discarded. 4414** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL, 4415** SQLite will invoke the destructor function X with parameter P exactly 4416** once, when the metadata is discarded. 4417** SQLite is free to discard the metadata at any time, including: <ul> 4418** <li> when the corresponding function parameter changes, or 4419** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the 4420** SQL statement, or 4421** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or 4422** <li> during the original sqlite3_set_auxdata() call when a memory 4423** allocation error occurs. </ul>)^ 4424** 4425** Note the last bullet in particular. The destructor X in 4426** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the 4427** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata() 4428** should be called near the end of the function implementation and the 4429** function implementation should not make any use of P after 4430** sqlite3_set_auxdata() has been called. 4431** 4432** ^(In practice, metadata is preserved between function calls for 4433** function parameters that are compile-time constants, including literal 4434** values and [parameters] and expressions composed from the same.)^ 4435** 4436** These routines must be called from the same thread in which 4437** the SQL function is running. 4438*/ 4439SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); 4440SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); 4441 4442 4443/* 4444** CAPI3REF: Constants Defining Special Destructor Behavior 4445** 4446** These are special values for the destructor that is passed in as the 4447** final argument to routines like [sqlite3_result_blob()]. ^If the destructor 4448** argument is SQLITE_STATIC, it means that the content pointer is constant 4449** and will never change. It does not need to be destroyed. ^The 4450** SQLITE_TRANSIENT value means that the content will likely change in 4451** the near future and that SQLite should make its own private copy of 4452** the content before returning. 4453** 4454** The typedef is necessary to work around problems in certain 4455** C++ compilers. 4456*/ 4457typedef void (*sqlite3_destructor_type)(void*); 4458#define SQLITE_STATIC ((sqlite3_destructor_type)0) 4459#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) 4460 4461/* 4462** CAPI3REF: Setting The Result Of An SQL Function 4463** 4464** These routines are used by the xFunc or xFinal callbacks that 4465** implement SQL functions and aggregates. See 4466** [sqlite3_create_function()] and [sqlite3_create_function16()] 4467** for additional information. 4468** 4469** These functions work very much like the [parameter binding] family of 4470** functions used to bind values to host parameters in prepared statements. 4471** Refer to the [SQL parameter] documentation for additional information. 4472** 4473** ^The sqlite3_result_blob() interface sets the result from 4474** an application-defined function to be the BLOB whose content is pointed 4475** to by the second parameter and which is N bytes long where N is the 4476** third parameter. 4477** 4478** ^The sqlite3_result_zeroblob() interfaces set the result of 4479** the application-defined function to be a BLOB containing all zero 4480** bytes and N bytes in size, where N is the value of the 2nd parameter. 4481** 4482** ^The sqlite3_result_double() interface sets the result from 4483** an application-defined function to be a floating point value specified 4484** by its 2nd argument. 4485** 4486** ^The sqlite3_result_error() and sqlite3_result_error16() functions 4487** cause the implemented SQL function to throw an exception. 4488** ^SQLite uses the string pointed to by the 4489** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() 4490** as the text of an error message. ^SQLite interprets the error 4491** message string from sqlite3_result_error() as UTF-8. ^SQLite 4492** interprets the string from sqlite3_result_error16() as UTF-16 in native 4493** byte order. ^If the third parameter to sqlite3_result_error() 4494** or sqlite3_result_error16() is negative then SQLite takes as the error 4495** message all text up through the first zero character. 4496** ^If the third parameter to sqlite3_result_error() or 4497** sqlite3_result_error16() is non-negative then SQLite takes that many 4498** bytes (not characters) from the 2nd parameter as the error message. 4499** ^The sqlite3_result_error() and sqlite3_result_error16() 4500** routines make a private copy of the error message text before 4501** they return. Hence, the calling function can deallocate or 4502** modify the text after they return without harm. 4503** ^The sqlite3_result_error_code() function changes the error code 4504** returned by SQLite as a result of an error in a function. ^By default, 4505** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() 4506** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. 4507** 4508** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an 4509** error indicating that a string or BLOB is too long to represent. 4510** 4511** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an 4512** error indicating that a memory allocation failed. 4513** 4514** ^The sqlite3_result_int() interface sets the return value 4515** of the application-defined function to be the 32-bit signed integer 4516** value given in the 2nd argument. 4517** ^The sqlite3_result_int64() interface sets the return value 4518** of the application-defined function to be the 64-bit signed integer 4519** value given in the 2nd argument. 4520** 4521** ^The sqlite3_result_null() interface sets the return value 4522** of the application-defined function to be NULL. 4523** 4524** ^The sqlite3_result_text(), sqlite3_result_text16(), 4525** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces 4526** set the return value of the application-defined function to be 4527** a text string which is represented as UTF-8, UTF-16 native byte order, 4528** UTF-16 little endian, or UTF-16 big endian, respectively. 4529** ^SQLite takes the text result from the application from 4530** the 2nd parameter of the sqlite3_result_text* interfaces. 4531** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4532** is negative, then SQLite takes result text from the 2nd parameter 4533** through the first zero character. 4534** ^If the 3rd parameter to the sqlite3_result_text* interfaces 4535** is non-negative, then as many bytes (not characters) of the text 4536** pointed to by the 2nd parameter are taken as the application-defined 4537** function result. If the 3rd parameter is non-negative, then it 4538** must be the byte offset into the string where the NUL terminator would 4539** appear if the string where NUL terminated. If any NUL characters occur 4540** in the string at a byte offset that is less than the value of the 3rd 4541** parameter, then the resulting string will contain embedded NULs and the 4542** result of expressions operating on strings with embedded NULs is undefined. 4543** ^If the 4th parameter to the sqlite3_result_text* interfaces 4544** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that 4545** function as the destructor on the text or BLOB result when it has 4546** finished using that result. 4547** ^If the 4th parameter to the sqlite3_result_text* interfaces or to 4548** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite 4549** assumes that the text or BLOB result is in constant space and does not 4550** copy the content of the parameter nor call a destructor on the content 4551** when it has finished using that result. 4552** ^If the 4th parameter to the sqlite3_result_text* interfaces 4553** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT 4554** then SQLite makes a copy of the result into space obtained from 4555** from [sqlite3_malloc()] before it returns. 4556** 4557** ^The sqlite3_result_value() interface sets the result of 4558** the application-defined function to be a copy the 4559** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The 4560** sqlite3_result_value() interface makes a copy of the [sqlite3_value] 4561** so that the [sqlite3_value] specified in the parameter may change or 4562** be deallocated after sqlite3_result_value() returns without harm. 4563** ^A [protected sqlite3_value] object may always be used where an 4564** [unprotected sqlite3_value] object is required, so either 4565** kind of [sqlite3_value] object can be used with this interface. 4566** 4567** If these routines are called from within the different thread 4568** than the one containing the application-defined function that received 4569** the [sqlite3_context] pointer, the results are undefined. 4570*/ 4571SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); 4572SQLITE_API void sqlite3_result_double(sqlite3_context*, double); 4573SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); 4574SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); 4575SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); 4576SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); 4577SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); 4578SQLITE_API void sqlite3_result_int(sqlite3_context*, int); 4579SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); 4580SQLITE_API void sqlite3_result_null(sqlite3_context*); 4581SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); 4582SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); 4583SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); 4584SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); 4585SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); 4586SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); 4587 4588/* 4589** CAPI3REF: Define New Collating Sequences 4590** 4591** ^These functions add, remove, or modify a [collation] associated 4592** with the [database connection] specified as the first argument. 4593** 4594** ^The name of the collation is a UTF-8 string 4595** for sqlite3_create_collation() and sqlite3_create_collation_v2() 4596** and a UTF-16 string in native byte order for sqlite3_create_collation16(). 4597** ^Collation names that compare equal according to [sqlite3_strnicmp()] are 4598** considered to be the same name. 4599** 4600** ^(The third argument (eTextRep) must be one of the constants: 4601** <ul> 4602** <li> [SQLITE_UTF8], 4603** <li> [SQLITE_UTF16LE], 4604** <li> [SQLITE_UTF16BE], 4605** <li> [SQLITE_UTF16], or 4606** <li> [SQLITE_UTF16_ALIGNED]. 4607** </ul>)^ 4608** ^The eTextRep argument determines the encoding of strings passed 4609** to the collating function callback, xCallback. 4610** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep 4611** force strings to be UTF16 with native byte order. 4612** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin 4613** on an even byte address. 4614** 4615** ^The fourth argument, pArg, is an application data pointer that is passed 4616** through as the first argument to the collating function callback. 4617** 4618** ^The fifth argument, xCallback, is a pointer to the collating function. 4619** ^Multiple collating functions can be registered using the same name but 4620** with different eTextRep parameters and SQLite will use whichever 4621** function requires the least amount of data transformation. 4622** ^If the xCallback argument is NULL then the collating function is 4623** deleted. ^When all collating functions having the same name are deleted, 4624** that collation is no longer usable. 4625** 4626** ^The collating function callback is invoked with a copy of the pArg 4627** application data pointer and with two strings in the encoding specified 4628** by the eTextRep argument. The collating function must return an 4629** integer that is negative, zero, or positive 4630** if the first string is less than, equal to, or greater than the second, 4631** respectively. A collating function must always return the same answer 4632** given the same inputs. If two or more collating functions are registered 4633** to the same collation name (using different eTextRep values) then all 4634** must give an equivalent answer when invoked with equivalent strings. 4635** The collating function must obey the following properties for all 4636** strings A, B, and C: 4637** 4638** <ol> 4639** <li> If A==B then B==A. 4640** <li> If A==B and B==C then A==C. 4641** <li> If A<B THEN B>A. 4642** <li> If A<B and B<C then A<C. 4643** </ol> 4644** 4645** If a collating function fails any of the above constraints and that 4646** collating function is registered and used, then the behavior of SQLite 4647** is undefined. 4648** 4649** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() 4650** with the addition that the xDestroy callback is invoked on pArg when 4651** the collating function is deleted. 4652** ^Collating functions are deleted when they are overridden by later 4653** calls to the collation creation functions or when the 4654** [database connection] is closed using [sqlite3_close()]. 4655** 4656** ^The xDestroy callback is <u>not</u> called if the 4657** sqlite3_create_collation_v2() function fails. Applications that invoke 4658** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should 4659** check the return code and dispose of the application data pointer 4660** themselves rather than expecting SQLite to deal with it for them. 4661** This is different from every other SQLite interface. The inconsistency 4662** is unfortunate but cannot be changed without breaking backwards 4663** compatibility. 4664** 4665** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. 4666*/ 4667SQLITE_API int sqlite3_create_collation( 4668 sqlite3*, 4669 const char *zName, 4670 int eTextRep, 4671 void *pArg, 4672 int(*xCompare)(void*,int,const void*,int,const void*) 4673); 4674SQLITE_API int sqlite3_create_collation_v2( 4675 sqlite3*, 4676 const char *zName, 4677 int eTextRep, 4678 void *pArg, 4679 int(*xCompare)(void*,int,const void*,int,const void*), 4680 void(*xDestroy)(void*) 4681); 4682SQLITE_API int sqlite3_create_collation16( 4683 sqlite3*, 4684 const void *zName, 4685 int eTextRep, 4686 void *pArg, 4687 int(*xCompare)(void*,int,const void*,int,const void*) 4688); 4689 4690/* 4691** CAPI3REF: Collation Needed Callbacks 4692** 4693** ^To avoid having to register all collation sequences before a database 4694** can be used, a single callback function may be registered with the 4695** [database connection] to be invoked whenever an undefined collation 4696** sequence is required. 4697** 4698** ^If the function is registered using the sqlite3_collation_needed() API, 4699** then it is passed the names of undefined collation sequences as strings 4700** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, 4701** the names are passed as UTF-16 in machine native byte order. 4702** ^A call to either function replaces the existing collation-needed callback. 4703** 4704** ^(When the callback is invoked, the first argument passed is a copy 4705** of the second argument to sqlite3_collation_needed() or 4706** sqlite3_collation_needed16(). The second argument is the database 4707** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], 4708** or [SQLITE_UTF16LE], indicating the most desirable form of the collation 4709** sequence function required. The fourth parameter is the name of the 4710** required collation sequence.)^ 4711** 4712** The callback function should register the desired collation using 4713** [sqlite3_create_collation()], [sqlite3_create_collation16()], or 4714** [sqlite3_create_collation_v2()]. 4715*/ 4716SQLITE_API int sqlite3_collation_needed( 4717 sqlite3*, 4718 void*, 4719 void(*)(void*,sqlite3*,int eTextRep,const char*) 4720); 4721SQLITE_API int sqlite3_collation_needed16( 4722 sqlite3*, 4723 void*, 4724 void(*)(void*,sqlite3*,int eTextRep,const void*) 4725); 4726 4727#ifdef SQLITE_HAS_CODEC 4728/* 4729** Specify the key for an encrypted database. This routine should be 4730** called right after sqlite3_open(). 4731** 4732** The code to implement this API is not available in the public release 4733** of SQLite. 4734*/ 4735SQLITE_API int sqlite3_key( 4736 sqlite3 *db, /* Database to be rekeyed */ 4737 const void *pKey, int nKey /* The key */ 4738); 4739SQLITE_API int sqlite3_key_v2( 4740 sqlite3 *db, /* Database to be rekeyed */ 4741 const char *zDbName, /* Name of the database */ 4742 const void *pKey, int nKey /* The key */ 4743); 4744 4745/* 4746** Change the key on an open database. If the current database is not 4747** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the 4748** database is decrypted. 4749** 4750** The code to implement this API is not available in the public release 4751** of SQLite. 4752*/ 4753SQLITE_API int sqlite3_rekey( 4754 sqlite3 *db, /* Database to be rekeyed */ 4755 const void *pKey, int nKey /* The new key */ 4756); 4757SQLITE_API int sqlite3_rekey_v2( 4758 sqlite3 *db, /* Database to be rekeyed */ 4759 const char *zDbName, /* Name of the database */ 4760 const void *pKey, int nKey /* The new key */ 4761); 4762 4763/* 4764** Specify the activation key for a SEE database. Unless 4765** activated, none of the SEE routines will work. 4766*/ 4767SQLITE_API void sqlite3_activate_see( 4768 const char *zPassPhrase /* Activation phrase */ 4769); 4770#endif 4771 4772#ifdef SQLITE_ENABLE_CEROD 4773/* 4774** Specify the activation key for a CEROD database. Unless 4775** activated, none of the CEROD routines will work. 4776*/ 4777SQLITE_API void sqlite3_activate_cerod( 4778 const char *zPassPhrase /* Activation phrase */ 4779); 4780#endif 4781 4782/* 4783** CAPI3REF: Suspend Execution For A Short Time 4784** 4785** The sqlite3_sleep() function causes the current thread to suspend execution 4786** for at least a number of milliseconds specified in its parameter. 4787** 4788** If the operating system does not support sleep requests with 4789** millisecond time resolution, then the time will be rounded up to 4790** the nearest second. The number of milliseconds of sleep actually 4791** requested from the operating system is returned. 4792** 4793** ^SQLite implements this interface by calling the xSleep() 4794** method of the default [sqlite3_vfs] object. If the xSleep() method 4795** of the default VFS is not implemented correctly, or not implemented at 4796** all, then the behavior of sqlite3_sleep() may deviate from the description 4797** in the previous paragraphs. 4798*/ 4799SQLITE_API int sqlite3_sleep(int); 4800 4801/* 4802** CAPI3REF: Name Of The Folder Holding Temporary Files 4803** 4804** ^(If this global variable is made to point to a string which is 4805** the name of a folder (a.k.a. directory), then all temporary files 4806** created by SQLite when using a built-in [sqlite3_vfs | VFS] 4807** will be placed in that directory.)^ ^If this variable 4808** is a NULL pointer, then SQLite performs a search for an appropriate 4809** temporary file directory. 4810** 4811** Applications are strongly discouraged from using this global variable. 4812** It is required to set a temporary folder on Windows Runtime (WinRT). 4813** But for all other platforms, it is highly recommended that applications 4814** neither read nor write this variable. This global variable is a relic 4815** that exists for backwards compatibility of legacy applications and should 4816** be avoided in new projects. 