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1 /* |
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2 ** 2001 September 15 |
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3 ** |
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4 ** The author disclaims copyright to this source code. In place of |
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5 ** a legal notice, here is a blessing: |
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6 ** |
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7 ** May you do good and not evil. |
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8 ** May you find forgiveness for yourself and forgive others. |
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9 ** May you share freely, never taking more than you give. |
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10 ** |
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11 ************************************************************************* |
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12 ** This header file defines the interface that the SQLite library |
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13 ** presents to client programs. If a C-function, structure, datatype, |
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14 ** or constant definition does not appear in this file, then it is |
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15 ** not a published API of SQLite, is subject to change without |
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16 ** notice, and should not be referenced by programs that use SQLite. |
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17 ** |
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18 ** Some of the definitions that are in this file are marked as |
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19 ** "experimental". Experimental interfaces are normally new |
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20 ** features recently added to SQLite. We do not anticipate changes |
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21 ** to experimental interfaces but reserve the right to make minor changes |
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22 ** if experience from use "in the wild" suggest such changes are prudent. |
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23 ** |
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24 ** The official C-language API documentation for SQLite is derived |
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25 ** from comments in this file. This file is the authoritative source |
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26 ** on how SQLite interfaces are suppose to operate. |
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27 ** |
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28 ** The name of this file under configuration management is "sqlite.h.in". |
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29 ** The makefile makes some minor changes to this file (such as inserting |
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30 ** the version number) and changes its name to "sqlite3.h" as |
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31 ** part of the build process. |
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32 */ |
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33 #ifndef _SQLITE3_H_ |
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34 #define _SQLITE3_H_ |
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35 #include <stdarg.h> /* Needed for the definition of va_list */ |
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36 |
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37 /* |
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38 ** Make sure we can call this stuff from C++. |
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39 */ |
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40 #ifdef __cplusplus |
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41 extern "C" { |
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42 #endif |
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43 |
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44 |
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45 /* |
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46 ** Add the ability to override 'extern' |
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47 */ |
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48 #ifndef SQLITE_EXTERN |
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49 # define SQLITE_EXTERN extern |
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50 #endif |
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51 |
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52 #ifndef SQLITE_API |
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53 # define SQLITE_API |
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54 #endif |
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55 |
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56 |
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57 /* |
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58 ** These no-op macros are used in front of interfaces to mark those |
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59 ** interfaces as either deprecated or experimental. New applications |
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60 ** should not use deprecated interfaces - they are support for backwards |
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61 ** compatibility only. Application writers should be aware that |
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62 ** experimental interfaces are subject to change in point releases. |
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63 ** |
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64 ** These macros used to resolve to various kinds of compiler magic that |
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65 ** would generate warning messages when they were used. But that |
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66 ** compiler magic ended up generating such a flurry of bug reports |
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67 ** that we have taken it all out and gone back to using simple |
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68 ** noop macros. |
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69 */ |
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70 #define SQLITE_DEPRECATED |
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71 #define SQLITE_EXPERIMENTAL |
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72 |
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73 /* |
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74 ** Ensure these symbols were not defined by some previous header file. |
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75 */ |
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76 #ifdef SQLITE_VERSION |
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77 # undef SQLITE_VERSION |
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78 #endif |
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79 #ifdef SQLITE_VERSION_NUMBER |
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80 # undef SQLITE_VERSION_NUMBER |
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81 #endif |
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82 |
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83 /* |
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84 ** CAPI3REF: Compile-Time Library Version Numbers |
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85 ** |
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86 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header |
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87 ** evaluates to a string literal that is the SQLite version in the |
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88 ** format "X.Y.Z" where X is the major version number (always 3 for |
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89 ** SQLite3) and Y is the minor version number and Z is the release number.)^ |
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90 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer |
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91 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same |
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92 ** numbers used in [SQLITE_VERSION].)^ |
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93 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also |
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94 ** be larger than the release from which it is derived. Either Y will |
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95 ** be held constant and Z will be incremented or else Y will be incremented |
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96 ** and Z will be reset to zero. |
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97 ** |
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98 ** Since version 3.6.18, SQLite source code has been stored in the |
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99 ** <a href="http://www.fossil-scm.org/">Fossil configuration management |
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100 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to |
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101 ** a string which identifies a particular check-in of SQLite |
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102 ** within its configuration management system. ^The SQLITE_SOURCE_ID |
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103 ** string contains the date and time of the check-in (UTC) and an SHA1 |
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104 ** hash of the entire source tree. |
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105 ** |
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106 ** See also: [sqlite3_libversion()], |
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107 ** [sqlite3_libversion_number()], [sqlite3_sourceid()], |
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108 ** [sqlite_version()] and [sqlite_source_id()]. |
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109 */ |
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110 #define SQLITE_VERSION "3.7.8" |
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111 #define SQLITE_VERSION_NUMBER 3007008 |
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112 #define SQLITE_SOURCE_ID "2011-09-19 14:49:19 3e0da808d2f5b4d12046e05980ca04578f581177" |
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113 |
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114 /* |
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115 ** CAPI3REF: Run-Time Library Version Numbers |
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116 ** KEYWORDS: sqlite3_version, sqlite3_sourceid |
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117 ** |
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118 ** These interfaces provide the same information as the [SQLITE_VERSION], |
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119 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros |
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120 ** but are associated with the library instead of the header file. ^(Cautious |
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121 ** programmers might include assert() statements in their application to |
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122 ** verify that values returned by these interfaces match the macros in |
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123 ** the header, and thus insure that the application is |
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124 ** compiled with matching library and header files. |
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125 ** |
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126 ** <blockquote><pre> |
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127 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER ); |
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128 ** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 ); |
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129 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 ); |
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130 ** </pre></blockquote>)^ |
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131 ** |
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132 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION] |
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133 ** macro. ^The sqlite3_libversion() function returns a pointer to the |
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134 ** to the sqlite3_version[] string constant. The sqlite3_libversion() |
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135 ** function is provided for use in DLLs since DLL users usually do not have |
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136 ** direct access to string constants within the DLL. ^The |
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137 ** sqlite3_libversion_number() function returns an integer equal to |
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138 ** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns |
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139 ** a pointer to a string constant whose value is the same as the |
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140 ** [SQLITE_SOURCE_ID] C preprocessor macro. |
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141 ** |
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142 ** See also: [sqlite_version()] and [sqlite_source_id()]. |
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143 */ |
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144 SQLITE_API SQLITE_EXTERN const char sqlite3_version[]; |
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145 SQLITE_API const char *sqlite3_libversion(void); |
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146 SQLITE_API const char *sqlite3_sourceid(void); |
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147 SQLITE_API int sqlite3_libversion_number(void); |
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148 |
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149 /* |
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150 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics |
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151 ** |
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152 ** ^The sqlite3_compileoption_used() function returns 0 or 1 |
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153 ** indicating whether the specified option was defined at |
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154 ** compile time. ^The SQLITE_ prefix may be omitted from the |
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155 ** option name passed to sqlite3_compileoption_used(). |
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156 ** |
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157 ** ^The sqlite3_compileoption_get() function allows iterating |
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158 ** over the list of options that were defined at compile time by |
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159 ** returning the N-th compile time option string. ^If N is out of range, |
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160 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_ |
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161 ** prefix is omitted from any strings returned by |
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162 ** sqlite3_compileoption_get(). |
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163 ** |
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164 ** ^Support for the diagnostic functions sqlite3_compileoption_used() |
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165 ** and sqlite3_compileoption_get() may be omitted by specifying the |
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166 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time. |
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167 ** |
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168 ** See also: SQL functions [sqlite_compileoption_used()] and |
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169 ** [sqlite_compileoption_get()] and the [compile_options pragma]. |
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170 */ |
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171 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS |
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172 SQLITE_API int sqlite3_compileoption_used(const char *zOptName); |
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173 SQLITE_API const char *sqlite3_compileoption_get(int N); |
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174 #endif |
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175 |
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176 /* |
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177 ** CAPI3REF: Test To See If The Library Is Threadsafe |
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178 ** |
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179 ** ^The sqlite3_threadsafe() function returns zero if and only if |
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180 ** SQLite was compiled mutexing code omitted due to the |
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181 ** [SQLITE_THREADSAFE] compile-time option being set to 0. |
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182 ** |
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183 ** SQLite can be compiled with or without mutexes. When |
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184 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes |
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185 ** are enabled and SQLite is threadsafe. When the |
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186 ** [SQLITE_THREADSAFE] macro is 0, |
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187 ** the mutexes are omitted. Without the mutexes, it is not safe |
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188 ** to use SQLite concurrently from more than one thread. |
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189 ** |
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190 ** Enabling mutexes incurs a measurable performance penalty. |
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191 ** So if speed is of utmost importance, it makes sense to disable |
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192 ** the mutexes. But for maximum safety, mutexes should be enabled. |
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193 ** ^The default behavior is for mutexes to be enabled. |
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194 ** |
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195 ** This interface can be used by an application to make sure that the |
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196 ** version of SQLite that it is linking against was compiled with |
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197 ** the desired setting of the [SQLITE_THREADSAFE] macro. |
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198 ** |
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199 ** This interface only reports on the compile-time mutex setting |
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200 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with |
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201 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but |
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202 ** can be fully or partially disabled using a call to [sqlite3_config()] |
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203 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD], |
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204 ** or [SQLITE_CONFIG_MUTEX]. ^(The return value of the |
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205 ** sqlite3_threadsafe() function shows only the compile-time setting of |
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206 ** thread safety, not any run-time changes to that setting made by |
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207 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe() |
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208 ** is unchanged by calls to sqlite3_config().)^ |
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209 ** |
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210 ** See the [threading mode] documentation for additional information. |
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211 */ |
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212 SQLITE_API int sqlite3_threadsafe(void); |
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213 |
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214 /* |
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215 ** CAPI3REF: Database Connection Handle |
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216 ** KEYWORDS: {database connection} {database connections} |
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217 ** |
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218 ** Each open SQLite database is represented by a pointer to an instance of |
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219 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3 |
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220 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and |
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221 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()] |
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222 ** is its destructor. There are many other interfaces (such as |
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223 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and |
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224 ** [sqlite3_busy_timeout()] to name but three) that are methods on an |
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225 ** sqlite3 object. |
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226 */ |
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227 typedef struct sqlite3 sqlite3; |
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228 |
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229 /* |
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230 ** CAPI3REF: 64-Bit Integer Types |
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231 ** KEYWORDS: sqlite_int64 sqlite_uint64 |
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232 ** |
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233 ** Because there is no cross-platform way to specify 64-bit integer types |
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234 ** SQLite includes typedefs for 64-bit signed and unsigned integers. |
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235 ** |
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236 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions. |
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237 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards |
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238 ** compatibility only. |
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239 ** |
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240 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values |
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241 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The |
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242 ** sqlite3_uint64 and sqlite_uint64 types can store integer values |
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243 ** between 0 and +18446744073709551615 inclusive. |
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244 */ |
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245 #ifdef SQLITE_INT64_TYPE |
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246 typedef SQLITE_INT64_TYPE sqlite_int64; |
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247 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64; |
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248 #elif defined(_MSC_VER) || defined(__BORLANDC__) |
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249 typedef __int64 sqlite_int64; |
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250 typedef unsigned __int64 sqlite_uint64; |
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251 #else |
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252 typedef long long int sqlite_int64; |
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253 typedef unsigned long long int sqlite_uint64; |
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254 #endif |
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255 typedef sqlite_int64 sqlite3_int64; |
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256 typedef sqlite_uint64 sqlite3_uint64; |
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257 |
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258 /* |
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259 ** If compiling for a processor that lacks floating point support, |
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260 ** substitute integer for floating-point. |
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261 */ |
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262 #ifdef SQLITE_OMIT_FLOATING_POINT |
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263 # define double sqlite3_int64 |
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264 #endif |
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265 |
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266 /* |
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267 ** CAPI3REF: Closing A Database Connection |
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268 ** |
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269 ** ^The sqlite3_close() routine is the destructor for the [sqlite3] object. |
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270 ** ^Calls to sqlite3_close() return SQLITE_OK if the [sqlite3] object is |
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271 ** successfully destroyed and all associated resources are deallocated. |
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272 ** |
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273 ** Applications must [sqlite3_finalize | finalize] all [prepared statements] |
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274 ** and [sqlite3_blob_close | close] all [BLOB handles] associated with |
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275 ** the [sqlite3] object prior to attempting to close the object. ^If |
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276 ** sqlite3_close() is called on a [database connection] that still has |
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277 ** outstanding [prepared statements] or [BLOB handles], then it returns |
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278 ** SQLITE_BUSY. |
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279 ** |
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280 ** ^If [sqlite3_close()] is invoked while a transaction is open, |
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281 ** the transaction is automatically rolled back. |
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282 ** |
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283 ** The C parameter to [sqlite3_close(C)] must be either a NULL |
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284 ** pointer or an [sqlite3] object pointer obtained |
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285 ** from [sqlite3_open()], [sqlite3_open16()], or |
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286 ** [sqlite3_open_v2()], and not previously closed. |
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287 ** ^Calling sqlite3_close() with a NULL pointer argument is a |
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288 ** harmless no-op. |
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289 */ |
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290 SQLITE_API int sqlite3_close(sqlite3 *); |
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291 |
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292 /* |
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293 ** The type for a callback function. |
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294 ** This is legacy and deprecated. It is included for historical |
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295 ** compatibility and is not documented. |
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296 */ |
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297 typedef int (*sqlite3_callback)(void*,int,char**, char**); |
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298 |
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299 /* |
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300 ** CAPI3REF: One-Step Query Execution Interface |
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301 ** |
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302 ** The sqlite3_exec() interface is a convenience wrapper around |
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303 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()], |
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304 ** that allows an application to run multiple statements of SQL |
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305 ** without having to use a lot of C code. |
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306 ** |
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307 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded, |
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308 ** semicolon-separate SQL statements passed into its 2nd argument, |
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309 ** in the context of the [database connection] passed in as its 1st |
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310 ** argument. ^If the callback function of the 3rd argument to |
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311 ** sqlite3_exec() is not NULL, then it is invoked for each result row |
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312 ** coming out of the evaluated SQL statements. ^The 4th argument to |
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313 ** sqlite3_exec() is relayed through to the 1st argument of each |
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314 ** callback invocation. ^If the callback pointer to sqlite3_exec() |
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315 ** is NULL, then no callback is ever invoked and result rows are |
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316 ** ignored. |
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317 ** |
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318 ** ^If an error occurs while evaluating the SQL statements passed into |
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319 ** sqlite3_exec(), then execution of the current statement stops and |
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320 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec() |
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321 ** is not NULL then any error message is written into memory obtained |
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322 ** from [sqlite3_malloc()] and passed back through the 5th parameter. |
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323 ** To avoid memory leaks, the application should invoke [sqlite3_free()] |
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324 ** on error message strings returned through the 5th parameter of |
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325 ** of sqlite3_exec() after the error message string is no longer needed. |
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326 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors |
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327 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to |
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328 ** NULL before returning. |
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329 ** |
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330 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec() |
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331 ** routine returns SQLITE_ABORT without invoking the callback again and |
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332 ** without running any subsequent SQL statements. |
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333 ** |
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334 ** ^The 2nd argument to the sqlite3_exec() callback function is the |
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335 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec() |
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336 ** callback is an array of pointers to strings obtained as if from |
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337 ** [sqlite3_column_text()], one for each column. ^If an element of a |
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338 ** result row is NULL then the corresponding string pointer for the |
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339 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the |
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340 ** sqlite3_exec() callback is an array of pointers to strings where each |
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341 ** entry represents the name of corresponding result column as obtained |
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342 ** from [sqlite3_column_name()]. |
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343 ** |
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344 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer |
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345 ** to an empty string, or a pointer that contains only whitespace and/or |
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346 ** SQL comments, then no SQL statements are evaluated and the database |
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347 ** is not changed. |
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348 ** |
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349 ** Restrictions: |
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350 ** |
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351 ** <ul> |
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352 ** <li> The application must insure that the 1st parameter to sqlite3_exec() |
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353 ** is a valid and open [database connection]. |
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354 ** <li> The application must not close [database connection] specified by |
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355 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running. |
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356 ** <li> The application must not modify the SQL statement text passed into |
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357 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running. |
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358 ** </ul> |
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359 */ |
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360 SQLITE_API int sqlite3_exec( |
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361 sqlite3*, /* An open database */ |
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362 const char *sql, /* SQL to be evaluated */ |
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363 int (*callback)(void*,int,char**,char**), /* Callback function */ |
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364 void *, /* 1st argument to callback */ |
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365 char **errmsg /* Error msg written here */ |
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366 ); |
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367 |
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368 /* |