4817** 4818** It is not safe to read or modify this variable in more than one 4819** thread at a time. It is not safe to read or modify this variable 4820** if a [database connection] is being used at the same time in a separate 4821** thread. 4822** It is intended that this variable be set once 4823** as part of process initialization and before any SQLite interface 4824** routines have been called and that this variable remain unchanged 4825** thereafter. 4826** 4827** ^The [temp_store_directory pragma] may modify this variable and cause 4828** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4829** the [temp_store_directory pragma] always assumes that any string 4830** that this variable points to is held in memory obtained from 4831** [sqlite3_malloc] and the pragma may attempt to free that memory 4832** using [sqlite3_free]. 4833** Hence, if this variable is modified directly, either it should be 4834** made NULL or made to point to memory obtained from [sqlite3_malloc] 4835** or else the use of the [temp_store_directory pragma] should be avoided. 4836** Except when requested by the [temp_store_directory pragma], SQLite 4837** does not free the memory that sqlite3_temp_directory points to. If 4838** the application wants that memory to be freed, it must do 4839** so itself, taking care to only do so after all [database connection] 4840** objects have been destroyed. 4841** 4842** <b>Note to Windows Runtime users:</b> The temporary directory must be set 4843** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various 4844** features that require the use of temporary files may fail. Here is an 4845** example of how to do this using C++ with the Windows Runtime: 4846** 4847** <blockquote><pre> 4848** LPCWSTR zPath = Windows::Storage::ApplicationData::Current-> 4849** TemporaryFolder->Path->Data(); 4850** char zPathBuf[MAX_PATH + 1]; 4851** memset(zPathBuf, 0, sizeof(zPathBuf)); 4852** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf), 4853** NULL, NULL); 4854** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf); 4855** </pre></blockquote> 4856*/ 4857SQLITE_API char *sqlite3_temp_directory; 4858 4859/* 4860** CAPI3REF: Name Of The Folder Holding Database Files 4861** 4862** ^(If this global variable is made to point to a string which is 4863** the name of a folder (a.k.a. directory), then all database files 4864** specified with a relative pathname and created or accessed by 4865** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed 4866** to be relative to that directory.)^ ^If this variable is a NULL 4867** pointer, then SQLite assumes that all database files specified 4868** with a relative pathname are relative to the current directory 4869** for the process. Only the windows VFS makes use of this global 4870** variable; it is ignored by the unix VFS. 4871** 4872** Changing the value of this variable while a database connection is 4873** open can result in a corrupt database. 4874** 4875** It is not safe to read or modify this variable in more than one 4876** thread at a time. It is not safe to read or modify this variable 4877** if a [database connection] is being used at the same time in a separate 4878** thread. 4879** It is intended that this variable be set once 4880** as part of process initialization and before any SQLite interface 4881** routines have been called and that this variable remain unchanged 4882** thereafter. 4883** 4884** ^The [data_store_directory pragma] may modify this variable and cause 4885** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, 4886** the [data_store_directory pragma] always assumes that any string 4887** that this variable points to is held in memory obtained from 4888** [sqlite3_malloc] and the pragma may attempt to free that memory 4889** using [sqlite3_free]. 4890** Hence, if this variable is modified directly, either it should be 4891** made NULL or made to point to memory obtained from [sqlite3_malloc] 4892** or else the use of the [data_store_directory pragma] should be avoided. 4893*/ 4894SQLITE_API char *sqlite3_data_directory; 4895 4896/* 4897** CAPI3REF: Test For Auto-Commit Mode 4898** KEYWORDS: {autocommit mode} 4899** 4900** ^The sqlite3_get_autocommit() interface returns non-zero or 4901** zero if the given database connection is or is not in autocommit mode, 4902** respectively. ^Autocommit mode is on by default. 4903** ^Autocommit mode is disabled by a [BEGIN] statement. 4904** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. 4905** 4906** If certain kinds of errors occur on a statement within a multi-statement 4907** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], 4908** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the 4909** transaction might be rolled back automatically. The only way to 4910** find out whether SQLite automatically rolled back the transaction after 4911** an error is to use this function. 4912** 4913** If another thread changes the autocommit status of the database 4914** connection while this routine is running, then the return value 4915** is undefined. 4916*/ 4917SQLITE_API int sqlite3_get_autocommit(sqlite3*); 4918 4919/* 4920** CAPI3REF: Find The Database Handle Of A Prepared Statement 4921** 4922** ^The sqlite3_db_handle interface returns the [database connection] handle 4923** to which a [prepared statement] belongs. ^The [database connection] 4924** returned by sqlite3_db_handle is the same [database connection] 4925** that was the first argument 4926** to the [sqlite3_prepare_v2()] call (or its variants) that was used to 4927** create the statement in the first place. 4928*/ 4929SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); 4930 4931/* 4932** CAPI3REF: Return The Filename For A Database Connection 4933** 4934** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename 4935** associated with database N of connection D. ^The main database file 4936** has the name "main". If there is no attached database N on the database 4937** connection D, or if database N is a temporary or in-memory database, then 4938** a NULL pointer is returned. 4939** 4940** ^The filename returned by this function is the output of the 4941** xFullPathname method of the [VFS]. ^In other words, the filename 4942** will be an absolute pathname, even if the filename used 4943** to open the database originally was a URI or relative pathname. 4944*/ 4945SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName); 4946 4947/* 4948** CAPI3REF: Determine if a database is read-only 4949** 4950** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N 4951** of connection D is read-only, 0 if it is read/write, or -1 if N is not 4952** the name of a database on connection D. 4953*/ 4954SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName); 4955 4956/* 4957** CAPI3REF: Find the next prepared statement 4958** 4959** ^This interface returns a pointer to the next [prepared statement] after 4960** pStmt associated with the [database connection] pDb. ^If pStmt is NULL 4961** then this interface returns a pointer to the first prepared statement 4962** associated with the database connection pDb. ^If no prepared statement 4963** satisfies the conditions of this routine, it returns NULL. 4964** 4965** The [database connection] pointer D in a call to 4966** [sqlite3_next_stmt(D,S)] must refer to an open database 4967** connection and in particular must not be a NULL pointer. 4968*/ 4969SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); 4970 4971/* 4972** CAPI3REF: Commit And Rollback Notification Callbacks 4973** 4974** ^The sqlite3_commit_hook() interface registers a callback 4975** function to be invoked whenever a transaction is [COMMIT | committed]. 4976** ^Any callback set by a previous call to sqlite3_commit_hook() 4977** for the same database connection is overridden. 4978** ^The sqlite3_rollback_hook() interface registers a callback 4979** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. 4980** ^Any callback set by a previous call to sqlite3_rollback_hook() 4981** for the same database connection is overridden. 4982** ^The pArg argument is passed through to the callback. 4983** ^If the callback on a commit hook function returns non-zero, 4984** then the commit is converted into a rollback. 4985** 4986** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions 4987** return the P argument from the previous call of the same function 4988** on the same [database connection] D, or NULL for 4989** the first call for each function on D. 4990** 4991** The commit and rollback hook callbacks are not reentrant. 4992** The callback implementation must not do anything that will modify 4993** the database connection that invoked the callback. Any actions 4994** to modify the database connection must be deferred until after the 4995** completion of the [sqlite3_step()] call that triggered the commit 4996** or rollback hook in the first place. 4997** Note that running any other SQL statements, including SELECT statements, 4998** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify 4999** the database connections for the meaning of "modify" in this paragraph. 5000** 5001** ^Registering a NULL function disables the callback. 5002** 5003** ^When the commit hook callback routine returns zero, the [COMMIT] 5004** operation is allowed to continue normally. ^If the commit hook 5005** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. 5006** ^The rollback hook is invoked on a rollback that results from a commit 5007** hook returning non-zero, just as it would be with any other rollback. 5008** 5009** ^For the purposes of this API, a transaction is said to have been 5010** rolled back if an explicit "ROLLBACK" statement is executed, or 5011** an error or constraint causes an implicit rollback to occur. 5012** ^The rollback callback is not invoked if a transaction is 5013** automatically rolled back because the database connection is closed. 5014** 5015** See also the [sqlite3_update_hook()] interface. 5016*/ 5017SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); 5018SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); 5019 5020/* 5021** CAPI3REF: Data Change Notification Callbacks 5022** 5023** ^The sqlite3_update_hook() interface registers a callback function 5024** with the [database connection] identified by the first argument 5025** to be invoked whenever a row is updated, inserted or deleted in 5026** a rowid table. 5027** ^Any callback set by a previous call to this function 5028** for the same database connection is overridden. 5029** 5030** ^The second argument is a pointer to the function to invoke when a 5031** row is updated, inserted or deleted in a rowid table. 5032** ^The first argument to the callback is a copy of the third argument 5033** to sqlite3_update_hook(). 5034** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], 5035** or [SQLITE_UPDATE], depending on the operation that caused the callback 5036** to be invoked. 5037** ^The third and fourth arguments to the callback contain pointers to the 5038** database and table name containing the affected row. 5039** ^The final callback parameter is the [rowid] of the row. 5040** ^In the case of an update, this is the [rowid] after the update takes place. 5041** 5042** ^(The update hook is not invoked when internal system tables are 5043** modified (i.e. sqlite_master and sqlite_sequence).)^ 5044** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified. 5045** 5046** ^In the current implementation, the update hook 5047** is not invoked when duplication rows are deleted because of an 5048** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook 5049** invoked when rows are deleted using the [truncate optimization]. 5050** The exceptions defined in this paragraph might change in a future 5051** release of SQLite. 5052** 5053** The update hook implementation must not do anything that will modify 5054** the database connection that invoked the update hook. Any actions 5055** to modify the database connection must be deferred until after the 5056** completion of the [sqlite3_step()] call that triggered the update hook. 5057** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their 5058** database connections for the meaning of "modify" in this paragraph. 5059** 5060** ^The sqlite3_update_hook(D,C,P) function 5061** returns the P argument from the previous call 5062** on the same [database connection] D, or NULL for 5063** the first call on D. 5064** 5065** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] 5066** interfaces. 5067*/ 5068SQLITE_API void *sqlite3_update_hook( 5069 sqlite3*, 5070 void(*)(void *,int ,char const *,char const *,sqlite3_int64), 5071 void* 5072); 5073 5074/* 5075** CAPI3REF: Enable Or Disable Shared Pager Cache 5076** 5077** ^(This routine enables or disables the sharing of the database cache 5078** and schema data structures between [database connection | connections] 5079** to the same database. Sharing is enabled if the argument is true 5080** and disabled if the argument is false.)^ 5081** 5082** ^Cache sharing is enabled and disabled for an entire process. 5083** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, 5084** sharing was enabled or disabled for each thread separately. 5085** 5086** ^(The cache sharing mode set by this interface effects all subsequent 5087** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. 5088** Existing database connections continue use the sharing mode 5089** that was in effect at the time they were opened.)^ 5090** 5091** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled 5092** successfully. An [error code] is returned otherwise.)^ 5093** 5094** ^Shared cache is disabled by default. But this might change in 5095** future releases of SQLite. Applications that care about shared 5096** cache setting should set it explicitly. 5097** 5098** This interface is threadsafe on processors where writing a 5099** 32-bit integer is atomic. 5100** 5101** See Also: [SQLite Shared-Cache Mode] 5102*/ 5103SQLITE_API int sqlite3_enable_shared_cache(int); 5104 5105/* 5106** CAPI3REF: Attempt To Free Heap Memory 5107** 5108** ^The sqlite3_release_memory() interface attempts to free N bytes 5109** of heap memory by deallocating non-essential memory allocations 5110** held by the database library. Memory used to cache database 5111** pages to improve performance is an example of non-essential memory. 5112** ^sqlite3_release_memory() returns the number of bytes actually freed, 5113** which might be more or less than the amount requested. 5114** ^The sqlite3_release_memory() routine is a no-op returning zero 5115** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5116** 5117** See also: [sqlite3_db_release_memory()] 5118*/ 5119SQLITE_API int sqlite3_release_memory(int); 5120 5121/* 5122** CAPI3REF: Free Memory Used By A Database Connection 5123** 5124** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap 5125** memory as possible from database connection D. Unlike the 5126** [sqlite3_release_memory()] interface, this interface is in effect even 5127** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is 5128** omitted. 5129** 5130** See also: [sqlite3_release_memory()] 5131*/ 5132SQLITE_API int sqlite3_db_release_memory(sqlite3*); 5133 5134/* 5135** CAPI3REF: Impose A Limit On Heap Size 5136** 5137** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the 5138** soft limit on the amount of heap memory that may be allocated by SQLite. 5139** ^SQLite strives to keep heap memory utilization below the soft heap 5140** limit by reducing the number of pages held in the page cache 5141** as heap memory usages approaches the limit. 5142** ^The soft heap limit is "soft" because even though SQLite strives to stay 5143** below the limit, it will exceed the limit rather than generate 5144** an [SQLITE_NOMEM] error. In other words, the soft heap limit 5145** is advisory only. 5146** 5147** ^The return value from sqlite3_soft_heap_limit64() is the size of 5148** the soft heap limit prior to the call, or negative in the case of an 5149** error. ^If the argument N is negative 5150** then no change is made to the soft heap limit. Hence, the current 5151** size of the soft heap limit can be determined by invoking 5152** sqlite3_soft_heap_limit64() with a negative argument. 5153** 5154** ^If the argument N is zero then the soft heap limit is disabled. 5155** 5156** ^(The soft heap limit is not enforced in the current implementation 5157** if one or more of following conditions are true: 5158** 5159** <ul> 5160** <li> The soft heap limit is set to zero. 5161** <li> Memory accounting is disabled using a combination of the 5162** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and 5163** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. 5164** <li> An alternative page cache implementation is specified using 5165** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...). 5166** <li> The page cache allocates from its own memory pool supplied 5167** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than 5168** from the heap. 5169** </ul>)^ 5170** 5171** Beginning with SQLite version 3.7.3, the soft heap limit is enforced 5172** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] 5173** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], 5174** the soft heap limit is enforced on every memory allocation. Without 5175** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced 5176** when memory is allocated by the page cache. Testing suggests that because 5177** the page cache is the predominate memory user in SQLite, most 5178** applications will achieve adequate soft heap limit enforcement without 5179** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. 5180** 5181** The circumstances under which SQLite will enforce the soft heap limit may 5182** changes in future releases of SQLite. 5183*/ 5184SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); 5185 5186/* 5187** CAPI3REF: Deprecated Soft Heap Limit Interface 5188** DEPRECATED 5189** 5190** This is a deprecated version of the [sqlite3_soft_heap_limit64()] 5191** interface. This routine is provided for historical compatibility 5192** only. All new applications should use the 5193** [sqlite3_soft_heap_limit64()] interface rather than this one. 5194*/ 5195SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); 5196 5197 5198/* 5199** CAPI3REF: Extract Metadata About A Column Of A Table 5200** 5201** ^This routine returns metadata about a specific column of a specific 5202** database table accessible using the [database connection] handle 5203** passed as the first function argument. 5204** 5205** ^The column is identified by the second, third and fourth parameters to 5206** this function. ^The second parameter is either the name of the database 5207** (i.e. "main", "temp", or an attached database) containing the specified 5208** table or NULL. ^If it is NULL, then all attached databases are searched 5209** for the table using the same algorithm used by the database engine to 5210** resolve unqualified table references. 5211** 5212** ^The third and fourth parameters to this function are the table and column 5213** name of the desired column, respectively. Neither of these parameters 5214** may be NULL. 5215** 5216** ^Metadata is returned by writing to the memory locations passed as the 5th 5217** and subsequent parameters to this function. ^Any of these arguments may be 5218** NULL, in which case the corresponding element of metadata is omitted. 5219** 5220** ^(<blockquote> 5221** <table border="1"> 5222** <tr><th> Parameter <th> Output<br>Type <th> Description 5223** 5224** <tr><td> 5th <td> const char* <td> Data type 5225** <tr><td> 6th <td> const char* <td> Name of default collation sequence 5226** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint 5227** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY 5228** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] 5229** </table> 5230** </blockquote>)^ 5231** 5232** ^The memory pointed to by the character pointers returned for the 5233** declaration type and collation sequence is valid only until the next 5234** call to any SQLite API function. 5235** 5236** ^If the specified table is actually a view, an [error code] is returned. 5237** 5238** ^If the specified column is "rowid", "oid" or "_rowid_" and an 5239** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output 5240** parameters are set for the explicitly declared column. ^(If there is no 5241** explicitly declared [INTEGER PRIMARY KEY] column, then the output 5242** parameters are set as follows: 5243** 5244** <pre> 5245** data type: "INTEGER" 5246** collation sequence: "BINARY" 5247** not null: 0 5248** primary key: 1 5249** auto increment: 0 5250** </pre>)^ 5251** 5252** ^(This function may load one or more schemas from database files. If an 5253** error occurs during this process, or if the requested table or column 5254** cannot be found, an [error code] is returned and an error message left 5255** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ 5256** 5257** ^This API is only available if the library was compiled with the 5258** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. 5259*/ 5260SQLITE_API int sqlite3_table_column_metadata( 5261 sqlite3 *db, /* Connection handle */ 5262 const char *zDbName, /* Database name or NULL */ 5263 const char *zTableName, /* Table name */ 5264 const char *zColumnName, /* Column name */ 5265 char const **pzDataType, /* OUTPUT: Declared data type */ 5266 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ 5267 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ 5268 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ 5269 int *pAutoinc /* OUTPUT: True if column is auto-increment */ 5270); 5271 5272/* 5273** CAPI3REF: Load An Extension 5274** 5275** ^This interface loads an SQLite extension library from the named file. 5276** 5277** ^The sqlite3_load_extension() interface attempts to load an 5278** [SQLite extension] library contained in the file zFile. If 5279** the file cannot be loaded directly, attempts are made to load 5280** with various operating-system specific extensions added. 5281** So for example, if "samplelib" cannot be loaded, then names like 5282** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might 5283** be tried also. 5284** 5285** ^The entry point is zProc. 5286** ^(zProc may be 0, in which case SQLite will try to come up with an 5287** entry point name on its own. It first tries "sqlite3_extension_init". 5288** If that does not work, it constructs a name "sqlite3_X_init" where the 5289** X is consists of the lower-case equivalent of all ASCII alphabetic 5290** characters in the filename from the last "/" to the first following 5291** "." and omitting any initial "lib".)^ 5292** ^The sqlite3_load_extension() interface returns 5293** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. 5294** ^If an error occurs and pzErrMsg is not 0, then the 5295** [sqlite3_load_extension()] interface shall attempt to 5296** fill *pzErrMsg with error message text stored in memory 5297** obtained from [sqlite3_malloc()]. The calling function 5298** should free this memory by calling [sqlite3_free()]. 5299** 5300** ^Extension loading must be enabled using 5301** [sqlite3_enable_load_extension()] prior to calling this API, 5302** otherwise an error will be returned. 5303** 5304** See also the [load_extension() SQL function]. 5305*/ 5306SQLITE_API int sqlite3_load_extension( 5307 sqlite3 *db, /* Load the extension into this database connection */ 5308 const char *zFile, /* Name of the shared library containing extension */ 5309 const char *zProc, /* Entry point. Derived from zFile if 0 */ 5310 char **pzErrMsg /* Put error message here if not 0 */ 5311); 5312 5313/* 5314** CAPI3REF: Enable Or Disable Extension Loading 5315** 5316** ^So as not to open security holes in older applications that are 5317** unprepared to deal with [extension loading], and as a means of disabling 5318** [extension loading] while evaluating user-entered SQL, the following API 5319** is provided to turn the [sqlite3_load_extension()] mechanism on and off. 5320** 5321** ^Extension loading is off by default. 5322** ^Call the sqlite3_enable_load_extension() routine with onoff==1 5323** to turn extension loading on and call it with onoff==0 to turn 5324** it back off again. 5325*/ 5326SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); 5327 5328/* 5329** CAPI3REF: Automatically Load Statically Linked Extensions 5330** 5331** ^This interface causes the xEntryPoint() function to be invoked for 5332** each new [database connection] that is created. The idea here is that 5333** xEntryPoint() is the entry point for a statically linked [SQLite extension] 5334** that is to be automatically loaded into all new database connections. 5335** 5336** ^(Even though the function prototype shows that xEntryPoint() takes 5337** no arguments and returns void, SQLite invokes xEntryPoint() with three 5338** arguments and expects and integer result as if the signature of the 5339** entry point where as follows: 5340** 5341** <blockquote><pre> 5342** int xEntryPoint( 5343** sqlite3 *db, 5344** const char **pzErrMsg, 5345** const struct sqlite3_api_routines *pThunk 5346** ); 5347** </pre></blockquote>)^ 5348** 5349** If the xEntryPoint routine encounters an error, it should make *pzErrMsg 5350** point to an appropriate error message (obtained from [sqlite3_mprintf()]) 5351** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg 5352** is NULL before calling the xEntryPoint(). ^SQLite will invoke 5353** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any 5354** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], 5355** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. 5356** 5357** ^Calling sqlite3_auto_extension(X) with an entry point X that is already 5358** on the list of automatic extensions is a harmless no-op. ^No entry point 5359** will be called more than once for each database connection that is opened. 5360** 5361** See also: [sqlite3_reset_auto_extension()] 5362** and [sqlite3_cancel_auto_extension()] 5363*/ 5364SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); 5365 5366/* 5367** CAPI3REF: Cancel Automatic Extension Loading 5368** 5369** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the 5370** initialization routine X that was registered using a prior call to 5371** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)] 5372** routine returns 1 if initialization routine X was successfully 5373** unregistered and it returns 0 if X was not on the list of initialization 5374** routines. 5375*/ 5376SQLITE_API int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void)); 5377 5378/* 5379** CAPI3REF: Reset Automatic Extension Loading 5380** 5381** ^This interface disables all automatic extensions previously 5382** registered using [sqlite3_auto_extension()]. 5383*/ 5384SQLITE_API void sqlite3_reset_auto_extension(void); 5385 5386/* 5387** The interface to the virtual-table mechanism is currently considered 5388** to be experimental. The interface might change in incompatible ways. 5389** If this is a problem for you, do not use the interface at this time. 5390** 5391** When the virtual-table mechanism stabilizes, we will declare the 5392** interface fixed, support it indefinitely, and remove this comment. 5393*/ 5394 5395/* 5396** Structures used by the virtual table interface 5397*/ 5398typedef struct sqlite3_vtab sqlite3_vtab; 5399typedef struct sqlite3_index_info sqlite3_index_info; 5400typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; 5401typedef struct sqlite3_module sqlite3_module; 5402 5403/* 5404** CAPI3REF: Virtual Table Object 5405** KEYWORDS: sqlite3_module {virtual table module} 5406** 5407** This structure, sometimes called a "virtual table module", 5408** defines the implementation of a [virtual tables]. 5409** This structure consists mostly of methods for the module. 5410** 5411** ^A virtual table module is created by filling in a persistent 5412** instance of this structure and passing a pointer to that instance 5413** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. 5414** ^The registration remains valid until it is replaced by a different 5415** module or until the [database connection] closes. The content 5416** of this structure must not change while it is registered with 5417** any database connection. 5418*/ 5419struct sqlite3_module { 5420 int iVersion; 5421 int (*xCreate)(sqlite3*, void *pAux, 5422 int argc, const char *const*argv, 5423 sqlite3_vtab **ppVTab, char**); 5424 int (*xConnect)(sqlite3*, void *pAux, 5425 int argc, const char *const*argv, 5426 sqlite3_vtab **ppVTab, char**); 5427 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); 5428 int (*xDisconnect)(sqlite3_vtab *pVTab); 5429 int (*xDestroy)(sqlite3_vtab *pVTab); 5430 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); 5431 int (*xClose)(sqlite3_vtab_cursor*); 5432 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, 5433 int argc, sqlite3_value **argv); 5434 int (*xNext)(sqlite3_vtab_cursor*); 5435 int (*xEof)(sqlite3_vtab_cursor*); 5436 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); 5437 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); 5438 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); 5439 int (*xBegin)(sqlite3_vtab *pVTab); 5440 int (*xSync)(sqlite3_vtab *pVTab); 5441 int (*xCommit)(sqlite3_vtab *pVTab); 5442 int (*xRollback)(sqlite3_vtab *pVTab); 5443 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, 5444 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), 5445 void **ppArg); 5446 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); 5447 /* The methods above are in version 1 of the sqlite_module object. Those 5448 ** below are for version 2 and greater. */ 5449 int (*xSavepoint)(sqlite3_vtab *pVTab, int); 5450 int (*xRelease)(sqlite3_vtab *pVTab, int); 5451 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); 5452}; 5453 5454/* 5455** CAPI3REF: Virtual Table Indexing Information 5456** KEYWORDS: sqlite3_index_info 5457** 5458** The sqlite3_index_info structure and its substructures is used as part 5459** of the [virtual table] interface to 5460** pass information into and receive the reply from the [xBestIndex] 5461** method of a [virtual table module]. The fields under **Inputs** are the 5462** inputs to xBestIndex and are read-only. xBestIndex inserts its 5463** results into the **Outputs** fields. 5464** 5465** ^(The aConstraint[] array records WHERE clause constraints of the form: 5466** 5467** <blockquote>column OP expr</blockquote> 5468** 5469** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is 5470** stored in aConstraint[].op using one of the 5471** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ 5472** ^(The index of the column is stored in 5473** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the 5474** expr on the right-hand side can be evaluated (and thus the constraint 5475** is usable) and false if it cannot.)^ 5476** 5477** ^The optimizer automatically inverts terms of the form "expr OP column" 5478** and makes other simplifications to the WHERE clause in an attempt to 5479** get as many WHERE clause terms into the form shown above as possible. 5480** ^The aConstraint[] array only reports WHERE clause terms that are 5481** relevant to the particular virtual table being queried. 5482** 5483** ^Information about the ORDER BY clause is stored in aOrderBy[]. 5484** ^Each term of aOrderBy records a column of the ORDER BY clause. 5485** 5486** The [xBestIndex] method must fill aConstraintUsage[] with information 5487** about what parameters to pass to xFilter. ^If argvIndex>0 then 5488** the right-hand side of the corresponding aConstraint[] is evaluated 5489** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit 5490** is true, then the constraint is assumed to be fully handled by the 5491** virtual table and is not checked again by SQLite.)^ 5492** 5493** ^The idxNum and idxPtr values are recorded and passed into the 5494** [xFilter] method. 5495** ^[sqlite3_free()] is used to free idxPtr if and only if 5496** needToFreeIdxPtr is true. 5497** 5498** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in 5499** the correct order to satisfy the ORDER BY clause so that no separate 5500** sorting step is required. 5501** 5502** ^The estimatedCost value is an estimate of the cost of a particular 5503** strategy. A cost of N indicates that the cost of the strategy is similar 5504** to a linear scan of an SQLite table with N rows. A cost of log(N) 5505** indicates that the expense of the operation is similar to that of a 5506** binary search on a unique indexed field of an SQLite table with N rows. 5507** 5508** ^The estimatedRows value is an estimate of the number of rows that 5509** will be returned by the strategy. 5510** 5511** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info 5512** structure for SQLite version 3.8.2. If a virtual table extension is 5513** used with an SQLite version earlier than 3.8.2, the results of attempting 5514** to read or write the estimatedRows field are undefined (but are likely 5515** to included crashing the application). The estimatedRows field should 5516** therefore only be used if [sqlite3_libversion_number()] returns a 5517** value greater than or equal to 3008002. 5518*/ 5519struct sqlite3_index_info { 5520 /* Inputs */ 5521 int nConstraint; /* Number of entries in aConstraint */ 5522 struct sqlite3_index_constraint { 5523 int iColumn; /* Column on left-hand side of constraint */ 5524 unsigned char op; /* Constraint operator */ 5525 unsigned char usable; /* True if this constraint is usable */ 5526 int iTermOffset; /* Used internally - xBestIndex should ignore */ 5527 } *aConstraint; /* Table of WHERE clause constraints */ 5528 int nOrderBy; /* Number of terms in the ORDER BY clause */ 5529 struct sqlite3_index_orderby { 5530 int iColumn; /* Column number */ 5531 unsigned char desc; /* True for DESC. False for ASC. */ 5532 } *aOrderBy; /* The ORDER BY clause */ 5533 /* Outputs */ 5534 struct sqlite3_index_constraint_usage { 5535 int argvIndex; /* if >0, constraint is part of argv to xFilter */ 5536 unsigned char omit; /* Do not code a test for this constraint */ 5537 } *aConstraintUsage; 5538 int idxNum; /* Number used to identify the index */ 5539 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ 5540 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ 5541 int orderByConsumed; /* True if output is already ordered */ 5542 double estimatedCost; /* Estimated cost of using this index */ 5543 /* Fields below are only available in SQLite 3.8.2 and later */ 5544 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */ 5545}; 5546 5547/* 5548** CAPI3REF: Virtual Table Constraint Operator Codes 5549** 5550** These macros defined the allowed values for the 5551** [sqlite3_index_info].aConstraint[].op field. Each value represents 5552** an operator that is part of a constraint term in the wHERE clause of 5553** a query that uses a [virtual table]. 5554*/ 5555#define SQLITE_INDEX_CONSTRAINT_EQ 2 5556#define SQLITE_INDEX_CONSTRAINT_GT 4 5557#define SQLITE_INDEX_CONSTRAINT_LE 8 5558#define SQLITE_INDEX_CONSTRAINT_LT 16 5559#define SQLITE_INDEX_CONSTRAINT_GE 32 5560#define SQLITE_INDEX_CONSTRAINT_MATCH 64 5561 5562/* 5563** CAPI3REF: Register A Virtual Table Implementation 5564** 5565** ^These routines are used to register a new [virtual table module] name. 5566** ^Module names must be registered before 5567** creating a new [virtual table] using the module and before using a 5568** preexisting [virtual table] for the module. 5569** 5570** ^The module name is registered on the [database connection] specified 5571** by the first parameter. ^The name of the module is given by the 5572** second parameter. ^The third parameter is a pointer to 5573** the implementation of the [virtual table module]. ^The fourth 5574** parameter is an arbitrary client data pointer that is passed through 5575** into the [xCreate] and [xConnect] methods of the virtual table module 5576** when a new virtual table is be being created or reinitialized. 5577** 5578** ^The sqlite3_create_module_v2() interface has a fifth parameter which 5579** is a pointer to a destructor for the pClientData. ^SQLite will 5580** invoke the destructor function (if it is not NULL) when SQLite 5581** no longer needs the pClientData pointer. ^The destructor will also 5582** be invoked if the call to sqlite3_create_module_v2() fails. 5583** ^The sqlite3_create_module() 5584** interface is equivalent to sqlite3_create_module_v2() with a NULL 5585** destructor. 5586*/ 5587SQLITE_API int sqlite3_create_module( 5588 sqlite3 *db, /* SQLite connection to register module with */ 5589 const char *zName, /* Name of the module */ 5590 const sqlite3_module *p, /* Methods for the module */ 5591 void *pClientData /* Client data for xCreate/xConnect */ 5592); 5593SQLITE_API int sqlite3_create_module_v2( 5594 sqlite3 *db, /* SQLite connection to register module with */ 5595 const char *zName, /* Name of the module */ 5596 const sqlite3_module *p, /* Methods for the module */ 5597 void *pClientData, /* Client data for xCreate/xConnect */ 5598 void(*xDestroy)(void*) /* Module destructor function */ 5599); 5600 5601/* 5602** CAPI3REF: Virtual Table Instance Object 5603** KEYWORDS: sqlite3_vtab 5604** 5605** Every [virtual table module] implementation uses a subclass 5606** of this object to describe a particular instance 5607** of the [virtual table]. Each subclass will 5608** be tailored to the specific needs of the module implementation. 5609** The purpose of this superclass is to define certain fields that are 5610** common to all module implementations. 5611** 5612** ^Virtual tables methods can set an error message by assigning a 5613** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should 5614** take care that any prior string is freed by a call to [sqlite3_free()] 5615** prior to assigning a new string to zErrMsg. ^After the error message 5616** is delivered up to the client application, the string will be automatically 5617** freed by sqlite3_free() and the zErrMsg field will be zeroed. 