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369 ** CAPI3REF: Result Codes |
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370 ** KEYWORDS: SQLITE_OK {error code} {error codes} |
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371 ** KEYWORDS: {result code} {result codes} |
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372 ** |
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373 ** Many SQLite functions return an integer result code from the set shown |
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374 ** here in order to indicates success or failure. |
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375 ** |
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376 ** New error codes may be added in future versions of SQLite. |
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377 ** |
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378 ** See also: [SQLITE_IOERR_READ | extended result codes], |
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379 ** [sqlite3_vtab_on_conflict()] [SQLITE_ROLLBACK | result codes]. |
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380 */ |
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381 #define SQLITE_OK 0 /* Successful result */ |
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382 /* beginning-of-error-codes */ |
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383 #define SQLITE_ERROR 1 /* SQL error or missing database */ |
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384 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */ |
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385 #define SQLITE_PERM 3 /* Access permission denied */ |
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386 #define SQLITE_ABORT 4 /* Callback routine requested an abort */ |
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387 #define SQLITE_BUSY 5 /* The database file is locked */ |
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388 #define SQLITE_LOCKED 6 /* A table in the database is locked */ |
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389 #define SQLITE_NOMEM 7 /* A malloc() failed */ |
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390 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */ |
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391 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/ |
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392 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */ |
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393 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */ |
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394 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */ |
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395 #define SQLITE_FULL 13 /* Insertion failed because database is full */ |
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396 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */ |
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397 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */ |
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398 #define SQLITE_EMPTY 16 /* Database is empty */ |
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399 #define SQLITE_SCHEMA 17 /* The database schema changed */ |
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400 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */ |
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401 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */ |
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402 #define SQLITE_MISMATCH 20 /* Data type mismatch */ |
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403 #define SQLITE_MISUSE 21 /* Library used incorrectly */ |
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404 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */ |
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405 #define SQLITE_AUTH 23 /* Authorization denied */ |
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406 #define SQLITE_FORMAT 24 /* Auxiliary database format error */ |
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407 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */ |
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408 #define SQLITE_NOTADB 26 /* File opened that is not a database file */ |
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409 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */ |
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410 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */ |
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411 /* end-of-error-codes */ |
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412 |
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413 /* |
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414 ** CAPI3REF: Extended Result Codes |
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415 ** KEYWORDS: {extended error code} {extended error codes} |
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416 ** KEYWORDS: {extended result code} {extended result codes} |
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417 ** |
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418 ** In its default configuration, SQLite API routines return one of 26 integer |
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419 ** [SQLITE_OK | result codes]. However, experience has shown that many of |
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420 ** these result codes are too coarse-grained. They do not provide as |
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421 ** much information about problems as programmers might like. In an effort to |
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422 ** address this, newer versions of SQLite (version 3.3.8 and later) include |
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423 ** support for additional result codes that provide more detailed information |
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424 ** about errors. The extended result codes are enabled or disabled |
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425 ** on a per database connection basis using the |
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426 ** [sqlite3_extended_result_codes()] API. |
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427 ** |
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428 ** Some of the available extended result codes are listed here. |
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429 ** One may expect the number of extended result codes will be expand |
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430 ** over time. Software that uses extended result codes should expect |
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431 ** to see new result codes in future releases of SQLite. |
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432 ** |
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433 ** The SQLITE_OK result code will never be extended. It will always |
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434 ** be exactly zero. |
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435 */ |
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436 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8)) |
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437 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8)) |
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438 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8)) |
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439 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8)) |
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440 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8)) |
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441 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8)) |
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442 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8)) |
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443 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8)) |
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444 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8)) |
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445 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8)) |
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446 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8)) |
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447 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8)) |
|
448 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8)) |
|
449 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8)) |
|
450 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8)) |
|
451 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8)) |
|
452 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8)) |
|
453 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8)) |
|
454 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8)) |
|
455 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8)) |
|
456 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8)) |
|
457 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8)) |
|
458 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8)) |
|
459 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8)) |
|
460 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8)) |
|
461 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8)) |
|
462 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8)) |
|
463 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8)) |
|
464 |
|
465 /* |
|
466 ** CAPI3REF: Flags For File Open Operations |
|
467 ** |
|
468 ** These bit values are intended for use in the |
|
469 ** 3rd parameter to the [sqlite3_open_v2()] interface and |
|
470 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method. |
|
471 */ |
|
472 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */ |
|
473 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */ |
|
474 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */ |
|
475 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */ |
|
476 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */ |
|
477 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */ |
|
478 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */ |
|
479 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */ |
|
480 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */ |
|
481 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */ |
|
482 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */ |
|
483 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */ |
|
484 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */ |
|
485 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */ |
|
486 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */ |
|
487 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */ |
|
488 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */ |
|
489 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */ |
|
490 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */ |
|
491 |
|
492 /* Reserved: 0x00F00000 */ |
|
493 |
|
494 /* |
|
495 ** CAPI3REF: Device Characteristics |
|
496 ** |
|
497 ** The xDeviceCharacteristics method of the [sqlite3_io_methods] |
|
498 ** object returns an integer which is a vector of the these |
|
499 ** bit values expressing I/O characteristics of the mass storage |
|
500 ** device that holds the file that the [sqlite3_io_methods] |
|
501 ** refers to. |
|
502 ** |
|
503 ** The SQLITE_IOCAP_ATOMIC property means that all writes of |
|
504 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values |
|
505 ** mean that writes of blocks that are nnn bytes in size and |
|
506 ** are aligned to an address which is an integer multiple of |
|
507 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means |
|
508 ** that when data is appended to a file, the data is appended |
|
509 ** first then the size of the file is extended, never the other |
|
510 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that |
|
511 ** information is written to disk in the same order as calls |
|
512 ** to xWrite(). |
|
513 */ |
|
514 #define SQLITE_IOCAP_ATOMIC 0x00000001 |
|
515 #define SQLITE_IOCAP_ATOMIC512 0x00000002 |
|
516 #define SQLITE_IOCAP_ATOMIC1K 0x00000004 |
|
517 #define SQLITE_IOCAP_ATOMIC2K 0x00000008 |
|
518 #define SQLITE_IOCAP_ATOMIC4K 0x00000010 |
|
519 #define SQLITE_IOCAP_ATOMIC8K 0x00000020 |
|
520 #define SQLITE_IOCAP_ATOMIC16K 0x00000040 |
|
521 #define SQLITE_IOCAP_ATOMIC32K 0x00000080 |
|
522 #define SQLITE_IOCAP_ATOMIC64K 0x00000100 |
|
523 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200 |
|
524 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400 |
|
525 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800 |
|
526 |
|
527 /* |
|
528 ** CAPI3REF: File Locking Levels |
|
529 ** |
|
530 ** SQLite uses one of these integer values as the second |
|
531 ** argument to calls it makes to the xLock() and xUnlock() methods |
|
532 ** of an [sqlite3_io_methods] object. |
|
533 */ |
|
534 #define SQLITE_LOCK_NONE 0 |
|
535 #define SQLITE_LOCK_SHARED 1 |
|
536 #define SQLITE_LOCK_RESERVED 2 |
|
537 #define SQLITE_LOCK_PENDING 3 |
|
538 #define SQLITE_LOCK_EXCLUSIVE 4 |
|
539 |
|
540 /* |
|
541 ** CAPI3REF: Synchronization Type Flags |
|
542 ** |
|
543 ** When SQLite invokes the xSync() method of an |
|
544 ** [sqlite3_io_methods] object it uses a combination of |
|
545 ** these integer values as the second argument. |
|
546 ** |
|
547 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the |
|
548 ** sync operation only needs to flush data to mass storage. Inode |
|
549 ** information need not be flushed. If the lower four bits of the flag |
|
550 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics. |
|
551 ** If the lower four bits equal SQLITE_SYNC_FULL, that means |
|
552 ** to use Mac OS X style fullsync instead of fsync(). |
|
553 ** |
|
554 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags |
|
555 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL |
|
556 ** settings. The [synchronous pragma] determines when calls to the |
|
557 ** xSync VFS method occur and applies uniformly across all platforms. |
|
558 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how |
|
559 ** energetic or rigorous or forceful the sync operations are and |
|
560 ** only make a difference on Mac OSX for the default SQLite code. |
|
561 ** (Third-party VFS implementations might also make the distinction |
|
562 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the |
|
563 ** operating systems natively supported by SQLite, only Mac OSX |
|
564 ** cares about the difference.) |
|
565 */ |
|
566 #define SQLITE_SYNC_NORMAL 0x00002 |
|
567 #define SQLITE_SYNC_FULL 0x00003 |
|
568 #define SQLITE_SYNC_DATAONLY 0x00010 |
|
569 |
|
570 /* |
|
571 ** CAPI3REF: OS Interface Open File Handle |
|
572 ** |
|
573 ** An [sqlite3_file] object represents an open file in the |
|
574 ** [sqlite3_vfs | OS interface layer]. Individual OS interface |
|
575 ** implementations will |
|
576 ** want to subclass this object by appending additional fields |
|
577 ** for their own use. The pMethods entry is a pointer to an |
|
578 ** [sqlite3_io_methods] object that defines methods for performing |
|
579 ** I/O operations on the open file. |
|
580 */ |
|
581 typedef struct sqlite3_file sqlite3_file; |
|
582 struct sqlite3_file { |
|
583 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */ |
|
584 }; |
|
585 |
|
586 /* |
|
587 ** CAPI3REF: OS Interface File Virtual Methods Object |
|
588 ** |
|
589 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an |
|
590 ** [sqlite3_file] object (or, more commonly, a subclass of the |
|
591 ** [sqlite3_file] object) with a pointer to an instance of this object. |
|
592 ** This object defines the methods used to perform various operations |
|
593 ** against the open file represented by the [sqlite3_file] object. |
|
594 ** |
|
595 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element |
|
596 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method |
|
597 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The |
|
598 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen] |
|
599 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element |
|
600 ** to NULL. |
|
601 ** |
|
602 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or |
|
603 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync(). |
|
604 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY] |
|
605 ** flag may be ORed in to indicate that only the data of the file |
|
606 ** and not its inode needs to be synced. |
|
607 ** |
|
608 ** The integer values to xLock() and xUnlock() are one of |
|
609 ** <ul> |
|
610 ** <li> [SQLITE_LOCK_NONE], |
|
611 ** <li> [SQLITE_LOCK_SHARED], |
|
612 ** <li> [SQLITE_LOCK_RESERVED], |
|
613 ** <li> [SQLITE_LOCK_PENDING], or |
|
614 ** <li> [SQLITE_LOCK_EXCLUSIVE]. |
|
615 ** </ul> |
|
616 ** xLock() increases the lock. xUnlock() decreases the lock. |
|
617 ** The xCheckReservedLock() method checks whether any database connection, |
|
618 ** either in this process or in some other process, is holding a RESERVED, |
|
619 ** PENDING, or EXCLUSIVE lock on the file. It returns true |
|
620 ** if such a lock exists and false otherwise. |
|
621 ** |
|
622 ** The xFileControl() method is a generic interface that allows custom |
|
623 ** VFS implementations to directly control an open file using the |
|
624 ** [sqlite3_file_control()] interface. The second "op" argument is an |
|
625 ** integer opcode. The third argument is a generic pointer intended to |
|
626 ** point to a structure that may contain arguments or space in which to |
|
627 ** write return values. Potential uses for xFileControl() might be |
|
628 ** functions to enable blocking locks with timeouts, to change the |
|
629 ** locking strategy (for example to use dot-file locks), to inquire |
|
630 ** about the status of a lock, or to break stale locks. The SQLite |
|
631 ** core reserves all opcodes less than 100 for its own use. |
|
632 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available. |
|
633 ** Applications that define a custom xFileControl method should use opcodes |
|
634 ** greater than 100 to avoid conflicts. VFS implementations should |
|
635 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not |
|
636 ** recognize. |
|
637 ** |
|
638 ** The xSectorSize() method returns the sector size of the |
|
639 ** device that underlies the file. The sector size is the |
|
640 ** minimum write that can be performed without disturbing |
|
641 ** other bytes in the file. The xDeviceCharacteristics() |
|
642 ** method returns a bit vector describing behaviors of the |
|
643 ** underlying device: |
|
644 ** |
|
645 ** <ul> |
|
646 ** <li> [SQLITE_IOCAP_ATOMIC] |
|
647 ** <li> [SQLITE_IOCAP_ATOMIC512] |
|
648 ** <li> [SQLITE_IOCAP_ATOMIC1K] |
|
649 ** <li> [SQLITE_IOCAP_ATOMIC2K] |
|
650 ** <li> [SQLITE_IOCAP_ATOMIC4K] |
|
651 ** <li> [SQLITE_IOCAP_ATOMIC8K] |
|
652 ** <li> [SQLITE_IOCAP_ATOMIC16K] |
|
653 ** <li> [SQLITE_IOCAP_ATOMIC32K] |
|
654 ** <li> [SQLITE_IOCAP_ATOMIC64K] |
|
655 ** <li> [SQLITE_IOCAP_SAFE_APPEND] |
|
656 ** <li> [SQLITE_IOCAP_SEQUENTIAL] |
|
657 ** </ul> |
|
658 ** |
|
659 ** The SQLITE_IOCAP_ATOMIC property means that all writes of |
|
660 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values |
|
661 ** mean that writes of blocks that are nnn bytes in size and |
|
662 ** are aligned to an address which is an integer multiple of |
|
663 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means |
|
664 ** that when data is appended to a file, the data is appended |
|
665 ** first then the size of the file is extended, never the other |
|
666 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that |
|
667 ** information is written to disk in the same order as calls |
|
668 ** to xWrite(). |
|
669 ** |
|
670 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill |
|
671 ** in the unread portions of the buffer with zeros. A VFS that |
|
672 ** fails to zero-fill short reads might seem to work. However, |
|
673 ** failure to zero-fill short reads will eventually lead to |
|
674 ** database corruption. |
|
675 */ |
|
676 typedef struct sqlite3_io_methods sqlite3_io_methods; |
|
677 struct sqlite3_io_methods { |
|
678 int iVersion; |
|
679 int (*xClose)(sqlite3_file*); |
|
680 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst); |
|
681 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst); |
|
682 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size); |
|
683 int (*xSync)(sqlite3_file*, int flags); |
|
684 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize); |
|
685 int (*xLock)(sqlite3_file*, int); |
|
686 int (*xUnlock)(sqlite3_file*, int); |
|
687 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut); |
|
688 int (*xFileControl)(sqlite3_file*, int op, void *pArg); |
|
689 int (*xSectorSize)(sqlite3_file*); |
|
690 int (*xDeviceCharacteristics)(sqlite3_file*); |
|
691 /* Methods above are valid for version 1 */ |
|
692 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**); |
|
693 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags); |
|
694 void (*xShmBarrier)(sqlite3_file*); |
|
695 int (*xShmUnmap)(sqlite3_file*, int deleteFlag); |
|
696 /* Methods above are valid for version 2 */ |
|
697 /* Additional methods may be added in future releases */ |
|
698 }; |
|
699 |
|
700 /* |
|
701 ** CAPI3REF: Standard File Control Opcodes |
|
702 ** |
|
703 ** These integer constants are opcodes for the xFileControl method |
|
704 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()] |
|
705 ** interface. |
|
706 ** |
|
707 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This |
|
708 ** opcode causes the xFileControl method to write the current state of |
|
709 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED], |
|
710 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE]) |
|
711 ** into an integer that the pArg argument points to. This capability |
|
712 ** is used during testing and only needs to be supported when SQLITE_TEST |
|
713 ** is defined. |
|
714 ** |
|
715 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS |
|
716 ** layer a hint of how large the database file will grow to be during the |
|
717 ** current transaction. This hint is not guaranteed to be accurate but it |
|
718 ** is often close. The underlying VFS might choose to preallocate database |
|
719 ** file space based on this hint in order to help writes to the database |
|
720 ** file run faster. |
|
721 ** |
|
722 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS |
|
723 ** extends and truncates the database file in chunks of a size specified |
|
724 ** by the user. The fourth argument to [sqlite3_file_control()] should |
|
725 ** point to an integer (type int) containing the new chunk-size to use |
|
726 ** for the nominated database. Allocating database file space in large |
|
727 ** chunks (say 1MB at a time), may reduce file-system fragmentation and |
|
728 ** improve performance on some systems. |
|
729 ** |
|
730 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer |
|
731 ** to the [sqlite3_file] object associated with a particular database |
|
732 ** connection. See the [sqlite3_file_control()] documentation for |
|
733 ** additional information. |
|
734 ** |
|
735 ** ^(The [SQLITE_FCNTL_SYNC_OMITTED] opcode is generated internally by |
|
736 ** SQLite and sent to all VFSes in place of a call to the xSync method |
|
737 ** when the database connection has [PRAGMA synchronous] set to OFF.)^ |
|
738 ** Some specialized VFSes need this signal in order to operate correctly |
|
739 ** when [PRAGMA synchronous | PRAGMA synchronous=OFF] is set, but most |
|
740 ** VFSes do not need this signal and should silently ignore this opcode. |
|
741 ** Applications should not call [sqlite3_file_control()] with this |
|
742 ** opcode as doing so may disrupt the operation of the specialized VFSes |
|
743 ** that do require it. |
|
744 ** |
|
745 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic |
|
746 ** retry counts and intervals for certain disk I/O operations for the |
|
747 ** windows [VFS] in order to work to provide robustness against |
|
748 ** anti-virus programs. By default, the windows VFS will retry file read, |
|
749 ** file write, and file delete opertions up to 10 times, with a delay |
|
750 ** of 25 milliseconds before the first retry and with the delay increasing |
|
751 ** by an additional 25 milliseconds with each subsequent retry. This |
|
752 ** opcode allows those to values (10 retries and 25 milliseconds of delay) |
|
753 ** to be adjusted. The values are changed for all database connections |
|
754 ** within the same process. The argument is a pointer to an array of two |
|
755 ** integers where the first integer i the new retry count and the second |
|
756 ** integer is the delay. If either integer is negative, then the setting |
|
757 ** is not changed but instead the prior value of that setting is written |
|
758 ** into the array entry, allowing the current retry settings to be |
|
759 ** interrogated. The zDbName parameter is ignored. |
|
760 ** |
|
761 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the |
|
762 ** persistent [WAL | Write AHead Log] setting. By default, the auxiliary |
|
763 ** write ahead log and shared memory files used for transaction control |
|
764 ** are automatically deleted when the latest connection to the database |
|
765 ** closes. Setting persistent WAL mode causes those files to persist after |
|
766 ** close. Persisting the files is useful when other processes that do not |
|
767 ** have write permission on the directory containing the database file want |
|
768 ** to read the database file, as the WAL and shared memory files must exist |
|
769 ** in order for the database to be readable. The fourth parameter to |
|
770 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer. |
|
771 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent |
|
772 ** WAL mode. If the integer is -1, then it is overwritten with the current |
|
773 ** WAL persistence setting. |
|
774 ** |
|
775 */ |
|
776 #define SQLITE_FCNTL_LOCKSTATE 1 |
|
777 #define SQLITE_GET_LOCKPROXYFILE 2 |
|
778 #define SQLITE_SET_LOCKPROXYFILE 3 |
|
779 #define SQLITE_LAST_ERRNO 4 |
|
780 #define SQLITE_FCNTL_SIZE_HINT 5 |
|
781 #define SQLITE_FCNTL_CHUNK_SIZE 6 |
|
782 #define SQLITE_FCNTL_FILE_POINTER 7 |
|
783 #define SQLITE_FCNTL_SYNC_OMITTED 8 |
|
784 #define SQLITE_FCNTL_WIN32_AV_RETRY 9 |
|
785 #define SQLITE_FCNTL_PERSIST_WAL 10 |
|
786 |
|
787 /* |
|
788 ** CAPI3REF: Mutex Handle |
|
789 ** |
|
790 ** The mutex module within SQLite defines [sqlite3_mutex] to be an |
|
791 ** abstract type for a mutex object. The SQLite core never looks |
|
792 ** at the internal representation of an [sqlite3_mutex]. It only |
|
793 ** deals with pointers to the [sqlite3_mutex] object. |
|
794 ** |
|
795 ** Mutexes are created using [sqlite3_mutex_alloc()]. |
|
796 */ |
|
797 typedef struct sqlite3_mutex sqlite3_mutex; |
|
798 |
|
799 /* |
|
800 ** CAPI3REF: OS Interface Object |
|
801 ** |
|
802 ** An instance of the sqlite3_vfs object defines the interface between |
|
803 ** the SQLite core and the underlying operating system. The "vfs" |
|
804 ** in the name of the object stands for "virtual file system". See |
|
805 ** the [VFS | VFS documentation] for further information. |
|
806 ** |
|
807 ** The value of the iVersion field is initially 1 but may be larger in |
|
808 ** future versions of SQLite. Additional fields may be appended to this |
|
809 ** object when the iVersion value is increased. Note that the structure |
|
810 ** of the sqlite3_vfs object changes in the transaction between |
|
811 ** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not |
|
812 ** modified. |
|
813 ** |
|
814 ** The szOsFile field is the size of the subclassed [sqlite3_file] |
|
815 ** structure used by this VFS. mxPathname is the maximum length of |
|
816 ** a pathname in this VFS. |
|
817 ** |
|
818 ** Registered sqlite3_vfs objects are kept on a linked list formed by |
|
819 ** the pNext pointer. The [sqlite3_vfs_register()] |
|
820 ** and [sqlite3_vfs_unregister()] interfaces manage this list |
|
821 ** in a thread-safe way. The [sqlite3_vfs_find()] interface |
|
822 ** searches the list. Neither the application code nor the VFS |
|
823 ** implementation should use the pNext pointer. |
|
824 ** |
|
825 ** The pNext field is the only field in the sqlite3_vfs |
|
826 ** structure that SQLite will ever modify. SQLite will only access |
|
827 ** or modify this field while holding a particular static mutex. |
|
828 ** The application should never modify anything within the sqlite3_vfs |
|
829 ** object once the object has been registered. |
|
830 ** |
|
831 ** The zName field holds the name of the VFS module. The name must |
|
832 ** be unique across all VFS modules. |
|
833 ** |
|
834 ** [[sqlite3_vfs.xOpen]] |
|
835 ** ^SQLite guarantees that the zFilename parameter to xOpen |
|
836 ** is either a NULL pointer or string obtained |
|
837 ** from xFullPathname() with an optional suffix added. |
|
838 ** ^If a suffix is added to the zFilename parameter, it will |
|
839 ** consist of a single "-" character followed by no more than |
|
840 ** 10 alphanumeric and/or "-" characters. |
|
841 ** ^SQLite further guarantees that |
|
842 ** the string will be valid and unchanged until xClose() is |
|
843 ** called. Because of the previous sentence, |
|
844 ** the [sqlite3_file] can safely store a pointer to the |
|
845 ** filename if it needs to remember the filename for some reason. |
|
846 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen |
|
847 ** must invent its own temporary name for the file. ^Whenever the |
|
848 ** xFilename parameter is NULL it will also be the case that the |
|
849 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE]. |
|
850 ** |
|
851 ** The flags argument to xOpen() includes all bits set in |
|
852 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()] |
|
853 ** or [sqlite3_open16()] is used, then flags includes at least |
|
854 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]. |
|
855 ** If xOpen() opens a file read-only then it sets *pOutFlags to |
|
856 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set. |
|
857 ** |
|
858 ** ^(SQLite will also add one of the following flags to the xOpen() |
|
859 ** call, depending on the object being opened: |
|
860 ** |
|
861 ** <ul> |
|
862 ** <li> [SQLITE_OPEN_MAIN_DB] |
|
863 ** <li> [SQLITE_OPEN_MAIN_JOURNAL] |
|
864 ** <li> [SQLITE_OPEN_TEMP_DB] |
|
865 ** <li> [SQLITE_OPEN_TEMP_JOURNAL] |
|
866 ** <li> [SQLITE_OPEN_TRANSIENT_DB] |
|
867 ** <li> [SQLITE_OPEN_SUBJOURNAL] |
|
868 ** <li> [SQLITE_OPEN_MASTER_JOURNAL] |
|
869 ** <li> [SQLITE_OPEN_WAL] |
|
870 ** </ul>)^ |
|
871 ** |
|
872 ** The file I/O implementation can use the object type flags to |
|
873 ** change the way it deals with files. For example, an application |
|
874 ** that does not care about crash recovery or rollback might make |
|
875 ** the open of a journal file a no-op. Writes to this journal would |
|
876 ** also be no-ops, and any attempt to read the journal would return |
|
877 ** SQLITE_IOERR. Or the implementation might recognize that a database |
|
878 ** file will be doing page-aligned sector reads and writes in a random |
|
879 ** order and set up its I/O subsystem accordingly. |
|
880 ** |
|
881 ** SQLite might also add one of the following flags to the xOpen method: |
|
882 ** |
|
883 ** <ul> |
|
884 ** <li> [SQLITE_OPEN_DELETEONCLOSE] |
|
885 ** <li> [SQLITE_OPEN_EXCLUSIVE] |
|
886 ** </ul> |
|
887 ** |
|
888 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be |
|
889 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE] |
|
890 ** will be set for TEMP databases and their journals, transient |
|
891 ** databases, and subjournals. |
|
892 ** |
|
893 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction |
|
894 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly |
|
895 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open() |
|
896 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the |
|
897 ** SQLITE_OPEN_CREATE, is used to indicate that file should always |
|
898 ** be created, and that it is an error if it already exists. |
|
899 ** It is <i>not</i> used to indicate the file should be opened |
|
900 ** for exclusive access. |
|
901 ** |
|
902 ** ^At least szOsFile bytes of memory are allocated by SQLite |
|
903 ** to hold the [sqlite3_file] structure passed as the third |
|
904 ** argument to xOpen. The xOpen method does not have to |
|
905 ** allocate the structure; it should just fill it in. Note that |
|
906 ** the xOpen method must set the sqlite3_file.pMethods to either |
|
907 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do |
|
908 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods |
|
909 ** element will be valid after xOpen returns regardless of the success |
|
910 ** or failure of the xOpen call. |
|
911 ** |
|
912 ** [[sqlite3_vfs.xAccess]] |
|
913 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS] |
|
914 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to |
|
915 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ] |
|
916 ** to test whether a file is at least readable. The file can be a |
|
917 ** directory. |
|
918 ** |
|
919 ** ^SQLite will always allocate at least mxPathname+1 bytes for the |
|
920 ** output buffer xFullPathname. The exact size of the output buffer |
|
921 ** is also passed as a parameter to both methods. If the output buffer |
|
922 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is |
|
923 ** handled as a fatal error by SQLite, vfs implementations should endeavor |
|
924 ** to prevent this by setting mxPathname to a sufficiently large value. |
|
925 ** |
|
926 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64() |
|
927 ** interfaces are not strictly a part of the filesystem, but they are |
|
928 ** included in the VFS structure for completeness. |
|
929 ** The xRandomness() function attempts to return nBytes bytes |
|
930 ** of good-quality randomness into zOut. The return value is |
|
931 ** the actual number of bytes of randomness obtained. |
|
932 ** The xSleep() method causes the calling thread to sleep for at |
|
933 ** least the number of microseconds given. ^The xCurrentTime() |
|
934 ** method returns a Julian Day Number for the current date and time as |
|
935 ** a floating point value. |
|
936 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian |
|
937 ** Day Number multiplied by 86400000 (the number of milliseconds in |
|
938 ** a 24-hour day). |
|
939 ** ^SQLite will use the xCurrentTimeInt64() method to get the current |
|
940 ** date and time if that method is available (if iVersion is 2 or |
|
941 ** greater and the function pointer is not NULL) and will fall back |
|
942 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable. |
|
943 ** |
|
944 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces |
|
945 ** are not used by the SQLite core. These optional interfaces are provided |
|
946 ** by some VFSes to facilitate testing of the VFS code. By overriding |
|
947 ** system calls with functions under its control, a test program can |
|
948 ** simulate faults and error conditions that would otherwise be difficult |
|
949 ** or impossible to induce. The set of system calls that can be overridden |
|
950 ** varies from one VFS to another, and from one version of the same VFS to the |
|
951 ** next. Applications that use these interfaces must be prepared for any |
|
952 ** or all of these interfaces to be NULL or for their behavior to change |
|
953 ** from one release to the next. Applications must not attempt to access |
|
954 ** any of these methods if the iVersion of the VFS is less than 3. |
|
955 */ |
|
956 typedef struct sqlite3_vfs sqlite3_vfs; |
|
957 typedef void (*sqlite3_syscall_ptr)(void); |
|
958 struct sqlite3_vfs { |
|
959 int iVersion; /* Structure version number (currently 3) */ |
|
960 int szOsFile; /* Size of subclassed sqlite3_file */ |
|
961 int mxPathname; /* Maximum file pathname length */ |
|
962 sqlite3_vfs *pNext; /* Next registered VFS */ |
|
963 const char *zName; /* Name of this virtual file system */ |
|
964 void *pAppData; /* Pointer to application-specific data */ |
|
965 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*, |