5618*/ 5619struct sqlite3_vtab { 5620 const sqlite3_module *pModule; /* The module for this virtual table */ 5621 int nRef; /* NO LONGER USED */ 5622 char *zErrMsg; /* Error message from sqlite3_mprintf() */ 5623 /* Virtual table implementations will typically add additional fields */ 5624}; 5625 5626/* 5627** CAPI3REF: Virtual Table Cursor Object 5628** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} 5629** 5630** Every [virtual table module] implementation uses a subclass of the 5631** following structure to describe cursors that point into the 5632** [virtual table] and are used 5633** to loop through the virtual table. Cursors are created using the 5634** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed 5635** by the [sqlite3_module.xClose | xClose] method. Cursors are used 5636** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods 5637** of the module. Each module implementation will define 5638** the content of a cursor structure to suit its own needs. 5639** 5640** This superclass exists in order to define fields of the cursor that 5641** are common to all implementations. 5642*/ 5643struct sqlite3_vtab_cursor { 5644 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ 5645 /* Virtual table implementations will typically add additional fields */ 5646}; 5647 5648/* 5649** CAPI3REF: Declare The Schema Of A Virtual Table 5650** 5651** ^The [xCreate] and [xConnect] methods of a 5652** [virtual table module] call this interface 5653** to declare the format (the names and datatypes of the columns) of 5654** the virtual tables they implement. 5655*/ 5656SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); 5657 5658/* 5659** CAPI3REF: Overload A Function For A Virtual Table 5660** 5661** ^(Virtual tables can provide alternative implementations of functions 5662** using the [xFindFunction] method of the [virtual table module]. 5663** But global versions of those functions 5664** must exist in order to be overloaded.)^ 5665** 5666** ^(This API makes sure a global version of a function with a particular 5667** name and number of parameters exists. If no such function exists 5668** before this API is called, a new function is created.)^ ^The implementation 5669** of the new function always causes an exception to be thrown. So 5670** the new function is not good for anything by itself. Its only 5671** purpose is to be a placeholder function that can be overloaded 5672** by a [virtual table]. 5673*/ 5674SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); 5675 5676/* 5677** The interface to the virtual-table mechanism defined above (back up 5678** to a comment remarkably similar to this one) is currently considered 5679** to be experimental. The interface might change in incompatible ways. 5680** If this is a problem for you, do not use the interface at this time. 5681** 5682** When the virtual-table mechanism stabilizes, we will declare the 5683** interface fixed, support it indefinitely, and remove this comment. 5684*/ 5685 5686/* 5687** CAPI3REF: A Handle To An Open BLOB 5688** KEYWORDS: {BLOB handle} {BLOB handles} 5689** 5690** An instance of this object represents an open BLOB on which 5691** [sqlite3_blob_open | incremental BLOB I/O] can be performed. 5692** ^Objects of this type are created by [sqlite3_blob_open()] 5693** and destroyed by [sqlite3_blob_close()]. 5694** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces 5695** can be used to read or write small subsections of the BLOB. 5696** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. 5697*/ 5698typedef struct sqlite3_blob sqlite3_blob; 5699 5700/* 5701** CAPI3REF: Open A BLOB For Incremental I/O 5702** 5703** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located 5704** in row iRow, column zColumn, table zTable in database zDb; 5705** in other words, the same BLOB that would be selected by: 5706** 5707** <pre> 5708** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; 5709** </pre>)^ 5710** 5711** ^If the flags parameter is non-zero, then the BLOB is opened for read 5712** and write access. ^If it is zero, the BLOB is opened for read access. 5713** ^It is not possible to open a column that is part of an index or primary 5714** key for writing. ^If [foreign key constraints] are enabled, it is 5715** not possible to open a column that is part of a [child key] for writing. 5716** 5717** ^Note that the database name is not the filename that contains 5718** the database but rather the symbolic name of the database that 5719** appears after the AS keyword when the database is connected using [ATTACH]. 5720** ^For the main database file, the database name is "main". 5721** ^For TEMP tables, the database name is "temp". 5722** 5723** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written 5724** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set 5725** to be a null pointer.)^ 5726** ^This function sets the [database connection] error code and message 5727** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related 5728** functions. ^Note that the *ppBlob variable is always initialized in a 5729** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob 5730** regardless of the success or failure of this routine. 5731** 5732** ^(If the row that a BLOB handle points to is modified by an 5733** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects 5734** then the BLOB handle is marked as "expired". 5735** This is true if any column of the row is changed, even a column 5736** other than the one the BLOB handle is open on.)^ 5737** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for 5738** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. 5739** ^(Changes written into a BLOB prior to the BLOB expiring are not 5740** rolled back by the expiration of the BLOB. Such changes will eventually 5741** commit if the transaction continues to completion.)^ 5742** 5743** ^Use the [sqlite3_blob_bytes()] interface to determine the size of 5744** the opened blob. ^The size of a blob may not be changed by this 5745** interface. Use the [UPDATE] SQL command to change the size of a 5746** blob. 5747** 5748** ^The [sqlite3_blob_open()] interface will fail for a [WITHOUT ROWID] 5749** table. Incremental BLOB I/O is not possible on [WITHOUT ROWID] tables. 5750** 5751** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces 5752** and the built-in [zeroblob] SQL function can be used, if desired, 5753** to create an empty, zero-filled blob in which to read or write using 5754** this interface. 5755** 5756** To avoid a resource leak, every open [BLOB handle] should eventually 5757** be released by a call to [sqlite3_blob_close()]. 5758*/ 5759SQLITE_API int sqlite3_blob_open( 5760 sqlite3*, 5761 const char *zDb, 5762 const char *zTable, 5763 const char *zColumn, 5764 sqlite3_int64 iRow, 5765 int flags, 5766 sqlite3_blob **ppBlob 5767); 5768 5769/* 5770** CAPI3REF: Move a BLOB Handle to a New Row 5771** 5772** ^This function is used to move an existing blob handle so that it points 5773** to a different row of the same database table. ^The new row is identified 5774** by the rowid value passed as the second argument. Only the row can be 5775** changed. ^The database, table and column on which the blob handle is open 5776** remain the same. Moving an existing blob handle to a new row can be 5777** faster than closing the existing handle and opening a new one. 5778** 5779** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - 5780** it must exist and there must be either a blob or text value stored in 5781** the nominated column.)^ ^If the new row is not present in the table, or if 5782** it does not contain a blob or text value, or if another error occurs, an 5783** SQLite error code is returned and the blob handle is considered aborted. 5784** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or 5785** [sqlite3_blob_reopen()] on an aborted blob handle immediately return 5786** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle 5787** always returns zero. 5788** 5789** ^This function sets the database handle error code and message. 5790*/ 5791SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); 5792 5793/* 5794** CAPI3REF: Close A BLOB Handle 5795** 5796** ^Closes an open [BLOB handle]. 5797** 5798** ^Closing a BLOB shall cause the current transaction to commit 5799** if there are no other BLOBs, no pending prepared statements, and the 5800** database connection is in [autocommit mode]. 5801** ^If any writes were made to the BLOB, they might be held in cache 5802** until the close operation if they will fit. 5803** 5804** ^(Closing the BLOB often forces the changes 5805** out to disk and so if any I/O errors occur, they will likely occur 5806** at the time when the BLOB is closed. Any errors that occur during 5807** closing are reported as a non-zero return value.)^ 5808** 5809** ^(The BLOB is closed unconditionally. Even if this routine returns 5810** an error code, the BLOB is still closed.)^ 5811** 5812** ^Calling this routine with a null pointer (such as would be returned 5813** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. 5814*/ 5815SQLITE_API int sqlite3_blob_close(sqlite3_blob *); 5816 5817/* 5818** CAPI3REF: Return The Size Of An Open BLOB 5819** 5820** ^Returns the size in bytes of the BLOB accessible via the 5821** successfully opened [BLOB handle] in its only argument. ^The 5822** incremental blob I/O routines can only read or overwriting existing 5823** blob content; they cannot change the size of a blob. 5824** 5825** This routine only works on a [BLOB handle] which has been created 5826** by a prior successful call to [sqlite3_blob_open()] and which has not 5827** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5828** to this routine results in undefined and probably undesirable behavior. 5829*/ 5830SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); 5831 5832/* 5833** CAPI3REF: Read Data From A BLOB Incrementally 5834** 5835** ^(This function is used to read data from an open [BLOB handle] into a 5836** caller-supplied buffer. N bytes of data are copied into buffer Z 5837** from the open BLOB, starting at offset iOffset.)^ 5838** 5839** ^If offset iOffset is less than N bytes from the end of the BLOB, 5840** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is 5841** less than zero, [SQLITE_ERROR] is returned and no data is read. 5842** ^The size of the blob (and hence the maximum value of N+iOffset) 5843** can be determined using the [sqlite3_blob_bytes()] interface. 5844** 5845** ^An attempt to read from an expired [BLOB handle] fails with an 5846** error code of [SQLITE_ABORT]. 5847** 5848** ^(On success, sqlite3_blob_read() returns SQLITE_OK. 5849** Otherwise, an [error code] or an [extended error code] is returned.)^ 5850** 5851** This routine only works on a [BLOB handle] which has been created 5852** by a prior successful call to [sqlite3_blob_open()] and which has not 5853** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5854** to this routine results in undefined and probably undesirable behavior. 5855** 5856** See also: [sqlite3_blob_write()]. 5857*/ 5858SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); 5859 5860/* 5861** CAPI3REF: Write Data Into A BLOB Incrementally 5862** 5863** ^This function is used to write data into an open [BLOB handle] from a 5864** caller-supplied buffer. ^N bytes of data are copied from the buffer Z 5865** into the open BLOB, starting at offset iOffset. 5866** 5867** ^If the [BLOB handle] passed as the first argument was not opened for 5868** writing (the flags parameter to [sqlite3_blob_open()] was zero), 5869** this function returns [SQLITE_READONLY]. 5870** 5871** ^This function may only modify the contents of the BLOB; it is 5872** not possible to increase the size of a BLOB using this API. 5873** ^If offset iOffset is less than N bytes from the end of the BLOB, 5874** [SQLITE_ERROR] is returned and no data is written. ^If N is 5875** less than zero [SQLITE_ERROR] is returned and no data is written. 5876** The size of the BLOB (and hence the maximum value of N+iOffset) 5877** can be determined using the [sqlite3_blob_bytes()] interface. 5878** 5879** ^An attempt to write to an expired [BLOB handle] fails with an 5880** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred 5881** before the [BLOB handle] expired are not rolled back by the 5882** expiration of the handle, though of course those changes might 5883** have been overwritten by the statement that expired the BLOB handle 5884** or by other independent statements. 5885** 5886** ^(On success, sqlite3_blob_write() returns SQLITE_OK. 5887** Otherwise, an [error code] or an [extended error code] is returned.)^ 5888** 5889** This routine only works on a [BLOB handle] which has been created 5890** by a prior successful call to [sqlite3_blob_open()] and which has not 5891** been closed by [sqlite3_blob_close()]. Passing any other pointer in 5892** to this routine results in undefined and probably undesirable behavior. 5893** 5894** See also: [sqlite3_blob_read()]. 5895*/ 5896SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); 5897 5898/* 5899** CAPI3REF: Virtual File System Objects 5900** 5901** A virtual filesystem (VFS) is an [sqlite3_vfs] object 5902** that SQLite uses to interact 5903** with the underlying operating system. Most SQLite builds come with a 5904** single default VFS that is appropriate for the host computer. 5905** New VFSes can be registered and existing VFSes can be unregistered. 5906** The following interfaces are provided. 5907** 5908** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. 5909** ^Names are case sensitive. 5910** ^Names are zero-terminated UTF-8 strings. 5911** ^If there is no match, a NULL pointer is returned. 5912** ^If zVfsName is NULL then the default VFS is returned. 5913** 5914** ^New VFSes are registered with sqlite3_vfs_register(). 5915** ^Each new VFS becomes the default VFS if the makeDflt flag is set. 5916** ^The same VFS can be registered multiple times without injury. 5917** ^To make an existing VFS into the default VFS, register it again 5918** with the makeDflt flag set. If two different VFSes with the 5919** same name are registered, the behavior is undefined. If a 5920** VFS is registered with a name that is NULL or an empty string, 5921** then the behavior is undefined. 5922** 5923** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. 5924** ^(If the default VFS is unregistered, another VFS is chosen as 5925** the default. The choice for the new VFS is arbitrary.)^ 5926*/ 5927SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); 5928SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); 5929SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); 5930 5931/* 5932** CAPI3REF: Mutexes 5933** 5934** The SQLite core uses these routines for thread 5935** synchronization. Though they are intended for internal 5936** use by SQLite, code that links against SQLite is 5937** permitted to use any of these routines. 5938** 5939** The SQLite source code contains multiple implementations 5940** of these mutex routines. An appropriate implementation 5941** is selected automatically at compile-time. ^(The following 5942** implementations are available in the SQLite core: 5943** 5944** <ul> 5945** <li> SQLITE_MUTEX_PTHREADS 5946** <li> SQLITE_MUTEX_W32 5947** <li> SQLITE_MUTEX_NOOP 5948** </ul>)^ 5949** 5950** ^The SQLITE_MUTEX_NOOP implementation is a set of routines 5951** that does no real locking and is appropriate for use in 5952** a single-threaded application. ^The SQLITE_MUTEX_PTHREADS and 5953** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix 5954** and Windows. 5955** 5956** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor 5957** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex 5958** implementation is included with the library. In this case the 5959** application must supply a custom mutex implementation using the 5960** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function 5961** before calling sqlite3_initialize() or any other public sqlite3_ 5962** function that calls sqlite3_initialize().)^ 5963** 5964** ^The sqlite3_mutex_alloc() routine allocates a new 5965** mutex and returns a pointer to it. ^If it returns NULL 5966** that means that a mutex could not be allocated. ^SQLite 5967** will unwind its stack and return an error. ^(The argument 5968** to sqlite3_mutex_alloc() is one of these integer constants: 5969** 5970** <ul> 5971** <li> SQLITE_MUTEX_FAST 5972** <li> SQLITE_MUTEX_RECURSIVE 5973** <li> SQLITE_MUTEX_STATIC_MASTER 5974** <li> SQLITE_MUTEX_STATIC_MEM 5975** <li> SQLITE_MUTEX_STATIC_OPEN 5976** <li> SQLITE_MUTEX_STATIC_PRNG 5977** <li> SQLITE_MUTEX_STATIC_LRU 5978** <li> SQLITE_MUTEX_STATIC_PMEM 5979** <li> SQLITE_MUTEX_STATIC_APP1 5980** <li> SQLITE_MUTEX_STATIC_APP2 5981** </ul>)^ 5982** 5983** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) 5984** cause sqlite3_mutex_alloc() to create 5985** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE 5986** is used but not necessarily so when SQLITE_MUTEX_FAST is used. 5987** The mutex implementation does not need to make a distinction 5988** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does 5989** not want to. ^SQLite will only request a recursive mutex in 5990** cases where it really needs one. ^If a faster non-recursive mutex 5991** implementation is available on the host platform, the mutex subsystem 5992** might return such a mutex in response to SQLITE_MUTEX_FAST. 5993** 5994** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other 5995** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return 5996** a pointer to a static preexisting mutex. ^Six static mutexes are 5997** used by the current version of SQLite. Future versions of SQLite 5998** may add additional static mutexes. Static mutexes are for internal 5999** use by SQLite only. Applications that use SQLite mutexes should 6000** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or 6001** SQLITE_MUTEX_RECURSIVE. 6002** 6003** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST 6004** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() 6005** returns a different mutex on every call. ^But for the static 6006** mutex types, the same mutex is returned on every call that has 6007** the same type number. 6008** 6009** ^The sqlite3_mutex_free() routine deallocates a previously 6010** allocated dynamic mutex. ^SQLite is careful to deallocate every 6011** dynamic mutex that it allocates. The dynamic mutexes must not be in 6012** use when they are deallocated. Attempting to deallocate a static 6013** mutex results in undefined behavior. ^SQLite never deallocates 6014** a static mutex. 6015** 6016** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt 6017** to enter a mutex. ^If another thread is already within the mutex, 6018** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return 6019** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] 6020** upon successful entry. ^(Mutexes created using 6021** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. 6022** In such cases the, 6023** mutex must be exited an equal number of times before another thread 6024** can enter.)^ ^(If the same thread tries to enter any other 6025** kind of mutex more than once, the behavior is undefined. 6026** SQLite will never exhibit 6027** such behavior in its own use of mutexes.)