|
966 int flags, int *pOutFlags); |
|
967 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir); |
|
968 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut); |
|
969 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut); |
|
970 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename); |
|
971 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg); |
|
972 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void); |
|
973 void (*xDlClose)(sqlite3_vfs*, void*); |
|
974 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut); |
|
975 int (*xSleep)(sqlite3_vfs*, int microseconds); |
|
976 int (*xCurrentTime)(sqlite3_vfs*, double*); |
|
977 int (*xGetLastError)(sqlite3_vfs*, int, char *); |
|
978 /* |
|
979 ** The methods above are in version 1 of the sqlite_vfs object |
|
980 ** definition. Those that follow are added in version 2 or later |
|
981 */ |
|
982 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*); |
|
983 /* |
|
984 ** The methods above are in versions 1 and 2 of the sqlite_vfs object. |
|
985 ** Those below are for version 3 and greater. |
|
986 */ |
|
987 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr); |
|
988 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName); |
|
989 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName); |
|
990 /* |
|
991 ** The methods above are in versions 1 through 3 of the sqlite_vfs object. |
|
992 ** New fields may be appended in figure versions. The iVersion |
|
993 ** value will increment whenever this happens. |
|
994 */ |
|
995 }; |
|
996 |
|
997 /* |
|
998 ** CAPI3REF: Flags for the xAccess VFS method |
|
999 ** |
|
1000 ** These integer constants can be used as the third parameter to |
|
1001 ** the xAccess method of an [sqlite3_vfs] object. They determine |
|
1002 ** what kind of permissions the xAccess method is looking for. |
|
1003 ** With SQLITE_ACCESS_EXISTS, the xAccess method |
|
1004 ** simply checks whether the file exists. |
|
1005 ** With SQLITE_ACCESS_READWRITE, the xAccess method |
|
1006 ** checks whether the named directory is both readable and writable |
|
1007 ** (in other words, if files can be added, removed, and renamed within |
|
1008 ** the directory). |
|
1009 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the |
|
1010 ** [temp_store_directory pragma], though this could change in a future |
|
1011 ** release of SQLite. |
|
1012 ** With SQLITE_ACCESS_READ, the xAccess method |
|
1013 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is |
|
1014 ** currently unused, though it might be used in a future release of |
|
1015 ** SQLite. |
|
1016 */ |
|
1017 #define SQLITE_ACCESS_EXISTS 0 |
|
1018 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */ |
|
1019 #define SQLITE_ACCESS_READ 2 /* Unused */ |
|
1020 |
|
1021 /* |
|
1022 ** CAPI3REF: Flags for the xShmLock VFS method |
|
1023 ** |
|
1024 ** These integer constants define the various locking operations |
|
1025 ** allowed by the xShmLock method of [sqlite3_io_methods]. The |
|
1026 ** following are the only legal combinations of flags to the |
|
1027 ** xShmLock method: |
|
1028 ** |
|
1029 ** <ul> |
|
1030 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED |
|
1031 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE |
|
1032 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED |
|
1033 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE |
|
1034 ** </ul> |
|
1035 ** |
|
1036 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as |
|
1037 ** was given no the corresponding lock. |
|
1038 ** |
|
1039 ** The xShmLock method can transition between unlocked and SHARED or |
|
1040 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED |
|
1041 ** and EXCLUSIVE. |
|
1042 */ |
|
1043 #define SQLITE_SHM_UNLOCK 1 |
|
1044 #define SQLITE_SHM_LOCK 2 |
|
1045 #define SQLITE_SHM_SHARED 4 |
|
1046 #define SQLITE_SHM_EXCLUSIVE 8 |
|
1047 |
|
1048 /* |
|
1049 ** CAPI3REF: Maximum xShmLock index |
|
1050 ** |
|
1051 ** The xShmLock method on [sqlite3_io_methods] may use values |
|
1052 ** between 0 and this upper bound as its "offset" argument. |
|
1053 ** The SQLite core will never attempt to acquire or release a |
|
1054 ** lock outside of this range |
|
1055 */ |
|
1056 #define SQLITE_SHM_NLOCK 8 |
|
1057 |
|
1058 |
|
1059 /* |
|
1060 ** CAPI3REF: Initialize The SQLite Library |
|
1061 ** |
|
1062 ** ^The sqlite3_initialize() routine initializes the |
|
1063 ** SQLite library. ^The sqlite3_shutdown() routine |
|
1064 ** deallocates any resources that were allocated by sqlite3_initialize(). |
|
1065 ** These routines are designed to aid in process initialization and |
|
1066 ** shutdown on embedded systems. Workstation applications using |
|
1067 ** SQLite normally do not need to invoke either of these routines. |
|
1068 ** |
|
1069 ** A call to sqlite3_initialize() is an "effective" call if it is |
|
1070 ** the first time sqlite3_initialize() is invoked during the lifetime of |
|
1071 ** the process, or if it is the first time sqlite3_initialize() is invoked |
|
1072 ** following a call to sqlite3_shutdown(). ^(Only an effective call |
|
1073 ** of sqlite3_initialize() does any initialization. All other calls |
|
1074 ** are harmless no-ops.)^ |
|
1075 ** |
|
1076 ** A call to sqlite3_shutdown() is an "effective" call if it is the first |
|
1077 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only |
|
1078 ** an effective call to sqlite3_shutdown() does any deinitialization. |
|
1079 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^ |
|
1080 ** |
|
1081 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown() |
|
1082 ** is not. The sqlite3_shutdown() interface must only be called from a |
|
1083 ** single thread. All open [database connections] must be closed and all |
|
1084 ** other SQLite resources must be deallocated prior to invoking |
|
1085 ** sqlite3_shutdown(). |
|
1086 ** |
|
1087 ** Among other things, ^sqlite3_initialize() will invoke |
|
1088 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown() |
|
1089 ** will invoke sqlite3_os_end(). |
|
1090 ** |
|
1091 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success. |
|
1092 ** ^If for some reason, sqlite3_initialize() is unable to initialize |
|
1093 ** the library (perhaps it is unable to allocate a needed resource such |
|
1094 ** as a mutex) it returns an [error code] other than [SQLITE_OK]. |
|
1095 ** |
|
1096 ** ^The sqlite3_initialize() routine is called internally by many other |
|
1097 ** SQLite interfaces so that an application usually does not need to |
|
1098 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()] |
|
1099 ** calls sqlite3_initialize() so the SQLite library will be automatically |
|
1100 ** initialized when [sqlite3_open()] is called if it has not be initialized |
|
1101 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT] |
|
1102 ** compile-time option, then the automatic calls to sqlite3_initialize() |
|
1103 ** are omitted and the application must call sqlite3_initialize() directly |
|
1104 ** prior to using any other SQLite interface. For maximum portability, |
|
1105 ** it is recommended that applications always invoke sqlite3_initialize() |
|
1106 ** directly prior to using any other SQLite interface. Future releases |
|
1107 ** of SQLite may require this. In other words, the behavior exhibited |
|
1108 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the |
|
1109 ** default behavior in some future release of SQLite. |
|
1110 ** |
|
1111 ** The sqlite3_os_init() routine does operating-system specific |
|
1112 ** initialization of the SQLite library. The sqlite3_os_end() |
|
1113 ** routine undoes the effect of sqlite3_os_init(). Typical tasks |
|
1114 ** performed by these routines include allocation or deallocation |
|
1115 ** of static resources, initialization of global variables, |
|
1116 ** setting up a default [sqlite3_vfs] module, or setting up |
|
1117 ** a default configuration using [sqlite3_config()]. |
|
1118 ** |
|
1119 ** The application should never invoke either sqlite3_os_init() |
|
1120 ** or sqlite3_os_end() directly. The application should only invoke |
|
1121 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init() |
|
1122 ** interface is called automatically by sqlite3_initialize() and |
|
1123 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate |
|
1124 ** implementations for sqlite3_os_init() and sqlite3_os_end() |
|
1125 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2. |
|
1126 ** When [custom builds | built for other platforms] |
|
1127 ** (using the [SQLITE_OS_OTHER=1] compile-time |
|
1128 ** option) the application must supply a suitable implementation for |
|
1129 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied |
|
1130 ** implementation of sqlite3_os_init() or sqlite3_os_end() |
|
1131 ** must return [SQLITE_OK] on success and some other [error code] upon |
|
1132 ** failure. |
|
1133 */ |
|
1134 SQLITE_API int sqlite3_initialize(void); |
|
1135 SQLITE_API int sqlite3_shutdown(void); |
|
1136 SQLITE_API int sqlite3_os_init(void); |
|
1137 SQLITE_API int sqlite3_os_end(void); |
|
1138 |
|
1139 /* |
|
1140 ** CAPI3REF: Configuring The SQLite Library |
|
1141 ** |
|
1142 ** The sqlite3_config() interface is used to make global configuration |
|
1143 ** changes to SQLite in order to tune SQLite to the specific needs of |
|
1144 ** the application. The default configuration is recommended for most |
|
1145 ** applications and so this routine is usually not necessary. It is |
|
1146 ** provided to support rare applications with unusual needs. |
|
1147 ** |
|
1148 ** The sqlite3_config() interface is not threadsafe. The application |
|
1149 ** must insure that no other SQLite interfaces are invoked by other |
|
1150 ** threads while sqlite3_config() is running. Furthermore, sqlite3_config() |
|
1151 ** may only be invoked prior to library initialization using |
|
1152 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()]. |
|
1153 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before |
|
1154 ** [sqlite3_shutdown()] then it will return SQLITE_MISUSE. |
|
1155 ** Note, however, that ^sqlite3_config() can be called as part of the |
|
1156 ** implementation of an application-defined [sqlite3_os_init()]. |
|
1157 ** |
|
1158 ** The first argument to sqlite3_config() is an integer |
|
1159 ** [configuration option] that determines |
|
1160 ** what property of SQLite is to be configured. Subsequent arguments |
|
1161 ** vary depending on the [configuration option] |
|
1162 ** in the first argument. |
|
1163 ** |
|
1164 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK]. |
|
1165 ** ^If the option is unknown or SQLite is unable to set the option |
|
1166 ** then this routine returns a non-zero [error code]. |
|
1167 */ |
|
1168 SQLITE_API int sqlite3_config(int, ...); |
|
1169 |
|
1170 /* |
|
1171 ** CAPI3REF: Configure database connections |
|
1172 ** |
|
1173 ** The sqlite3_db_config() interface is used to make configuration |
|
1174 ** changes to a [database connection]. The interface is similar to |
|
1175 ** [sqlite3_config()] except that the changes apply to a single |
|
1176 ** [database connection] (specified in the first argument). |
|
1177 ** |
|
1178 ** The second argument to sqlite3_db_config(D,V,...) is the |
|
1179 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code |
|
1180 ** that indicates what aspect of the [database connection] is being configured. |
|
1181 ** Subsequent arguments vary depending on the configuration verb. |
|
1182 ** |
|
1183 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if |
|
1184 ** the call is considered successful. |
|
1185 */ |
|
1186 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...); |
|
1187 |
|
1188 /* |
|
1189 ** CAPI3REF: Memory Allocation Routines |
|
1190 ** |
|
1191 ** An instance of this object defines the interface between SQLite |
|
1192 ** and low-level memory allocation routines. |
|
1193 ** |
|
1194 ** This object is used in only one place in the SQLite interface. |
|
1195 ** A pointer to an instance of this object is the argument to |
|
1196 ** [sqlite3_config()] when the configuration option is |
|
1197 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC]. |
|
1198 ** By creating an instance of this object |
|
1199 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC]) |
|
1200 ** during configuration, an application can specify an alternative |
|
1201 ** memory allocation subsystem for SQLite to use for all of its |
|
1202 ** dynamic memory needs. |
|
1203 ** |
|
1204 ** Note that SQLite comes with several [built-in memory allocators] |
|
1205 ** that are perfectly adequate for the overwhelming majority of applications |
|
1206 ** and that this object is only useful to a tiny minority of applications |
|
1207 ** with specialized memory allocation requirements. This object is |
|
1208 ** also used during testing of SQLite in order to specify an alternative |
|
1209 ** memory allocator that simulates memory out-of-memory conditions in |
|
1210 ** order to verify that SQLite recovers gracefully from such |
|
1211 ** conditions. |
|
1212 ** |
|
1213 ** The xMalloc, xRealloc, and xFree methods must work like the |
|
1214 ** malloc(), realloc() and free() functions from the standard C library. |
|
1215 ** ^SQLite guarantees that the second argument to |
|
1216 ** xRealloc is always a value returned by a prior call to xRoundup. |
|
1217 ** |
|
1218 ** xSize should return the allocated size of a memory allocation |
|
1219 ** previously obtained from xMalloc or xRealloc. The allocated size |
|
1220 ** is always at least as big as the requested size but may be larger. |
|
1221 ** |
|
1222 ** The xRoundup method returns what would be the allocated size of |
|
1223 ** a memory allocation given a particular requested size. Most memory |
|
1224 ** allocators round up memory allocations at least to the next multiple |
|
1225 ** of 8. Some allocators round up to a larger multiple or to a power of 2. |
|
1226 ** Every memory allocation request coming in through [sqlite3_malloc()] |
|
1227 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0, |
|
1228 ** that causes the corresponding memory allocation to fail. |
|
1229 ** |
|
1230 ** The xInit method initializes the memory allocator. (For example, |
|
1231 ** it might allocate any require mutexes or initialize internal data |
|
1232 ** structures. The xShutdown method is invoked (indirectly) by |
|
1233 ** [sqlite3_shutdown()] and should deallocate any resources acquired |
|
1234 ** by xInit. The pAppData pointer is used as the only parameter to |
|
1235 ** xInit and xShutdown. |
|
1236 ** |
|
1237 ** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes |
|
1238 ** the xInit method, so the xInit method need not be threadsafe. The |
|
1239 ** xShutdown method is only called from [sqlite3_shutdown()] so it does |
|
1240 ** not need to be threadsafe either. For all other methods, SQLite |
|
1241 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the |
|
1242 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which |
|
1243 ** it is by default) and so the methods are automatically serialized. |
|
1244 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other |
|
1245 ** methods must be threadsafe or else make their own arrangements for |
|
1246 ** serialization. |
|
1247 ** |
|
1248 ** SQLite will never invoke xInit() more than once without an intervening |
|
1249 ** call to xShutdown(). |
|
1250 */ |
|
1251 typedef struct sqlite3_mem_methods sqlite3_mem_methods; |
|
1252 struct sqlite3_mem_methods { |
|
1253 void *(*xMalloc)(int); /* Memory allocation function */ |
|
1254 void (*xFree)(void*); /* Free a prior allocation */ |
|
1255 void *(*xRealloc)(void*,int); /* Resize an allocation */ |
|
1256 int (*xSize)(void*); /* Return the size of an allocation */ |
|
1257 int (*xRoundup)(int); /* Round up request size to allocation size */ |
|
1258 int (*xInit)(void*); /* Initialize the memory allocator */ |
|
1259 void (*xShutdown)(void*); /* Deinitialize the memory allocator */ |
|
1260 void *pAppData; /* Argument to xInit() and xShutdown() */ |
|
1261 }; |
|
1262 |
|
1263 /* |
|
1264 ** CAPI3REF: Configuration Options |
|
1265 ** KEYWORDS: {configuration option} |
|
1266 ** |
|
1267 ** These constants are the available integer configuration options that |
|
1268 ** can be passed as the first argument to the [sqlite3_config()] interface. |
|
1269 ** |
|
1270 ** New configuration options may be added in future releases of SQLite. |
|
1271 ** Existing configuration options might be discontinued. Applications |
|
1272 ** should check the return code from [sqlite3_config()] to make sure that |
|
1273 ** the call worked. The [sqlite3_config()] interface will return a |
|
1274 ** non-zero [error code] if a discontinued or unsupported configuration option |
|
1275 ** is invoked. |
|
1276 ** |
|
1277 ** <dl> |
|
1278 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt> |
|
1279 ** <dd>There are no arguments to this option. ^This option sets the |
|
1280 ** [threading mode] to Single-thread. In other words, it disables |
|
1281 ** all mutexing and puts SQLite into a mode where it can only be used |
|
1282 ** by a single thread. ^If SQLite is compiled with |
|
1283 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
|
1284 ** it is not possible to change the [threading mode] from its default |
|
1285 ** value of Single-thread and so [sqlite3_config()] will return |
|
1286 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD |
|
1287 ** configuration option.</dd> |
|
1288 ** |
|
1289 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt> |
|
1290 ** <dd>There are no arguments to this option. ^This option sets the |
|
1291 ** [threading mode] to Multi-thread. In other words, it disables |
|
1292 ** mutexing on [database connection] and [prepared statement] objects. |
|
1293 ** The application is responsible for serializing access to |
|
1294 ** [database connections] and [prepared statements]. But other mutexes |
|
1295 ** are enabled so that SQLite will be safe to use in a multi-threaded |
|
1296 ** environment as long as no two threads attempt to use the same |
|
1297 ** [database connection] at the same time. ^If SQLite is compiled with |
|
1298 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
|
1299 ** it is not possible to set the Multi-thread [threading mode] and |
|
1300 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the |
|
1301 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd> |
|
1302 ** |
|
1303 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt> |
|
1304 ** <dd>There are no arguments to this option. ^This option sets the |
|
1305 ** [threading mode] to Serialized. In other words, this option enables |
|
1306 ** all mutexes including the recursive |
|
1307 ** mutexes on [database connection] and [prepared statement] objects. |
|
1308 ** In this mode (which is the default when SQLite is compiled with |
|
1309 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access |
|
1310 ** to [database connections] and [prepared statements] so that the |
|
1311 ** application is free to use the same [database connection] or the |
|
1312 ** same [prepared statement] in different threads at the same time. |
|
1313 ** ^If SQLite is compiled with |
|
1314 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
|
1315 ** it is not possible to set the Serialized [threading mode] and |
|
1316 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the |
|
1317 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd> |
|
1318 ** |
|
1319 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt> |
|
1320 ** <dd> ^(This option takes a single argument which is a pointer to an |
|
1321 ** instance of the [sqlite3_mem_methods] structure. The argument specifies |
|
1322 ** alternative low-level memory allocation routines to be used in place of |
|
1323 ** the memory allocation routines built into SQLite.)^ ^SQLite makes |
|
1324 ** its own private copy of the content of the [sqlite3_mem_methods] structure |
|
1325 ** before the [sqlite3_config()] call returns.</dd> |
|
1326 ** |
|
1327 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt> |
|
1328 ** <dd> ^(This option takes a single argument which is a pointer to an |
|
1329 ** instance of the [sqlite3_mem_methods] structure. The [sqlite3_mem_methods] |
|
1330 ** structure is filled with the currently defined memory allocation routines.)^ |
|
1331 ** This option can be used to overload the default memory allocation |
|
1332 ** routines with a wrapper that simulations memory allocation failure or |
|
1333 ** tracks memory usage, for example. </dd> |
|
1334 ** |
|
1335 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt> |
|
1336 ** <dd> ^This option takes single argument of type int, interpreted as a |
|
1337 ** boolean, which enables or disables the collection of memory allocation |
|
1338 ** statistics. ^(When memory allocation statistics are disabled, the |
|
1339 ** following SQLite interfaces become non-operational: |
|
1340 ** <ul> |
|
1341 ** <li> [sqlite3_memory_used()] |
|
1342 ** <li> [sqlite3_memory_highwater()] |
|
1343 ** <li> [sqlite3_soft_heap_limit64()] |
|
1344 ** <li> [sqlite3_status()] |
|
1345 ** </ul>)^ |
|
1346 ** ^Memory allocation statistics are enabled by default unless SQLite is |
|
1347 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory |
|
1348 ** allocation statistics are disabled by default. |
|
1349 ** </dd> |
|
1350 ** |
|
1351 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt> |
|
1352 ** <dd> ^This option specifies a static memory buffer that SQLite can use for |
|
1353 ** scratch memory. There are three arguments: A pointer an 8-byte |
|
1354 ** aligned memory buffer from which the scratch allocations will be |
|
1355 ** drawn, the size of each scratch allocation (sz), |
|
1356 ** and the maximum number of scratch allocations (N). The sz |
|
1357 ** argument must be a multiple of 16. |
|
1358 ** The first argument must be a pointer to an 8-byte aligned buffer |
|
1359 ** of at least sz*N bytes of memory. |
|
1360 ** ^SQLite will use no more than two scratch buffers per thread. So |
|
1361 ** N should be set to twice the expected maximum number of threads. |
|
1362 ** ^SQLite will never require a scratch buffer that is more than 6 |
|
1363 ** times the database page size. ^If SQLite needs needs additional |
|
1364 ** scratch memory beyond what is provided by this configuration option, then |
|
1365 ** [sqlite3_malloc()] will be used to obtain the memory needed.</dd> |
|
1366 ** |
|
1367 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt> |
|
1368 ** <dd> ^This option specifies a static memory buffer that SQLite can use for |
|
1369 ** the database page cache with the default page cache implementation. |
|
1370 ** This configuration should not be used if an application-define page |
|
1371 ** cache implementation is loaded using the SQLITE_CONFIG_PCACHE option. |
|
1372 ** There are three arguments to this option: A pointer to 8-byte aligned |
|
1373 ** memory, the size of each page buffer (sz), and the number of pages (N). |
|
1374 ** The sz argument should be the size of the largest database page |
|
1375 ** (a power of two between 512 and 32768) plus a little extra for each |
|
1376 ** page header. ^The page header size is 20 to 40 bytes depending on |
|
1377 ** the host architecture. ^It is harmless, apart from the wasted memory, |
|
1378 ** to make sz a little too large. The first |
|
1379 ** argument should point to an allocation of at least sz*N bytes of memory. |
|
1380 ** ^SQLite will use the memory provided by the first argument to satisfy its |
|
1381 ** memory needs for the first N pages that it adds to cache. ^If additional |
|
1382 ** page cache memory is needed beyond what is provided by this option, then |
|
1383 ** SQLite goes to [sqlite3_malloc()] for the additional storage space. |
|
1384 ** The pointer in the first argument must |
|
1385 ** be aligned to an 8-byte boundary or subsequent behavior of SQLite |
|
1386 ** will be undefined.</dd> |
|
1387 ** |
|
1388 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt> |
|
1389 ** <dd> ^This option specifies a static memory buffer that SQLite will use |
|
1390 ** for all of its dynamic memory allocation needs beyond those provided |
|
1391 ** for by [SQLITE_CONFIG_SCRATCH] and [SQLITE_CONFIG_PAGECACHE]. |
|
1392 ** There are three arguments: An 8-byte aligned pointer to the memory, |
|
1393 ** the number of bytes in the memory buffer, and the minimum allocation size. |
|
1394 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts |
|
1395 ** to using its default memory allocator (the system malloc() implementation), |
|
1396 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the |
|
1397 ** memory pointer is not NULL and either [SQLITE_ENABLE_MEMSYS3] or |
|
1398 ** [SQLITE_ENABLE_MEMSYS5] are defined, then the alternative memory |
|
1399 ** allocator is engaged to handle all of SQLites memory allocation needs. |
|
1400 ** The first pointer (the memory pointer) must be aligned to an 8-byte |
|
1401 ** boundary or subsequent behavior of SQLite will be undefined. |
|
1402 ** The minimum allocation size is capped at 2^12. Reasonable values |
|
1403 ** for the minimum allocation size are 2^5 through 2^8.</dd> |
|
1404 ** |
|
1405 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt> |
|
1406 ** <dd> ^(This option takes a single argument which is a pointer to an |
|
1407 ** instance of the [sqlite3_mutex_methods] structure. The argument specifies |
|
1408 ** alternative low-level mutex routines to be used in place |
|
1409 ** the mutex routines built into SQLite.)^ ^SQLite makes a copy of the |
|
1410 ** content of the [sqlite3_mutex_methods] structure before the call to |
|
1411 ** [sqlite3_config()] returns. ^If SQLite is compiled with |
|
1412 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
|
1413 ** the entire mutexing subsystem is omitted from the build and hence calls to |
|
1414 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will |
|
1415 ** return [SQLITE_ERROR].</dd> |
|
1416 ** |
|
1417 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt> |
|
1418 ** <dd> ^(This option takes a single argument which is a pointer to an |
|
1419 ** instance of the [sqlite3_mutex_methods] structure. The |
|
1420 ** [sqlite3_mutex_methods] |
|
1421 ** structure is filled with the currently defined mutex routines.)^ |
|
1422 ** This option can be used to overload the default mutex allocation |
|
1423 ** routines with a wrapper used to track mutex usage for performance |
|
1424 ** profiling or testing, for example. ^If SQLite is compiled with |
|
1425 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then |
|
1426 ** the entire mutexing subsystem is omitted from the build and hence calls to |
|
1427 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will |
|
1428 ** return [SQLITE_ERROR].</dd> |
|
1429 ** |
|
1430 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt> |
|
1431 ** <dd> ^(This option takes two arguments that determine the default |
|
1432 ** memory allocation for the lookaside memory allocator on each |
|
1433 ** [database connection]. The first argument is the |
|
1434 ** size of each lookaside buffer slot and the second is the number of |
|
1435 ** slots allocated to each database connection.)^ ^(This option sets the |
|
1436 ** <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE] |
|
1437 ** verb to [sqlite3_db_config()] can be used to change the lookaside |
|
1438 ** configuration on individual connections.)^ </dd> |
|
1439 ** |
|
1440 ** [[SQLITE_CONFIG_PCACHE]] <dt>SQLITE_CONFIG_PCACHE</dt> |
|
1441 ** <dd> ^(This option takes a single argument which is a pointer to |
|
1442 ** an [sqlite3_pcache_methods] object. This object specifies the interface |
|
1443 ** to a custom page cache implementation.)^ ^SQLite makes a copy of the |
|
1444 ** object and uses it for page cache memory allocations.</dd> |
|
1445 ** |
|
1446 ** [[SQLITE_CONFIG_GETPCACHE]] <dt>SQLITE_CONFIG_GETPCACHE</dt> |
|
1447 ** <dd> ^(This option takes a single argument which is a pointer to an |
|
1448 ** [sqlite3_pcache_methods] object. SQLite copies of the current |
|
1449 ** page cache implementation into that object.)^ </dd> |
|
1450 ** |
|
1451 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt> |
|
1452 ** <dd> ^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a |
|
1453 ** function with a call signature of void(*)(void*,int,const char*), |
|
1454 ** and a pointer to void. ^If the function pointer is not NULL, it is |
|
1455 ** invoked by [sqlite3_log()] to process each logging event. ^If the |
|
1456 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op. |
|
1457 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is |
|
1458 ** passed through as the first parameter to the application-defined logger |
|
1459 ** function whenever that function is invoked. ^The second parameter to |
|
1460 ** the logger function is a copy of the first parameter to the corresponding |
|
1461 ** [sqlite3_log()] call and is intended to be a [result code] or an |
|
1462 ** [extended result code]. ^The third parameter passed to the logger is |
|
1463 ** log message after formatting via [sqlite3_snprintf()]. |
|
1464 ** The SQLite logging interface is not reentrant; the logger function |
|
1465 ** supplied by the application must not invoke any SQLite interface. |
|
1466 ** In a multi-threaded application, the application-defined logger |
|
1467 ** function must be threadsafe. </dd> |
|
1468 ** |
|
1469 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI |
|
1470 ** <dd> This option takes a single argument of type int. If non-zero, then |
|
1471 ** URI handling is globally enabled. If the parameter is zero, then URI handling |
|
1472 ** is globally disabled. If URI handling is globally enabled, all filenames |
|
1473 ** passed to [sqlite3_open()], [sqlite3_open_v2()], [sqlite3_open16()] or |
|
1474 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless |
|
1475 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database |
|
1476 ** connection is opened. If it is globally disabled, filenames are |
|
1477 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the |
|
1478 ** database connection is opened. By default, URI handling is globally |
|
1479 ** disabled. The default value may be changed by compiling with the |
|
1480 ** [SQLITE_USE_URI] symbol defined. |
|
1481 ** </dl> |
|
1482 */ |
|
1483 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */ |
|
1484 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */ |
|
1485 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */ |
|
1486 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */ |
|
1487 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */ |
|
1488 #define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */ |
|
1489 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */ |
|
1490 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */ |
|
1491 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */ |
|
1492 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */ |
|
1493 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */ |
|
1494 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */ |
|
1495 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */ |
|
1496 #define SQLITE_CONFIG_PCACHE 14 /* sqlite3_pcache_methods* */ |
|
1497 #define SQLITE_CONFIG_GETPCACHE 15 /* sqlite3_pcache_methods* */ |
|
1498 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */ |
|
1499 #define SQLITE_CONFIG_URI 17 /* int */ |
|
1500 |
|
1501 /* |
|
1502 ** CAPI3REF: Database Connection Configuration Options |
|
1503 ** |
|
1504 ** These constants are the available integer configuration options that |
|
1505 ** can be passed as the second argument to the [sqlite3_db_config()] interface. |
|
1506 ** |
|
1507 ** New configuration options may be added in future releases of SQLite. |
|
1508 ** Existing configuration options might be discontinued. Applications |
|
1509 ** should check the return code from [sqlite3_db_config()] to make sure that |
|
1510 ** the call worked. ^The [sqlite3_db_config()] interface will return a |
|
1511 ** non-zero [error code] if a discontinued or unsupported configuration option |
|
1512 ** is invoked. |
|
1513 ** |
|
1514 ** <dl> |
|
1515 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt> |
|
1516 ** <dd> ^This option takes three additional arguments that determine the |
|
1517 ** [lookaside memory allocator] configuration for the [database connection]. |
|
1518 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a |
|
1519 ** pointer to a memory buffer to use for lookaside memory. |
|
1520 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb |
|
1521 ** may be NULL in which case SQLite will allocate the |
|
1522 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the |
|
1523 ** size of each lookaside buffer slot. ^The third argument is the number of |
|
1524 ** slots. The size of the buffer in the first argument must be greater than |
|
1525 ** or equal to the product of the second and third arguments. The buffer |
|
1526 ** must be aligned to an 8-byte boundary. ^If the second argument to |
|
1527 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally |
|
1528 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory |
|
1529 ** configuration for a database connection can only be changed when that |
|
1530 ** connection is not currently using lookaside memory, or in other words |
|
1531 ** when the "current value" returned by |
|
1532 ** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero. |
|
1533 ** Any attempt to change the lookaside memory configuration when lookaside |
|
1534 ** memory is in use leaves the configuration unchanged and returns |
|
1535 ** [SQLITE_BUSY].)^</dd> |
|
1536 ** |
|
1537 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt> |
|
1538 ** <dd> ^This option is used to enable or disable the enforcement of |
|
1539 ** [foreign key constraints]. There should be two additional arguments. |
|
1540 ** The first argument is an integer which is 0 to disable FK enforcement, |
|
1541 ** positive to enable FK enforcement or negative to leave FK enforcement |
|
1542 ** unchanged. The second parameter is a pointer to an integer into which |
|
1543 ** is written 0 or 1 to indicate whether FK enforcement is off or on |
|
1544 ** following this call. The second parameter may be a NULL pointer, in |
|
1545 ** which case the FK enforcement setting is not reported back. </dd> |
|
1546 ** |
|
1547 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt> |
|
1548 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers]. |
|
1549 ** There should be two additional arguments. |
|
1550 ** The first argument is an integer which is 0 to disable triggers, |
|
1551 ** positive to enable triggers or negative to leave the setting unchanged. |
|
1552 ** The second parameter is a pointer to an integer into which |
|
1553 ** is written 0 or 1 to indicate whether triggers are disabled or enabled |
|
1554 ** following this call. The second parameter may be a NULL pointer, in |
|
1555 ** which case the trigger setting is not reported back. </dd> |
|
1556 ** |
|
1557 ** </dl> |
|
1558 */ |
|
1559 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */ |
|
1560 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */ |
|
1561 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */ |
|
1562 |
|
1563 |
|
1564 /* |
|
1565 ** CAPI3REF: Enable Or Disable Extended Result Codes |
|
1566 ** |
|
1567 ** ^The sqlite3_extended_result_codes() routine enables or disables the |
|
1568 ** [extended result codes] feature of SQLite. ^The extended result |
|
1569 ** codes are disabled by default for historical compatibility. |
|
1570 */ |
|
1571 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff); |
|
1572 |
|
1573 /* |
|
1574 ** CAPI3REF: Last Insert Rowid |
|
1575 ** |
|
1576 ** ^Each entry in an SQLite table has a unique 64-bit signed |
|
1577 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available |
|
1578 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those |
|
1579 ** names are not also used by explicitly declared columns. ^If |
|
1580 ** the table has a column of type [INTEGER PRIMARY KEY] then that column |
|
1581 ** is another alias for the rowid. |
|
1582 ** |
|
1583 ** ^This routine returns the [rowid] of the most recent |
|
1584 ** successful [INSERT] into the database from the [database connection] |
|
1585 ** in the first argument. ^As of SQLite version 3.7.7, this routines |
|
1586 ** records the last insert rowid of both ordinary tables and [virtual tables]. |
|
1587 ** ^If no successful [INSERT]s |
|
1588 ** have ever occurred on that database connection, zero is returned. |
|
1589 ** |
|
1590 ** ^(If an [INSERT] occurs within a trigger or within a [virtual table] |
|
1591 ** method, then this routine will return the [rowid] of the inserted |
|
1592 ** row as long as the trigger or virtual table method is running. |
|
1593 ** But once the trigger or virtual table method ends, the value returned |
|
1594 ** by this routine reverts to what it was before the trigger or virtual |
|
1595 ** table method began.)^ |
|
1596 ** |
|
1597 ** ^An [INSERT] that fails due to a constraint violation is not a |
|
1598 ** successful [INSERT] and does not change the value returned by this |
|
1599 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK, |
|
1600 ** and INSERT OR ABORT make no changes to the return value of this |
|
1601 ** routine when their insertion fails. ^(When INSERT OR REPLACE |
|
1602 ** encounters a constraint violation, it does not fail. The |
|
1603 ** INSERT continues to completion after deleting rows that caused |
|
1604 ** the constraint problem so INSERT OR REPLACE will always change |
|
1605 ** the return value of this interface.)^ |
|
1606 ** |
|
1607 ** ^For the purposes of this routine, an [INSERT] is considered to |
|
1608 ** be successful even if it is subsequently rolled back. |
|
1609 ** |
|
1610 ** This function is accessible to SQL statements via the |
|
1611 ** [last_insert_rowid() SQL function]. |
|
1612 ** |
|
1613 ** If a separate thread performs a new [INSERT] on the same |
|
1614 ** database connection while the [sqlite3_last_insert_rowid()] |
|
1615 ** function is running and thus changes the last insert [rowid], |
|
1616 ** then the value returned by [sqlite3_last_insert_rowid()] is |
|
1617 ** unpredictable and might not equal either the old or the new |
|
1618 ** last insert [rowid]. |
|
1619 */ |
|
1620 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*); |
|
1621 |
|
1622 /* |
|
1623 ** CAPI3REF: Count The Number Of Rows Modified |
|
1624 ** |
|
1625 ** ^This function returns the number of database rows that were changed |
|
1626 ** or inserted or deleted by the most recently completed SQL statement |
|
1627 ** on the [database connection] specified by the first parameter. |
|
1628 ** ^(Only changes that are directly specified by the [INSERT], [UPDATE], |
|
1629 ** or [DELETE] statement are counted. Auxiliary changes caused by |
|
1630 ** triggers or [foreign key actions] are not counted.)^ Use the |
|
1631 ** [sqlite3_total_changes()] function to find the total number of changes |
|
1632 ** including changes caused by triggers and foreign key actions. |
|
1633 ** |
|
1634 ** ^Changes to a view that are simulated by an [INSTEAD OF trigger] |
|
1635 ** are not counted. Only real table changes are counted. |
|
1636 ** |
|
1637 ** ^(A "row change" is a change to a single row of a single table |
|
1638 ** caused by an INSERT, DELETE, or UPDATE statement. Rows that |
|
1639 ** are changed as side effects of [REPLACE] constraint resolution, |
|
1640 ** rollback, ABORT processing, [DROP TABLE], or by any other |
|
1641 ** mechanisms do not count as direct row changes.)^ |
|
1642 ** |
|
1643 ** A "trigger context" is a scope of execution that begins and |
|
1644 ** ends with the script of a [CREATE TRIGGER | trigger]. |
|
1645 ** Most SQL statements are |
|
1646 ** evaluated outside of any trigger. This is the "top level" |
|
1647 ** trigger context. If a trigger fires from the top level, a |
|
1648 ** new trigger context is entered for the duration of that one |
|
1649 ** trigger. Subtriggers create subcontexts for their duration. |
|
1650 ** |
|
1651 ** ^Calling [sqlite3_exec()] or [sqlite3_step()] recursively does |
|
1652 ** not create a new trigger context. |
|
1653 ** |
|
1654 ** ^This function returns the number of direct row changes in the |
|
1655 ** most recent INSERT, UPDATE, or DELETE statement within the same |
|
1656 ** trigger context. |
|
1657 ** |
|
1658 ** ^Thus, when called from the top level, this function returns the |
|
1659 ** number of changes in the most recent INSERT, UPDATE, or DELETE |
|
1660 ** that also occurred at the top level. ^(Within the body of a trigger, |
|
1661 ** the sqlite3_changes() interface can be called to find the number of |
|
1662 ** changes in the most recently completed INSERT, UPDATE, or DELETE |
|
1663 ** statement within the body of the same trigger. |
|
1664 ** However, the number returned does not include changes |
|
1665 ** caused by subtriggers since those have their own context.)^ |
|
1666 ** |
|
1667 ** See also the [sqlite3_total_changes()] interface, the |
|
1668 ** [count_changes pragma], and the [changes() SQL function]. |
|
1669 ** |
|
1670 ** If a separate thread makes changes on the same database connection |
|
1671 ** while [sqlite3_changes()] is running then the value returned |
|
1672 ** is unpredictable and not meaningful. |
|
1673 */ |
|
1674 SQLITE_API int sqlite3_changes(sqlite3*); |
|
1675 |
|
1676 /* |
|
1677 ** CAPI3REF: Total Number Of Rows Modified |
|
1678 ** |
|
1679 ** ^This function returns the number of row changes caused by [INSERT], |
|
1680 ** [UPDATE] or [DELETE] statements since the [database connection] was opened. |
|
1681 ** ^(The count returned by sqlite3_total_changes() includes all changes |
|
1682 ** from all [CREATE TRIGGER | trigger] contexts and changes made by |
|
1683 ** [foreign key actions]. However, |
|
1684 ** the count does not include changes used to implement [REPLACE] constraints, |
|
1685 ** do rollbacks or ABORT processing, or [DROP TABLE] processing. The |
|
1686 ** count does not include rows of views that fire an [INSTEAD OF trigger], |
|
1687 ** though if the INSTEAD OF trigger makes changes of its own, those changes |
|
1688 ** are counted.)^ |
|
1689 ** ^The sqlite3_total_changes() function counts the changes as soon as |
|
1690 ** the statement that makes them is completed (when the statement handle |
|
1691 ** is passed to [sqlite3_reset()] or [sqlite3_finalize()]). |
|
1692 ** |
|
1693 ** See also the [sqlite3_changes()] interface, the |
|
1694 ** [count_changes pragma], and the [total_changes() SQL function]. |
|
1695 ** |
|
1696 ** If a separate thread makes changes on the same database connection |
|
1697 ** while [sqlite3_total_changes()] is running then the value |
|
1698 ** returned is unpredictable and not meaningful. |
|
1699 */ |
|
1700 SQLITE_API int sqlite3_total_changes(sqlite3*); |
|
1701 |
|
1702 /* |
|
1703 ** CAPI3REF: Interrupt A Long-Running Query |
|
1704 ** |
|
1705 ** ^This function causes any pending database operation to abort and |
|
1706 ** return at its earliest opportunity. This routine is typically |
|
1707 ** called in response to a user action such as pressing "Cancel" |
|
1708 ** or Ctrl-C where the user wants a long query operation to halt |
|
1709 ** immediately. |
|
1710 ** |
|
1711 ** ^It is safe to call this routine from a thread different from the |
|
1712 ** thread that is currently running the database operation. But it |
|
1713 ** is not safe to call this routine with a [database connection] that |
|
1714 ** is closed or might close before sqlite3_interrupt() returns. |
|
1715 ** |
|
1716 ** ^If an SQL operation is very nearly finished at the time when |
|
1717 ** sqlite3_interrupt() is called, then it might not have an opportunity |
|
1718 ** to be interrupted and might continue to completion. |
|
1719 ** |
|
1720 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT]. |
|
1721 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE |
|
1722 ** that is inside an explicit transaction, then the entire transaction |
|
1723 ** will be rolled back automatically. |
|
1724 ** |
|
1725 ** ^The sqlite3_interrupt(D) call is in effect until all currently running |
|
1726 ** SQL statements on [database connection] D complete. ^Any new SQL statements |
|
1727 ** that are started after the sqlite3_interrupt() call and before the |
|
1728 ** running statements reaches zero are interrupted as if they had been |
|
1729 ** running prior to the sqlite3_interrupt() call. ^New SQL statements |
|
1730 ** that are started after the running statement count reaches zero are |
|
1731 ** not effected by the sqlite3_interrupt(). |
|
1732 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running |
|
1733 ** SQL statements is a no-op and has no effect on SQL statements |
|
1734 ** that are started after the sqlite3_interrupt() call returns. |
|
1735 ** |
|
1736 ** If the database connection closes while [sqlite3_interrupt()] |
|
1737 ** is running then bad things will likely happen. |
|
1738 */ |
|
1739 SQLITE_API void sqlite3_interrupt(sqlite3*); |
|
1740 |
|
1741 /* |
|
1742 ** CAPI3REF: Determine If An SQL Statement Is Complete |
|
1743 ** |
|
1744 ** These routines are useful during command-line input to determine if the |
|
1745 ** currently entered text seems to form a complete SQL statement or |
|
1746 ** if additional input is needed before sending the text into |
|
1747 ** SQLite for parsing. ^These routines return 1 if the input string |
|
1748 ** appears to be a complete SQL statement. ^A statement is judged to be |
|
1749 ** complete if it ends with a semicolon token and is not a prefix of a |
|
1750 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within |
|
1751 ** string literals or quoted identifier names or comments are not |
|
1752 ** independent tokens (they are part of the token in which they are |
|
1753 ** embedded) and thus do not count as a statement terminator. ^Whitespace |
|
1754 ** and comments that follow the final semicolon are ignored. |
|
1755 ** |
|
1756 ** ^These routines return 0 if the statement is incomplete. ^If a |
|
1757 ** memory allocation fails, then SQLITE_NOMEM is returned. |
|
1758 ** |
|
1759 ** ^These routines do not parse the SQL statements thus |
|
1760 ** will not detect syntactically incorrect SQL. |
|
1761 ** |
|
1762 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior |
|
1763 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked |
|
1764 ** automatically by sqlite3_complete16(). If that initialization fails, |
|
1765 ** then the return value from sqlite3_complete16() will be non-zero |
|
1766 ** regardless of whether or not the input SQL is complete.)^ |
|
1767 ** |
|
1768 ** The input to [sqlite3_complete()] must be a zero-terminated |
|
1769 ** UTF-8 string. |
|
1770 ** |
|
1771 ** The input to [sqlite3_complete16()] must be a zero-terminated |
|
1772 ** UTF-16 string in native byte order. |
|
1773 */ |
|
1774 SQLITE_API int sqlite3_complete(const char *sql); |
|
1775 SQLITE_API int sqlite3_complete16(const void *sql); |
|
1776 |
|
1777 /* |
|
1778 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors |
|
1779 ** |
|
1780 ** ^This routine sets a callback function that might be invoked whenever |
|
1781 ** an attempt is made to open a database table that another thread |
|
1782 ** or process has locked. |
|
1783 ** |
|
1784 ** ^If the busy callback is NULL, then [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] |
|
1785 ** is returned immediately upon encountering the lock. ^If the busy callback |
|
1786 ** is not NULL, then the callback might be invoked with two arguments. |
|
1787 ** |
|
1788 ** ^The first argument to the busy handler is a copy of the void* pointer which |
|
1789 ** is the third argument to sqlite3_busy_handler(). ^The second argument to |
|
1790 ** the busy handler callback is the number of times that the busy handler has |
|
1791 ** been invoked for this locking event. ^If the |
|
1792 ** busy callback returns 0, then no additional attempts are made to |
|
1793 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned. |
|
1794 ** ^If the callback returns non-zero, then another attempt |
|
1795 ** is made to open the database for reading and the cycle repeats. |
|
1796 ** |
|
1797 ** The presence of a busy handler does not guarantee that it will be invoked |
|
1798 ** when there is lock contention. ^If SQLite determines that invoking the busy |
|
1799 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY] |
|
1800 ** or [SQLITE_IOERR_BLOCKED] instead of invoking the busy handler. |
|
1801 ** Consider a scenario where one process is holding a read lock that |
|
1802 ** it is trying to promote to a reserved lock and |
|
1803 ** a second process is holding a reserved lock that it is trying |
|
1804 ** to promote to an exclusive lock. The first process cannot proceed |
|
1805 ** because it is blocked by the second and the second process cannot |
|
1806 ** proceed because it is blocked by the first. If both processes |
|
1807 ** invoke the busy handlers, neither will make any progress. Therefore, |
|
1808 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this |
|
1809 ** will induce the first process to release its read lock and allow |
|
1810 ** the second process to proceed. |
|
1811 ** |
|
1812 ** ^The default busy callback is NULL. |
|
1813 ** |
|
1814 ** ^The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] |
|
1815 ** when SQLite is in the middle of a large transaction where all the |
|
1816 ** changes will not fit into the in-memory cache. SQLite will |
|
1817 ** already hold a RESERVED lock on the database file, but it needs |
|
1818 ** to promote this lock to EXCLUSIVE so that it can spill cache |
|
1819 ** pages into the database file without harm to concurrent |
|
1820 ** readers. ^If it is unable to promote the lock, then the in-memory |
|
1821 ** cache will be left in an inconsistent state and so the error |
|
1822 ** code is promoted from the relatively benign [SQLITE_BUSY] to |
|
1823 ** the more severe [SQLITE_IOERR_BLOCKED]. ^This error code promotion |
|
1824 ** forces an automatic rollback of the changes. See the |
|
1825 ** <a href="/cvstrac/wiki?p=CorruptionFollowingBusyError"> |
|
1826 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why |
|
1827 ** this is important. |
|
1828 ** |
|
1829 ** ^(There can only be a single busy handler defined for each |
|
1830 ** [database connection]. Setting a new busy handler clears any |
|
1831 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()] |
|
1832 ** will also set or clear the busy handler. |
|
1833 ** |
|
1834 ** The busy callback should not take any actions which modify the |
|
1835 ** database connection that invoked the busy handler. Any such actions |
|
1836 ** result in undefined behavior. |
|
1837 ** |
|
1838 ** A busy handler must not close the database connection |
|
1839 ** or [prepared statement] that invoked the busy handler. |
|
1840 */ |
|
1841 SQLITE_API int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*); |
|
1842 |
|
1843 /* |
|
1844 ** CAPI3REF: Set A Busy Timeout |
|
1845 ** |
|
1846 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps |
|
1847 ** for a specified amount of time when a table is locked. ^The handler |
|
1848 ** will sleep multiple times until at least "ms" milliseconds of sleeping |
|
1849 ** have accumulated. ^After at least "ms" milliseconds of sleeping, |
|
1850 ** the handler returns 0 which causes [sqlite3_step()] to return |
|
1851 ** [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED]. |
|
1852 ** |
|
1853 ** ^Calling this routine with an argument less than or equal to zero |
|
1854 ** turns off all busy handlers. |
|
1855 ** |
|
1856 ** ^(There can only be a single busy handler for a particular |
|
1857 ** [database connection] any any given moment. If another busy handler |
|
1858 ** was defined (using [sqlite3_busy_handler()]) prior to calling |
|
1859 ** this routine, that other busy handler is cleared.)^ |
|
1860 */ |
|
1861 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms); |
|
1862 |
|
1863 /* |
|
1864 ** CAPI3REF: Convenience Routines For Running Queries |
|
1865 ** |
|
1866 ** This is a legacy interface that is preserved for backwards compatibility. |
|
1867 ** Use of this interface is not recommended. |
|
1868 ** |
|
1869 ** Definition: A <b>result table</b> is memory data structure created by the |
|
1870 ** [sqlite3_get_table()] interface. A result table records the |
|
1871 ** complete query results from one or more queries. |
|
1872 ** |
|
1873 ** The table conceptually has a number of rows and columns. But |
|
1874 ** these numbers are not part of the result table itself. These |
|
1875 ** numbers are obtained separately. Let N be the number of rows |
|
1876 ** and M be the number of columns. |
|
1877 ** |
|
1878 ** A result table is an array of pointers to zero-terminated UTF-8 strings. |
|
1879 ** There are (N+1)*M elements in the array. The first M pointers point |
|
1880 ** to zero-terminated strings that contain the names of the columns. |
|
1881 ** The remaining entries all point to query results. NULL values result |
|
1882 ** in NULL pointers. All other values are in their UTF-8 zero-terminated |
|
1883 ** string representation as returned by [sqlite3_column_text()]. |
|
1884 ** |
|
1885 ** A result table might consist of one or more memory allocations. |
|
1886 ** It is not safe to pass a result table directly to [sqlite3_free()]. |
|
1887 ** A result table should be deallocated using [sqlite3_free_table()]. |
|
1888 ** |
|
1889 ** ^(As an example of the result table format, suppose a query result |
|
1890 ** is as follows: |
|
1891 ** |
|
1892 ** <blockquote><pre> |
|
1893 ** Name | Age |
|
1894 ** ----------------------- |
|
1895 ** Alice | 43 |
|
1896 ** Bob | 28 |
|
1897 ** Cindy | 21 |
|
1898 ** </pre></blockquote> |
|
1899 ** |
|
1900 ** There are two column (M==2) and three rows (N==3). Thus the |
|
1901 ** result table has 8 entries. Suppose the result table is stored |
|
1902 ** in an array names azResult. Then azResult holds this content: |
|
1903 ** |
|
1904 ** <blockquote><pre> |
|
1905 ** azResult[0] = "Name"; |
|
1906 ** azResult[1] = "Age"; |
|
1907 ** azResult[2] = "Alice"; |
|
1908 ** azResult[3] = "43"; |
|
1909 ** azResult[4] = "Bob"; |
|
1910 ** azResult[5] = "28"; |
|
1911 ** azResult[6] = "Cindy"; |
|
1912 ** azResult[7] = "21"; |
|
1913 ** </pre></blockquote>)^ |
|
1914 ** |
|
1915 ** ^The sqlite3_get_table() function evaluates one or more |
|
1916 ** semicolon-separated SQL statements in the zero-terminated UTF-8 |
|
1917 ** string of its 2nd parameter and returns a result table to the |
|
1918 ** pointer given in its 3rd parameter. |
|
1919 ** |
|
1920 ** After the application has finished with the result from sqlite3_get_table(), |
|
1921 ** it must pass the result table pointer to sqlite3_free_table() in order to |
|
1922 ** release the memory that was malloced. Because of the way the |
|
1923 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling |
|
1924 ** function must not try to call [sqlite3_free()] directly. Only |
|
1925 ** [sqlite3_free_table()] is able to release the memory properly and safely. |
|
1926 ** |
|
1927 ** The sqlite3_get_table() interface is implemented as a wrapper around |
|
1928 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access |
|
1929 ** to any internal data structures of SQLite. It uses only the public |
|
1930 ** interface defined here. As a consequence, errors that occur in the |
|
1931 ** wrapper layer outside of the internal [sqlite3_exec()] call are not |
|
1932 ** reflected in subsequent calls to [sqlite3_errcode()] or |
|
1933 ** [sqlite3_errmsg()]. |
|
1934 */ |
|
1935 SQLITE_API int sqlite3_get_table( |
|
1936 sqlite3 *db, /* An open database */ |
|
1937 const char *zSql, /* SQL to be evaluated */ |
|
1938 char ***pazResult, /* Results of the query */ |
|
1939 int *pnRow, /* Number of result rows written here */ |
|
1940 int *pnColumn, /* Number of result columns written here */ |
|
1941 char **pzErrmsg /* Error msg written here */ |
|
1942 ); |
|
1943 SQLITE_API void sqlite3_free_table(char **result); |
|
1944 |
|
1945 /* |
|
1946 ** CAPI3REF: Formatted String Printing Functions |
|
1947 ** |
|
1948 ** These routines are work-alikes of the "printf()" family of functions |
|
1949 ** from the standard C library. |
|
1950 ** |
|
1951 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their |
|
1952 ** results into memory obtained from [sqlite3_malloc()]. |
|
1953 ** The strings returned by these two routines should be |
|
1954 ** released by [sqlite3_free()]. ^Both routines return a |
|
1955 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough |
|
1956 ** memory to hold the resulting string. |
|
1957 ** |
|
1958 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from |
|
1959 ** the standard C library. The result is written into the |
|
1960 ** buffer supplied as the second parameter whose size is given by |
|
1961 ** the first parameter. Note that the order of the |
|
1962 ** first two parameters is reversed from snprintf().)^ This is an |
|
1963 ** historical accident that cannot be fixed without breaking |
|
1964 ** backwards compatibility. ^(Note also that sqlite3_snprintf() |
|
1965 ** returns a pointer to its buffer instead of the number of |
|
1966 ** characters actually written into the buffer.)^ We admit that |
|
1967 ** the number of characters written would be a more useful return |
|
1968 ** value but we cannot change the implementation of sqlite3_snprintf() |
|
1969 ** now without breaking compatibility. |
|
1970 ** |
|
1971 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf() |
|
1972 ** guarantees that the buffer is always zero-terminated. ^The first |
|
1973 ** parameter "n" is the total size of the buffer, including space for |
|
1974 ** the zero terminator. So the longest string that can be completely |
|
1975 ** written will be n-1 characters. |
|
1976 ** |
|
1977 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf(). |
|
1978 ** |
|
1979 ** These routines all implement some additional formatting |
|
1980 ** options that are useful for constructing SQL statements. |
|
1981 ** All of the usual printf() formatting options apply. In addition, there |
|
1982 ** is are "%q", "%Q", and "%z" options. |
|
1983 ** |
|
1984 ** ^(The %q option works like %s in that it substitutes a null-terminated |
|
1985 ** string from the argument list. But %q also doubles every '\'' character. |
|
1986 ** %q is designed for use inside a string literal.)^ By doubling each '\'' |
|
1987 ** character it escapes that character and allows it to be inserted into |
|
1988 ** the string. |
|
1989 ** |
|
1990 ** For example, assume the string variable zText contains text as follows: |
|
1991 ** |
|
1992 ** <blockquote><pre> |
|
1993 ** char *zText = "It's a happy day!"; |
|
1994 ** </pre></blockquote> |
|
1995 ** |
|
1996 ** One can use this text in an SQL statement as follows: |
|
1997 ** |
|
1998 ** <blockquote><pre> |
|
1999 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText); |
|
2000 ** sqlite3_exec(db, zSQL, 0, 0, 0); |
|
2001 ** sqlite3_free(zSQL); |
|
2002 ** </pre></blockquote> |
|
2003 ** |
|
2004 ** Because the %q format string is used, the '\'' character in zText |
|
2005 ** is escaped and the SQL generated is as follows: |
|
2006 ** |
|
2007 ** <blockquote><pre> |
|
2008 ** INSERT INTO table1 VALUES('It''s a happy day!') |
|
2009 ** </pre></blockquote> |
|
2010 ** |
|
2011 ** This is correct. Had we used %s instead of %q, the generated SQL |
|
2012 ** would have looked like this: |
|
2013 ** |
|
2014 ** <blockquote><pre> |
|
2015 ** INSERT INTO table1 VALUES('It's a happy day!'); |
|
2016 ** </pre></blockquote> |
|
2017 ** |
|
2018 ** This second example is an SQL syntax error. As a general rule you should |
|
2019 ** always use %q instead of %s when inserting text into a string literal. |
|
2020 ** |
|
2021 ** ^(The %Q option works like %q except it also adds single quotes around |
|
2022 ** the outside of the total string. Additionally, if the parameter in the |
|
2023 ** argument list is a NULL pointer, %Q substitutes the text "NULL" (without |
|
2024 ** single quotes).)^ So, for example, one could say: |
|
2025 ** |
|
2026 ** <blockquote><pre> |
|
2027 ** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText); |
|
2028 ** sqlite3_exec(db, zSQL, 0, 0, 0); |
|
2029 ** sqlite3_free(zSQL); |
|
2030 ** </pre></blockquote> |
|
2031 ** |
|
2032 ** The code above will render a correct SQL statement in the zSQL |
|
2033 ** variable even if the zText variable is a NULL pointer. |
|
2034 ** |
|
2035 ** ^(The "%z" formatting option works like "%s" but with the |
|
2036 ** addition that after the string has been read and copied into |
|
2037 ** the result, [sqlite3_free()] is called on the input string.)^ |
|
2038 */ |
|
2039 SQLITE_API char *sqlite3_mprintf(const char*,...); |
|
2040 SQLITE_API char *sqlite3_vmprintf(const char*, va_list); |
|
2041 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...); |
|
2042 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list); |
|
2043 |
|
2044 /* |
|
2045 ** CAPI3REF: Memory Allocation Subsystem |
|
2046 ** |
|
2047 ** The SQLite core uses these three routines for all of its own |
|
2048 ** internal memory allocation needs. "Core" in the previous sentence |
|
2049 ** does not include operating-system specific VFS implementation. The |
|
2050 ** Windows VFS uses native malloc() and free() for some operations. |
|
2051 ** |
|
2052 ** ^The sqlite3_malloc() routine returns a pointer to a block |
|
2053 ** of memory at least N bytes in length, where N is the parameter. |
|
2054 ** ^If sqlite3_malloc() is unable to obtain sufficient free |
|
2055 ** memory, it returns a NULL pointer. ^If the parameter N to |
|
2056 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns |
|
2057 ** a NULL pointer. |
|
2058 ** |
|
2059 ** ^Calling sqlite3_free() with a pointer previously returned |
|
2060 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so |
|
2061 ** that it might be reused. ^The sqlite3_free() routine is |
|
2062 ** a no-op if is called with a NULL pointer. Passing a NULL pointer |
|
2063 ** to sqlite3_free() is harmless. After being freed, memory |
|
2064 ** should neither be read nor written. Even reading previously freed |
|
2065 ** memory might result in a segmentation fault or other severe error. |
|
2066 ** Memory corruption, a segmentation fault, or other severe error |
|
2067 ** might result if sqlite3_free() is called with a non-NULL pointer that |
|
2068 ** was not obtained from sqlite3_malloc() or sqlite3_realloc(). |
|
2069 ** |
|
2070 ** ^(The sqlite3_realloc() interface attempts to resize a |
|
2071 ** prior memory allocation to be at least N bytes, where N is the |
|
2072 ** second parameter. The memory allocation to be resized is the first |
|
2073 ** parameter.)^ ^ If the first parameter to sqlite3_realloc() |
|
2074 ** is a NULL pointer then its behavior is identical to calling |
|
2075 ** sqlite3_malloc(N) where N is the second parameter to sqlite3_realloc(). |
|
2076 ** ^If the second parameter to sqlite3_realloc() is zero or |
|
2077 ** negative then the behavior is exactly the same as calling |
|
2078 ** sqlite3_free(P) where P is the first parameter to sqlite3_realloc(). |
|
2079 ** ^sqlite3_realloc() returns a pointer to a memory allocation |
|
2080 ** of at least N bytes in size or NULL if sufficient memory is unavailable. |
|
2081 ** ^If M is the size of the prior allocation, then min(N,M) bytes |
|
2082 ** of the prior allocation are copied into the beginning of buffer returned |
|
2083 ** by sqlite3_realloc() and the prior allocation is freed. |
|
2084 ** ^If sqlite3_realloc() returns NULL, then the prior allocation |
|
2085 ** is not freed. |
|
2086 ** |
|
2087 ** ^The memory returned by sqlite3_malloc() and sqlite3_realloc() |
|
2088 ** is always aligned to at least an 8 byte boundary, or to a |
|
2089 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time |
|
2090 ** option is used. |
|
2091 ** |
|
2092 ** In SQLite version 3.5.0 and 3.5.1, it was possible to define |
|
2093 ** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in |
|
2094 ** implementation of these routines to be omitted. That capability |
|
2095 ** is no longer provided. Only built-in memory allocators can be used. |
|
2096 ** |
|
2097 ** The Windows OS interface layer calls |
|
2098 ** the system malloc() and free() directly when converting |
|
2099 ** filenames between the UTF-8 encoding used by SQLite |
|
2100 ** and whatever filename encoding is used by the particular Windows |
|
2101 ** installation. Memory allocation errors are detected, but |
|
2102 ** they are reported back as [SQLITE_CANTOPEN] or |
|
2103 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM]. |
|
2104 ** |
|
2105 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()] |
|
2106 ** must be either NULL or else pointers obtained from a prior |
|
2107 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have |
|
2108 ** not yet been released. |
|
2109 ** |
|
2110 ** The application must not read or write any part of |
|
2111 ** a block of memory after it has been released using |
|
2112 ** [sqlite3_free()] or [sqlite3_realloc()]. |
|
2113 */ |
|
2114 SQLITE_API void *sqlite3_malloc(int); |
|
2115 SQLITE_API void *sqlite3_realloc(void*, int); |
|
2116 SQLITE_API void sqlite3_free(void*); |
|
2117 |
|
2118 /* |
|
2119 ** CAPI3REF: Memory Allocator Statistics |
|
2120 ** |
|
2121 ** SQLite provides these two interfaces for reporting on the status |
|
2122 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()] |
|
2123 ** routines, which form the built-in memory allocation subsystem. |
|
2124 ** |
|
2125 ** ^The [sqlite3_memory_used()] routine returns the number of bytes |
|
2126 ** of memory currently outstanding (malloced but not freed). |
|
2127 ** ^The [sqlite3_memory_highwater()] routine returns the maximum |
|
2128 ** value of [sqlite3_memory_used()] since the high-water mark |
|
2129 ** was last reset. ^The values returned by [sqlite3_memory_used()] and |
|
2130 ** [sqlite3_memory_highwater()] include any overhead |
|
2131 ** added by SQLite in its implementation of [sqlite3_malloc()], |
|
2132 ** but not overhead added by the any underlying system library |
|
2133 ** routines that [sqlite3_malloc()] may call. |
|
2134 ** |
|
2135 ** ^The memory high-water mark is reset to the current value of |
|
2136 ** [sqlite3_memory_used()] if and only if the parameter to |
|
2137 ** [sqlite3_memory_highwater()] is true. ^The value returned |
|
2138 ** by [sqlite3_memory_highwater(1)] is the high-water mark |
|
2139 ** prior to the reset. |
|
2140 */ |
|
2141 SQLITE_API sqlite3_int64 sqlite3_memory_used(void); |
|
2142 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag); |
|
2143 |
|
2144 /* |
|
2145 ** CAPI3REF: Pseudo-Random Number Generator |
|
2146 ** |
|
2147 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to |
|
2148 ** select random [ROWID | ROWIDs] when inserting new records into a table that |
|
2149 ** already uses the largest possible [ROWID]. The PRNG is also used for |
|
2150 ** the build-in random() and randomblob() SQL functions. This interface allows |
|
2151 ** applications to access the same PRNG for other purposes. |
|
2152 ** |
|
2153 ** ^A call to this routine stores N bytes of randomness into buffer P. |
|
2154 ** |
|
2155 ** ^The first time this routine is invoked (either internally or by |
|
2156 ** the application) the PRNG is seeded using randomness obtained |
|
2157 ** from the xRandomness method of the default [sqlite3_vfs] object. |
|
2158 ** ^On all subsequent invocations, the pseudo-randomness is generated |
|
2159 ** internally and without recourse to the [sqlite3_vfs] xRandomness |
|
2160 ** method. |
|
2161 */ |
|
2162 SQLITE_API void sqlite3_randomness(int N, void *P); |
|
2163 |
|
2164 /* |
|
2165 ** CAPI3REF: Compile-Time Authorization Callbacks |
|
2166 ** |
|
2167 ** ^This routine registers an authorizer callback with a particular |
|
2168 ** [database connection], supplied in the first argument. |
|
2169 ** ^The authorizer callback is invoked as SQL statements are being compiled |
|
2170 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()], |
|
2171 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various |
|
2172 ** points during the compilation process, as logic is being created |
|
2173 ** to perform various actions, the authorizer callback is invoked to |
|
2174 ** see if those actions are allowed. ^The authorizer callback should |
|
2175 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the |
|
2176 ** specific action but allow the SQL statement to continue to be |
|
2177 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be |
|
2178 ** rejected with an error. ^If the authorizer callback returns |
|
2179 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY] |
|
2180 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered |
|
2181 ** the authorizer will fail with an error message. |
|
2182 ** |
|
2183 ** When the callback returns [SQLITE_OK], that means the operation |
|
2184 ** requested is ok. ^When the callback returns [SQLITE_DENY], the |
|
2185 ** [sqlite3_prepare_v2()] or equivalent call that triggered the |
|
2186 ** authorizer will fail with an error message explaining that |
|
2187 ** access is denied. |
|
2188 ** |
|
2189 ** ^The first parameter to the authorizer callback is a copy of the third |
|
2190 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter |
|
2191 ** to the callback is an integer [SQLITE_COPY | action code] that specifies |
|
2192 ** the particular action to be authorized. ^The third through sixth parameters |
|
2193 ** to the callback are zero-terminated strings that contain additional |
|
2194 ** details about the action to be authorized. |
|
2195 ** |
|
2196 ** ^If the action code is [SQLITE_READ] |
|
2197 ** and the callback returns [SQLITE_IGNORE] then the |
|
2198 ** [prepared statement] statement is constructed to substitute |
|
2199 ** a NULL value in place of the table column that would have |
|
2200 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE] |
|
2201 ** return can be used to deny an untrusted user access to individual |
|
2202 ** columns of a table. |
|
2203 ** ^If the action code is [SQLITE_DELETE] and the callback returns |
|
2204 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the |
|
2205 ** [truncate optimization] is disabled and all rows are deleted individually. |
|
2206 ** |
|
2207 ** An authorizer is used when [sqlite3_prepare | preparing] |
|
2208 ** SQL statements from an untrusted source, to ensure that the SQL statements |
|
2209 ** do not try to access data they are not allowed to see, or that they do not |
|
2210 ** try to execute malicious statements that damage the database. For |
|
2211 ** example, an application may allow a user to enter arbitrary |
|
2212 ** SQL queries for evaluation by a database. But the application does |
|
2213 ** not want the user to be able to make arbitrary changes to the |
|
2214 ** database. An authorizer could then be put in place while the |
|
2215 ** user-entered SQL is being [sqlite3_prepare | prepared] that |
|
2216 ** disallows everything except [SELECT] statements. |
|
2217 ** |
|
2218 ** Applications that need to process SQL from untrusted sources |
|
2219 ** might also consider lowering resource limits using [sqlite3_limit()] |
|
2220 ** and limiting database size using the [max_page_count] [PRAGMA] |
|
2221 ** in addition to using an authorizer. |
|
2222 ** |
|
2223 ** ^(Only a single authorizer can be in place on a database connection |
|
2224 ** at a time. Each call to sqlite3_set_authorizer overrides the |
|
2225 ** previous call.)^ ^Disable the authorizer by installing a NULL callback. |
|
2226 ** The authorizer is disabled by default. |
|
2227 ** |
|
2228 ** The authorizer callback must not do anything that will modify |
|
2229 ** the database connection that invoked the authorizer callback. |
|
2230 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
|
2231 ** database connections for the meaning of "modify" in this paragraph. |
|
2232 ** |
|
2233 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the |
|
2234 ** statement might be re-prepared during [sqlite3_step()] due to a |
|
2235 ** schema change. Hence, the application should ensure that the |
|
2236 ** correct authorizer callback remains in place during the [sqlite3_step()]. |
|
2237 ** |
|
2238 ** ^Note that the authorizer callback is invoked only during |
|
2239 ** [sqlite3_prepare()] or its variants. Authorization is not |
|
2240 ** performed during statement evaluation in [sqlite3_step()], unless |
|
2241 ** as stated in the previous paragraph, sqlite3_step() invokes |
|