^ 6028** 6029** ^(Some systems (for example, Windows 95) do not support the operation 6030** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() 6031** will always return SQLITE_BUSY. The SQLite core only ever uses 6032** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ 6033** 6034** ^The sqlite3_mutex_leave() routine exits a mutex that was 6035** previously entered by the same thread. ^(The behavior 6036** is undefined if the mutex is not currently entered by the 6037** calling thread or is not currently allocated. SQLite will 6038** never do either.)^ 6039** 6040** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or 6041** sqlite3_mutex_leave() is a NULL pointer, then all three routines 6042** behave as no-ops. 6043** 6044** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. 6045*/ 6046SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); 6047SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); 6048SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); 6049SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); 6050SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); 6051 6052/* 6053** CAPI3REF: Mutex Methods Object 6054** 6055** An instance of this structure defines the low-level routines 6056** used to allocate and use mutexes. 6057** 6058** Usually, the default mutex implementations provided by SQLite are 6059** sufficient, however the user has the option of substituting a custom 6060** implementation for specialized deployments or systems for which SQLite 6061** does not provide a suitable implementation. In this case, the user 6062** creates and populates an instance of this structure to pass 6063** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. 6064** Additionally, an instance of this structure can be used as an 6065** output variable when querying the system for the current mutex 6066** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. 6067** 6068** ^The xMutexInit method defined by this structure is invoked as 6069** part of system initialization by the sqlite3_initialize() function. 6070** ^The xMutexInit routine is called by SQLite exactly once for each 6071** effective call to [sqlite3_initialize()]. 6072** 6073** ^The xMutexEnd method defined by this structure is invoked as 6074** part of system shutdown by the sqlite3_shutdown() function. The 6075** implementation of this method is expected to release all outstanding 6076** resources obtained by the mutex methods implementation, especially 6077** those obtained by the xMutexInit method. ^The xMutexEnd() 6078** interface is invoked exactly once for each call to [sqlite3_shutdown()]. 6079** 6080** ^(The remaining seven methods defined by this structure (xMutexAlloc, 6081** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and 6082** xMutexNotheld) implement the following interfaces (respectively): 6083** 6084** <ul> 6085** <li> [sqlite3_mutex_alloc()] </li> 6086** <li> [sqlite3_mutex_free()] </li> 6087** <li> [sqlite3_mutex_enter()] </li> 6088** <li> [sqlite3_mutex_try()] </li> 6089** <li> [sqlite3_mutex_leave()] </li> 6090** <li> [sqlite3_mutex_held()] </li> 6091** <li> [sqlite3_mutex_notheld()] </li> 6092** </ul>)^ 6093** 6094** The only difference is that the public sqlite3_XXX functions enumerated 6095** above silently ignore any invocations that pass a NULL pointer instead 6096** of a valid mutex handle. The implementations of the methods defined 6097** by this structure are not required to handle this case, the results 6098** of passing a NULL pointer instead of a valid mutex handle are undefined 6099** (i.e. it is acceptable to provide an implementation that segfaults if 6100** it is passed a NULL pointer). 6101** 6102** The xMutexInit() method must be threadsafe. ^It must be harmless to 6103** invoke xMutexInit() multiple times within the same process and without 6104** intervening calls to xMutexEnd(). Second and subsequent calls to 6105** xMutexInit() must be no-ops. 6106** 6107** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] 6108** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory 6109** allocation for a static mutex. ^However xMutexAlloc() may use SQLite 6110** memory allocation for a fast or recursive mutex. 6111** 6112** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is 6113** called, but only if the prior call to xMutexInit returned SQLITE_OK. 6114** If xMutexInit fails in any way, it is expected to clean up after itself 6115** prior to returning. 6116*/ 6117typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; 6118struct sqlite3_mutex_methods { 6119 int (*xMutexInit)(void); 6120 int (*xMutexEnd)(void); 6121 sqlite3_mutex *(*xMutexAlloc)(int); 6122 void (*xMutexFree)(sqlite3_mutex *); 6123 void (*xMutexEnter)(sqlite3_mutex *); 6124 int (*xMutexTry)(sqlite3_mutex *); 6125 void (*xMutexLeave)(sqlite3_mutex *); 6126 int (*xMutexHeld)(sqlite3_mutex *); 6127 int (*xMutexNotheld)(sqlite3_mutex *); 6128}; 6129 6130/* 6131** CAPI3REF: Mutex Verification Routines 6132** 6133** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines 6134** are intended for use inside assert() statements. ^The SQLite core 6135** never uses these routines except inside an assert() and applications 6136** are advised to follow the lead of the core. ^The SQLite core only 6137** provides implementations for these routines when it is compiled 6138** with the SQLITE_DEBUG flag. ^External mutex implementations 6139** are only required to provide these routines if SQLITE_DEBUG is 6140** defined and if NDEBUG is not defined. 6141** 6142** ^These routines should return true if the mutex in their argument 6143** is held or not held, respectively, by the calling thread. 6144** 6145** ^The implementation is not required to provide versions of these 6146** routines that actually work. If the implementation does not provide working 6147** versions of these routines, it should at least provide stubs that always 6148** return true so that one does not get spurious assertion failures. 6149** 6150** ^If the argument to sqlite3_mutex_held() is a NULL pointer then 6151** the routine should return 1. This seems counter-intuitive since 6152** clearly the mutex cannot be held if it does not exist. But 6153** the reason the mutex does not exist is because the build is not 6154** using mutexes. And we do not want the assert() containing the 6155** call to sqlite3_mutex_held() to fail, so a non-zero return is 6156** the appropriate thing to do. ^The sqlite3_mutex_notheld() 6157** interface should also return 1 when given a NULL pointer. 6158*/ 6159#ifndef NDEBUG 6160SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); 6161SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); 6162#endif 6163 6164/* 6165** CAPI3REF: Mutex Types 6166** 6167** The [sqlite3_mutex_alloc()] interface takes a single argument 6168** which is one of these integer constants. 6169** 6170** The set of static mutexes may change from one SQLite release to the 6171** next. Applications that override the built-in mutex logic must be 6172** prepared to accommodate additional static mutexes. 6173*/ 6174#define SQLITE_MUTEX_FAST 0 6175#define SQLITE_MUTEX_RECURSIVE 1 6176#define SQLITE_MUTEX_STATIC_MASTER 2 6177#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ 6178#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ 6179#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ 6180#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ 6181#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ 6182#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ 6183#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ 6184#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */ 6185#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */ 6186#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */ 6187 6188/* 6189** CAPI3REF: Retrieve the mutex for a database connection 6190** 6191** ^This interface returns a pointer the [sqlite3_mutex] object that 6192** serializes access to the [database connection] given in the argument 6193** when the [threading mode] is Serialized. 6194** ^If the [threading mode] is Single-thread or Multi-thread then this 6195** routine returns a NULL pointer. 6196*/ 6197SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); 6198 6199/* 6200** CAPI3REF: Low-Level Control Of Database Files 6201** 6202** ^The [sqlite3_file_control()] interface makes a direct call to the 6203** xFileControl method for the [sqlite3_io_methods] object associated 6204** with a particular database identified by the second argument. ^The 6205** name of the database is "main" for the main database or "temp" for the 6206** TEMP database, or the name that appears after the AS keyword for 6207** databases that are added using the [ATTACH] SQL command. 6208** ^A NULL pointer can be used in place of "main" to refer to the 6209** main database file. 6210** ^The third and fourth parameters to this routine 6211** are passed directly through to the second and third parameters of 6212** the xFileControl method. ^The return value of the xFileControl 6213** method becomes the return value of this routine. 6214** 6215** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes 6216** a pointer to the underlying [sqlite3_file] object to be written into 6217** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER 6218** case is a short-circuit path which does not actually invoke the 6219** underlying sqlite3_io_methods.xFileControl method. 6220** 6221** ^If the second parameter (zDbName) does not match the name of any 6222** open database file, then SQLITE_ERROR is returned. ^This error 6223** code is not remembered and will not be recalled by [sqlite3_errcode()] 6224** or [sqlite3_errmsg()]. The underlying xFileControl method might 6225** also return SQLITE_ERROR. There is no way to distinguish between 6226** an incorrect zDbName and an SQLITE_ERROR return from the underlying 6227** xFileControl method. 6228** 6229** See also: [SQLITE_FCNTL_LOCKSTATE] 6230*/ 6231SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); 6232 6233/* 6234** CAPI3REF: Testing Interface 6235** 6236** ^The sqlite3_test_control() interface is used to read out internal 6237** state of SQLite and to inject faults into SQLite for testing 6238** purposes. ^The first parameter is an operation code that determines 6239** the number, meaning, and operation of all subsequent parameters. 6240** 6241** This interface is not for use by applications. It exists solely 6242** for verifying the correct operation of the SQLite library. Depending 6243** on how the SQLite library is compiled, this interface might not exist. 6244** 6245** The details of the operation codes, their meanings, the parameters 6246** they take, and what they do are all subject to change without notice. 6247** Unlike most of the SQLite API, this function is not guaranteed to 6248** operate consistently from one release to the next. 6249*/ 6250SQLITE_API int sqlite3_test_control(int op, ...); 6251 6252/* 6253** CAPI3REF: Testing Interface Operation Codes 6254** 6255** These constants are the valid operation code parameters used 6256** as the first argument to [sqlite3_test_control()]. 6257** 6258** These parameters and their meanings are subject to change 6259** without notice. These values are for testing purposes only. 6260** Applications should not use any of these parameters or the 6261** [sqlite3_test_control()] interface. 6262*/ 6263#define SQLITE_TESTCTRL_FIRST 5 6264#define SQLITE_TESTCTRL_PRNG_SAVE 5 6265#define SQLITE_TESTCTRL_PRNG_RESTORE 6 6266#define SQLITE_TESTCTRL_PRNG_RESET 7 6267#define SQLITE_TESTCTRL_BITVEC_TEST 8 6268#define SQLITE_TESTCTRL_FAULT_INSTALL 9 6269#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 6270#define SQLITE_TESTCTRL_PENDING_BYTE 11 6271#define SQLITE_TESTCTRL_ASSERT 12 6272#define SQLITE_TESTCTRL_ALWAYS 13 6273#define SQLITE_TESTCTRL_RESERVE 14 6274#define SQLITE_TESTCTRL_OPTIMIZATIONS 15 6275#define SQLITE_TESTCTRL_ISKEYWORD 16 6276#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 6277#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18 6278#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 6279#define SQLITE_TESTCTRL_NEVER_CORRUPT 20 6280#define SQLITE_TESTCTRL_VDBE_COVERAGE 21 6281#define SQLITE_TESTCTRL_BYTEORDER 22 6282#define SQLITE_TESTCTRL_ISINIT 23 6283#define SQLITE_TESTCTRL_LAST 23 6284 6285/* 6286** CAPI3REF: SQLite Runtime Status 6287** 6288** ^This interface is used to retrieve runtime status information 6289** about the performance of SQLite, and optionally to reset various 6290** highwater marks. ^The first argument is an integer code for 6291** the specific parameter to measure. ^(Recognized integer codes 6292** are of the form [status parameters | SQLITE_STATUS_...].)^ 6293** ^The current value of the parameter is returned into *pCurrent. 6294** ^The highest recorded value is returned in *pHighwater. ^If the 6295** resetFlag is true, then the highest record value is reset after 6296** *pHighwater is written. ^(Some parameters do not record the highest 6297** value. For those parameters 6298** nothing is written into *pHighwater and the resetFlag is ignored.)^ 6299** ^(Other parameters record only the highwater mark and not the current 6300** value. For these latter parameters nothing is written into *pCurrent.)^ 6301** 6302** ^The sqlite3_status() routine returns SQLITE_OK on success and a 6303** non-zero [error code] on failure. 6304** 6305** This routine is threadsafe but is not atomic. This routine can be 6306** called while other threads are running the same or different SQLite 6307** interfaces. However the values returned in *pCurrent and 6308** *pHighwater reflect the status of SQLite at different points in time 6309** and it is possible that another thread might change the parameter 6310** in between the times when *pCurrent and *pHighwater are written. 6311** 6312** See also: [sqlite3_db_status()] 6313*/ 6314SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); 6315 6316 6317/* 6318** CAPI3REF: Status Parameters 6319** KEYWORDS: {status parameters} 6320** 6321** These integer constants designate various run-time status parameters 6322** that can be returned by [sqlite3_status()]. 6323** 6324** <dl> 6325** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> 6326** <dd>This parameter is the current amount of memory checked out 6327** using [sqlite3_malloc()], either directly or indirectly. The 6328** figure includes calls made to [sqlite3_malloc()] by the application 6329** and internal memory usage by the SQLite library. Scratch memory 6330** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache 6331** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in 6332** this parameter. The amount returned is the sum of the allocation 6333** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ 6334** 6335** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> 6336** <dd>This parameter records the largest memory allocation request 6337** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their 6338** internal equivalents). Only the value returned in the 6339** *pHighwater parameter to [sqlite3_status()] is of interest. 6340** The value written into the *pCurrent parameter is undefined.</dd>)^ 6341** 6342** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> 6343** <dd>This parameter records the number of separate memory allocations 6344** currently checked out.</dd>)^ 6345** 6346** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> 6347** <dd>This parameter returns the number of pages used out of the 6348** [pagecache memory allocator] that was configured using 6349** [SQLITE_CONFIG_PAGECACHE]. The 6350** value returned is in pages, not in bytes.</dd>)^ 6351** 6352** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] 6353** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> 6354** <dd>This parameter returns the number of bytes of page cache 6355** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] 6356** buffer and where forced to overflow to [sqlite3_malloc()]. The 6357** returned value includes allocations that overflowed because they 6358** where too large (they were larger than the "sz" parameter to 6359** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because 6360** no space was left in the page cache.</dd>)^ 6361** 6362** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> 6363** <dd>This parameter records the largest memory allocation request 6364** handed to [pagecache memory allocator]. Only the value returned in the 6365** *pHighwater parameter to [sqlite3_status()] is of interest. 6366** The value written into the *pCurrent parameter is undefined.</dd>)^ 6367** 6368** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> 6369** <dd>This parameter returns the number of allocations used out of the 6370** [scratch memory allocator] configured using 6371** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not 6372** in bytes. Since a single thread may only have one scratch allocation 6373** outstanding at time, this parameter also reports the number of threads 6374** using scratch memory at the same time.</dd>)^ 6375** 6376** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> 6377** <dd>This parameter returns the number of bytes of scratch memory 6378** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] 6379** buffer and where forced to overflow to [sqlite3_malloc()]. The values 6380** returned include overflows because the requested allocation was too 6381** larger (that is, because the requested allocation was larger than the 6382** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer 6383** slots were available. 6384** </dd>)^ 6385** 6386** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> 6387** <dd>This parameter records the largest memory allocation request 6388** handed to [scratch memory allocator]. Only the value returned in the 6389** *pHighwater parameter to [sqlite3_status()] is of interest. 6390** The value written into the *pCurrent parameter is undefined.</dd>)^ 6391** 6392** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> 6393** <dd>This parameter records the deepest parser stack. It is only 6394** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ 6395** </dl> 6396** 6397** New status parameters may be added from time to time. 6398*/ 6399#define SQLITE_STATUS_MEMORY_USED 0 6400#define SQLITE_STATUS_PAGECACHE_USED 1 6401#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 6402#define SQLITE_STATUS_SCRATCH_USED 3 6403#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 6404#define SQLITE_STATUS_MALLOC_SIZE 5 6405#define SQLITE_STATUS_PARSER_STACK 6 6406#define SQLITE_STATUS_PAGECACHE_SIZE 7 6407#define SQLITE_STATUS_SCRATCH_SIZE 8 6408#define SQLITE_STATUS_MALLOC_COUNT 9 6409 6410/* 6411** CAPI3REF: Database Connection Status 6412** 6413** ^This interface is used to retrieve runtime status information 6414** about a single [database connection]. ^The first argument is the 6415** database connection object to be interrogated. ^The second argument 6416** is an integer constant, taken from the set of 6417** [SQLITE_DBSTATUS options], that 6418** determines the parameter to interrogate. The set of 6419** [SQLITE_DBSTATUS options] is likely 6420** to grow in future releases of SQLite. 6421** 6422** ^The current value of the requested parameter is written into *pCur 6423** and the highest instantaneous value is written into *pHiwtr. ^If 6424** the resetFlg is true, then the highest instantaneous value is 6425** reset back down to the current value. 