2242 ** sqlite3_prepare_v2() to reprepare a statement after a schema change. |
|
2243 */ |
|
2244 SQLITE_API int sqlite3_set_authorizer( |
|
2245 sqlite3*, |
|
2246 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*), |
|
2247 void *pUserData |
|
2248 ); |
|
2249 |
|
2250 /* |
|
2251 ** CAPI3REF: Authorizer Return Codes |
|
2252 ** |
|
2253 ** The [sqlite3_set_authorizer | authorizer callback function] must |
|
2254 ** return either [SQLITE_OK] or one of these two constants in order |
|
2255 ** to signal SQLite whether or not the action is permitted. See the |
|
2256 ** [sqlite3_set_authorizer | authorizer documentation] for additional |
|
2257 ** information. |
|
2258 ** |
|
2259 ** Note that SQLITE_IGNORE is also used as a [SQLITE_ROLLBACK | return code] |
|
2260 ** from the [sqlite3_vtab_on_conflict()] interface. |
|
2261 */ |
|
2262 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */ |
|
2263 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */ |
|
2264 |
|
2265 /* |
|
2266 ** CAPI3REF: Authorizer Action Codes |
|
2267 ** |
|
2268 ** The [sqlite3_set_authorizer()] interface registers a callback function |
|
2269 ** that is invoked to authorize certain SQL statement actions. The |
|
2270 ** second parameter to the callback is an integer code that specifies |
|
2271 ** what action is being authorized. These are the integer action codes that |
|
2272 ** the authorizer callback may be passed. |
|
2273 ** |
|
2274 ** These action code values signify what kind of operation is to be |
|
2275 ** authorized. The 3rd and 4th parameters to the authorization |
|
2276 ** callback function will be parameters or NULL depending on which of these |
|
2277 ** codes is used as the second parameter. ^(The 5th parameter to the |
|
2278 ** authorizer callback is the name of the database ("main", "temp", |
|
2279 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback |
|
2280 ** is the name of the inner-most trigger or view that is responsible for |
|
2281 ** the access attempt or NULL if this access attempt is directly from |
|
2282 ** top-level SQL code. |
|
2283 */ |
|
2284 /******************************************* 3rd ************ 4th ***********/ |
|
2285 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */ |
|
2286 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */ |
|
2287 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */ |
|
2288 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */ |
|
2289 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */ |
|
2290 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */ |
|
2291 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */ |
|
2292 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */ |
|
2293 #define SQLITE_DELETE 9 /* Table Name NULL */ |
|
2294 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */ |
|
2295 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */ |
|
2296 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */ |
|
2297 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */ |
|
2298 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */ |
|
2299 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */ |
|
2300 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */ |
|
2301 #define SQLITE_DROP_VIEW 17 /* View Name NULL */ |
|
2302 #define SQLITE_INSERT 18 /* Table Name NULL */ |
|
2303 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */ |
|
2304 #define SQLITE_READ 20 /* Table Name Column Name */ |
|
2305 #define SQLITE_SELECT 21 /* NULL NULL */ |
|
2306 #define SQLITE_TRANSACTION 22 /* Operation NULL */ |
|
2307 #define SQLITE_UPDATE 23 /* Table Name Column Name */ |
|
2308 #define SQLITE_ATTACH 24 /* Filename NULL */ |
|
2309 #define SQLITE_DETACH 25 /* Database Name NULL */ |
|
2310 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */ |
|
2311 #define SQLITE_REINDEX 27 /* Index Name NULL */ |
|
2312 #define SQLITE_ANALYZE 28 /* Table Name NULL */ |
|
2313 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */ |
|
2314 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */ |
|
2315 #define SQLITE_FUNCTION 31 /* NULL Function Name */ |
|
2316 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */ |
|
2317 #define SQLITE_COPY 0 /* No longer used */ |
|
2318 |
|
2319 /* |
|
2320 ** CAPI3REF: Tracing And Profiling Functions |
|
2321 ** |
|
2322 ** These routines register callback functions that can be used for |
|
2323 ** tracing and profiling the execution of SQL statements. |
|
2324 ** |
|
2325 ** ^The callback function registered by sqlite3_trace() is invoked at |
|
2326 ** various times when an SQL statement is being run by [sqlite3_step()]. |
|
2327 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the |
|
2328 ** SQL statement text as the statement first begins executing. |
|
2329 ** ^(Additional sqlite3_trace() callbacks might occur |
|
2330 ** as each triggered subprogram is entered. The callbacks for triggers |
|
2331 ** contain a UTF-8 SQL comment that identifies the trigger.)^ |
|
2332 ** |
|
2333 ** ^The callback function registered by sqlite3_profile() is invoked |
|
2334 ** as each SQL statement finishes. ^The profile callback contains |
|
2335 ** the original statement text and an estimate of wall-clock time |
|
2336 ** of how long that statement took to run. ^The profile callback |
|
2337 ** time is in units of nanoseconds, however the current implementation |
|
2338 ** is only capable of millisecond resolution so the six least significant |
|
2339 ** digits in the time are meaningless. Future versions of SQLite |
|
2340 ** might provide greater resolution on the profiler callback. The |
|
2341 ** sqlite3_profile() function is considered experimental and is |
|
2342 ** subject to change in future versions of SQLite. |
|
2343 */ |
|
2344 SQLITE_API void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*); |
|
2345 SQLITE_API SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*, |
|
2346 void(*xProfile)(void*,const char*,sqlite3_uint64), void*); |
|
2347 |
|
2348 /* |
|
2349 ** CAPI3REF: Query Progress Callbacks |
|
2350 ** |
|
2351 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback |
|
2352 ** function X to be invoked periodically during long running calls to |
|
2353 ** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for |
|
2354 ** database connection D. An example use for this |
|
2355 ** interface is to keep a GUI updated during a large query. |
|
2356 ** |
|
2357 ** ^The parameter P is passed through as the only parameter to the |
|
2358 ** callback function X. ^The parameter N is the number of |
|
2359 ** [virtual machine instructions] that are evaluated between successive |
|
2360 ** invocations of the callback X. |
|
2361 ** |
|
2362 ** ^Only a single progress handler may be defined at one time per |
|
2363 ** [database connection]; setting a new progress handler cancels the |
|
2364 ** old one. ^Setting parameter X to NULL disables the progress handler. |
|
2365 ** ^The progress handler is also disabled by setting N to a value less |
|
2366 ** than 1. |
|
2367 ** |
|
2368 ** ^If the progress callback returns non-zero, the operation is |
|
2369 ** interrupted. This feature can be used to implement a |
|
2370 ** "Cancel" button on a GUI progress dialog box. |
|
2371 ** |
|
2372 ** The progress handler callback must not do anything that will modify |
|
2373 ** the database connection that invoked the progress handler. |
|
2374 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
|
2375 ** database connections for the meaning of "modify" in this paragraph. |
|
2376 ** |
|
2377 */ |
|
2378 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*); |
|
2379 |
|
2380 /* |
|
2381 ** CAPI3REF: Opening A New Database Connection |
|
2382 ** |
|
2383 ** ^These routines open an SQLite database file as specified by the |
|
2384 ** filename argument. ^The filename argument is interpreted as UTF-8 for |
|
2385 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte |
|
2386 ** order for sqlite3_open16(). ^(A [database connection] handle is usually |
|
2387 ** returned in *ppDb, even if an error occurs. The only exception is that |
|
2388 ** if SQLite is unable to allocate memory to hold the [sqlite3] object, |
|
2389 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3] |
|
2390 ** object.)^ ^(If the database is opened (and/or created) successfully, then |
|
2391 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The |
|
2392 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain |
|
2393 ** an English language description of the error following a failure of any |
|
2394 ** of the sqlite3_open() routines. |
|
2395 ** |
|
2396 ** ^The default encoding for the database will be UTF-8 if |
|
2397 ** sqlite3_open() or sqlite3_open_v2() is called and |
|
2398 ** UTF-16 in the native byte order if sqlite3_open16() is used. |
|
2399 ** |
|
2400 ** Whether or not an error occurs when it is opened, resources |
|
2401 ** associated with the [database connection] handle should be released by |
|
2402 ** passing it to [sqlite3_close()] when it is no longer required. |
|
2403 ** |
|
2404 ** The sqlite3_open_v2() interface works like sqlite3_open() |
|
2405 ** except that it accepts two additional parameters for additional control |
|
2406 ** over the new database connection. ^(The flags parameter to |
|
2407 ** sqlite3_open_v2() can take one of |
|
2408 ** the following three values, optionally combined with the |
|
2409 ** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE], |
|
2410 ** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^ |
|
2411 ** |
|
2412 ** <dl> |
|
2413 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt> |
|
2414 ** <dd>The database is opened in read-only mode. If the database does not |
|
2415 ** already exist, an error is returned.</dd>)^ |
|
2416 ** |
|
2417 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt> |
|
2418 ** <dd>The database is opened for reading and writing if possible, or reading |
|
2419 ** only if the file is write protected by the operating system. In either |
|
2420 ** case the database must already exist, otherwise an error is returned.</dd>)^ |
|
2421 ** |
|
2422 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt> |
|
2423 ** <dd>The database is opened for reading and writing, and is created if |
|
2424 ** it does not already exist. This is the behavior that is always used for |
|
2425 ** sqlite3_open() and sqlite3_open16().</dd>)^ |
|
2426 ** </dl> |
|
2427 ** |
|
2428 ** If the 3rd parameter to sqlite3_open_v2() is not one of the |
|
2429 ** combinations shown above optionally combined with other |
|
2430 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits] |
|
2431 ** then the behavior is undefined. |
|
2432 ** |
|
2433 ** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection |
|
2434 ** opens in the multi-thread [threading mode] as long as the single-thread |
|
2435 ** mode has not been set at compile-time or start-time. ^If the |
|
2436 ** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens |
|
2437 ** in the serialized [threading mode] unless single-thread was |
|
2438 ** previously selected at compile-time or start-time. |
|
2439 ** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be |
|
2440 ** eligible to use [shared cache mode], regardless of whether or not shared |
|
2441 ** cache is enabled using [sqlite3_enable_shared_cache()]. ^The |
|
2442 ** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not |
|
2443 ** participate in [shared cache mode] even if it is enabled. |
|
2444 ** |
|
2445 ** ^The fourth parameter to sqlite3_open_v2() is the name of the |
|
2446 ** [sqlite3_vfs] object that defines the operating system interface that |
|
2447 ** the new database connection should use. ^If the fourth parameter is |
|
2448 ** a NULL pointer then the default [sqlite3_vfs] object is used. |
|
2449 ** |
|
2450 ** ^If the filename is ":memory:", then a private, temporary in-memory database |
|
2451 ** is created for the connection. ^This in-memory database will vanish when |
|
2452 ** the database connection is closed. Future versions of SQLite might |
|
2453 ** make use of additional special filenames that begin with the ":" character. |
|
2454 ** It is recommended that when a database filename actually does begin with |
|
2455 ** a ":" character you should prefix the filename with a pathname such as |
|
2456 ** "./" to avoid ambiguity. |
|
2457 ** |
|
2458 ** ^If the filename is an empty string, then a private, temporary |
|
2459 ** on-disk database will be created. ^This private database will be |
|
2460 ** automatically deleted as soon as the database connection is closed. |
|
2461 ** |
|
2462 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3> |
|
2463 ** |
|
2464 ** ^If [URI filename] interpretation is enabled, and the filename argument |
|
2465 ** begins with "file:", then the filename is interpreted as a URI. ^URI |
|
2466 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is |
|
2467 ** set in the fourth argument to sqlite3_open_v2(), or if it has |
|
2468 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the |
|
2469 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option. |
|
2470 ** As of SQLite version 3.7.7, URI filename interpretation is turned off |
|
2471 ** by default, but future releases of SQLite might enable URI filename |
|
2472 ** interpretation by default. See "[URI filenames]" for additional |
|
2473 ** information. |
|
2474 ** |
|
2475 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an |
|
2476 ** authority, then it must be either an empty string or the string |
|
2477 ** "localhost". ^If the authority is not an empty string or "localhost", an |
|
2478 ** error is returned to the caller. ^The fragment component of a URI, if |
|
2479 ** present, is ignored. |
|
2480 ** |
|
2481 ** ^SQLite uses the path component of the URI as the name of the disk file |
|
2482 ** which contains the database. ^If the path begins with a '/' character, |
|
2483 ** then it is interpreted as an absolute path. ^If the path does not begin |
|
2484 ** with a '/' (meaning that the authority section is omitted from the URI) |
|
2485 ** then the path is interpreted as a relative path. |
|
2486 ** ^On windows, the first component of an absolute path |
|
2487 ** is a drive specification (e.g. "C:"). |
|
2488 ** |
|
2489 ** [[core URI query parameters]] |
|
2490 ** The query component of a URI may contain parameters that are interpreted |
|
2491 ** either by SQLite itself, or by a [VFS | custom VFS implementation]. |
|
2492 ** SQLite interprets the following three query parameters: |
|
2493 ** |
|
2494 ** <ul> |
|
2495 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of |
|
2496 ** a VFS object that provides the operating system interface that should |
|
2497 ** be used to access the database file on disk. ^If this option is set to |
|
2498 ** an empty string the default VFS object is used. ^Specifying an unknown |
|
2499 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is |
|
2500 ** present, then the VFS specified by the option takes precedence over |
|
2501 ** the value passed as the fourth parameter to sqlite3_open_v2(). |
|
2502 ** |
|
2503 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw" or |
|
2504 ** "rwc". Attempting to set it to any other value is an error)^. |
|
2505 ** ^If "ro" is specified, then the database is opened for read-only |
|
2506 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the |
|
2507 ** third argument to sqlite3_prepare_v2(). ^If the mode option is set to |
|
2508 ** "rw", then the database is opened for read-write (but not create) |
|
2509 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had |
|
2510 ** been set. ^Value "rwc" is equivalent to setting both |
|
2511 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If sqlite3_open_v2() is |
|
2512 ** used, it is an error to specify a value for the mode parameter that is |
|
2513 ** less restrictive than that specified by the flags passed as the third |
|
2514 ** parameter. |
|
2515 ** |
|
2516 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or |
|
2517 ** "private". ^Setting it to "shared" is equivalent to setting the |
|
2518 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to |
|
2519 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is |
|
2520 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit. |
|
2521 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in |
|
2522 ** a URI filename, its value overrides any behaviour requested by setting |
|
2523 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag. |
|
2524 ** </ul> |
|
2525 ** |
|
2526 ** ^Specifying an unknown parameter in the query component of a URI is not an |
|
2527 ** error. Future versions of SQLite might understand additional query |
|
2528 ** parameters. See "[query parameters with special meaning to SQLite]" for |
|
2529 ** additional information. |
|
2530 ** |
|
2531 ** [[URI filename examples]] <h3>URI filename examples</h3> |
|
2532 ** |
|
2533 ** <table border="1" align=center cellpadding=5> |
|
2534 ** <tr><th> URI filenames <th> Results |
|
2535 ** <tr><td> file:data.db <td> |
|
2536 ** Open the file "data.db" in the current directory. |
|
2537 ** <tr><td> file:/home/fred/data.db<br> |
|
2538 ** file:///home/fred/data.db <br> |
|
2539 ** file://localhost/home/fred/data.db <br> <td> |
|
2540 ** Open the database file "/home/fred/data.db". |
|
2541 ** <tr><td> file://darkstar/home/fred/data.db <td> |
|
2542 ** An error. "darkstar" is not a recognized authority. |
|
2543 ** <tr><td style="white-space:nowrap"> |
|
2544 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db |
|
2545 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive |
|
2546 ** C:. Note that the %20 escaping in this example is not strictly |
|
2547 ** necessary - space characters can be used literally |
|
2548 ** in URI filenames. |
|
2549 ** <tr><td> file:data.db?mode=ro&cache=private <td> |
|
2550 ** Open file "data.db" in the current directory for read-only access. |
|
2551 ** Regardless of whether or not shared-cache mode is enabled by |
|
2552 ** default, use a private cache. |
|
2553 ** <tr><td> file:/home/fred/data.db?vfs=unix-nolock <td> |
|
2554 ** Open file "/home/fred/data.db". Use the special VFS "unix-nolock". |
|
2555 ** <tr><td> file:data.db?mode=readonly <td> |
|
2556 ** An error. "readonly" is not a valid option for the "mode" parameter. |
|
2557 ** </table> |
|
2558 ** |
|
2559 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and |
|
2560 ** query components of a URI. A hexadecimal escape sequence consists of a |
|
2561 ** percent sign - "%" - followed by exactly two hexadecimal digits |
|
2562 ** specifying an octet value. ^Before the path or query components of a |
|
2563 ** URI filename are interpreted, they are encoded using UTF-8 and all |
|
2564 ** hexadecimal escape sequences replaced by a single byte containing the |
|
2565 ** corresponding octet. If this process generates an invalid UTF-8 encoding, |
|
2566 ** the results are undefined. |
|
2567 ** |
|
2568 ** <b>Note to Windows users:</b> The encoding used for the filename argument |
|
2569 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever |
|
2570 ** codepage is currently defined. Filenames containing international |
|
2571 ** characters must be converted to UTF-8 prior to passing them into |
|
2572 ** sqlite3_open() or sqlite3_open_v2(). |
|
2573 */ |
|
2574 SQLITE_API int sqlite3_open( |
|
2575 const char *filename, /* Database filename (UTF-8) */ |
|
2576 sqlite3 **ppDb /* OUT: SQLite db handle */ |
|
2577 ); |
|
2578 SQLITE_API int sqlite3_open16( |
|
2579 const void *filename, /* Database filename (UTF-16) */ |
|
2580 sqlite3 **ppDb /* OUT: SQLite db handle */ |
|
2581 ); |
|
2582 SQLITE_API int sqlite3_open_v2( |
|
2583 const char *filename, /* Database filename (UTF-8) */ |
|
2584 sqlite3 **ppDb, /* OUT: SQLite db handle */ |
|
2585 int flags, /* Flags */ |
|
2586 const char *zVfs /* Name of VFS module to use */ |
|
2587 ); |
|
2588 |
|
2589 /* |
|
2590 ** CAPI3REF: Obtain Values For URI Parameters |
|
2591 ** |
|
2592 ** This is a utility routine, useful to VFS implementations, that checks |
|
2593 ** to see if a database file was a URI that contained a specific query |
|
2594 ** parameter, and if so obtains the value of the query parameter. |
|
2595 ** |
|
2596 ** The zFilename argument is the filename pointer passed into the xOpen() |
|
2597 ** method of a VFS implementation. The zParam argument is the name of the |
|
2598 ** query parameter we seek. This routine returns the value of the zParam |
|
2599 ** parameter if it exists. If the parameter does not exist, this routine |
|
2600 ** returns a NULL pointer. |
|
2601 ** |
|
2602 ** If the zFilename argument to this function is not a pointer that SQLite |
|
2603 ** passed into the xOpen VFS method, then the behavior of this routine |
|
2604 ** is undefined and probably undesirable. |
|
2605 */ |
|
2606 SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam); |
|
2607 |
|
2608 |
|
2609 /* |
|
2610 ** CAPI3REF: Error Codes And Messages |
|
2611 ** |
|
2612 ** ^The sqlite3_errcode() interface returns the numeric [result code] or |
|
2613 ** [extended result code] for the most recent failed sqlite3_* API call |
|
2614 ** associated with a [database connection]. If a prior API call failed |
|
2615 ** but the most recent API call succeeded, the return value from |
|
2616 ** sqlite3_errcode() is undefined. ^The sqlite3_extended_errcode() |
|
2617 ** interface is the same except that it always returns the |
|
2618 ** [extended result code] even when extended result codes are |
|
2619 ** disabled. |
|
2620 ** |
|
2621 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language |
|
2622 ** text that describes the error, as either UTF-8 or UTF-16 respectively. |
|
2623 ** ^(Memory to hold the error message string is managed internally. |
|
2624 ** The application does not need to worry about freeing the result. |
|
2625 ** However, the error string might be overwritten or deallocated by |
|
2626 ** subsequent calls to other SQLite interface functions.)^ |
|
2627 ** |
|
2628 ** When the serialized [threading mode] is in use, it might be the |
|
2629 ** case that a second error occurs on a separate thread in between |
|
2630 ** the time of the first error and the call to these interfaces. |
|
2631 ** When that happens, the second error will be reported since these |
|
2632 ** interfaces always report the most recent result. To avoid |
|
2633 ** this, each thread can obtain exclusive use of the [database connection] D |
|
2634 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning |
|
2635 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after |
|
2636 ** all calls to the interfaces listed here are completed. |
|
2637 ** |
|
2638 ** If an interface fails with SQLITE_MISUSE, that means the interface |
|
2639 ** was invoked incorrectly by the application. In that case, the |
|
2640 ** error code and message may or may not be set. |
|
2641 */ |
|
2642 SQLITE_API int sqlite3_errcode(sqlite3 *db); |
|
2643 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db); |
|
2644 SQLITE_API const char *sqlite3_errmsg(sqlite3*); |
|
2645 SQLITE_API const void *sqlite3_errmsg16(sqlite3*); |
|
2646 |
|
2647 /* |
|
2648 ** CAPI3REF: SQL Statement Object |
|
2649 ** KEYWORDS: {prepared statement} {prepared statements} |
|
2650 ** |
|
2651 ** An instance of this object represents a single SQL statement. |
|
2652 ** This object is variously known as a "prepared statement" or a |
|
2653 ** "compiled SQL statement" or simply as a "statement". |
|
2654 ** |
|
2655 ** The life of a statement object goes something like this: |
|
2656 ** |
|
2657 ** <ol> |
|
2658 ** <li> Create the object using [sqlite3_prepare_v2()] or a related |
|
2659 ** function. |
|
2660 ** <li> Bind values to [host parameters] using the sqlite3_bind_*() |
|
2661 ** interfaces. |
|
2662 ** <li> Run the SQL by calling [sqlite3_step()] one or more times. |
|
2663 ** <li> Reset the statement using [sqlite3_reset()] then go back |
|
2664 ** to step 2. Do this zero or more times. |
|
2665 ** <li> Destroy the object using [sqlite3_finalize()]. |
|
2666 ** </ol> |
|
2667 ** |
|
2668 ** Refer to documentation on individual methods above for additional |
|
2669 ** information. |
|
2670 */ |
|
2671 typedef struct sqlite3_stmt sqlite3_stmt; |
|
2672 |
|
2673 /* |
|
2674 ** CAPI3REF: Run-time Limits |
|
2675 ** |
|
2676 ** ^(This interface allows the size of various constructs to be limited |
|
2677 ** on a connection by connection basis. The first parameter is the |
|
2678 ** [database connection] whose limit is to be set or queried. The |
|
2679 ** second parameter is one of the [limit categories] that define a |
|
2680 ** class of constructs to be size limited. The third parameter is the |
|
2681 ** new limit for that construct.)^ |
|
2682 ** |
|
2683 ** ^If the new limit is a negative number, the limit is unchanged. |
|
2684 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a |
|
2685 ** [limits | hard upper bound] |
|
2686 ** set at compile-time by a C preprocessor macro called |
|
2687 ** [limits | SQLITE_MAX_<i>NAME</i>]. |
|
2688 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^ |
|
2689 ** ^Attempts to increase a limit above its hard upper bound are |
|
2690 ** silently truncated to the hard upper bound. |
|
2691 ** |
|
2692 ** ^Regardless of whether or not the limit was changed, the |
|
2693 ** [sqlite3_limit()] interface returns the prior value of the limit. |
|
2694 ** ^Hence, to find the current value of a limit without changing it, |
|
2695 ** simply invoke this interface with the third parameter set to -1. |
|
2696 ** |
|
2697 ** Run-time limits are intended for use in applications that manage |
|
2698 ** both their own internal database and also databases that are controlled |
|
2699 ** by untrusted external sources. An example application might be a |
|
2700 ** web browser that has its own databases for storing history and |
|
2701 ** separate databases controlled by JavaScript applications downloaded |
|
2702 ** off the Internet. The internal databases can be given the |
|
2703 ** large, default limits. Databases managed by external sources can |
|
2704 ** be given much smaller limits designed to prevent a denial of service |
|
2705 ** attack. Developers might also want to use the [sqlite3_set_authorizer()] |
|
2706 ** interface to further control untrusted SQL. The size of the database |
|
2707 ** created by an untrusted script can be contained using the |
|
2708 ** [max_page_count] [PRAGMA]. |
|
2709 ** |
|
2710 ** New run-time limit categories may be added in future releases. |
|
2711 */ |
|
2712 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal); |
|
2713 |
|
2714 /* |
|
2715 ** CAPI3REF: Run-Time Limit Categories |
|
2716 ** KEYWORDS: {limit category} {*limit categories} |
|
2717 ** |
|
2718 ** These constants define various performance limits |
|
2719 ** that can be lowered at run-time using [sqlite3_limit()]. |
|
2720 ** The synopsis of the meanings of the various limits is shown below. |
|
2721 ** Additional information is available at [limits | Limits in SQLite]. |
|
2722 ** |
|
2723 ** <dl> |
|
2724 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt> |
|
2725 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^ |
|
2726 ** |
|
2727 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt> |
|
2728 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^ |
|
2729 ** |
|
2730 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt> |
|
2731 ** <dd>The maximum number of columns in a table definition or in the |
|
2732 ** result set of a [SELECT] or the maximum number of columns in an index |
|
2733 ** or in an ORDER BY or GROUP BY clause.</dd>)^ |
|
2734 ** |
|
2735 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt> |
|
2736 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^ |
|
2737 ** |
|
2738 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt> |
|
2739 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^ |
|
2740 ** |
|
2741 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt> |
|
2742 ** <dd>The maximum number of instructions in a virtual machine program |
|
2743 ** used to implement an SQL statement. This limit is not currently |
|
2744 ** enforced, though that might be added in some future release of |
|
2745 ** SQLite.</dd>)^ |
|
2746 ** |
|
2747 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt> |
|
2748 ** <dd>The maximum number of arguments on a function.</dd>)^ |
|
2749 ** |
|
2750 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt> |
|
2751 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd> |
|
2752 ** |
|
2753 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]] |
|
2754 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt> |
|
2755 ** <dd>The maximum length of the pattern argument to the [LIKE] or |
|
2756 ** [GLOB] operators.</dd>)^ |
|
2757 ** |
|
2758 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]] |
|
2759 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt> |
|
2760 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^ |
|
2761 ** |
|
2762 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt> |
|
2763 ** <dd>The maximum depth of recursion for triggers.</dd>)^ |
|
2764 ** </dl> |
|
2765 */ |
|
2766 #define SQLITE_LIMIT_LENGTH 0 |
|
2767 #define SQLITE_LIMIT_SQL_LENGTH 1 |
|
2768 #define SQLITE_LIMIT_COLUMN 2 |
|
2769 #define SQLITE_LIMIT_EXPR_DEPTH 3 |
|
2770 #define SQLITE_LIMIT_COMPOUND_SELECT 4 |
|
2771 #define SQLITE_LIMIT_VDBE_OP 5 |
|
2772 #define SQLITE_LIMIT_FUNCTION_ARG 6 |
|
2773 #define SQLITE_LIMIT_ATTACHED 7 |
|
2774 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8 |
|
2775 #define SQLITE_LIMIT_VARIABLE_NUMBER 9 |
|
2776 #define SQLITE_LIMIT_TRIGGER_DEPTH 10 |
|
2777 |
|
2778 /* |
|
2779 ** CAPI3REF: Compiling An SQL Statement |
|
2780 ** KEYWORDS: {SQL statement compiler} |
|
2781 ** |
|
2782 ** To execute an SQL query, it must first be compiled into a byte-code |
|
2783 ** program using one of these routines. |
|
2784 ** |
|
2785 ** The first argument, "db", is a [database connection] obtained from a |
|
2786 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or |
|
2787 ** [sqlite3_open16()]. The database connection must not have been closed. |
|
2788 ** |
|
2789 ** The second argument, "zSql", is the statement to be compiled, encoded |
|
2790 ** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2() |
|
2791 ** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2() |
|
2792 ** use UTF-16. |
|
2793 ** |
|
2794 ** ^If the nByte argument is less than zero, then zSql is read up to the |
|
2795 ** first zero terminator. ^If nByte is non-negative, then it is the maximum |
|
2796 ** number of bytes read from zSql. ^When nByte is non-negative, the |
|
2797 ** zSql string ends at either the first '\000' or '\u0000' character or |
|
2798 ** the nByte-th byte, whichever comes first. If the caller knows |
|
2799 ** that the supplied string is nul-terminated, then there is a small |
|
2800 ** performance advantage to be gained by passing an nByte parameter that |
|
2801 ** is equal to the number of bytes in the input string <i>including</i> |
|
2802 ** the nul-terminator bytes. |
|
2803 ** |
|
2804 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte |
|
2805 ** past the end of the first SQL statement in zSql. These routines only |
|
2806 ** compile the first statement in zSql, so *pzTail is left pointing to |
|
2807 ** what remains uncompiled. |
|
2808 ** |
|
2809 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be |
|
2810 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set |
|
2811 ** to NULL. ^If the input text contains no SQL (if the input is an empty |
|
2812 ** string or a comment) then *ppStmt is set to NULL. |
|
2813 ** The calling procedure is responsible for deleting the compiled |
|
2814 ** SQL statement using [sqlite3_finalize()] after it has finished with it. |
|
2815 ** ppStmt may not be NULL. |
|
2816 ** |
|
2817 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK]; |
|
2818 ** otherwise an [error code] is returned. |
|
2819 ** |
|
2820 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are |
|
2821 ** recommended for all new programs. The two older interfaces are retained |
|
2822 ** for backwards compatibility, but their use is discouraged. |
|
2823 ** ^In the "v2" interfaces, the prepared statement |
|
2824 ** that is returned (the [sqlite3_stmt] object) contains a copy of the |
|
2825 ** original SQL text. This causes the [sqlite3_step()] interface to |
|
2826 ** behave differently in three ways: |
|
2827 ** |
|
2828 ** <ol> |
|
2829 ** <li> |
|
2830 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it |
|
2831 ** always used to do, [sqlite3_step()] will automatically recompile the SQL |
|
2832 ** statement and try to run it again. |
|
2833 ** </li> |
|
2834 ** |
|
2835 ** <li> |
|
2836 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed |
|
2837 ** [error codes] or [extended error codes]. ^The legacy behavior was that |
|
2838 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code |
|
2839 ** and the application would have to make a second call to [sqlite3_reset()] |
|
2840 ** in order to find the underlying cause of the problem. With the "v2" prepare |
|
2841 ** interfaces, the underlying reason for the error is returned immediately. |
|
2842 ** </li> |
|
2843 ** |
|
2844 ** <li> |
|
2845 ** ^If the specific value bound to [parameter | host parameter] in the |
|
2846 ** WHERE clause might influence the choice of query plan for a statement, |
|
2847 ** then the statement will be automatically recompiled, as if there had been |
|
2848 ** a schema change, on the first [sqlite3_step()] call following any change |
|
2849 ** to the [sqlite3_bind_text | bindings] of that [parameter]. |
|
2850 ** ^The specific value of WHERE-clause [parameter] might influence the |
|
2851 ** choice of query plan if the parameter is the left-hand side of a [LIKE] |
|
2852 ** or [GLOB] operator or if the parameter is compared to an indexed column |
|
2853 ** and the [SQLITE_ENABLE_STAT2] compile-time option is enabled. |
|
2854 ** the |
|
2855 ** </li> |
|
2856 ** </ol> |
|
2857 */ |
|
2858 SQLITE_API int sqlite3_prepare( |
|
2859 sqlite3 *db, /* Database handle */ |
|
2860 const char *zSql, /* SQL statement, UTF-8 encoded */ |
|
2861 int nByte, /* Maximum length of zSql in bytes. */ |
|
2862 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
|
2863 const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
|
2864 ); |
|
2865 SQLITE_API int sqlite3_prepare_v2( |
|
2866 sqlite3 *db, /* Database handle */ |
|
2867 const char *zSql, /* SQL statement, UTF-8 encoded */ |
|
2868 int nByte, /* Maximum length of zSql in bytes. */ |
|
2869 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
|
2870 const char **pzTail /* OUT: Pointer to unused portion of zSql */ |
|
2871 ); |
|
2872 SQLITE_API int sqlite3_prepare16( |
|
2873 sqlite3 *db, /* Database handle */ |
|
2874 const void *zSql, /* SQL statement, UTF-16 encoded */ |
|
2875 int nByte, /* Maximum length of zSql in bytes. */ |
|
2876 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
|
2877 const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
|
2878 ); |
|
2879 SQLITE_API int sqlite3_prepare16_v2( |
|
2880 sqlite3 *db, /* Database handle */ |
|
2881 const void *zSql, /* SQL statement, UTF-16 encoded */ |
|
2882 int nByte, /* Maximum length of zSql in bytes. */ |
|
2883 sqlite3_stmt **ppStmt, /* OUT: Statement handle */ |
|
2884 const void **pzTail /* OUT: Pointer to unused portion of zSql */ |
|
2885 ); |
|
2886 |
|
2887 /* |
|
2888 ** CAPI3REF: Retrieving Statement SQL |
|
2889 ** |
|
2890 ** ^This interface can be used to retrieve a saved copy of the original |
|
2891 ** SQL text used to create a [prepared statement] if that statement was |
|
2892 ** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()]. |
|
2893 */ |
|
2894 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt); |
|
2895 |
|
2896 /* |
|
2897 ** CAPI3REF: Determine If An SQL Statement Writes The Database |
|
2898 ** |
|
2899 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if |
|
2900 ** and only if the [prepared statement] X makes no direct changes to |
|
2901 ** the content of the database file. |
|
2902 ** |
|
2903 ** Note that [application-defined SQL functions] or |
|
2904 ** [virtual tables] might change the database indirectly as a side effect. |
|
2905 ** ^(For example, if an application defines a function "eval()" that |
|
2906 ** calls [sqlite3_exec()], then the following SQL statement would |
|
2907 ** change the database file through side-effects: |
|
2908 ** |
|
2909 ** <blockquote><pre> |
|
2910 ** SELECT eval('DELETE FROM t1') FROM t2; |
|
2911 ** </pre></blockquote> |
|
2912 ** |
|
2913 ** But because the [SELECT] statement does not change the database file |
|
2914 ** directly, sqlite3_stmt_readonly() would still return true.)^ |
|
2915 ** |
|
2916 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK], |
|
2917 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true, |
|
2918 ** since the statements themselves do not actually modify the database but |
|
2919 ** rather they control the timing of when other statements modify the |
|
2920 ** database. ^The [ATTACH] and [DETACH] statements also cause |
|
2921 ** sqlite3_stmt_readonly() to return true since, while those statements |
|
2922 ** change the configuration of a database connection, they do not make |
|
2923 ** changes to the content of the database files on disk. |
|
2924 */ |
|
2925 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt); |
|
2926 |
|
2927 /* |
|
2928 ** CAPI3REF: Dynamically Typed Value Object |
|
2929 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value} |
|
2930 ** |
|
2931 ** SQLite uses the sqlite3_value object to represent all values |
|
2932 ** that can be stored in a database table. SQLite uses dynamic typing |
|
2933 ** for the values it stores. ^Values stored in sqlite3_value objects |
|
2934 ** can be integers, floating point values, strings, BLOBs, or NULL. |
|
2935 ** |
|
2936 ** An sqlite3_value object may be either "protected" or "unprotected". |
|
2937 ** Some interfaces require a protected sqlite3_value. Other interfaces |
|
2938 ** will accept either a protected or an unprotected sqlite3_value. |
|
2939 ** Every interface that accepts sqlite3_value arguments specifies |
|
2940 ** whether or not it requires a protected sqlite3_value. |
|
2941 ** |
|
2942 ** The terms "protected" and "unprotected" refer to whether or not |
|
2943 ** a mutex is held. An internal mutex is held for a protected |
|
2944 ** sqlite3_value object but no mutex is held for an unprotected |
|
2945 ** sqlite3_value object. If SQLite is compiled to be single-threaded |
|
2946 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0) |
|
2947 ** or if SQLite is run in one of reduced mutex modes |
|
2948 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD] |
|
2949 ** then there is no distinction between protected and unprotected |
|
2950 ** sqlite3_value objects and they can be used interchangeably. However, |
|
2951 ** for maximum code portability it is recommended that applications |
|
2952 ** still make the distinction between protected and unprotected |
|
2953 ** sqlite3_value objects even when not strictly required. |
|
2954 ** |
|
2955 ** ^The sqlite3_value objects that are passed as parameters into the |
|
2956 ** implementation of [application-defined SQL functions] are protected. |
|
2957 ** ^The sqlite3_value object returned by |
|
2958 ** [sqlite3_column_value()] is unprotected. |
|
2959 ** Unprotected sqlite3_value objects may only be used with |
|
2960 ** [sqlite3_result_value()] and [sqlite3_bind_value()]. |
|
2961 ** The [sqlite3_value_blob | sqlite3_value_type()] family of |
|
2962 ** interfaces require protected sqlite3_value objects. |
|
2963 */ |
|
2964 typedef struct Mem sqlite3_value; |
|
2965 |
|
2966 /* |
|
2967 ** CAPI3REF: SQL Function Context Object |
|
2968 ** |
|
2969 ** The context in which an SQL function executes is stored in an |
|
2970 ** sqlite3_context object. ^A pointer to an sqlite3_context object |
|
2971 ** is always first parameter to [application-defined SQL functions]. |
|
2972 ** The application-defined SQL function implementation will pass this |
|
2973 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()], |
|
2974 ** [sqlite3_aggregate_context()], [sqlite3_user_data()], |
|
2975 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()], |
|
2976 ** and/or [sqlite3_set_auxdata()]. |
|
2977 */ |
|
2978 typedef struct sqlite3_context sqlite3_context; |
|
2979 |
|
2980 /* |
|
2981 ** CAPI3REF: Binding Values To Prepared Statements |
|
2982 ** KEYWORDS: {host parameter} {host parameters} {host parameter name} |
|
2983 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding} |
|
2984 ** |
|
2985 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants, |
|
2986 ** literals may be replaced by a [parameter] that matches one of following |
|
2987 ** templates: |
|
2988 ** |
|
2989 ** <ul> |
|
2990 ** <li> ? |
|
2991 ** <li> ?NNN |
|
2992 ** <li> :VVV |
|
2993 ** <li> @VVV |
|
2994 ** <li> $VVV |
|
2995 ** </ul> |
|
2996 ** |
|
2997 ** In the templates above, NNN represents an integer literal, |
|
2998 ** and VVV represents an alphanumeric identifier.)^ ^The values of these |
|
2999 ** parameters (also called "host parameter names" or "SQL parameters") |
|
3000 ** can be set using the sqlite3_bind_*() routines defined here. |
|
3001 ** |
|
3002 ** ^The first argument to the sqlite3_bind_*() routines is always |
|
3003 ** a pointer to the [sqlite3_stmt] object returned from |
|
3004 ** [sqlite3_prepare_v2()] or its variants. |
|
3005 ** |
|
3006 ** ^The second argument is the index of the SQL parameter to be set. |
|
3007 ** ^The leftmost SQL parameter has an index of 1. ^When the same named |
|
3008 ** SQL parameter is used more than once, second and subsequent |
|
3009 ** occurrences have the same index as the first occurrence. |
|
3010 ** ^The index for named parameters can be looked up using the |
|
3011 ** [sqlite3_bind_parameter_index()] API if desired. ^The index |
|
3012 ** for "?NNN" parameters is the value of NNN. |
|
3013 ** ^The NNN value must be between 1 and the [sqlite3_limit()] |
|
3014 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999). |
|
3015 ** |
|
3016 ** ^The third argument is the value to bind to the parameter. |
|
3017 ** |
|
3018 ** ^(In those routines that have a fourth argument, its value is the |
|
3019 ** number of bytes in the parameter. To be clear: the value is the |
|
3020 ** number of <u>bytes</u> in the value, not the number of characters.)^ |
|
3021 ** ^If the fourth parameter is negative, the length of the string is |
|
3022 ** the number of bytes up to the first zero terminator. |
|
3023 ** |
|
3024 ** ^The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and |
|
3025 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or |
|
3026 ** string after SQLite has finished with it. ^The destructor is called |
|
3027 ** to dispose of the BLOB or string even if the call to sqlite3_bind_blob(), |
|
3028 ** sqlite3_bind_text(), or sqlite3_bind_text16() fails. |
|
3029 ** ^If the fifth argument is |
|
3030 ** the special value [SQLITE_STATIC], then SQLite assumes that the |
|
3031 ** information is in static, unmanaged space and does not need to be freed. |
|
3032 ** ^If the fifth argument has the value [SQLITE_TRANSIENT], then |
|
3033 ** SQLite makes its own private copy of the data immediately, before |
|
3034 ** the sqlite3_bind_*() routine returns. |
|
3035 ** |
|
3036 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that |
|
3037 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory |
|
3038 ** (just an integer to hold its size) while it is being processed. |
|
3039 ** Zeroblobs are intended to serve as placeholders for BLOBs whose |
|
3040 ** content is later written using |
|
3041 ** [sqlite3_blob_open | incremental BLOB I/O] routines. |
|
3042 ** ^A negative value for the zeroblob results in a zero-length BLOB. |
|
3043 ** |
|
3044 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer |
|
3045 ** for the [prepared statement] or with a prepared statement for which |
|
3046 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()], |
|
3047 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_() |
|
3048 ** routine is passed a [prepared statement] that has been finalized, the |
|
3049 ** result is undefined and probably harmful. |
|
3050 ** |
|
3051 ** ^Bindings are not cleared by the [sqlite3_reset()] routine. |
|
3052 ** ^Unbound parameters are interpreted as NULL. |
|
3053 ** |
|
3054 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an |
|
3055 ** [error code] if anything goes wrong. |
|
3056 ** ^[SQLITE_RANGE] is returned if the parameter |
|
3057 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails. |
|
3058 ** |
|
3059 ** See also: [sqlite3_bind_parameter_count()], |
|
3060 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()]. |
|
3061 */ |
|
3062 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*)); |
|
3063 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double); |
|
3064 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int); |
|
3065 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64); |
|
3066 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int); |
|
3067 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*)); |
|
3068 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*)); |
|
3069 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*); |
|
3070 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n); |
|
3071 |
|
3072 /* |
|
3073 ** CAPI3REF: Number Of SQL Parameters |
|
3074 ** |
|
3075 ** ^This routine can be used to find the number of [SQL parameters] |
|
3076 ** in a [prepared statement]. SQL parameters are tokens of the |
|
3077 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as |
|
3078 ** placeholders for values that are [sqlite3_bind_blob | bound] |
|
3079 ** to the parameters at a later time. |
|
3080 ** |
|
3081 ** ^(This routine actually returns the index of the largest (rightmost) |
|
3082 ** parameter. For all forms except ?NNN, this will correspond to the |
|
3083 ** number of unique parameters. If parameters of the ?NNN form are used, |
|
3084 ** there may be gaps in the list.)^ |
|
3085 ** |
|
3086 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
|
3087 ** [sqlite3_bind_parameter_name()], and |
|
3088 ** [sqlite3_bind_parameter_index()]. |
|
3089 */ |
|
3090 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*); |
|
3091 |
|
3092 /* |
|
3093 ** CAPI3REF: Name Of A Host Parameter |
|
3094 ** |
|
3095 ** ^The sqlite3_bind_parameter_name(P,N) interface returns |
|
3096 ** the name of the N-th [SQL parameter] in the [prepared statement] P. |
|
3097 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA" |
|
3098 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA" |
|
3099 ** respectively. |
|
3100 ** In other words, the initial ":" or "$" or "@" or "?" |
|
3101 ** is included as part of the name.)^ |
|
3102 ** ^Parameters of the form "?" without a following integer have no name |
|
3103 ** and are referred to as "nameless" or "anonymous parameters". |
|
3104 ** |
|
3105 ** ^The first host parameter has an index of 1, not 0. |
|
3106 ** |
|
3107 ** ^If the value N is out of range or if the N-th parameter is |
|
3108 ** nameless, then NULL is returned. ^The returned string is |
|
3109 ** always in UTF-8 encoding even if the named parameter was |
|
3110 ** originally specified as UTF-16 in [sqlite3_prepare16()] or |
|
3111 ** [sqlite3_prepare16_v2()]. |
|
3112 ** |
|
3113 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
|
3114 ** [sqlite3_bind_parameter_count()], and |
|
3115 ** [sqlite3_bind_parameter_index()]. |
|
3116 */ |
|
3117 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int); |
|
3118 |
|
3119 /* |
|
3120 ** CAPI3REF: Index Of A Parameter With A Given Name |
|
3121 ** |
|
3122 ** ^Return the index of an SQL parameter given its name. ^The |
|
3123 ** index value returned is suitable for use as the second |
|
3124 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero |
|
3125 ** is returned if no matching parameter is found. ^The parameter |
|
3126 ** name must be given in UTF-8 even if the original statement |
|
3127 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()]. |
|
3128 ** |
|
3129 ** See also: [sqlite3_bind_blob|sqlite3_bind()], |
|
3130 ** [sqlite3_bind_parameter_count()], and |
|
3131 ** [sqlite3_bind_parameter_index()]. |
|
3132 */ |
|
3133 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName); |
|
3134 |
|
3135 /* |
|
3136 ** CAPI3REF: Reset All Bindings On A Prepared Statement |
|
3137 ** |
|
3138 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset |
|
3139 ** the [sqlite3_bind_blob | bindings] on a [prepared statement]. |
|
3140 ** ^Use this routine to reset all host parameters to NULL. |
|
3141 */ |
|
3142 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*); |
|
3143 |
|
3144 /* |
|
3145 ** CAPI3REF: Number Of Columns In A Result Set |
|
3146 ** |
|
3147 ** ^Return the number of columns in the result set returned by the |
|
3148 ** [prepared statement]. ^This routine returns 0 if pStmt is an SQL |
|
3149 ** statement that does not return data (for example an [UPDATE]). |
|
3150 ** |
|
3151 ** See also: [sqlite3_data_count()] |
|
3152 */ |
|
3153 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt); |
|
3154 |
|
3155 /* |
|
3156 ** CAPI3REF: Column Names In A Result Set |
|
3157 ** |
|
3158 ** ^These routines return the name assigned to a particular column |
|
3159 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name() |
|
3160 ** interface returns a pointer to a zero-terminated UTF-8 string |
|
3161 ** and sqlite3_column_name16() returns a pointer to a zero-terminated |
|
3162 ** UTF-16 string. ^The first parameter is the [prepared statement] |
|
3163 ** that implements the [SELECT] statement. ^The second parameter is the |
|
3164 ** column number. ^The leftmost column is number 0. |
|
3165 ** |
|
3166 ** ^The returned string pointer is valid until either the [prepared statement] |
|
3167 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically |
|
3168 ** reprepared by the first call to [sqlite3_step()] for a particular run |
|
3169 ** or until the next call to |
|
3170 ** sqlite3_column_name() or sqlite3_column_name16() on the same column. |
|
3171 ** |
|
3172 ** ^If sqlite3_malloc() fails during the processing of either routine |
|
3173 ** (for example during a conversion from UTF-8 to UTF-16) then a |
|
3174 ** NULL pointer is returned. |
|
3175 ** |
|
3176 ** ^The name of a result column is the value of the "AS" clause for |
|
3177 ** that column, if there is an AS clause. If there is no AS clause |
|
3178 ** then the name of the column is unspecified and may change from |
|
3179 ** one release of SQLite to the next. |
|
3180 */ |
|
3181 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N); |
|
3182 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N); |
|
3183 |
|
3184 /* |
|
3185 ** CAPI3REF: Source Of Data In A Query Result |
|
3186 ** |
|
3187 ** ^These routines provide a means to determine the database, table, and |
|
3188 ** table column that is the origin of a particular result column in |
|
3189 ** [SELECT] statement. |
|
3190 ** ^The name of the database or table or column can be returned as |
|
3191 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return |
|
3192 ** the database name, the _table_ routines return the table name, and |
|
3193 ** the origin_ routines return the column name. |
|
3194 ** ^The returned string is valid until the [prepared statement] is destroyed |
|
3195 ** using [sqlite3_finalize()] or until the statement is automatically |
|
3196 ** reprepared by the first call to [sqlite3_step()] for a particular run |
|
3197 ** or until the same information is requested |
|
3198 ** again in a different encoding. |
|
3199 ** |
|
3200 ** ^The names returned are the original un-aliased names of the |
|
3201 ** database, table, and column. |
|
3202 ** |
|
3203 ** ^The first argument to these interfaces is a [prepared statement]. |
|
3204 ** ^These functions return information about the Nth result column returned by |
|
3205 ** the statement, where N is the second function argument. |
|
3206 ** ^The left-most column is column 0 for these routines. |
|
3207 ** |
|
3208 ** ^If the Nth column returned by the statement is an expression or |
|
3209 ** subquery and is not a column value, then all of these functions return |
|
3210 ** NULL. ^These routine might also return NULL if a memory allocation error |
|
3211 ** occurs. ^Otherwise, they return the name of the attached database, table, |
|
3212 ** or column that query result column was extracted from. |
|
3213 ** |
|
3214 ** ^As with all other SQLite APIs, those whose names end with "16" return |
|
3215 ** UTF-16 encoded strings and the other functions return UTF-8. |
|
3216 ** |
|
3217 ** ^These APIs are only available if the library was compiled with the |
|
3218 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol. |
|
3219 ** |
|
3220 ** If two or more threads call one or more of these routines against the same |
|
3221 ** prepared statement and column at the same time then the results are |
|
3222 ** undefined. |
|
3223 ** |
|
3224 ** If two or more threads call one or more |
|
3225 ** [sqlite3_column_database_name | column metadata interfaces] |
|
3226 ** for the same [prepared statement] and result column |
|
3227 ** at the same time then the results are undefined. |
|
3228 */ |
|
3229 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int); |
|
3230 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int); |
|
3231 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int); |
|
3232 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int); |
|
3233 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int); |
|
3234 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int); |
|
3235 |
|
3236 /* |
|
3237 ** CAPI3REF: Declared Datatype Of A Query Result |
|
3238 ** |
|
3239 ** ^(The first parameter is a [prepared statement]. |
|
3240 ** If this statement is a [SELECT] statement and the Nth column of the |
|
3241 ** returned result set of that [SELECT] is a table column (not an |
|
3242 ** expression or subquery) then the declared type of the table |
|
3243 ** column is returned.)^ ^If the Nth column of the result set is an |
|
3244 ** expression or subquery, then a NULL pointer is returned. |
|
3245 ** ^The returned string is always UTF-8 encoded. |
|
3246 ** |
|
3247 ** ^(For example, given the database schema: |
|
3248 ** |
|
3249 ** CREATE TABLE t1(c1 VARIANT); |
|
3250 ** |
|
3251 ** and the following statement to be compiled: |
|
3252 ** |
|
3253 ** SELECT c1 + 1, c1 FROM t1; |
|
3254 ** |
|
3255 ** this routine would return the string "VARIANT" for the second result |
|
3256 ** column (i==1), and a NULL pointer for the first result column (i==0).)^ |
|
3257 ** |
|
3258 ** ^SQLite uses dynamic run-time typing. ^So just because a column |
|
3259 ** is declared to contain a particular type does not mean that the |
|
3260 ** data stored in that column is of the declared type. SQLite is |
|
3261 ** strongly typed, but the typing is dynamic not static. ^Type |
|
3262 ** is associated with individual values, not with the containers |
|
3263 ** used to hold those values. |
|
3264 */ |
|
3265 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int); |
|
3266 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int); |
|
3267 |
|
3268 /* |
|
3269 ** CAPI3REF: Evaluate An SQL Statement |
|
3270 ** |
|
3271 ** After a [prepared statement] has been prepared using either |
|
3272 ** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy |
|
3273 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function |
|
3274 ** must be called one or more times to evaluate the statement. |
|
3275 ** |
|
3276 ** The details of the behavior of the sqlite3_step() interface depend |
|
3277 ** on whether the statement was prepared using the newer "v2" interface |
|
3278 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy |
|
3279 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the |
|
3280 ** new "v2" interface is recommended for new applications but the legacy |
|
3281 ** interface will continue to be supported. |
|
3282 ** |
|
3283 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY], |
|
3284 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE]. |
|
3285 ** ^With the "v2" interface, any of the other [result codes] or |
|
3286 ** [extended result codes] might be returned as well. |
|
3287 ** |
|
3288 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the |
|
3289 ** database locks it needs to do its job. ^If the statement is a [COMMIT] |
|
3290 ** or occurs outside of an explicit transaction, then you can retry the |
|
3291 ** statement. If the statement is not a [COMMIT] and occurs within an |
|
3292 ** explicit transaction then you should rollback the transaction before |
|
3293 ** continuing. |
|
3294 ** |
|
3295 ** ^[SQLITE_DONE] means that the statement has finished executing |
|
3296 ** successfully. sqlite3_step() should not be called again on this virtual |
|
3297 ** machine without first calling [sqlite3_reset()] to reset the virtual |
|
3298 ** machine back to its initial state. |
|
3299 ** |
|
3300 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW] |
|
3301 ** is returned each time a new row of data is ready for processing by the |
|
3302 ** caller. The values may be accessed using the [column access functions]. |
|
3303 ** sqlite3_step() is called again to retrieve the next row of data. |
|
3304 ** |
|
3305 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint |
|
3306 ** violation) has occurred. sqlite3_step() should not be called again on |
|
3307 ** the VM. More information may be found by calling [sqlite3_errmsg()]. |
|
3308 ** ^With the legacy interface, a more specific error code (for example, |
|
3309 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth) |
|
3310 ** can be obtained by calling [sqlite3_reset()] on the |
|
3311 ** [prepared statement]. ^In the "v2" interface, |
|
3312 ** the more specific error code is returned directly by sqlite3_step(). |
|
3313 ** |
|
3314 ** [SQLITE_MISUSE] means that the this routine was called inappropriately. |
|
3315 ** Perhaps it was called on a [prepared statement] that has |
|
3316 ** already been [sqlite3_finalize | finalized] or on one that had |
|
3317 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could |
|
3318 ** be the case that the same database connection is being used by two or |
|
3319 ** more threads at the same moment in time. |
|
3320 ** |
|
3321 ** For all versions of SQLite up to and including 3.6.23.1, a call to |
|
3322 ** [sqlite3_reset()] was required after sqlite3_step() returned anything |
|
3323 ** other than [SQLITE_ROW] before any subsequent invocation of |
|
3324 ** sqlite3_step(). Failure to reset the prepared statement using |
|
3325 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from |
|
3326 ** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began |
|
3327 ** calling [sqlite3_reset()] automatically in this circumstance rather |
|
3328 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility |
|
3329 ** break because any application that ever receives an SQLITE_MISUSE error |
|
3330 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option |
|
3331 ** can be used to restore the legacy behavior. |
|
3332 ** |
|
3333 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step() |
|
3334 ** API always returns a generic error code, [SQLITE_ERROR], following any |
|
3335 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call |
|
3336 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the |
|
3337 ** specific [error codes] that better describes the error. |
|
3338 ** We admit that this is a goofy design. The problem has been fixed |
|
3339 ** with the "v2" interface. If you prepare all of your SQL statements |
|
3340 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead |
|
3341 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces, |
|
3342 ** then the more specific [error codes] are returned directly |
|
3343 ** by sqlite3_step(). The use of the "v2" interface is recommended. |
|
3344 */ |
|
3345 SQLITE_API int sqlite3_step(sqlite3_stmt*); |
|
3346 |
|
3347 /* |
|
3348 ** CAPI3REF: Number of columns in a result set |
|
3349 ** |
|
3350 ** ^The sqlite3_data_count(P) interface returns the number of columns in the |
|
3351 ** current row of the result set of [prepared statement] P. |
|
3352 ** ^If prepared statement P does not have results ready to return |
|
3353 ** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of |
|
3354 ** interfaces) then sqlite3_data_count(P) returns 0. |
|
3355 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer. |
|
3356 ** |
|
3357 ** See also: [sqlite3_column_count()] |
|
3358 */ |
|
3359 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt); |
|
3360 |
|
3361 /* |
|
3362 ** CAPI3REF: Fundamental Datatypes |
|
3363 ** KEYWORDS: SQLITE_TEXT |
|
3364 ** |
|
3365 ** ^(Every value in SQLite has one of five fundamental datatypes: |
|
3366 ** |
|
3367 ** <ul> |
|
3368 ** <li> 64-bit signed integer |
|
3369 ** <li> 64-bit IEEE floating point number |
|
3370 ** <li> string |
|
3371 ** <li> BLOB |
|
3372 ** <li> NULL |
|
3373 ** </ul>)^ |
|
3374 ** |
|
3375 ** These constants are codes for each of those types. |
|
3376 ** |
|
3377 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2 |
|
3378 ** for a completely different meaning. Software that links against both |
|
3379 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not |
|
3380 ** SQLITE_TEXT. |
|
3381 */ |
|
3382 #define SQLITE_INTEGER 1 |
|
3383 #define SQLITE_FLOAT 2 |
|
3384 #define SQLITE_BLOB 4 |
|
3385 #define SQLITE_NULL 5 |
|
3386 #ifdef SQLITE_TEXT |
|
3387 # undef SQLITE_TEXT |
|
3388 #else |
|
3389 # define SQLITE_TEXT 3 |
|
3390 #endif |
|
3391 #define SQLITE3_TEXT 3 |
|
3392 |
|
3393 /* |
|
3394 ** CAPI3REF: Result Values From A Query |
|
3395 ** KEYWORDS: {column access functions} |
|
3396 ** |
|
3397 ** These routines form the "result set" interface. |
|
3398 ** |
|
3399 ** ^These routines return information about a single column of the current |
|
3400 ** result row of a query. ^In every case the first argument is a pointer |
|
3401 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*] |
|
3402 ** that was returned from [sqlite3_prepare_v2()] or one of its variants) |
|
3403 ** and the second argument is the index of the column for which information |
|
3404 ** should be returned. ^The leftmost column of the result set has the index 0. |
|
3405 ** ^The number of columns in the result can be determined using |
|
3406 ** [sqlite3_column_count()]. |
|
3407 ** |
|
3408 ** If the SQL statement does not currently point to a valid row, or if the |
|
3409 ** column index is out of range, the result is undefined. |
|
3410 ** These routines may only be called when the most recent call to |
|
3411 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither |
|
3412 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently. |
|
3413 ** If any of these routines are called after [sqlite3_reset()] or |
|
3414 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned |
|
3415 ** something other than [SQLITE_ROW], the results are undefined. |
|
3416 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()] |
|
3417 ** are called from a different thread while any of these routines |
|
3418 ** are pending, then the results are undefined. |
|
3419 ** |
|
3420 ** ^The sqlite3_column_type() routine returns the |
|
3421 ** [SQLITE_INTEGER | datatype code] for the initial data type |
|
3422 ** of the result column. ^The returned value is one of [SQLITE_INTEGER], |
|
3423 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value |
|
3424 ** returned by sqlite3_column_type() is only meaningful if no type |
|
3425 ** conversions have occurred as described below. After a type conversion, |
|
3426 ** the value returned by sqlite3_column_type() is undefined. Future |
|
3427 ** versions of SQLite may change the behavior of sqlite3_column_type() |
|
3428 ** following a type conversion. |
|
3429 ** |
|
3430 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes() |
|
3431 ** routine returns the number of bytes in that BLOB or string. |
|
3432 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts |
|
3433 ** the string to UTF-8 and then returns the number of bytes. |
|
3434 ** ^If the result is a numeric value then sqlite3_column_bytes() uses |
|
3435 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns |
|
3436 ** the number of bytes in that string. |
|
3437 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero. |
|
3438 ** |
|
3439 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16() |
|
3440 ** routine returns the number of bytes in that BLOB or string. |
|
3441 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts |
|
3442 ** the string to UTF-16 and then returns the number of bytes. |
|
3443 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses |
|
3444 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns |
|
3445 ** the number of bytes in that string. |
|
3446 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero. |
|
3447 ** |
|
3448 ** ^The values returned by [sqlite3_column_bytes()] and |
|
3449 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end |
|
3450 ** of the string. ^For clarity: the values returned by |
|
3451 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of |
|
3452 ** bytes in the string, not the number of characters. |
|
3453 ** |
|
3454 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(), |
|
3455 ** even empty strings, are always zero terminated. ^The return |
|
3456 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer. |
|
3457 ** |
|
3458 ** ^The object returned by [sqlite3_column_value()] is an |
|
3459 ** [unprotected sqlite3_value] object. An unprotected sqlite3_value object |
|
3460 ** may only be used with [sqlite3_bind_value()] and [sqlite3_result_value()]. |
|
3461 ** If the [unprotected sqlite3_value] object returned by |
|
3462 ** [sqlite3_column_value()] is used in any other way, including calls |
|
3463 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()], |
|
3464 ** or [sqlite3_value_bytes()], then the behavior is undefined. |
|
3465 ** |
|
3466 ** These routines attempt to convert the value where appropriate. ^For |
|
3467 ** example, if the internal representation is FLOAT and a text result |
|
3468 ** is requested, [sqlite3_snprintf()] is used internally to perform the |
|
3469 ** conversion automatically. ^(The following table details the conversions |
|
3470 ** that are applied: |
|
3471 ** |
|
3472 ** <blockquote> |
|
3473 ** <table border="1"> |
|
3474 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion |
|
3475 ** |
|
3476 ** <tr><td> NULL <td> INTEGER <td> Result is 0 |
|
3477 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0 |
|
3478 ** <tr><td> NULL <td> TEXT <td> Result is NULL pointer |
|
3479 ** <tr><td> NULL <td> BLOB <td> Result is NULL pointer |
|
3480 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float |
|
3481 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer |
|
3482 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT |
|
3483 ** <tr><td> FLOAT <td> INTEGER <td> Convert from float to integer |
|
3484 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float |
|
3485 ** <tr><td> FLOAT <td> BLOB <td> Same as FLOAT->TEXT |
|
3486 ** <tr><td> TEXT <td> INTEGER <td> Use atoi() |
|
3487 ** <tr><td> TEXT <td> FLOAT <td> Use atof() |
|
3488 ** <tr><td> TEXT <td> BLOB <td> No change |
|
3489 ** <tr><td> BLOB <td> INTEGER <td> Convert to TEXT then use atoi() |
|
3490 ** <tr><td> BLOB <td> FLOAT <td> Convert to TEXT then use atof() |
|
3491 ** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed |
|
3492 ** </table> |
|
3493 ** </blockquote>)^ |
|
3494 ** |
|
3495 ** The table above makes reference to standard C library functions atoi() |
|
3496 ** and atof(). SQLite does not really use these functions. It has its |
|
3497 ** own equivalent internal routines. The atoi() and atof() names are |
|
3498 ** used in the table for brevity and because they are familiar to most |
|
3499 ** C programmers. |
|
3500 ** |
|
3501 ** Note that when type conversions occur, pointers returned by prior |
|
3502 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or |
|
3503 ** sqlite3_column_text16() may be invalidated. |
|
3504 ** Type conversions and pointer invalidations might occur |
|
3505 ** in the following cases: |
|
3506 ** |
|
3507 ** <ul> |
|
3508 ** <li> The initial content is a BLOB and sqlite3_column_text() or |
|
3509 ** sqlite3_column_text16() is called. A zero-terminator might |
|
3510 ** need to be added to the string.</li> |
|
3511 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or |
|
3512 ** sqlite3_column_text16() is called. The content must be converted |
|
3513 ** to UTF-16.</li> |
|
3514 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or |
|
3515 ** sqlite3_column_text() is called. The content must be converted |
|
3516 ** to UTF-8.</li> |
|
3517 ** </ul> |
|
3518 ** |
|
3519 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do |
|
3520 ** not invalidate a prior pointer, though of course the content of the buffer |
|
3521 ** that the prior pointer references will have been modified. Other kinds |
|
3522 ** of conversion are done in place when it is possible, but sometimes they |
|
3523 ** are not possible and in those cases prior pointers are invalidated. |
|
3524 ** |
|
3525 ** The safest and easiest to remember policy is to invoke these routines |
|
3526 ** in one of the following ways: |
|
3527 ** |
|
3528 ** <ul> |
|
3529 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li> |
|
3530 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li> |
|
3531 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li> |
|
3532 ** </ul> |
|
3533 ** |
|
3534 ** In other words, you should call sqlite3_column_text(), |
|
3535 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result |
|
3536 ** into the desired format, then invoke sqlite3_column_bytes() or |
|
3537 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls |
|
3538 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to |
|
3539 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16() |
|
3540 ** with calls to sqlite3_column_bytes(). |
|
3541 ** |
|
3542 ** ^The pointers returned are valid until a type conversion occurs as |
|
3543 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or |
|
3544 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings |
|
3545 ** and BLOBs is freed automatically. Do <b>not</b> pass the pointers returned |
|
3546 ** [sqlite3_column_blob()], [sqlite3_column_text()], etc. into |
|
3547 ** [sqlite3_free()]. |
|
3548 ** |
|
3549 ** ^(If a memory allocation error occurs during the evaluation of any |
|
3550 ** of these routines, a default value is returned. The default value |
|
3551 ** is either the integer 0, the floating point number 0.0, or a NULL |
|
3552 ** pointer. Subsequent calls to [sqlite3_errcode()] will return |
|
3553 ** [SQLITE_NOMEM].)^ |
|
3554 */ |
|
3555 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); |
|
3556 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol); |
|
3557 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol); |
|
3558 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol); |
|
3559 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol); |
|
3560 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); |
|
3561 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol); |
|
3562 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol); |
|
3563 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol); |
|
3564 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol); |
|
3565 |
|
3566 /* |
|
3567 ** CAPI3REF: Destroy A Prepared Statement Object |
|
3568 ** |
|
3569 ** ^The sqlite3_finalize() function is called to delete a [prepared statement]. |
|
3570 ** ^If the most recent evaluation of the statement encountered no errors |
|
3571 ** or if the statement is never been evaluated, then sqlite3_finalize() returns |
|
3572 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then |
|
3573 ** sqlite3_finalize(S) returns the appropriate [error code] or |
|
3574 ** [extended error code]. |
|
3575 ** |
|
3576 ** ^The sqlite3_finalize(S) routine can be called at any point during |
|
3577 ** the life cycle of [prepared statement] S: |
|
3578 ** before statement S is ever evaluated, after |
|
3579 ** one or more calls to [sqlite3_reset()], or after any call |
|
3580 ** to [sqlite3_step()] regardless of whether or not the statement has |
|
3581 ** completed execution. |
|
3582 ** |
|
3583 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op. |
|
3584 ** |
|
3585 ** The application must finalize every [prepared statement] in order to avoid |