6426** 6427** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a 6428** non-zero [error code] on failure. 6429** 6430** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. 6431*/ 6432SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); 6433 6434/* 6435** CAPI3REF: Status Parameters for database connections 6436** KEYWORDS: {SQLITE_DBSTATUS options} 6437** 6438** These constants are the available integer "verbs" that can be passed as 6439** the second argument to the [sqlite3_db_status()] interface. 6440** 6441** New verbs may be added in future releases of SQLite. Existing verbs 6442** might be discontinued. Applications should check the return code from 6443** [sqlite3_db_status()] to make sure that the call worked. 6444** The [sqlite3_db_status()] interface will return a non-zero error code 6445** if a discontinued or unsupported verb is invoked. 6446** 6447** <dl> 6448** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> 6449** <dd>This parameter returns the number of lookaside memory slots currently 6450** checked out.</dd>)^ 6451** 6452** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> 6453** <dd>This parameter returns the number malloc attempts that were 6454** satisfied using lookaside memory. Only the high-water value is meaningful; 6455** the current value is always zero.)^ 6456** 6457** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] 6458** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> 6459** <dd>This parameter returns the number malloc attempts that might have 6460** been satisfied using lookaside memory but failed due to the amount of 6461** memory requested being larger than the lookaside slot size. 6462** Only the high-water value is meaningful; 6463** the current value is always zero.)^ 6464** 6465** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] 6466** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> 6467** <dd>This parameter returns the number malloc attempts that might have 6468** been satisfied using lookaside memory but failed due to all lookaside 6469** memory already being in use. 6470** Only the high-water value is meaningful; 6471** the current value is always zero.)^ 6472** 6473** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> 6474** <dd>This parameter returns the approximate number of of bytes of heap 6475** memory used by all pager caches associated with the database connection.)^ 6476** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. 6477** 6478** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> 6479** <dd>This parameter returns the approximate number of of bytes of heap 6480** memory used to store the schema for all databases associated 6481** with the connection - main, temp, and any [ATTACH]-ed databases.)^ 6482** ^The full amount of memory used by the schemas is reported, even if the 6483** schema memory is shared with other database connections due to 6484** [shared cache mode] being enabled. 6485** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. 6486** 6487** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> 6488** <dd>This parameter returns the approximate number of of bytes of heap 6489** and lookaside memory used by all prepared statements associated with 6490** the database connection.)^ 6491** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. 6492** </dd> 6493** 6494** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt> 6495** <dd>This parameter returns the number of pager cache hits that have 6496** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT 6497** is always 0. 6498** </dd> 6499** 6500** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt> 6501** <dd>This parameter returns the number of pager cache misses that have 6502** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS 6503** is always 0. 6504** </dd> 6505** 6506** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt> 6507** <dd>This parameter returns the number of dirty cache entries that have 6508** been written to disk. Specifically, the number of pages written to the 6509** wal file in wal mode databases, or the number of pages written to the 6510** database file in rollback mode databases. Any pages written as part of 6511** transaction rollback or database recovery operations are not included. 6512** If an IO or other error occurs while writing a page to disk, the effect 6513** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The 6514** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0. 6515** </dd> 6516** 6517** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt> 6518** <dd>This parameter returns zero for the current value if and only if 6519** all foreign key constraints (deferred or immediate) have been 6520** resolved.)^ ^The highwater mark is always 0. 6521** </dd> 6522** </dl> 6523*/ 6524#define SQLITE_DBSTATUS_LOOKASIDE_USED 0 6525#define SQLITE_DBSTATUS_CACHE_USED 1 6526#define SQLITE_DBSTATUS_SCHEMA_USED 2 6527#define SQLITE_DBSTATUS_STMT_USED 3 6528#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 6529#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 6530#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 6531#define SQLITE_DBSTATUS_CACHE_HIT 7 6532#define SQLITE_DBSTATUS_CACHE_MISS 8 6533#define SQLITE_DBSTATUS_CACHE_WRITE 9 6534#define SQLITE_DBSTATUS_DEFERRED_FKS 10 6535#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */ 6536 6537 6538/* 6539** CAPI3REF: Prepared Statement Status 6540** 6541** ^(Each prepared statement maintains various 6542** [SQLITE_STMTSTATUS counters] that measure the number 6543** of times it has performed specific operations.)^ These counters can 6544** be used to monitor the performance characteristics of the prepared 6545** statements. For example, if the number of table steps greatly exceeds 6546** the number of table searches or result rows, that would tend to indicate 6547** that the prepared statement is using a full table scan rather than 6548** an index. 6549** 6550** ^(This interface is used to retrieve and reset counter values from 6551** a [prepared statement]. The first argument is the prepared statement 6552** object to be interrogated. The second argument 6553** is an integer code for a specific [SQLITE_STMTSTATUS counter] 6554** to be interrogated.)^ 6555** ^The current value of the requested counter is returned. 6556** ^If the resetFlg is true, then the counter is reset to zero after this 6557** interface call returns. 6558** 6559** See also: [sqlite3_status()] and [sqlite3_db_status()]. 6560*/ 6561SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); 6562 6563/* 6564** CAPI3REF: Status Parameters for prepared statements 6565** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} 6566** 6567** These preprocessor macros define integer codes that name counter 6568** values associated with the [sqlite3_stmt_status()] interface. 6569** The meanings of the various counters are as follows: 6570** 6571** <dl> 6572** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> 6573** <dd>^This is the number of times that SQLite has stepped forward in 6574** a table as part of a full table scan. Large numbers for this counter 6575** may indicate opportunities for performance improvement through 6576** careful use of indices.</dd> 6577** 6578** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> 6579** <dd>^This is the number of sort operations that have occurred. 6580** A non-zero value in this counter may indicate an opportunity to 6581** improvement performance through careful use of indices.</dd> 6582** 6583** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> 6584** <dd>^This is the number of rows inserted into transient indices that 6585** were created automatically in order to help joins run faster. 6586** A non-zero value in this counter may indicate an opportunity to 6587** improvement performance by adding permanent indices that do not 6588** need to be reinitialized each time the statement is run.</dd> 6589** 6590** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt> 6591** <dd>^This is the number of virtual machine operations executed 6592** by the prepared statement if that number is less than or equal 6593** to 2147483647. The number of virtual machine operations can be 6594** used as a proxy for the total work done by the prepared statement. 6595** If the number of virtual machine operations exceeds 2147483647 6596** then the value returned by this statement status code is undefined. 6597** </dd> 6598** </dl> 6599*/ 6600#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 6601#define SQLITE_STMTSTATUS_SORT 2 6602#define SQLITE_STMTSTATUS_AUTOINDEX 3 6603#define SQLITE_STMTSTATUS_VM_STEP 4 6604 6605/* 6606** CAPI3REF: Custom Page Cache Object 6607** 6608** The sqlite3_pcache type is opaque. It is implemented by 6609** the pluggable module. The SQLite core has no knowledge of 6610** its size or internal structure and never deals with the 6611** sqlite3_pcache object except by holding and passing pointers 6612** to the object. 6613** 6614** See [sqlite3_pcache_methods2] for additional information. 6615*/ 6616typedef struct sqlite3_pcache sqlite3_pcache; 6617 6618/* 6619** CAPI3REF: Custom Page Cache Object 6620** 6621** The sqlite3_pcache_page object represents a single page in the 6622** page cache. The page cache will allocate instances of this 6623** object. Various methods of the page cache use pointers to instances 6624** of this object as parameters or as their return value. 6625** 6626** See [sqlite3_pcache_methods2] for additional information. 6627*/ 6628typedef struct sqlite3_pcache_page sqlite3_pcache_page; 6629struct sqlite3_pcache_page { 6630 void *pBuf; /* The content of the page */ 6631 void *pExtra; /* Extra information associated with the page */ 6632}; 6633 6634/* 6635** CAPI3REF: Application Defined Page Cache. 6636** KEYWORDS: {page cache} 6637** 6638** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can 6639** register an alternative page cache implementation by passing in an 6640** instance of the sqlite3_pcache_methods2 structure.)^ 6641** In many applications, most of the heap memory allocated by 6642** SQLite is used for the page cache. 6643** By implementing a 6644** custom page cache using this API, an application can better control 6645** the amount of memory consumed by SQLite, the way in which 6646** that memory is allocated and released, and the policies used to 6647** determine exactly which parts of a database file are cached and for 6648** how long. 6649** 6650** The alternative page cache mechanism is an 6651** extreme measure that is only needed by the most demanding applications. 6652** The built-in page cache is recommended for most uses. 6653** 6654** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an 6655** internal buffer by SQLite within the call to [sqlite3_config]. Hence 6656** the application may discard the parameter after the call to 6657** [sqlite3_config()] returns.)^ 6658** 6659** [[the xInit() page cache method]] 6660** ^(The xInit() method is called once for each effective 6661** call to [sqlite3_initialize()])^ 6662** (usually only once during the lifetime of the process). ^(The xInit() 6663** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^ 6664** The intent of the xInit() method is to set up global data structures 6665** required by the custom page cache implementation. 6666** ^(If the xInit() method is NULL, then the 6667** built-in default page cache is used instead of the application defined 6668** page cache.)^ 6669** 6670** [[the xShutdown() page cache method]] 6671** ^The xShutdown() method is called by [sqlite3_shutdown()]. 6672** It can be used to clean up 6673** any outstanding resources before process shutdown, if required. 6674** ^The xShutdown() method may be NULL. 6675** 6676** ^SQLite automatically serializes calls to the xInit method, 6677** so the xInit method need not be threadsafe. ^The 6678** xShutdown method is only called from [sqlite3_shutdown()] so it does 6679** not need to be threadsafe either. All other methods must be threadsafe 6680** in multithreaded applications. 6681** 6682** ^SQLite will never invoke xInit() more than once without an intervening 6683** call to xShutdown(). 6684** 6685** [[the xCreate() page cache methods]] 6686** ^SQLite invokes the xCreate() method to construct a new cache instance. 6687** SQLite will typically create one cache instance for each open database file, 6688** though this is not guaranteed. ^The 6689** first parameter, szPage, is the size in bytes of the pages that must 6690** be allocated by the cache. ^szPage will always a power of two. ^The 6691** second parameter szExtra is a number of bytes of extra storage 6692** associated with each page cache entry. ^The szExtra parameter will 6693** a number less than 250. SQLite will use the 6694** extra szExtra bytes on each page to store metadata about the underlying 6695** database page on disk. The value passed into szExtra depends 6696** on the SQLite version, the target platform, and how SQLite was compiled. 6697** ^The third argument to xCreate(), bPurgeable, is true if the cache being 6698** created will be used to cache database pages of a file stored on disk, or 6699** false if it is used for an in-memory database. The cache implementation 6700** does not have to do anything special based with the value of bPurgeable; 6701** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will 6702** never invoke xUnpin() except to deliberately delete a page. 6703** ^In other words, calls to xUnpin() on a cache with bPurgeable set to 6704** false will always have the "discard" flag set to true. 6705** ^Hence, a cache created with bPurgeable false will 6706** never contain any unpinned pages. 6707** 6708** [[the xCachesize() page cache method]] 6709** ^(The xCachesize() method may be called at any time by SQLite to set the 6710** suggested maximum cache-size (number of pages stored by) the cache 6711** instance passed as the first argument. This is the value configured using 6712** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable 6713** parameter, the implementation is not required to do anything with this 6714** value; it is advisory only. 6715** 6716** [[the xPagecount() page cache methods]] 6717** The xPagecount() method must return the number of pages currently 6718** stored in the cache, both pinned and unpinned. 6719** 6720** [[the xFetch() page cache methods]] 6721** The xFetch() method locates a page in the cache and returns a pointer to 6722** an sqlite3_pcache_page object associated with that page, or a NULL pointer. 6723** The pBuf element of the returned sqlite3_pcache_page object will be a 6724** pointer to a buffer of szPage bytes used to store the content of a 6725** single database page. The pExtra element of sqlite3_pcache_page will be 6726** a pointer to the szExtra bytes of extra storage that SQLite has requested 6727** for each entry in the page cache. 6728** 6729** The page to be fetched is determined by the key. ^The minimum key value 6730** is 1. After it has been retrieved using xFetch, the page is considered 6731** to be "pinned". 6732** 6733** If the requested page is already in the page cache, then the page cache 6734** implementation must return a pointer to the page buffer with its content 6735** intact. If the requested page is not already in the cache, then the 6736** cache implementation should use the value of the createFlag 6737** parameter to help it determined what action to take: 6738** 6739** <table border=1 width=85% align=center> 6740** <tr><th> createFlag <th> Behavior when page is not already in cache 6741** <tr><td> 0 <td> Do not allocate a new page. Return NULL. 6742** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. 6743** Otherwise return NULL. 6744** <tr><td> 2 <td> Make every effort to allocate a new page. Only return 6745** NULL if allocating a new page is effectively impossible. 6746** </table> 6747** 6748** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite 6749** will only use a createFlag of 2 after a prior call with a createFlag of 1 6750** failed.)^ In between the to xFetch() calls, SQLite may 6751** attempt to unpin one or more cache pages by spilling the content of 6752** pinned pages to disk and synching the operating system disk cache. 6753** 6754** [[the xUnpin() page cache method]] 6755** ^xUnpin() is called by SQLite with a pointer to a currently pinned page 6756** as its second argument. If the third parameter, discard, is non-zero, 6757** then the page must be evicted from the cache. 6758** ^If the discard parameter is 6759** zero, then the page may be discarded or retained at the discretion of 6760** page cache implementation. ^The page cache implementation 6761** may choose to evict unpinned pages at any time. 6762** 6763** The cache must not perform any reference counting. A single 6764** call to xUnpin() unpins the page regardless of the number of prior calls 6765** to xFetch(). 6766** 6767** [[the xRekey() page cache methods]] 6768** The xRekey() method is used to change the key value associated with the 6769** page passed as the second argument. If the cache 6770** previously contains an entry associated with newKey, it must be 6771** discarded. ^Any prior cache entry associated with newKey is guaranteed not 6772** to be pinned. 6773** 6774** When SQLite calls the xTruncate() method, the cache must discard all 6775** existing cache entries with page numbers (keys) greater than or equal 6776** to the value of the iLimit parameter passed to xTruncate(). If any 6777** of these pages are pinned, they are implicitly unpinned, meaning that 6778** they can be safely discarded. 6779** 6780** [[the xDestroy() page cache method]] 6781** ^The xDestroy() method is used to delete a cache allocated by xCreate(). 6782** All resources associated with the specified cache should be freed. ^After 6783** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] 6784** handle invalid, and will not use it with any other sqlite3_pcache_methods2 6785** functions. 6786** 6787** [[the xShrink() page cache method]] 6788** ^SQLite invokes the xShrink() method when it wants the page cache to 6789** free up as much of heap memory as possible. The page cache implementation 6790** is not obligated to free any memory, but well-behaved implementations should 6791** do their best. 6792*/ 6793typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2; 6794struct sqlite3_pcache_methods2 { 6795 int iVersion; 6796 void *pArg; 6797 int (*xInit)(void*); 6798 void (*xShutdown)(void*); 6799 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable); 6800 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6801 int (*xPagecount)(sqlite3_pcache*); 6802 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6803 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard); 6804 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*, 6805 unsigned oldKey, unsigned newKey); 6806 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6807 void (*xDestroy)(sqlite3_pcache*); 6808 void (*xShrink)(sqlite3_pcache*); 6809}; 6810 6811/* 6812** This is the obsolete pcache_methods object that has now been replaced 6813** by sqlite3_pcache_methods2. This object is not used by SQLite. It is 6814** retained in the header file for backwards compatibility only. 6815*/ 6816typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; 6817struct sqlite3_pcache_methods { 6818 void *pArg; 6819 int (*xInit)(void*); 6820 void (*xShutdown)(void*); 6821 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); 6822 void (*xCachesize)(sqlite3_pcache*, int nCachesize); 6823 int (*xPagecount)(sqlite3_pcache*); 6824 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); 6825 void (*xUnpin)(sqlite3_pcache*, void*, int discard); 6826 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); 6827 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); 6828 void (*xDestroy)(sqlite3_pcache*); 6829}; 6830 6831 6832/* 6833** CAPI3REF: Online Backup Object 6834** 6835** The sqlite3_backup object records state information about an ongoing 6836** online backup operation. ^The sqlite3_backup object is created by 6837** a call to [sqlite3_backup_init()] and is destroyed by a call to 6838** [sqlite3_backup_finish()]. 