|
3586 ** resource leaks. It is a grievous error for the application to try to use |
|
3587 ** a prepared statement after it has been finalized. Any use of a prepared |
|
3588 ** statement after it has been finalized can result in undefined and |
|
3589 ** undesirable behavior such as segfaults and heap corruption. |
|
3590 */ |
|
3591 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt); |
|
3592 |
|
3593 /* |
|
3594 ** CAPI3REF: Reset A Prepared Statement Object |
|
3595 ** |
|
3596 ** The sqlite3_reset() function is called to reset a [prepared statement] |
|
3597 ** object back to its initial state, ready to be re-executed. |
|
3598 ** ^Any SQL statement variables that had values bound to them using |
|
3599 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values. |
|
3600 ** Use [sqlite3_clear_bindings()] to reset the bindings. |
|
3601 ** |
|
3602 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S |
|
3603 ** back to the beginning of its program. |
|
3604 ** |
|
3605 ** ^If the most recent call to [sqlite3_step(S)] for the |
|
3606 ** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE], |
|
3607 ** or if [sqlite3_step(S)] has never before been called on S, |
|
3608 ** then [sqlite3_reset(S)] returns [SQLITE_OK]. |
|
3609 ** |
|
3610 ** ^If the most recent call to [sqlite3_step(S)] for the |
|
3611 ** [prepared statement] S indicated an error, then |
|
3612 ** [sqlite3_reset(S)] returns an appropriate [error code]. |
|
3613 ** |
|
3614 ** ^The [sqlite3_reset(S)] interface does not change the values |
|
3615 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S. |
|
3616 */ |
|
3617 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt); |
|
3618 |
|
3619 /* |
|
3620 ** CAPI3REF: Create Or Redefine SQL Functions |
|
3621 ** KEYWORDS: {function creation routines} |
|
3622 ** KEYWORDS: {application-defined SQL function} |
|
3623 ** KEYWORDS: {application-defined SQL functions} |
|
3624 ** |
|
3625 ** ^These functions (collectively known as "function creation routines") |
|
3626 ** are used to add SQL functions or aggregates or to redefine the behavior |
|
3627 ** of existing SQL functions or aggregates. The only differences between |
|
3628 ** these routines are the text encoding expected for |
|
3629 ** the second parameter (the name of the function being created) |
|
3630 ** and the presence or absence of a destructor callback for |
|
3631 ** the application data pointer. |
|
3632 ** |
|
3633 ** ^The first parameter is the [database connection] to which the SQL |
|
3634 ** function is to be added. ^If an application uses more than one database |
|
3635 ** connection then application-defined SQL functions must be added |
|
3636 ** to each database connection separately. |
|
3637 ** |
|
3638 ** ^The second parameter is the name of the SQL function to be created or |
|
3639 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8 |
|
3640 ** representation, exclusive of the zero-terminator. ^Note that the name |
|
3641 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes. |
|
3642 ** ^Any attempt to create a function with a longer name |
|
3643 ** will result in [SQLITE_MISUSE] being returned. |
|
3644 ** |
|
3645 ** ^The third parameter (nArg) |
|
3646 ** is the number of arguments that the SQL function or |
|
3647 ** aggregate takes. ^If this parameter is -1, then the SQL function or |
|
3648 ** aggregate may take any number of arguments between 0 and the limit |
|
3649 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third |
|
3650 ** parameter is less than -1 or greater than 127 then the behavior is |
|
3651 ** undefined. |
|
3652 ** |
|
3653 ** ^The fourth parameter, eTextRep, specifies what |
|
3654 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for |
|
3655 ** its parameters. Every SQL function implementation must be able to work |
|
3656 ** with UTF-8, UTF-16le, or UTF-16be. But some implementations may be |
|
3657 ** more efficient with one encoding than another. ^An application may |
|
3658 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple |
|
3659 ** times with the same function but with different values of eTextRep. |
|
3660 ** ^When multiple implementations of the same function are available, SQLite |
|
3661 ** will pick the one that involves the least amount of data conversion. |
|
3662 ** If there is only a single implementation which does not care what text |
|
3663 ** encoding is used, then the fourth argument should be [SQLITE_ANY]. |
|
3664 ** |
|
3665 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the |
|
3666 ** function can gain access to this pointer using [sqlite3_user_data()].)^ |
|
3667 ** |
|
3668 ** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are |
|
3669 ** pointers to C-language functions that implement the SQL function or |
|
3670 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc |
|
3671 ** callback only; NULL pointers must be passed as the xStep and xFinal |
|
3672 ** parameters. ^An aggregate SQL function requires an implementation of xStep |
|
3673 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing |
|
3674 ** SQL function or aggregate, pass NULL pointers for all three function |
|
3675 ** callbacks. |
|
3676 ** |
|
3677 ** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL, |
|
3678 ** then it is destructor for the application data pointer. |
|
3679 ** The destructor is invoked when the function is deleted, either by being |
|
3680 ** overloaded or when the database connection closes.)^ |
|
3681 ** ^The destructor is also invoked if the call to |
|
3682 ** sqlite3_create_function_v2() fails. |
|
3683 ** ^When the destructor callback of the tenth parameter is invoked, it |
|
3684 ** is passed a single argument which is a copy of the application data |
|
3685 ** pointer which was the fifth parameter to sqlite3_create_function_v2(). |
|
3686 ** |
|
3687 ** ^It is permitted to register multiple implementations of the same |
|
3688 ** functions with the same name but with either differing numbers of |
|
3689 ** arguments or differing preferred text encodings. ^SQLite will use |
|
3690 ** the implementation that most closely matches the way in which the |
|
3691 ** SQL function is used. ^A function implementation with a non-negative |
|
3692 ** nArg parameter is a better match than a function implementation with |
|
3693 ** a negative nArg. ^A function where the preferred text encoding |
|
3694 ** matches the database encoding is a better |
|
3695 ** match than a function where the encoding is different. |
|
3696 ** ^A function where the encoding difference is between UTF16le and UTF16be |
|
3697 ** is a closer match than a function where the encoding difference is |
|
3698 ** between UTF8 and UTF16. |
|
3699 ** |
|
3700 ** ^Built-in functions may be overloaded by new application-defined functions. |
|
3701 ** |
|
3702 ** ^An application-defined function is permitted to call other |
|
3703 ** SQLite interfaces. However, such calls must not |
|
3704 ** close the database connection nor finalize or reset the prepared |
|
3705 ** statement in which the function is running. |
|
3706 */ |
|
3707 SQLITE_API int sqlite3_create_function( |
|
3708 sqlite3 *db, |
|
3709 const char *zFunctionName, |
|
3710 int nArg, |
|
3711 int eTextRep, |
|
3712 void *pApp, |
|
3713 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
|
3714 void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
|
3715 void (*xFinal)(sqlite3_context*) |
|
3716 ); |
|
3717 SQLITE_API int sqlite3_create_function16( |
|
3718 sqlite3 *db, |
|
3719 const void *zFunctionName, |
|
3720 int nArg, |
|
3721 int eTextRep, |
|
3722 void *pApp, |
|
3723 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
|
3724 void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
|
3725 void (*xFinal)(sqlite3_context*) |
|
3726 ); |
|
3727 SQLITE_API int sqlite3_create_function_v2( |
|
3728 sqlite3 *db, |
|
3729 const char *zFunctionName, |
|
3730 int nArg, |
|
3731 int eTextRep, |
|
3732 void *pApp, |
|
3733 void (*xFunc)(sqlite3_context*,int,sqlite3_value**), |
|
3734 void (*xStep)(sqlite3_context*,int,sqlite3_value**), |
|
3735 void (*xFinal)(sqlite3_context*), |
|
3736 void(*xDestroy)(void*) |
|
3737 ); |
|
3738 |
|
3739 /* |
|
3740 ** CAPI3REF: Text Encodings |
|
3741 ** |
|
3742 ** These constant define integer codes that represent the various |
|
3743 ** text encodings supported by SQLite. |
|
3744 */ |
|
3745 #define SQLITE_UTF8 1 |
|
3746 #define SQLITE_UTF16LE 2 |
|
3747 #define SQLITE_UTF16BE 3 |
|
3748 #define SQLITE_UTF16 4 /* Use native byte order */ |
|
3749 #define SQLITE_ANY 5 /* sqlite3_create_function only */ |
|
3750 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */ |
|
3751 |
|
3752 /* |
|
3753 ** CAPI3REF: Deprecated Functions |
|
3754 ** DEPRECATED |
|
3755 ** |
|
3756 ** These functions are [deprecated]. In order to maintain |
|
3757 ** backwards compatibility with older code, these functions continue |
|
3758 ** to be supported. However, new applications should avoid |
|
3759 ** the use of these functions. To help encourage people to avoid |
|
3760 ** using these functions, we are not going to tell you what they do. |
|
3761 */ |
|
3762 #ifndef SQLITE_OMIT_DEPRECATED |
|
3763 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*); |
|
3764 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*); |
|
3765 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*); |
|
3766 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void); |
|
3767 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void); |
|
3768 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),void*,sqlite3_int64); |
|
3769 #endif |
|
3770 |
|
3771 /* |
|
3772 ** CAPI3REF: Obtaining SQL Function Parameter Values |
|
3773 ** |
|
3774 ** The C-language implementation of SQL functions and aggregates uses |
|
3775 ** this set of interface routines to access the parameter values on |
|
3776 ** the function or aggregate. |
|
3777 ** |
|
3778 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters |
|
3779 ** to [sqlite3_create_function()] and [sqlite3_create_function16()] |
|
3780 ** define callbacks that implement the SQL functions and aggregates. |
|
3781 ** The 3rd parameter to these callbacks is an array of pointers to |
|
3782 ** [protected sqlite3_value] objects. There is one [sqlite3_value] object for |
|
3783 ** each parameter to the SQL function. These routines are used to |
|
3784 ** extract values from the [sqlite3_value] objects. |
|
3785 ** |
|
3786 ** These routines work only with [protected sqlite3_value] objects. |
|
3787 ** Any attempt to use these routines on an [unprotected sqlite3_value] |
|
3788 ** object results in undefined behavior. |
|
3789 ** |
|
3790 ** ^These routines work just like the corresponding [column access functions] |
|
3791 ** except that these routines take a single [protected sqlite3_value] object |
|
3792 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number. |
|
3793 ** |
|
3794 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string |
|
3795 ** in the native byte-order of the host machine. ^The |
|
3796 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces |
|
3797 ** extract UTF-16 strings as big-endian and little-endian respectively. |
|
3798 ** |
|
3799 ** ^(The sqlite3_value_numeric_type() interface attempts to apply |
|
3800 ** numeric affinity to the value. This means that an attempt is |
|
3801 ** made to convert the value to an integer or floating point. If |
|
3802 ** such a conversion is possible without loss of information (in other |
|
3803 ** words, if the value is a string that looks like a number) |
|
3804 ** then the conversion is performed. Otherwise no conversion occurs. |
|
3805 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^ |
|
3806 ** |
|
3807 ** Please pay particular attention to the fact that the pointer returned |
|
3808 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or |
|
3809 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to |
|
3810 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()], |
|
3811 ** or [sqlite3_value_text16()]. |
|
3812 ** |
|
3813 ** These routines must be called from the same thread as |
|
3814 ** the SQL function that supplied the [sqlite3_value*] parameters. |
|
3815 */ |
|
3816 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*); |
|
3817 SQLITE_API int sqlite3_value_bytes(sqlite3_value*); |
|
3818 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*); |
|
3819 SQLITE_API double sqlite3_value_double(sqlite3_value*); |
|
3820 SQLITE_API int sqlite3_value_int(sqlite3_value*); |
|
3821 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*); |
|
3822 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*); |
|
3823 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*); |
|
3824 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*); |
|
3825 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*); |
|
3826 SQLITE_API int sqlite3_value_type(sqlite3_value*); |
|
3827 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*); |
|
3828 |
|
3829 /* |
|
3830 ** CAPI3REF: Obtain Aggregate Function Context |
|
3831 ** |
|
3832 ** Implementations of aggregate SQL functions use this |
|
3833 ** routine to allocate memory for storing their state. |
|
3834 ** |
|
3835 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called |
|
3836 ** for a particular aggregate function, SQLite |
|
3837 ** allocates N of memory, zeroes out that memory, and returns a pointer |
|
3838 ** to the new memory. ^On second and subsequent calls to |
|
3839 ** sqlite3_aggregate_context() for the same aggregate function instance, |
|
3840 ** the same buffer is returned. Sqlite3_aggregate_context() is normally |
|
3841 ** called once for each invocation of the xStep callback and then one |
|
3842 ** last time when the xFinal callback is invoked. ^(When no rows match |
|
3843 ** an aggregate query, the xStep() callback of the aggregate function |
|
3844 ** implementation is never called and xFinal() is called exactly once. |
|
3845 ** In those cases, sqlite3_aggregate_context() might be called for the |
|
3846 ** first time from within xFinal().)^ |
|
3847 ** |
|
3848 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer if N is |
|
3849 ** less than or equal to zero or if a memory allocate error occurs. |
|
3850 ** |
|
3851 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is |
|
3852 ** determined by the N parameter on first successful call. Changing the |
|
3853 ** value of N in subsequent call to sqlite3_aggregate_context() within |
|
3854 ** the same aggregate function instance will not resize the memory |
|
3855 ** allocation.)^ |
|
3856 ** |
|
3857 ** ^SQLite automatically frees the memory allocated by |
|
3858 ** sqlite3_aggregate_context() when the aggregate query concludes. |
|
3859 ** |
|
3860 ** The first parameter must be a copy of the |
|
3861 ** [sqlite3_context | SQL function context] that is the first parameter |
|
3862 ** to the xStep or xFinal callback routine that implements the aggregate |
|
3863 ** function. |
|
3864 ** |
|
3865 ** This routine must be called from the same thread in which |
|
3866 ** the aggregate SQL function is running. |
|
3867 */ |
|
3868 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes); |
|
3869 |
|
3870 /* |
|
3871 ** CAPI3REF: User Data For Functions |
|
3872 ** |
|
3873 ** ^The sqlite3_user_data() interface returns a copy of |
|
3874 ** the pointer that was the pUserData parameter (the 5th parameter) |
|
3875 ** of the [sqlite3_create_function()] |
|
3876 ** and [sqlite3_create_function16()] routines that originally |
|
3877 ** registered the application defined function. |
|
3878 ** |
|
3879 ** This routine must be called from the same thread in which |
|
3880 ** the application-defined function is running. |
|
3881 */ |
|
3882 SQLITE_API void *sqlite3_user_data(sqlite3_context*); |
|
3883 |
|
3884 /* |
|
3885 ** CAPI3REF: Database Connection For Functions |
|
3886 ** |
|
3887 ** ^The sqlite3_context_db_handle() interface returns a copy of |
|
3888 ** the pointer to the [database connection] (the 1st parameter) |
|
3889 ** of the [sqlite3_create_function()] |
|
3890 ** and [sqlite3_create_function16()] routines that originally |
|
3891 ** registered the application defined function. |
|
3892 */ |
|
3893 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*); |
|
3894 |
|
3895 /* |
|
3896 ** CAPI3REF: Function Auxiliary Data |
|
3897 ** |
|
3898 ** The following two functions may be used by scalar SQL functions to |
|
3899 ** associate metadata with argument values. If the same value is passed to |
|
3900 ** multiple invocations of the same SQL function during query execution, under |
|
3901 ** some circumstances the associated metadata may be preserved. This may |
|
3902 ** be used, for example, to add a regular-expression matching scalar |
|
3903 ** function. The compiled version of the regular expression is stored as |
|
3904 ** metadata associated with the SQL value passed as the regular expression |
|
3905 ** pattern. The compiled regular expression can be reused on multiple |
|
3906 ** invocations of the same function so that the original pattern string |
|
3907 ** does not need to be recompiled on each invocation. |
|
3908 ** |
|
3909 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata |
|
3910 ** associated by the sqlite3_set_auxdata() function with the Nth argument |
|
3911 ** value to the application-defined function. ^If no metadata has been ever |
|
3912 ** been set for the Nth argument of the function, or if the corresponding |
|
3913 ** function parameter has changed since the meta-data was set, |
|
3914 ** then sqlite3_get_auxdata() returns a NULL pointer. |
|
3915 ** |
|
3916 ** ^The sqlite3_set_auxdata() interface saves the metadata |
|
3917 ** pointed to by its 3rd parameter as the metadata for the N-th |
|
3918 ** argument of the application-defined function. Subsequent |
|
3919 ** calls to sqlite3_get_auxdata() might return this data, if it has |
|
3920 ** not been destroyed. |
|
3921 ** ^If it is not NULL, SQLite will invoke the destructor |
|
3922 ** function given by the 4th parameter to sqlite3_set_auxdata() on |
|
3923 ** the metadata when the corresponding function parameter changes |
|
3924 ** or when the SQL statement completes, whichever comes first. |
|
3925 ** |
|
3926 ** SQLite is free to call the destructor and drop metadata on any |
|
3927 ** parameter of any function at any time. ^The only guarantee is that |
|
3928 ** the destructor will be called before the metadata is dropped. |
|
3929 ** |
|
3930 ** ^(In practice, metadata is preserved between function calls for |
|
3931 ** expressions that are constant at compile time. This includes literal |
|
3932 ** values and [parameters].)^ |
|
3933 ** |
|
3934 ** These routines must be called from the same thread in which |
|
3935 ** the SQL function is running. |
|
3936 */ |
|
3937 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N); |
|
3938 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*)); |
|
3939 |
|
3940 |
|
3941 /* |
|
3942 ** CAPI3REF: Constants Defining Special Destructor Behavior |
|
3943 ** |
|
3944 ** These are special values for the destructor that is passed in as the |
|
3945 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor |
|
3946 ** argument is SQLITE_STATIC, it means that the content pointer is constant |
|
3947 ** and will never change. It does not need to be destroyed. ^The |
|
3948 ** SQLITE_TRANSIENT value means that the content will likely change in |
|
3949 ** the near future and that SQLite should make its own private copy of |
|
3950 ** the content before returning. |
|
3951 ** |
|
3952 ** The typedef is necessary to work around problems in certain |
|
3953 ** C++ compilers. See ticket #2191. |
|
3954 */ |
|
3955 typedef void (*sqlite3_destructor_type)(void*); |
|
3956 #define SQLITE_STATIC ((sqlite3_destructor_type)0) |
|
3957 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1) |
|
3958 |
|
3959 /* |
|
3960 ** CAPI3REF: Setting The Result Of An SQL Function |
|
3961 ** |
|
3962 ** These routines are used by the xFunc or xFinal callbacks that |
|
3963 ** implement SQL functions and aggregates. See |
|
3964 ** [sqlite3_create_function()] and [sqlite3_create_function16()] |
|
3965 ** for additional information. |
|
3966 ** |
|
3967 ** These functions work very much like the [parameter binding] family of |
|
3968 ** functions used to bind values to host parameters in prepared statements. |
|
3969 ** Refer to the [SQL parameter] documentation for additional information. |
|
3970 ** |
|
3971 ** ^The sqlite3_result_blob() interface sets the result from |
|
3972 ** an application-defined function to be the BLOB whose content is pointed |
|
3973 ** to by the second parameter and which is N bytes long where N is the |
|
3974 ** third parameter. |
|
3975 ** |
|
3976 ** ^The sqlite3_result_zeroblob() interfaces set the result of |
|
3977 ** the application-defined function to be a BLOB containing all zero |
|
3978 ** bytes and N bytes in size, where N is the value of the 2nd parameter. |
|
3979 ** |
|
3980 ** ^The sqlite3_result_double() interface sets the result from |
|
3981 ** an application-defined function to be a floating point value specified |
|
3982 ** by its 2nd argument. |
|
3983 ** |
|
3984 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions |
|
3985 ** cause the implemented SQL function to throw an exception. |
|
3986 ** ^SQLite uses the string pointed to by the |
|
3987 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16() |
|
3988 ** as the text of an error message. ^SQLite interprets the error |
|
3989 ** message string from sqlite3_result_error() as UTF-8. ^SQLite |
|
3990 ** interprets the string from sqlite3_result_error16() as UTF-16 in native |
|
3991 ** byte order. ^If the third parameter to sqlite3_result_error() |
|
3992 ** or sqlite3_result_error16() is negative then SQLite takes as the error |
|
3993 ** message all text up through the first zero character. |
|
3994 ** ^If the third parameter to sqlite3_result_error() or |
|
3995 ** sqlite3_result_error16() is non-negative then SQLite takes that many |
|
3996 ** bytes (not characters) from the 2nd parameter as the error message. |
|
3997 ** ^The sqlite3_result_error() and sqlite3_result_error16() |
|
3998 ** routines make a private copy of the error message text before |
|
3999 ** they return. Hence, the calling function can deallocate or |
|
4000 ** modify the text after they return without harm. |
|
4001 ** ^The sqlite3_result_error_code() function changes the error code |
|
4002 ** returned by SQLite as a result of an error in a function. ^By default, |
|
4003 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error() |
|
4004 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR. |
|
4005 ** |
|
4006 ** ^The sqlite3_result_toobig() interface causes SQLite to throw an error |
|
4007 ** indicating that a string or BLOB is too long to represent. |
|
4008 ** |
|
4009 ** ^The sqlite3_result_nomem() interface causes SQLite to throw an error |
|
4010 ** indicating that a memory allocation failed. |
|
4011 ** |
|
4012 ** ^The sqlite3_result_int() interface sets the return value |
|
4013 ** of the application-defined function to be the 32-bit signed integer |
|
4014 ** value given in the 2nd argument. |
|
4015 ** ^The sqlite3_result_int64() interface sets the return value |
|
4016 ** of the application-defined function to be the 64-bit signed integer |
|
4017 ** value given in the 2nd argument. |
|
4018 ** |
|
4019 ** ^The sqlite3_result_null() interface sets the return value |
|
4020 ** of the application-defined function to be NULL. |
|
4021 ** |
|
4022 ** ^The sqlite3_result_text(), sqlite3_result_text16(), |
|
4023 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces |
|
4024 ** set the return value of the application-defined function to be |
|
4025 ** a text string which is represented as UTF-8, UTF-16 native byte order, |
|
4026 ** UTF-16 little endian, or UTF-16 big endian, respectively. |
|
4027 ** ^SQLite takes the text result from the application from |
|
4028 ** the 2nd parameter of the sqlite3_result_text* interfaces. |
|
4029 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces |
|
4030 ** is negative, then SQLite takes result text from the 2nd parameter |
|
4031 ** through the first zero character. |
|
4032 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces |
|
4033 ** is non-negative, then as many bytes (not characters) of the text |
|
4034 ** pointed to by the 2nd parameter are taken as the application-defined |
|
4035 ** function result. |
|
4036 ** ^If the 4th parameter to the sqlite3_result_text* interfaces |
|
4037 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that |
|
4038 ** function as the destructor on the text or BLOB result when it has |
|
4039 ** finished using that result. |
|
4040 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to |
|
4041 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite |
|
4042 ** assumes that the text or BLOB result is in constant space and does not |
|
4043 ** copy the content of the parameter nor call a destructor on the content |
|
4044 ** when it has finished using that result. |
|
4045 ** ^If the 4th parameter to the sqlite3_result_text* interfaces |
|
4046 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT |
|
4047 ** then SQLite makes a copy of the result into space obtained from |
|
4048 ** from [sqlite3_malloc()] before it returns. |
|
4049 ** |
|
4050 ** ^The sqlite3_result_value() interface sets the result of |
|
4051 ** the application-defined function to be a copy the |
|
4052 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The |
|
4053 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value] |
|
4054 ** so that the [sqlite3_value] specified in the parameter may change or |
|
4055 ** be deallocated after sqlite3_result_value() returns without harm. |
|
4056 ** ^A [protected sqlite3_value] object may always be used where an |
|
4057 ** [unprotected sqlite3_value] object is required, so either |
|
4058 ** kind of [sqlite3_value] object can be used with this interface. |
|
4059 ** |
|
4060 ** If these routines are called from within the different thread |
|
4061 ** than the one containing the application-defined function that received |
|
4062 ** the [sqlite3_context] pointer, the results are undefined. |
|
4063 */ |
|
4064 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*)); |
|
4065 SQLITE_API void sqlite3_result_double(sqlite3_context*, double); |
|
4066 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int); |
|
4067 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int); |
|
4068 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*); |
|
4069 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*); |
|
4070 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int); |
|
4071 SQLITE_API void sqlite3_result_int(sqlite3_context*, int); |
|
4072 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64); |
|
4073 SQLITE_API void sqlite3_result_null(sqlite3_context*); |
|
4074 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*)); |
|
4075 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*)); |
|
4076 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*)); |
|
4077 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*)); |
|
4078 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*); |
|
4079 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n); |
|
4080 |
|
4081 /* |
|
4082 ** CAPI3REF: Define New Collating Sequences |
|
4083 ** |
|
4084 ** ^These functions add, remove, or modify a [collation] associated |
|
4085 ** with the [database connection] specified as the first argument. |
|
4086 ** |
|
4087 ** ^The name of the collation is a UTF-8 string |
|
4088 ** for sqlite3_create_collation() and sqlite3_create_collation_v2() |
|
4089 ** and a UTF-16 string in native byte order for sqlite3_create_collation16(). |
|
4090 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are |
|
4091 ** considered to be the same name. |
|
4092 ** |
|
4093 ** ^(The third argument (eTextRep) must be one of the constants: |
|
4094 ** <ul> |
|
4095 ** <li> [SQLITE_UTF8], |
|
4096 ** <li> [SQLITE_UTF16LE], |
|
4097 ** <li> [SQLITE_UTF16BE], |
|
4098 ** <li> [SQLITE_UTF16], or |
|
4099 ** <li> [SQLITE_UTF16_ALIGNED]. |
|
4100 ** </ul>)^ |
|
4101 ** ^The eTextRep argument determines the encoding of strings passed |
|
4102 ** to the collating function callback, xCallback. |
|
4103 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep |
|
4104 ** force strings to be UTF16 with native byte order. |
|
4105 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin |
|
4106 ** on an even byte address. |
|
4107 ** |
|
4108 ** ^The fourth argument, pArg, is an application data pointer that is passed |
|
4109 ** through as the first argument to the collating function callback. |
|
4110 ** |
|
4111 ** ^The fifth argument, xCallback, is a pointer to the collating function. |
|
4112 ** ^Multiple collating functions can be registered using the same name but |
|
4113 ** with different eTextRep parameters and SQLite will use whichever |
|
4114 ** function requires the least amount of data transformation. |
|
4115 ** ^If the xCallback argument is NULL then the collating function is |
|
4116 ** deleted. ^When all collating functions having the same name are deleted, |
|
4117 ** that collation is no longer usable. |
|
4118 ** |
|
4119 ** ^The collating function callback is invoked with a copy of the pArg |
|
4120 ** application data pointer and with two strings in the encoding specified |
|
4121 ** by the eTextRep argument. The collating function must return an |
|
4122 ** integer that is negative, zero, or positive |
|
4123 ** if the first string is less than, equal to, or greater than the second, |
|
4124 ** respectively. A collating function must always return the same answer |
|
4125 ** given the same inputs. If two or more collating functions are registered |
|
4126 ** to the same collation name (using different eTextRep values) then all |
|
4127 ** must give an equivalent answer when invoked with equivalent strings. |
|
4128 ** The collating function must obey the following properties for all |
|
4129 ** strings A, B, and C: |
|
4130 ** |
|
4131 ** <ol> |
|
4132 ** <li> If A==B then B==A. |
|
4133 ** <li> If A==B and B==C then A==C. |
|
4134 ** <li> If A<B THEN B>A. |
|
4135 ** <li> If A<B and B<C then A<C. |
|
4136 ** </ol> |
|
4137 ** |
|
4138 ** If a collating function fails any of the above constraints and that |
|
4139 ** collating function is registered and used, then the behavior of SQLite |
|
4140 ** is undefined. |
|
4141 ** |
|
4142 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation() |
|
4143 ** with the addition that the xDestroy callback is invoked on pArg when |
|
4144 ** the collating function is deleted. |
|
4145 ** ^Collating functions are deleted when they are overridden by later |
|
4146 ** calls to the collation creation functions or when the |
|
4147 ** [database connection] is closed using [sqlite3_close()]. |
|
4148 ** |
|
4149 ** ^The xDestroy callback is <u>not</u> called if the |
|
4150 ** sqlite3_create_collation_v2() function fails. Applications that invoke |
|
4151 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should |
|
4152 ** check the return code and dispose of the application data pointer |
|
4153 ** themselves rather than expecting SQLite to deal with it for them. |
|
4154 ** This is different from every other SQLite interface. The inconsistency |
|
4155 ** is unfortunate but cannot be changed without breaking backwards |
|
4156 ** compatibility. |
|
4157 ** |
|
4158 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()]. |
|
4159 */ |
|
4160 SQLITE_API int sqlite3_create_collation( |
|
4161 sqlite3*, |
|
4162 const char *zName, |
|
4163 int eTextRep, |
|
4164 void *pArg, |
|
4165 int(*xCompare)(void*,int,const void*,int,const void*) |
|
4166 ); |
|
4167 SQLITE_API int sqlite3_create_collation_v2( |
|
4168 sqlite3*, |
|
4169 const char *zName, |
|
4170 int eTextRep, |
|
4171 void *pArg, |
|
4172 int(*xCompare)(void*,int,const void*,int,const void*), |
|
4173 void(*xDestroy)(void*) |
|
4174 ); |
|
4175 SQLITE_API int sqlite3_create_collation16( |
|
4176 sqlite3*, |
|
4177 const void *zName, |
|
4178 int eTextRep, |
|
4179 void *pArg, |
|
4180 int(*xCompare)(void*,int,const void*,int,const void*) |
|
4181 ); |
|
4182 |
|
4183 /* |
|
4184 ** CAPI3REF: Collation Needed Callbacks |
|
4185 ** |
|
4186 ** ^To avoid having to register all collation sequences before a database |
|
4187 ** can be used, a single callback function may be registered with the |
|
4188 ** [database connection] to be invoked whenever an undefined collation |
|
4189 ** sequence is required. |
|
4190 ** |
|
4191 ** ^If the function is registered using the sqlite3_collation_needed() API, |
|
4192 ** then it is passed the names of undefined collation sequences as strings |
|
4193 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used, |
|
4194 ** the names are passed as UTF-16 in machine native byte order. |
|
4195 ** ^A call to either function replaces the existing collation-needed callback. |
|
4196 ** |
|
4197 ** ^(When the callback is invoked, the first argument passed is a copy |
|
4198 ** of the second argument to sqlite3_collation_needed() or |
|
4199 ** sqlite3_collation_needed16(). The second argument is the database |
|
4200 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], |
|
4201 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation |
|
4202 ** sequence function required. The fourth parameter is the name of the |
|
4203 ** required collation sequence.)^ |
|
4204 ** |
|
4205 ** The callback function should register the desired collation using |
|
4206 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or |
|
4207 ** [sqlite3_create_collation_v2()]. |
|
4208 */ |
|
4209 SQLITE_API int sqlite3_collation_needed( |
|
4210 sqlite3*, |
|
4211 void*, |
|
4212 void(*)(void*,sqlite3*,int eTextRep,const char*) |
|
4213 ); |
|
4214 SQLITE_API int sqlite3_collation_needed16( |
|
4215 sqlite3*, |
|
4216 void*, |
|
4217 void(*)(void*,sqlite3*,int eTextRep,const void*) |
|
4218 ); |
|
4219 |
|
4220 #ifdef SQLITE_HAS_CODEC |
|
4221 /* |
|
4222 ** Specify the key for an encrypted database. This routine should be |
|
4223 ** called right after sqlite3_open(). |
|
4224 ** |
|
4225 ** The code to implement this API is not available in the public release |
|
4226 ** of SQLite. |
|
4227 */ |
|
4228 SQLITE_API int sqlite3_key( |
|
4229 sqlite3 *db, /* Database to be rekeyed */ |
|
4230 const void *pKey, int nKey /* The key */ |
|
4231 ); |
|
4232 |
|
4233 /* |
|
4234 ** Change the key on an open database. If the current database is not |
|
4235 ** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the |
|
4236 ** database is decrypted. |
|
4237 ** |
|
4238 ** The code to implement this API is not available in the public release |
|
4239 ** of SQLite. |
|
4240 */ |
|
4241 SQLITE_API int sqlite3_rekey( |
|
4242 sqlite3 *db, /* Database to be rekeyed */ |
|
4243 const void *pKey, int nKey /* The new key */ |
|
4244 ); |
|
4245 |
|
4246 /* |
|
4247 ** Specify the activation key for a SEE database. Unless |
|
4248 ** activated, none of the SEE routines will work. |
|
4249 */ |
|
4250 SQLITE_API void sqlite3_activate_see( |
|
4251 const char *zPassPhrase /* Activation phrase */ |
|
4252 ); |
|
4253 #endif |
|
4254 |
|
4255 #ifdef SQLITE_ENABLE_CEROD |
|
4256 /* |
|
4257 ** Specify the activation key for a CEROD database. Unless |
|
4258 ** activated, none of the CEROD routines will work. |
|
4259 */ |
|
4260 SQLITE_API void sqlite3_activate_cerod( |
|
4261 const char *zPassPhrase /* Activation phrase */ |
|
4262 ); |
|
4263 #endif |
|
4264 |
|
4265 /* |
|
4266 ** CAPI3REF: Suspend Execution For A Short Time |
|
4267 ** |
|
4268 ** The sqlite3_sleep() function causes the current thread to suspend execution |
|
4269 ** for at least a number of milliseconds specified in its parameter. |
|
4270 ** |
|
4271 ** If the operating system does not support sleep requests with |
|
4272 ** millisecond time resolution, then the time will be rounded up to |
|
4273 ** the nearest second. The number of milliseconds of sleep actually |
|
4274 ** requested from the operating system is returned. |
|
4275 ** |
|
4276 ** ^SQLite implements this interface by calling the xSleep() |
|
4277 ** method of the default [sqlite3_vfs] object. If the xSleep() method |
|
4278 ** of the default VFS is not implemented correctly, or not implemented at |