6839** 6840** See Also: [Using the SQLite Online Backup API] 6841*/ 6842typedef struct sqlite3_backup sqlite3_backup; 6843 6844/* 6845** CAPI3REF: Online Backup API. 6846** 6847** The backup API copies the content of one database into another. 6848** It is useful either for creating backups of databases or 6849** for copying in-memory databases to or from persistent files. 6850** 6851** See Also: [Using the SQLite Online Backup API] 6852** 6853** ^SQLite holds a write transaction open on the destination database file 6854** for the duration of the backup operation. 6855** ^The source database is read-locked only while it is being read; 6856** it is not locked continuously for the entire backup operation. 6857** ^Thus, the backup may be performed on a live source database without 6858** preventing other database connections from 6859** reading or writing to the source database while the backup is underway. 6860** 6861** ^(To perform a backup operation: 6862** <ol> 6863** <li><b>sqlite3_backup_init()</b> is called once to initialize the 6864** backup, 6865** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer 6866** the data between the two databases, and finally 6867** <li><b>sqlite3_backup_finish()</b> is called to release all resources 6868** associated with the backup operation. 6869** </ol>)^ 6870** There should be exactly one call to sqlite3_backup_finish() for each 6871** successful call to sqlite3_backup_init(). 6872** 6873** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> 6874** 6875** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the 6876** [database connection] associated with the destination database 6877** and the database name, respectively. 6878** ^The database name is "main" for the main database, "temp" for the 6879** temporary database, or the name specified after the AS keyword in 6880** an [ATTACH] statement for an attached database. 6881** ^The S and M arguments passed to 6882** sqlite3_backup_init(D,N,S,M) identify the [database connection] 6883** and database name of the source database, respectively. 6884** ^The source and destination [database connections] (parameters S and D) 6885** must be different or else sqlite3_backup_init(D,N,S,M) will fail with 6886** an error. 6887** 6888** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is 6889** returned and an error code and error message are stored in the 6890** destination [database connection] D. 6891** ^The error code and message for the failed call to sqlite3_backup_init() 6892** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or 6893** [sqlite3_errmsg16()] functions. 6894** ^A successful call to sqlite3_backup_init() returns a pointer to an 6895** [sqlite3_backup] object. 6896** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and 6897** sqlite3_backup_finish() functions to perform the specified backup 6898** operation. 6899** 6900** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> 6901** 6902** ^Function sqlite3_backup_step(B,N) will copy up to N pages between 6903** the source and destination databases specified by [sqlite3_backup] object B. 6904** ^If N is negative, all remaining source pages are copied. 6905** ^If sqlite3_backup_step(B,N) successfully copies N pages and there 6906** are still more pages to be copied, then the function returns [SQLITE_OK]. 6907** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages 6908** from source to destination, then it returns [SQLITE_DONE]. 6909** ^If an error occurs while running sqlite3_backup_step(B,N), 6910** then an [error code] is returned. ^As well as [SQLITE_OK] and 6911** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], 6912** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an 6913** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. 6914** 6915** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if 6916** <ol> 6917** <li> the destination database was opened read-only, or 6918** <li> the destination database is using write-ahead-log journaling 6919** and the destination and source page sizes differ, or 6920** <li> the destination database is an in-memory database and the 6921** destination and source page sizes differ. 6922** </ol>)^ 6923** 6924** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then 6925** the [sqlite3_busy_handler | busy-handler function] 6926** is invoked (if one is specified). ^If the 6927** busy-handler returns non-zero before the lock is available, then 6928** [SQLITE_BUSY] is returned to the caller. ^In this case the call to 6929** sqlite3_backup_step() can be retried later. ^If the source 6930** [database connection] 6931** is being used to write to the source database when sqlite3_backup_step() 6932** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this 6933** case the call to sqlite3_backup_step() can be retried later on. ^(If 6934** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or 6935** [SQLITE_READONLY] is returned, then 6936** there is no point in retrying the call to sqlite3_backup_step(). These 6937** errors are considered fatal.)^ The application must accept 6938** that the backup operation has failed and pass the backup operation handle 6939** to the sqlite3_backup_finish() to release associated resources. 6940** 6941** ^The first call to sqlite3_backup_step() obtains an exclusive lock 6942** on the destination file. ^The exclusive lock is not released until either 6943** sqlite3_backup_finish() is called or the backup operation is complete 6944** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to 6945** sqlite3_backup_step() obtains a [shared lock] on the source database that 6946** lasts for the duration of the sqlite3_backup_step() call. 6947** ^Because the source database is not locked between calls to 6948** sqlite3_backup_step(), the source database may be modified mid-way 6949** through the backup process. ^If the source database is modified by an 6950** external process or via a database connection other than the one being 6951** used by the backup operation, then the backup will be automatically 6952** restarted by the next call to sqlite3_backup_step(). ^If the source 6953** database is modified by the using the same database connection as is used 6954** by the backup operation, then the backup database is automatically 6955** updated at the same time. 6956** 6957** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> 6958** 6959** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the 6960** application wishes to abandon the backup operation, the application 6961** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). 6962** ^The sqlite3_backup_finish() interfaces releases all 6963** resources associated with the [sqlite3_backup] object. 6964** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any 6965** active write-transaction on the destination database is rolled back. 6966** The [sqlite3_backup] object is invalid 6967** and may not be used following a call to sqlite3_backup_finish(). 6968** 6969** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no 6970** sqlite3_backup_step() errors occurred, regardless or whether or not 6971** sqlite3_backup_step() completed. 6972** ^If an out-of-memory condition or IO error occurred during any prior 6973** sqlite3_backup_step() call on the same [sqlite3_backup] object, then 6974** sqlite3_backup_finish() returns the corresponding [error code]. 6975** 6976** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() 6977** is not a permanent error and does not affect the return value of 6978** sqlite3_backup_finish(). 6979** 6980** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] 6981** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> 6982** 6983** ^Each call to sqlite3_backup_step() sets two values inside 6984** the [sqlite3_backup] object: the number of pages still to be backed 6985** up and the total number of pages in the source database file. 6986** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces 6987** retrieve these two values, respectively. 6988** 6989** ^The values returned by these functions are only updated by 6990** sqlite3_backup_step(). ^If the source database is modified during a backup 6991** operation, then the values are not updated to account for any extra 6992** pages that need to be updated or the size of the source database file 6993** changing. 6994** 6995** <b>Concurrent Usage of Database Handles</b> 6996** 6997** ^The source [database connection] may be used by the application for other 6998** purposes while a backup operation is underway or being initialized. 6999** ^If SQLite is compiled and configured to support threadsafe database 7000** connections, then the source database connection may be used concurrently 7001** from within other threads. 7002** 7003** However, the application must guarantee that the destination 7004** [database connection] is not passed to any other API (by any thread) after 7005** sqlite3_backup_init() is called and before the corresponding call to 7006** sqlite3_backup_finish(). SQLite does not currently check to see 7007** if the application incorrectly accesses the destination [database connection] 7008** and so no error code is reported, but the operations may malfunction 7009** nevertheless. Use of the destination database connection while a 7010** backup is in progress might also also cause a mutex deadlock. 7011** 7012** If running in [shared cache mode], the application must 7013** guarantee that the shared cache used by the destination database 7014** is not accessed while the backup is running. In practice this means 7015** that the application must guarantee that the disk file being 7016** backed up to is not accessed by any connection within the process, 7017** not just the specific connection that was passed to sqlite3_backup_init(). 7018** 7019** The [sqlite3_backup] object itself is partially threadsafe. Multiple 7020** threads may safely make multiple concurrent calls to sqlite3_backup_step(). 7021** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() 7022** APIs are not strictly speaking threadsafe. If they are invoked at the 7023** same time as another thread is invoking sqlite3_backup_step() it is 7024** possible that they return invalid values. 7025*/ 7026SQLITE_API sqlite3_backup *sqlite3_backup_init( 7027 sqlite3 *pDest, /* Destination database handle */ 7028 const char *zDestName, /* Destination database name */ 7029 sqlite3 *pSource, /* Source database handle */ 7030 const char *zSourceName /* Source database name */ 7031); 7032SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); 7033SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); 7034SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); 7035SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); 7036 7037/* 7038** CAPI3REF: Unlock Notification 7039** 7040** ^When running in shared-cache mode, a database operation may fail with 7041** an [SQLITE_LOCKED] error if the required locks on the shared-cache or 7042** individual tables within the shared-cache cannot be obtained. See 7043** [SQLite Shared-Cache Mode] for a description of shared-cache locking. 7044** ^This API may be used to register a callback that SQLite will invoke 7045** when the connection currently holding the required lock relinquishes it. 7046** ^This API is only available if the library was compiled with the 7047** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. 7048** 7049** See Also: [Using the SQLite Unlock Notification Feature]. 7050** 7051** ^Shared-cache locks are released when a database connection concludes 7052** its current transaction, either by committing it or rolling it back. 7053** 7054** ^When a connection (known as the blocked connection) fails to obtain a 7055** shared-cache lock and SQLITE_LOCKED is returned to the caller, the 7056** identity of the database connection (the blocking connection) that 7057** has locked the required resource is stored internally. ^After an 7058** application receives an SQLITE_LOCKED error, it may call the 7059** sqlite3_unlock_notify() method with the blocked connection handle as 7060** the first argument to register for a callback that will be invoked 7061** when the blocking connections current transaction is concluded. ^The 7062** callback is invoked from within the [sqlite3_step] or [sqlite3_close] 7063** call that concludes the blocking connections transaction. 7064** 7065** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, 7066** there is a chance that the blocking connection will have already 7067** concluded its transaction by the time sqlite3_unlock_notify() is invoked. 7068** If this happens, then the specified callback is invoked immediately, 7069** from within the call to sqlite3_unlock_notify().)^ 7070** 7071** ^If the blocked connection is attempting to obtain a write-lock on a 7072** shared-cache table, and more than one other connection currently holds 7073** a read-lock on the same table, then SQLite arbitrarily selects one of 7074** the other connections to use as the blocking connection. 7075** 7076** ^(There may be at most one unlock-notify callback registered by a 7077** blocked connection. If sqlite3_unlock_notify() is called when the 7078** blocked connection already has a registered unlock-notify callback, 7079** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is 7080** called with a NULL pointer as its second argument, then any existing 7081** unlock-notify callback is canceled. ^The blocked connections 7082** unlock-notify callback may also be canceled by closing the blocked 7083** connection using [sqlite3_close()]. 7084** 7085** The unlock-notify callback is not reentrant. If an application invokes 7086** any sqlite3_xxx API functions from within an unlock-notify callback, a 7087** crash or deadlock may be the result. 7088** 7089** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always 7090** returns SQLITE_OK. 7091** 7092** <b>Callback Invocation Details</b> 7093** 7094** When an unlock-notify callback is registered, the application provides a 7095** single void* pointer that is passed to the callback when it is invoked. 7096** However, the signature of the callback function allows SQLite to pass 7097** it an array of void* context pointers. The first argument passed to 7098** an unlock-notify callback is a pointer to an array of void* pointers, 7099** and the second is the number of entries in the array. 7100** 7101** When a blocking connections transaction is concluded, there may be 7102** more than one blocked connection that has registered for an unlock-notify 7103** callback. ^If two or more such blocked connections have specified the 7104** same callback function, then instead of invoking the callback function 7105** multiple times, it is invoked once with the set of void* context pointers 7106** specified by the blocked connections bundled together into an array. 7107** This gives the application an opportunity to prioritize any actions 7108** related to the set of unblocked database connections. 7109** 7110** <b>Deadlock Detection</b> 7111** 7112** Assuming that after registering for an unlock-notify callback a 7113** database waits for the callback to be issued before taking any further 7114** action (a reasonable assumption), then using this API may cause the 7115** application to deadlock. For example, if connection X is waiting for 7116** connection Y's transaction to be concluded, and similarly connection 7117** Y is waiting on connection X's transaction, then neither connection 7118** will proceed and the system may remain deadlocked indefinitely. 7119** 7120** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock 7121** detection. ^If a given call to sqlite3_unlock_notify() would put the 7122** system in a deadlocked state, then SQLITE_LOCKED is returned and no 7123** unlock-notify callback is registered. The system is said to be in 7124** a deadlocked state if connection A has registered for an unlock-notify 7125** callback on the conclusion of connection B's transaction, and connection 7126** B has itself registered for an unlock-notify callback when connection 7127** A's transaction is concluded. ^Indirect deadlock is also detected, so 7128** the system is also considered to be deadlocked if connection B has 7129** registered for an unlock-notify callback on the conclusion of connection 7130** C's transaction, where connection C is waiting on connection A. ^Any 7131** number of levels of indirection are allowed. 7132** 7133** <b>The "DROP TABLE" Exception</b> 7134** 7135** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost 7136** always appropriate to call sqlite3_unlock_notify(). There is however, 7137** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, 7138** SQLite checks if there are any currently executing SELECT statements 7139** that belong to the same connection. If there are, SQLITE_LOCKED is 7140** returned. In this case there is no "blocking connection", so invoking 7141** sqlite3_unlock_notify() results in the unlock-notify callback being 7142** invoked immediately. If the application then re-attempts the "DROP TABLE" 7143** or "DROP INDEX" query, an infinite loop might be the result. 7144** 7145** One way around this problem is to check the extended error code returned 7146** by an sqlite3_step() call. ^(If there is a blocking connection, then the 7147** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in 7148** the special "DROP TABLE/INDEX" case, the extended error code is just 7149** SQLITE_LOCKED.)^ 7150*/ 7151SQLITE_API int sqlite3_unlock_notify( 7152 sqlite3 *pBlocked, /* Waiting connection */ 7153 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ 7154 void *pNotifyArg /* Argument to pass to xNotify */ 7155); 7156 7157 7158/* 7159** CAPI3REF: String Comparison 7160** 7161** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications 7162** and extensions to compare the contents of two buffers containing UTF-8 7163** strings in a case-independent fashion, using the same definition of "case 7164** independence" that SQLite uses internally when comparing identifiers. 7165*/ 7166SQLITE_API int sqlite3_stricmp(const char *, const char *); 7167SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); 7168 7169/* 7170** CAPI3REF: String Globbing 7171* 7172** ^The [sqlite3_strglob(P,X)] interface returns zero if string X matches 7173** the glob pattern P, and it returns non-zero if string X does not match 7174** the glob pattern P. ^The definition of glob pattern matching used in 7175** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the 7176** SQL dialect used by SQLite. ^The sqlite3_strglob(P,X) function is case 7177** sensitive. 7178** 7179** Note that this routine returns zero on a match and non-zero if the strings 7180** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()]. 7181*/ 7182SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr); 7183 7184/* 7185** CAPI3REF: Error Logging Interface 7186** 7187** ^The [sqlite3_log()] interface writes a message into the [error log] 7188** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. 7189** ^If logging is enabled, the zFormat string and subsequent arguments are 7190** used with [sqlite3_snprintf()] to generate the final output string. 7191** 7192** The sqlite3_log() interface is intended for use by extensions such as 7193** virtual tables, collating functions, and SQL functions. While there is 7194** nothing to prevent an application from calling sqlite3_log(), doing so 7195** is considered bad form. 7196** 7197** The zFormat string must not be NULL. 7198** 7199** To avoid deadlocks and other threading problems, the sqlite3_log() routine 7200** will not use dynamically allocated memory. The log message is stored in 7201** a fixed-length buffer on the stack. If the log message is longer than 7202** a few hundred characters, it will be truncated to the length of the 7203** buffer. 7204*/ 7205SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); 7206 7207/* 7208** CAPI3REF: Write-Ahead Log Commit Hook 7209** 7210** ^The [sqlite3_wal_hook()] function is used to register a callback that 7211** will be invoked each time a database connection commits data to a 7212** [write-ahead log] (i.e. whenever a transaction is committed in 7213** [journal_mode | journal_mode=WAL mode]). 7214** 7215** ^The callback is invoked by SQLite after the commit has taken place and 7216** the associated write-lock on the database released, so the implementation 7217** may read, write or [checkpoint] the database as required. 7218** 7219** ^The first parameter passed to the callback function when it is invoked 7220** is a copy of the third parameter passed to sqlite3_wal_hook() when 7221** registering the callback. ^The second is a copy of the database handle. 7222** ^The third parameter is the name of the database that was written to - 7223** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter 7224** is the number of pages currently in the write-ahead log file, 7225** including those that were just committed. 7226** 7227** The callback function should normally return [SQLITE_OK]. ^If an error 7228** code is returned, that error will propagate back up through the 7229** SQLite code base to cause the statement that provoked the callback 7230** to report an error, though the commit will have still occurred. If the 7231** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value 7232** that does not correspond to any valid SQLite error code, the results 7233** are undefined. 7234** 7235** A single database handle may have at most a single write-ahead log callback 7236** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any 7237** previously registered write-ahead log callback. ^Note that the 7238** [sqlite3_wal_autocheckpoint()] interface and the 7239** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will 7240** those overwrite any prior [sqlite3_wal_hook()] settings. 7241*/ 7242SQLITE_API void *sqlite3_wal_hook( 7243 sqlite3*, 7244 int(*)(void *,sqlite3*,const char*,int), 7245 void* 7246); 7247 7248/* 7249** CAPI3REF: Configure an auto-checkpoint 7250** 7251** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around 7252** [sqlite3_wal_hook()] that causes any database on [database connection] D 7253** to automatically [checkpoint] 7254** after committing a transaction if there are N or 7255** more frames in the [write-ahead log] file. ^Passing zero or 7256** a negative value as the nFrame parameter disables automatic 7257** checkpoints entirely. 7258** 7259** ^The callback registered by this function replaces any existing callback 7260** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback 7261** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism 7262** configured by this function. 7263** 7264** ^The [wal_autocheckpoint pragma] can be used to invoke this interface 7265** from SQL. 7266** 7267** ^Checkpoints initiated by this mechanism are 7268** [sqlite3_wal_checkpoint_v2|PASSIVE]. 7269** 7270** ^Every new [database connection] defaults to having the auto-checkpoint 7271** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] 7272** pages. The use of this interface 7273** is only necessary if the default setting is found to be suboptimal 7274** for a particular application. 7275*/ 7276SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); 7277 7278/* 7279** CAPI3REF: Checkpoint a database 7280** 7281** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X 7282** on [database connection] D to be [checkpointed]. ^If X is NULL or an 7283** empty string, then a checkpoint is run on all databases of 7284** connection D. ^If the database connection D is not in 7285** [WAL | write-ahead log mode] then this interface is a harmless no-op. 7286** ^The [sqlite3_wal_checkpoint(D,X)] interface initiates a 7287** [sqlite3_wal_checkpoint_v2|PASSIVE] checkpoint. 7288** Use the [sqlite3_wal_checkpoint_v2()] interface to get a FULL 7289** or RESET checkpoint. 7290** 7291** ^The [wal_checkpoint pragma] can be used to invoke this interface 7292** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the 7293** [wal_autocheckpoint pragma] can be used to cause this interface to be 7294** run whenever the WAL reaches a certain size threshold. 7295** 7296** See also: [sqlite3_wal_checkpoint_v2()] 7297*/ 7298SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); 7299 7300/* 7301** CAPI3REF: Checkpoint a database 7302** 7303** Run a checkpoint operation on WAL database zDb attached to database 7304** handle db. The specific operation is determined by the value of the 7305** eMode parameter: 7306** 7307** <dl> 7308** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> 7309** Checkpoint as many frames as possible without waiting for any database 7310** readers or writers to finish. Sync the db file if all frames in the log 7311** are checkpointed. This mode is the same as calling 7312** sqlite3_wal_checkpoint(). The [sqlite3_busy_handler|busy-handler callback] 7313** is never invoked. 7314** 7315** <dt>SQLITE_CHECKPOINT_FULL<dd> 7316** This mode blocks (it invokes the 7317** [sqlite3_busy_handler|busy-handler callback]) until there is no 7318** database writer and all readers are reading from the most recent database 7319** snapshot. It then checkpoints all frames in the log file and syncs the 7320** database file. This call blocks database writers while it is running, 7321** but not database readers. 7322** 7323** <dt>SQLITE_CHECKPOINT_RESTART<dd> 7324** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after 7325** checkpointing the log file it blocks (calls the 7326** [sqlite3_busy_handler|busy-handler callback]) 7327** until all readers are reading from the database file only. This ensures 7328** that the next client to write to the database file restarts the log file 7329** from the beginning. This call blocks database writers while it is running, 7330** but not database readers. 7331** </dl> 7332** 7333** If pnLog is not NULL, then *pnLog is set to the total number of frames in 7334** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to 7335** the total number of checkpointed frames (including any that were already 7336** checkpointed when this function is called). *pnLog and *pnCkpt may be 7337** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. 7338** If no values are available because of an error, they are both set to -1 7339** before returning to communicate this to the caller. 7340** 7341** All calls obtain an exclusive "checkpoint" lock on the database file. If 7342** any other process is running a checkpoint operation at the same time, the 7343** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a 7344** busy-handler configured, it will not be invoked in this case. 7345** 7346** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive 7347** "writer" lock on the database file. If the writer lock cannot be obtained 7348** immediately, and a busy-handler is configured, it is invoked and the writer 7349** lock retried until either the busy-handler returns 0 or the lock is 7350** successfully obtained. The busy-handler is also invoked while waiting for 7351** database readers as described above. If the busy-handler returns 0 before 7352** the writer lock is obtained or while waiting for database readers, the 7353** checkpoint operation proceeds from that point in the same way as 7354** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible 7355** without blocking any further. SQLITE_BUSY is returned in this case. 7356** 7357** If parameter zDb is NULL or points to a zero length string, then the 7358** specified operation is attempted on all WAL databases. In this case the 7359** values written to output parameters *pnLog and *pnCkpt are undefined. If 7360** an SQLITE_BUSY error is encountered when processing one or more of the 7361** attached WAL databases, the operation is still attempted on any remaining 7362** attached databases and SQLITE_BUSY is returned to the caller. If any other 7363** error occurs while processing an attached database, processing is abandoned 7364** and the error code returned to the caller immediately. If no error 7365** (SQLITE_BUSY or otherwise) is encountered while processing the attached 7366** databases, SQLITE_OK is returned. 7367** 7368** If database zDb is the name of an attached database that is not in WAL 7369** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If 7370** zDb is not NULL (or a zero length string) and is not the name of any 7371** attached database, SQLITE_ERROR is returned to the caller. 7372*/ 7373SQLITE_API int sqlite3_wal_checkpoint_v2( 7374 sqlite3 *db, /* Database handle */ 7375 const char *zDb, /* Name of attached database (or NULL) */ 7376 int eMode, /* SQLITE_CHECKPOINT_* value */ 7377 int *pnLog, /* OUT: Size of WAL log in frames */ 7378 int *pnCkpt /* OUT: Total number of frames checkpointed */ 7379); 7380 7381/* 7382** CAPI3REF: Checkpoint operation parameters 7383** 7384** These constants can be used as the 3rd parameter to 7385** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] 7386** documentation for additional information about the meaning and use of 7387** each of these values. 7388*/ 7389#define SQLITE_CHECKPOINT_PASSIVE 0 7390#define SQLITE_CHECKPOINT_FULL 1 7391#define SQLITE_CHECKPOINT_RESTART 2 7392 7393/* 7394** CAPI3REF: Virtual Table Interface Configuration 7395** 7396** This function may be called by either the [xConnect] or [xCreate] method 7397** of a [virtual table] implementation to configure 7398** various facets of the virtual table interface. 7399** 7400** If this interface is invoked outside the context of an xConnect or 7401** xCreate virtual table method then the behavior is undefined. 7402** 7403** At present, there is only one option that may be configured using 7404** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options 7405** may be added in the future. 7406*/ 7407SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); 7408 7409/* 7410** CAPI3REF: Virtual Table Configuration Options 7411** 7412** These macros define the various options to the 7413** [sqlite3_vtab_config()] interface that [virtual table] implementations 7414** can use to customize and optimize their behavior. 7415** 7416** <dl> 7417** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT 7418** <dd>Calls of the form 7419** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, 7420** where X is an integer. If X is zero, then the [virtual table] whose 7421** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not 7422** support constraints. In this configuration (which is the default) if 7423** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire 7424** statement is rolled back as if [ON CONFLICT | OR ABORT] had been 7425** specified as part of the users SQL statement, regardless of the actual 7426** ON CONFLICT mode specified. 7427** 7428** If X is non-zero, then the virtual table implementation guarantees 7429** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before 7430** any modifications to internal or persistent data structures have been made. 7431** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite 7432** is able to roll back a statement or database transaction, and abandon 7433** or continue processing the current SQL statement as appropriate. 7434** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns 7435** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode 7436** had been ABORT. 7437** 7438** Virtual table implementations that are required to handle OR REPLACE 7439** must do so within the [xUpdate] method. If a call to the 7440** [sqlite3_vtab_on_conflict()] function indicates that the current ON 7441** CONFLICT policy is REPLACE, the virtual table implementation should 7442** silently replace the appropriate rows within the xUpdate callback and 7443** return SQLITE_OK. Or, if this is not possible, it may return 7444** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT 7445** constraint handling. 7446** </dl> 7447*/ 7448#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 7449 7450/* 7451** CAPI3REF: Determine The Virtual Table Conflict Policy 7452** 7453** This function may only be called from within a call to the [xUpdate] method 7454** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The 7455** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], 7456** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode 7457** of the SQL statement that triggered the call to the [xUpdate] method of the 7458** [virtual table]. 7459*/ 7460SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); 7461 7462/* 7463** CAPI3REF: Conflict resolution modes 7464** KEYWORDS: {conflict resolution mode} 7465** 7466** These constants are returned by [sqlite3_vtab_on_conflict()] to 7467** inform a [virtual table] implementation what the [ON CONFLICT] mode 7468** is for the SQL statement being evaluated. 7469** 7470** Note that the [SQLITE_IGNORE] constant is also used as a potential 7471** return value from the [sqlite3_set_authorizer()] callback and that 7472** [SQLITE_ABORT] is also a [result code]. 7473*/ 7474#define SQLITE_ROLLBACK 1 7475/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ 7476#define SQLITE_FAIL 3 7477/* #define SQLITE_ABORT 4 // Also an error code */ 7478#define SQLITE_REPLACE 5 7479 7480 7481 7482/* 7483** Undo the hack that converts floating point types to integer for 7484** builds on processors without floating point support. 7485*/ 7486#ifdef SQLITE_OMIT_FLOATING_POINT 7487# undef double 7488#endif 7489 7490#if 0 7491} /* End of the 'extern "C"' block */ 7492#endif 7493#endif /* _SQLITE3_H_ */ 7494 7495/* 7496** 2010 August 30 7497** 7498** The author disclaims copyright to this source code. In place of 7499** a legal notice, here is a blessing: 7500** 7501** May you do good and not evil. 7502** May you find forgiveness for yourself and forgive others. 7503** May you share freely, never taking more than you give. 7504** 7505************************************************************************* 7506*/ 7507 7508#ifndef _SQLITE3RTREE_H_ 7509#define _SQLITE3RTREE_H_ 7510 7511 7512#if 0 7513extern "C" { 7514#endif 7515 7516typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; 7517typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info; 7518 7519/* The double-precision datatype used by RTree depends on the 7520** SQLITE_RTREE_INT_ONLY compile-time option. 7521*/ 7522#ifdef SQLITE_RTREE_INT_ONLY 7523 typedef sqlite3_int64 sqlite3_rtree_dbl; 7524#else 7525 typedef double sqlite3_rtree_dbl; 7526#endif 7527 7528/* 7529** Register a geometry callback named zGeom that can be used as part of an 7530** R-Tree geometry query as follows: 7531** 7532** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) 7533*/ 7534SQLITE_API int sqlite3_rtree_geometry_callback( 7535 sqlite3 *db, 7536 const char *zGeom, 7537 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*), 7538 void *pContext 7539); 7540 7541 7542/* 7543** A pointer to a structure of the following type is passed as the first 7544** argument to callbacks registered using rtree_geometry_callback(). 7545*/ 7546struct sqlite3_rtree_geometry { 7547 void *pContext; /* Copy of pContext passed to s_r_g_c() */ 7548 int nParam; /* Size of array aParam[] */ 7549 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */ 7550 void *pUser; /* Callback implementation user data */ 7551 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ 7552}; 7553 7554/* 7555** Register a 2nd-generation geometry callback named zScore that can be 7556** used as part of an R-Tree geometry query as follows: 7557** 7558** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...) 7559*/ 7560SQLITE_API int sqlite3_rtree_query_callback( 7561 sqlite3 *db, 7562 const char *zQueryFunc, 7563 int (*xQueryFunc)(sqlite3_rtree_query_info*), 7564 void *pContext, 7565 void (*xDestructor)(void*) 7566); 7567 7568 7569/* 7570** A pointer to a structure of the following type is passed as the 7571** argument to scored geometry callback registered using 7572** sqlite3_rtree_query_callback(). 7573** 7574** Note that the first 5 fields of this structure are identical to 7575** sqlite3_rtree_geometry. This structure is a subclass of 7576** sqlite3_rtree_geometry. 7577*/ 7578struct sqlite3_rtree_query_info { 7579 void *pContext; /* pContext from when function registered */ 7580 int nParam; /* Number of function parameters */ 7581 sqlite3_rtree_dbl *aParam; /* value of function parameters */ 7582 void *pUser; /* callback can use this, if desired */ 7583 void (*xDelUser)(void*); /* function to free pUser */ 7584 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */ 7585 unsigned int *anQueue; /* Number of pending entries in the queue */ 7586 int nCoord; /* Number of coordinates */ 7587 int iLevel; /* Level of current node or entry */ 7588 int mxLevel; /* The largest iLevel value in the tree */ 7589 sqlite3_int64 iRowid; /* Rowid for current entry */ 7590 sqlite3_rtree_dbl rParentScore; /* Score of parent node */ 7591 int eParentWithin; /* Visibility of parent node */ 7592 int eWithin; /* OUT: Visiblity */ 7593 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */ 7594}; 7595 7596/* 7597** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin. 7598*/ 7599#define NOT_WITHIN 0 /* Object completely outside of query region */ 7600#define PARTLY_WITHIN 1 /* Object partially overlaps query region */ 7601#define FULLY_WITHIN 2 /* Object fully contained within query region */ 7602 7603 7604#if 0 7605} /* end of the 'extern "C"' block */ 7606#endif 7607 7608#endif /* ifndef _SQLITE3RTREE_H_ */ 7609 7610 7611/*****