|
4279 ** all, then the behavior of sqlite3_sleep() may deviate from the description |
|
4280 ** in the previous paragraphs. |
|
4281 */ |
|
4282 SQLITE_API int sqlite3_sleep(int); |
|
4283 |
|
4284 /* |
|
4285 ** CAPI3REF: Name Of The Folder Holding Temporary Files |
|
4286 ** |
|
4287 ** ^(If this global variable is made to point to a string which is |
|
4288 ** the name of a folder (a.k.a. directory), then all temporary files |
|
4289 ** created by SQLite when using a built-in [sqlite3_vfs | VFS] |
|
4290 ** will be placed in that directory.)^ ^If this variable |
|
4291 ** is a NULL pointer, then SQLite performs a search for an appropriate |
|
4292 ** temporary file directory. |
|
4293 ** |
|
4294 ** It is not safe to read or modify this variable in more than one |
|
4295 ** thread at a time. It is not safe to read or modify this variable |
|
4296 ** if a [database connection] is being used at the same time in a separate |
|
4297 ** thread. |
|
4298 ** It is intended that this variable be set once |
|
4299 ** as part of process initialization and before any SQLite interface |
|
4300 ** routines have been called and that this variable remain unchanged |
|
4301 ** thereafter. |
|
4302 ** |
|
4303 ** ^The [temp_store_directory pragma] may modify this variable and cause |
|
4304 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore, |
|
4305 ** the [temp_store_directory pragma] always assumes that any string |
|
4306 ** that this variable points to is held in memory obtained from |
|
4307 ** [sqlite3_malloc] and the pragma may attempt to free that memory |
|
4308 ** using [sqlite3_free]. |
|
4309 ** Hence, if this variable is modified directly, either it should be |
|
4310 ** made NULL or made to point to memory obtained from [sqlite3_malloc] |
|
4311 ** or else the use of the [temp_store_directory pragma] should be avoided. |
|
4312 */ |
|
4313 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory; |
|
4314 |
|
4315 /* |
|
4316 ** CAPI3REF: Test For Auto-Commit Mode |
|
4317 ** KEYWORDS: {autocommit mode} |
|
4318 ** |
|
4319 ** ^The sqlite3_get_autocommit() interface returns non-zero or |
|
4320 ** zero if the given database connection is or is not in autocommit mode, |
|
4321 ** respectively. ^Autocommit mode is on by default. |
|
4322 ** ^Autocommit mode is disabled by a [BEGIN] statement. |
|
4323 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK]. |
|
4324 ** |
|
4325 ** If certain kinds of errors occur on a statement within a multi-statement |
|
4326 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR], |
|
4327 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the |
|
4328 ** transaction might be rolled back automatically. The only way to |
|
4329 ** find out whether SQLite automatically rolled back the transaction after |
|
4330 ** an error is to use this function. |
|
4331 ** |
|
4332 ** If another thread changes the autocommit status of the database |
|
4333 ** connection while this routine is running, then the return value |
|
4334 ** is undefined. |
|
4335 */ |
|
4336 SQLITE_API int sqlite3_get_autocommit(sqlite3*); |
|
4337 |
|
4338 /* |
|
4339 ** CAPI3REF: Find The Database Handle Of A Prepared Statement |
|
4340 ** |
|
4341 ** ^The sqlite3_db_handle interface returns the [database connection] handle |
|
4342 ** to which a [prepared statement] belongs. ^The [database connection] |
|
4343 ** returned by sqlite3_db_handle is the same [database connection] |
|
4344 ** that was the first argument |
|
4345 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to |
|
4346 ** create the statement in the first place. |
|
4347 */ |
|
4348 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*); |
|
4349 |
|
4350 /* |
|
4351 ** CAPI3REF: Find the next prepared statement |
|
4352 ** |
|
4353 ** ^This interface returns a pointer to the next [prepared statement] after |
|
4354 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL |
|
4355 ** then this interface returns a pointer to the first prepared statement |
|
4356 ** associated with the database connection pDb. ^If no prepared statement |
|
4357 ** satisfies the conditions of this routine, it returns NULL. |
|
4358 ** |
|
4359 ** The [database connection] pointer D in a call to |
|
4360 ** [sqlite3_next_stmt(D,S)] must refer to an open database |
|
4361 ** connection and in particular must not be a NULL pointer. |
|
4362 */ |
|
4363 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt); |
|
4364 |
|
4365 /* |
|
4366 ** CAPI3REF: Commit And Rollback Notification Callbacks |
|
4367 ** |
|
4368 ** ^The sqlite3_commit_hook() interface registers a callback |
|
4369 ** function to be invoked whenever a transaction is [COMMIT | committed]. |
|
4370 ** ^Any callback set by a previous call to sqlite3_commit_hook() |
|
4371 ** for the same database connection is overridden. |
|
4372 ** ^The sqlite3_rollback_hook() interface registers a callback |
|
4373 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back]. |
|
4374 ** ^Any callback set by a previous call to sqlite3_rollback_hook() |
|
4375 ** for the same database connection is overridden. |
|
4376 ** ^The pArg argument is passed through to the callback. |
|
4377 ** ^If the callback on a commit hook function returns non-zero, |
|
4378 ** then the commit is converted into a rollback. |
|
4379 ** |
|
4380 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions |
|
4381 ** return the P argument from the previous call of the same function |
|
4382 ** on the same [database connection] D, or NULL for |
|
4383 ** the first call for each function on D. |
|
4384 ** |
|
4385 ** The callback implementation must not do anything that will modify |
|
4386 ** the database connection that invoked the callback. Any actions |
|
4387 ** to modify the database connection must be deferred until after the |
|
4388 ** completion of the [sqlite3_step()] call that triggered the commit |
|
4389 ** or rollback hook in the first place. |
|
4390 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
|
4391 ** database connections for the meaning of "modify" in this paragraph. |
|
4392 ** |
|
4393 ** ^Registering a NULL function disables the callback. |
|
4394 ** |
|
4395 ** ^When the commit hook callback routine returns zero, the [COMMIT] |
|
4396 ** operation is allowed to continue normally. ^If the commit hook |
|
4397 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK]. |
|
4398 ** ^The rollback hook is invoked on a rollback that results from a commit |
|
4399 ** hook returning non-zero, just as it would be with any other rollback. |
|
4400 ** |
|
4401 ** ^For the purposes of this API, a transaction is said to have been |
|
4402 ** rolled back if an explicit "ROLLBACK" statement is executed, or |
|
4403 ** an error or constraint causes an implicit rollback to occur. |
|
4404 ** ^The rollback callback is not invoked if a transaction is |
|
4405 ** automatically rolled back because the database connection is closed. |
|
4406 ** |
|
4407 ** See also the [sqlite3_update_hook()] interface. |
|
4408 */ |
|
4409 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*); |
|
4410 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); |
|
4411 |
|
4412 /* |
|
4413 ** CAPI3REF: Data Change Notification Callbacks |
|
4414 ** |
|
4415 ** ^The sqlite3_update_hook() interface registers a callback function |
|
4416 ** with the [database connection] identified by the first argument |
|
4417 ** to be invoked whenever a row is updated, inserted or deleted. |
|
4418 ** ^Any callback set by a previous call to this function |
|
4419 ** for the same database connection is overridden. |
|
4420 ** |
|
4421 ** ^The second argument is a pointer to the function to invoke when a |
|
4422 ** row is updated, inserted or deleted. |
|
4423 ** ^The first argument to the callback is a copy of the third argument |
|
4424 ** to sqlite3_update_hook(). |
|
4425 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE], |
|
4426 ** or [SQLITE_UPDATE], depending on the operation that caused the callback |
|
4427 ** to be invoked. |
|
4428 ** ^The third and fourth arguments to the callback contain pointers to the |
|
4429 ** database and table name containing the affected row. |
|
4430 ** ^The final callback parameter is the [rowid] of the row. |
|
4431 ** ^In the case of an update, this is the [rowid] after the update takes place. |
|
4432 ** |
|
4433 ** ^(The update hook is not invoked when internal system tables are |
|
4434 ** modified (i.e. sqlite_master and sqlite_sequence).)^ |
|
4435 ** |
|
4436 ** ^In the current implementation, the update hook |
|
4437 ** is not invoked when duplication rows are deleted because of an |
|
4438 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook |
|
4439 ** invoked when rows are deleted using the [truncate optimization]. |
|
4440 ** The exceptions defined in this paragraph might change in a future |
|
4441 ** release of SQLite. |
|
4442 ** |
|
4443 ** The update hook implementation must not do anything that will modify |
|
4444 ** the database connection that invoked the update hook. Any actions |
|
4445 ** to modify the database connection must be deferred until after the |
|
4446 ** completion of the [sqlite3_step()] call that triggered the update hook. |
|
4447 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their |
|
4448 ** database connections for the meaning of "modify" in this paragraph. |
|
4449 ** |
|
4450 ** ^The sqlite3_update_hook(D,C,P) function |
|
4451 ** returns the P argument from the previous call |
|
4452 ** on the same [database connection] D, or NULL for |
|
4453 ** the first call on D. |
|
4454 ** |
|
4455 ** See also the [sqlite3_commit_hook()] and [sqlite3_rollback_hook()] |
|
4456 ** interfaces. |
|
4457 */ |
|
4458 SQLITE_API void *sqlite3_update_hook( |
|
4459 sqlite3*, |
|
4460 void(*)(void *,int ,char const *,char const *,sqlite3_int64), |
|
4461 void* |
|
4462 ); |
|
4463 |
|
4464 /* |
|
4465 ** CAPI3REF: Enable Or Disable Shared Pager Cache |
|
4466 ** KEYWORDS: {shared cache} |
|
4467 ** |
|
4468 ** ^(This routine enables or disables the sharing of the database cache |
|
4469 ** and schema data structures between [database connection | connections] |
|
4470 ** to the same database. Sharing is enabled if the argument is true |
|
4471 ** and disabled if the argument is false.)^ |
|
4472 ** |
|
4473 ** ^Cache sharing is enabled and disabled for an entire process. |
|
4474 ** This is a change as of SQLite version 3.5.0. In prior versions of SQLite, |
|
4475 ** sharing was enabled or disabled for each thread separately. |
|
4476 ** |
|
4477 ** ^(The cache sharing mode set by this interface effects all subsequent |
|
4478 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()]. |
|
4479 ** Existing database connections continue use the sharing mode |
|
4480 ** that was in effect at the time they were opened.)^ |
|
4481 ** |
|
4482 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled |
|
4483 ** successfully. An [error code] is returned otherwise.)^ |
|
4484 ** |
|
4485 ** ^Shared cache is disabled by default. But this might change in |
|
4486 ** future releases of SQLite. Applications that care about shared |
|
4487 ** cache setting should set it explicitly. |
|
4488 ** |
|
4489 ** See Also: [SQLite Shared-Cache Mode] |
|
4490 */ |
|
4491 SQLITE_API int sqlite3_enable_shared_cache(int); |
|
4492 |
|
4493 /* |
|
4494 ** CAPI3REF: Attempt To Free Heap Memory |
|
4495 ** |
|
4496 ** ^The sqlite3_release_memory() interface attempts to free N bytes |
|
4497 ** of heap memory by deallocating non-essential memory allocations |
|
4498 ** held by the database library. Memory used to cache database |
|
4499 ** pages to improve performance is an example of non-essential memory. |
|
4500 ** ^sqlite3_release_memory() returns the number of bytes actually freed, |
|
4501 ** which might be more or less than the amount requested. |
|
4502 ** ^The sqlite3_release_memory() routine is a no-op returning zero |
|
4503 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT]. |
|
4504 */ |
|
4505 SQLITE_API int sqlite3_release_memory(int); |
|
4506 |
|
4507 /* |
|
4508 ** CAPI3REF: Impose A Limit On Heap Size |
|
4509 ** |
|
4510 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the |
|
4511 ** soft limit on the amount of heap memory that may be allocated by SQLite. |
|
4512 ** ^SQLite strives to keep heap memory utilization below the soft heap |
|
4513 ** limit by reducing the number of pages held in the page cache |
|
4514 ** as heap memory usages approaches the limit. |
|
4515 ** ^The soft heap limit is "soft" because even though SQLite strives to stay |
|
4516 ** below the limit, it will exceed the limit rather than generate |
|
4517 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit |
|
4518 ** is advisory only. |
|
4519 ** |
|
4520 ** ^The return value from sqlite3_soft_heap_limit64() is the size of |
|
4521 ** the soft heap limit prior to the call. ^If the argument N is negative |
|
4522 ** then no change is made to the soft heap limit. Hence, the current |
|
4523 ** size of the soft heap limit can be determined by invoking |
|
4524 ** sqlite3_soft_heap_limit64() with a negative argument. |
|
4525 ** |
|
4526 ** ^If the argument N is zero then the soft heap limit is disabled. |
|
4527 ** |
|
4528 ** ^(The soft heap limit is not enforced in the current implementation |
|
4529 ** if one or more of following conditions are true: |
|
4530 ** |
|
4531 ** <ul> |
|
4532 ** <li> The soft heap limit is set to zero. |
|
4533 ** <li> Memory accounting is disabled using a combination of the |
|
4534 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and |
|
4535 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option. |
|
4536 ** <li> An alternative page cache implementation is specified using |
|
4537 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE],...). |
|
4538 ** <li> The page cache allocates from its own memory pool supplied |
|
4539 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than |
|
4540 ** from the heap. |
|
4541 ** </ul>)^ |
|
4542 ** |
|
4543 ** Beginning with SQLite version 3.7.3, the soft heap limit is enforced |
|
4544 ** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT] |
|
4545 ** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT], |
|
4546 ** the soft heap limit is enforced on every memory allocation. Without |
|
4547 ** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced |
|
4548 ** when memory is allocated by the page cache. Testing suggests that because |
|
4549 ** the page cache is the predominate memory user in SQLite, most |
|
4550 ** applications will achieve adequate soft heap limit enforcement without |
|
4551 ** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT]. |
|
4552 ** |
|
4553 ** The circumstances under which SQLite will enforce the soft heap limit may |
|
4554 ** changes in future releases of SQLite. |
|
4555 */ |
|
4556 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N); |
|
4557 |
|
4558 /* |
|
4559 ** CAPI3REF: Deprecated Soft Heap Limit Interface |
|
4560 ** DEPRECATED |
|
4561 ** |
|
4562 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()] |
|
4563 ** interface. This routine is provided for historical compatibility |
|
4564 ** only. All new applications should use the |
|
4565 ** [sqlite3_soft_heap_limit64()] interface rather than this one. |
|
4566 */ |
|
4567 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N); |
|
4568 |
|
4569 |
|
4570 /* |
|
4571 ** CAPI3REF: Extract Metadata About A Column Of A Table |
|
4572 ** |
|
4573 ** ^This routine returns metadata about a specific column of a specific |
|
4574 ** database table accessible using the [database connection] handle |
|
4575 ** passed as the first function argument. |
|
4576 ** |
|
4577 ** ^The column is identified by the second, third and fourth parameters to |
|
4578 ** this function. ^The second parameter is either the name of the database |
|
4579 ** (i.e. "main", "temp", or an attached database) containing the specified |
|
4580 ** table or NULL. ^If it is NULL, then all attached databases are searched |
|
4581 ** for the table using the same algorithm used by the database engine to |
|
4582 ** resolve unqualified table references. |
|
4583 ** |
|
4584 ** ^The third and fourth parameters to this function are the table and column |
|
4585 ** name of the desired column, respectively. Neither of these parameters |
|
4586 ** may be NULL. |
|
4587 ** |
|
4588 ** ^Metadata is returned by writing to the memory locations passed as the 5th |
|
4589 ** and subsequent parameters to this function. ^Any of these arguments may be |
|
4590 ** NULL, in which case the corresponding element of metadata is omitted. |
|
4591 ** |
|
4592 ** ^(<blockquote> |
|
4593 ** <table border="1"> |
|
4594 ** <tr><th> Parameter <th> Output<br>Type <th> Description |
|
4595 ** |
|
4596 ** <tr><td> 5th <td> const char* <td> Data type |
|
4597 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence |
|
4598 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint |
|
4599 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY |
|
4600 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT] |
|
4601 ** </table> |
|
4602 ** </blockquote>)^ |
|
4603 ** |
|
4604 ** ^The memory pointed to by the character pointers returned for the |
|
4605 ** declaration type and collation sequence is valid only until the next |
|
4606 ** call to any SQLite API function. |
|
4607 ** |
|
4608 ** ^If the specified table is actually a view, an [error code] is returned. |
|
4609 ** |
|
4610 ** ^If the specified column is "rowid", "oid" or "_rowid_" and an |
|
4611 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output |
|
4612 ** parameters are set for the explicitly declared column. ^(If there is no |
|
4613 ** explicitly declared [INTEGER PRIMARY KEY] column, then the output |
|
4614 ** parameters are set as follows: |
|
4615 ** |
|
4616 ** <pre> |
|
4617 ** data type: "INTEGER" |
|
4618 ** collation sequence: "BINARY" |
|
4619 ** not null: 0 |
|
4620 ** primary key: 1 |
|
4621 ** auto increment: 0 |
|
4622 ** </pre>)^ |
|
4623 ** |
|
4624 ** ^(This function may load one or more schemas from database files. If an |
|
4625 ** error occurs during this process, or if the requested table or column |
|
4626 ** cannot be found, an [error code] is returned and an error message left |
|
4627 ** in the [database connection] (to be retrieved using sqlite3_errmsg()).)^ |
|
4628 ** |
|
4629 ** ^This API is only available if the library was compiled with the |
|
4630 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol defined. |
|
4631 */ |
|
4632 SQLITE_API int sqlite3_table_column_metadata( |
|
4633 sqlite3 *db, /* Connection handle */ |
|
4634 const char *zDbName, /* Database name or NULL */ |
|
4635 const char *zTableName, /* Table name */ |
|
4636 const char *zColumnName, /* Column name */ |
|
4637 char const **pzDataType, /* OUTPUT: Declared data type */ |
|
4638 char const **pzCollSeq, /* OUTPUT: Collation sequence name */ |
|
4639 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */ |
|
4640 int *pPrimaryKey, /* OUTPUT: True if column part of PK */ |
|
4641 int *pAutoinc /* OUTPUT: True if column is auto-increment */ |
|
4642 ); |
|
4643 |
|
4644 /* |
|
4645 ** CAPI3REF: Load An Extension |
|
4646 ** |
|
4647 ** ^This interface loads an SQLite extension library from the named file. |
|
4648 ** |
|
4649 ** ^The sqlite3_load_extension() interface attempts to load an |
|
4650 ** SQLite extension library contained in the file zFile. |
|
4651 ** |
|
4652 ** ^The entry point is zProc. |
|
4653 ** ^zProc may be 0, in which case the name of the entry point |
|
4654 ** defaults to "sqlite3_extension_init". |
|
4655 ** ^The sqlite3_load_extension() interface returns |
|
4656 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong. |
|
4657 ** ^If an error occurs and pzErrMsg is not 0, then the |
|
4658 ** [sqlite3_load_extension()] interface shall attempt to |
|
4659 ** fill *pzErrMsg with error message text stored in memory |
|
4660 ** obtained from [sqlite3_malloc()]. The calling function |
|
4661 ** should free this memory by calling [sqlite3_free()]. |
|
4662 ** |
|
4663 ** ^Extension loading must be enabled using |
|
4664 ** [sqlite3_enable_load_extension()] prior to calling this API, |
|
4665 ** otherwise an error will be returned. |
|
4666 ** |
|
4667 ** See also the [load_extension() SQL function]. |
|
4668 */ |
|
4669 SQLITE_API int sqlite3_load_extension( |
|
4670 sqlite3 *db, /* Load the extension into this database connection */ |
|
4671 const char *zFile, /* Name of the shared library containing extension */ |
|
4672 const char *zProc, /* Entry point. Derived from zFile if 0 */ |
|
4673 char **pzErrMsg /* Put error message here if not 0 */ |
|
4674 ); |
|
4675 |
|
4676 /* |
|
4677 ** CAPI3REF: Enable Or Disable Extension Loading |
|
4678 ** |
|
4679 ** ^So as not to open security holes in older applications that are |
|
4680 ** unprepared to deal with extension loading, and as a means of disabling |
|
4681 ** extension loading while evaluating user-entered SQL, the following API |
|
4682 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off. |
|
4683 ** |
|
4684 ** ^Extension loading is off by default. See ticket #1863. |
|
4685 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1 |
|
4686 ** to turn extension loading on and call it with onoff==0 to turn |
|
4687 ** it back off again. |
|
4688 */ |
|
4689 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff); |
|
4690 |
|
4691 /* |
|
4692 ** CAPI3REF: Automatically Load Statically Linked Extensions |
|
4693 ** |
|
4694 ** ^This interface causes the xEntryPoint() function to be invoked for |
|
4695 ** each new [database connection] that is created. The idea here is that |
|
4696 ** xEntryPoint() is the entry point for a statically linked SQLite extension |
|
4697 ** that is to be automatically loaded into all new database connections. |
|
4698 ** |
|
4699 ** ^(Even though the function prototype shows that xEntryPoint() takes |
|
4700 ** no arguments and returns void, SQLite invokes xEntryPoint() with three |
|
4701 ** arguments and expects and integer result as if the signature of the |
|
4702 ** entry point where as follows: |
|
4703 ** |
|
4704 ** <blockquote><pre> |
|
4705 ** int xEntryPoint( |
|
4706 ** sqlite3 *db, |
|
4707 ** const char **pzErrMsg, |
|
4708 ** const struct sqlite3_api_routines *pThunk |
|
4709 ** ); |
|
4710 ** </pre></blockquote>)^ |
|
4711 ** |
|
4712 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg |
|
4713 ** point to an appropriate error message (obtained from [sqlite3_mprintf()]) |
|
4714 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg |
|
4715 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke |
|
4716 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any |
|
4717 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()], |
|
4718 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail. |
|
4719 ** |
|
4720 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already |
|
4721 ** on the list of automatic extensions is a harmless no-op. ^No entry point |
|
4722 ** will be called more than once for each database connection that is opened. |
|
4723 ** |
|
4724 ** See also: [sqlite3_reset_auto_extension()]. |
|
4725 */ |
|
4726 SQLITE_API int sqlite3_auto_extension(void (*xEntryPoint)(void)); |
|
4727 |
|
4728 /* |
|
4729 ** CAPI3REF: Reset Automatic Extension Loading |
|
4730 ** |
|
4731 ** ^This interface disables all automatic extensions previously |
|
4732 ** registered using [sqlite3_auto_extension()]. |
|
4733 */ |
|
4734 SQLITE_API void sqlite3_reset_auto_extension(void); |
|
4735 |
|
4736 /* |
|
4737 ** The interface to the virtual-table mechanism is currently considered |
|
4738 ** to be experimental. The interface might change in incompatible ways. |
|
4739 ** If this is a problem for you, do not use the interface at this time. |
|
4740 ** |
|
4741 ** When the virtual-table mechanism stabilizes, we will declare the |
|
4742 ** interface fixed, support it indefinitely, and remove this comment. |
|
4743 */ |
|
4744 |
|
4745 /* |
|
4746 ** Structures used by the virtual table interface |
|
4747 */ |
|
4748 typedef struct sqlite3_vtab sqlite3_vtab; |
|
4749 typedef struct sqlite3_index_info sqlite3_index_info; |
|
4750 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor; |
|
4751 typedef struct sqlite3_module sqlite3_module; |
|
4752 |
|
4753 /* |
|
4754 ** CAPI3REF: Virtual Table Object |
|
4755 ** KEYWORDS: sqlite3_module {virtual table module} |
|
4756 ** |
|
4757 ** This structure, sometimes called a "virtual table module", |
|
4758 ** defines the implementation of a [virtual tables]. |
|
4759 ** This structure consists mostly of methods for the module. |
|
4760 ** |
|
4761 ** ^A virtual table module is created by filling in a persistent |
|
4762 ** instance of this structure and passing a pointer to that instance |
|
4763 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()]. |
|
4764 ** ^The registration remains valid until it is replaced by a different |
|
4765 ** module or until the [database connection] closes. The content |
|
4766 ** of this structure must not change while it is registered with |
|
4767 ** any database connection. |
|
4768 */ |
|
4769 struct sqlite3_module { |
|
4770 int iVersion; |
|
4771 int (*xCreate)(sqlite3*, void *pAux, |
|
4772 int argc, const char *const*argv, |
|
4773 sqlite3_vtab **ppVTab, char**); |
|
4774 int (*xConnect)(sqlite3*, void *pAux, |
|
4775 int argc, const char *const*argv, |
|
4776 sqlite3_vtab **ppVTab, char**); |
|
4777 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*); |
|
4778 int (*xDisconnect)(sqlite3_vtab *pVTab); |
|
4779 int (*xDestroy)(sqlite3_vtab *pVTab); |
|
4780 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor); |
|
4781 int (*xClose)(sqlite3_vtab_cursor*); |
|
4782 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, |
|
4783 int argc, sqlite3_value **argv); |
|
4784 int (*xNext)(sqlite3_vtab_cursor*); |
|
4785 int (*xEof)(sqlite3_vtab_cursor*); |
|
4786 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int); |
|
4787 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid); |
|
4788 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *); |
|
4789 int (*xBegin)(sqlite3_vtab *pVTab); |
|
4790 int (*xSync)(sqlite3_vtab *pVTab); |
|
4791 int (*xCommit)(sqlite3_vtab *pVTab); |
|
4792 int (*xRollback)(sqlite3_vtab *pVTab); |
|
4793 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName, |
|
4794 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**), |
|
4795 void **ppArg); |
|
4796 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew); |
|
4797 /* The methods above are in version 1 of the sqlite_module object. Those |
|
4798 ** below are for version 2 and greater. */ |
|
4799 int (*xSavepoint)(sqlite3_vtab *pVTab, int); |
|
4800 int (*xRelease)(sqlite3_vtab *pVTab, int); |
|
4801 int (*xRollbackTo)(sqlite3_vtab *pVTab, int); |
|
4802 }; |
|
4803 |
|
4804 /* |
|
4805 ** CAPI3REF: Virtual Table Indexing Information |
|
4806 ** KEYWORDS: sqlite3_index_info |
|
4807 ** |
|
4808 ** The sqlite3_index_info structure and its substructures is used as part |
|
4809 ** of the [virtual table] interface to |
|
4810 ** pass information into and receive the reply from the [xBestIndex] |
|
4811 ** method of a [virtual table module]. The fields under **Inputs** are the |
|
4812 ** inputs to xBestIndex and are read-only. xBestIndex inserts its |
|
4813 ** results into the **Outputs** fields. |
|
4814 ** |
|
4815 ** ^(The aConstraint[] array records WHERE clause constraints of the form: |
|
4816 ** |
|
4817 ** <blockquote>column OP expr</blockquote> |
|
4818 ** |
|
4819 ** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is |
|
4820 ** stored in aConstraint[].op using one of the |
|
4821 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^ |
|
4822 ** ^(The index of the column is stored in |
|
4823 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the |
|
4824 ** expr on the right-hand side can be evaluated (and thus the constraint |
|
4825 ** is usable) and false if it cannot.)^ |
|
4826 ** |
|
4827 ** ^The optimizer automatically inverts terms of the form "expr OP column" |
|
4828 ** and makes other simplifications to the WHERE clause in an attempt to |
|
4829 ** get as many WHERE clause terms into the form shown above as possible. |
|
4830 ** ^The aConstraint[] array only reports WHERE clause terms that are |
|
4831 ** relevant to the particular virtual table being queried. |
|
4832 ** |
|
4833 ** ^Information about the ORDER BY clause is stored in aOrderBy[]. |
|
4834 ** ^Each term of aOrderBy records a column of the ORDER BY clause. |
|
4835 ** |
|
4836 ** The [xBestIndex] method must fill aConstraintUsage[] with information |
|
4837 ** about what parameters to pass to xFilter. ^If argvIndex>0 then |
|
4838 ** the right-hand side of the corresponding aConstraint[] is evaluated |
|
4839 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit |
|
4840 ** is true, then the constraint is assumed to be fully handled by the |
|
4841 ** virtual table and is not checked again by SQLite.)^ |
|
4842 ** |
|
4843 ** ^The idxNum and idxPtr values are recorded and passed into the |
|
4844 ** [xFilter] method. |
|
4845 ** ^[sqlite3_free()] is used to free idxPtr if and only if |
|
4846 ** needToFreeIdxPtr is true. |
|
4847 ** |
|
4848 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in |
|
4849 ** the correct order to satisfy the ORDER BY clause so that no separate |
|
4850 ** sorting step is required. |
|
4851 ** |
|
4852 ** ^The estimatedCost value is an estimate of the cost of doing the |
|
4853 ** particular lookup. A full scan of a table with N entries should have |
|
4854 ** a cost of N. A binary search of a table of N entries should have a |
|
4855 ** cost of approximately log(N). |
|
4856 */ |
|
4857 struct sqlite3_index_info { |
|
4858 /* Inputs */ |
|
4859 int nConstraint; /* Number of entries in aConstraint */ |
|
4860 struct sqlite3_index_constraint { |
|
4861 int iColumn; /* Column on left-hand side of constraint */ |
|
4862 unsigned char op; /* Constraint operator */ |
|
4863 unsigned char usable; /* True if this constraint is usable */ |
|
4864 int iTermOffset; /* Used internally - xBestIndex should ignore */ |
|
4865 } *aConstraint; /* Table of WHERE clause constraints */ |
|
4866 int nOrderBy; /* Number of terms in the ORDER BY clause */ |
|
4867 struct sqlite3_index_orderby { |
|
4868 int iColumn; /* Column number */ |
|
4869 unsigned char desc; /* True for DESC. False for ASC. */ |
|
4870 } *aOrderBy; /* The ORDER BY clause */ |
|
4871 /* Outputs */ |
|
4872 struct sqlite3_index_constraint_usage { |
|
4873 int argvIndex; /* if >0, constraint is part of argv to xFilter */ |
|
4874 unsigned char omit; /* Do not code a test for this constraint */ |
|
4875 } *aConstraintUsage; |
|
4876 int idxNum; /* Number used to identify the index */ |
|
4877 char *idxStr; /* String, possibly obtained from sqlite3_malloc */ |
|
4878 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */ |
|
4879 int orderByConsumed; /* True if output is already ordered */ |
|
4880 double estimatedCost; /* Estimated cost of using this index */ |
|
4881 }; |
|
4882 |
|
4883 /* |
|
4884 ** CAPI3REF: Virtual Table Constraint Operator Codes |
|
4885 ** |
|
4886 ** These macros defined the allowed values for the |
|
4887 ** [sqlite3_index_info].aConstraint[].op field. Each value represents |
|
4888 ** an operator that is part of a constraint term in the wHERE clause of |
|
4889 ** a query that uses a [virtual table]. |
|
4890 */ |
|
4891 #define SQLITE_INDEX_CONSTRAINT_EQ 2 |
|
4892 #define SQLITE_INDEX_CONSTRAINT_GT 4 |
|
4893 #define SQLITE_INDEX_CONSTRAINT_LE 8 |
|
4894 #define SQLITE_INDEX_CONSTRAINT_LT 16 |
|
4895 #define SQLITE_INDEX_CONSTRAINT_GE 32 |
|
4896 #define SQLITE_INDEX_CONSTRAINT_MATCH 64 |
|
4897 |
|
4898 /* |
|
4899 ** CAPI3REF: Register A Virtual Table Implementation |
|
4900 ** |
|
4901 ** ^These routines are used to register a new [virtual table module] name. |
|
4902 ** ^Module names must be registered before |
|
4903 ** creating a new [virtual table] using the module and before using a |
|
4904 ** preexisting [virtual table] for the module. |
|
4905 ** |
|
4906 ** ^The module name is registered on the [database connection] specified |
|
4907 ** by the first parameter. ^The name of the module is given by the |
|
4908 ** second parameter. ^The third parameter is a pointer to |
|
4909 ** the implementation of the [virtual table module]. ^The fourth |
|
4910 ** parameter is an arbitrary client data pointer that is passed through |
|
4911 ** into the [xCreate] and [xConnect] methods of the virtual table module |
|
4912 ** when a new virtual table is be being created or reinitialized. |
|
4913 ** |
|
4914 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which |
|
4915 ** is a pointer to a destructor for the pClientData. ^SQLite will |
|
4916 ** invoke the destructor function (if it is not NULL) when SQLite |
|
4917 ** no longer needs the pClientData pointer. ^The destructor will also |
|
4918 ** be invoked if the call to sqlite3_create_module_v2() fails. |
|
4919 ** ^The sqlite3_create_module() |
|
4920 ** interface is equivalent to sqlite3_create_module_v2() with a NULL |
|
4921 ** destructor. |
|
4922 */ |
|
4923 SQLITE_API int sqlite3_create_module( |
|
4924 sqlite3 *db, /* SQLite connection to register module with */ |
|
4925 const char *zName, /* Name of the module */ |
|
4926 const sqlite3_module *p, /* Methods for the module */ |
|
4927 void *pClientData /* Client data for xCreate/xConnect */ |
|
4928 ); |
|
4929 SQLITE_API int sqlite3_create_module_v2( |
|
4930 sqlite3 *db, /* SQLite connection to register module with */ |
|
4931 const char *zName, /* Name of the module */ |
|
4932 const sqlite3_module *p, /* Methods for the module */ |
|
4933 void *pClientData, /* Client data for xCreate/xConnect */ |
|
4934 void(*xDestroy)(void*) /* Module destructor function */ |
|
4935 ); |
|
4936 |
|
4937 /* |
|
4938 ** CAPI3REF: Virtual Table Instance Object |
|
4939 ** KEYWORDS: sqlite3_vtab |
|
4940 ** |
|
4941 ** Every [virtual table module] implementation uses a subclass |
|
4942 ** of this object to describe a particular instance |
|
4943 ** of the [virtual table]. Each subclass will |
|
4944 ** be tailored to the specific needs of the module implementation. |
|
4945 ** The purpose of this superclass is to define certain fields that are |
|
4946 ** common to all module implementations. |
|
4947 ** |
|
4948 ** ^Virtual tables methods can set an error message by assigning a |
|
4949 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should |
|
4950 ** take care that any prior string is freed by a call to [sqlite3_free()] |
|
4951 ** prior to assigning a new string to zErrMsg. ^After the error message |
|
4952 ** is delivered up to the client application, the string will be automatically |
|
4953 ** freed by sqlite3_free() and the zErrMsg field will be zeroed. |
|
4954 */ |
|
4955 struct sqlite3_vtab { |
|
4956 const sqlite3_module *pModule; /* The module for this virtual table */ |
|
4957 int nRef; /* NO LONGER USED */ |
|
4958 char *zErrMsg; /* Error message from sqlite3_mprintf() */ |
|
4959 /* Virtual table implementations will typically add additional fields */ |
|
4960 }; |
|
4961 |
|
4962 /* |
|
4963 ** CAPI3REF: Virtual Table Cursor Object |
|
4964 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor} |
|
4965 ** |
|
4966 ** Every [virtual table module] implementation uses a subclass of the |
|
4967 ** following structure to describe cursors that point into the |
|
4968 ** [virtual table] and are used |
|
4969 ** to loop through the virtual table. Cursors are created using the |
|
4970 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed |
|
4971 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used |
|
4972 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods |
|
4973 ** of the module. Each module implementation will define |
|
4974 ** the content of a cursor structure to suit its own needs. |
|
4975 ** |
|
4976 ** This superclass exists in order to define fields of the cursor that |
|
4977 ** are common to all implementations. |
|
4978 */ |
|
4979 struct sqlite3_vtab_cursor { |
|
4980 sqlite3_vtab *pVtab; /* Virtual table of this cursor */ |
|
4981 /* Virtual table implementations will typically add additional fields */ |
|
4982 }; |
|
4983 |
|
4984 /* |
|
4985 ** CAPI3REF: Declare The Schema Of A Virtual Table |
|
4986 ** |
|
4987 ** ^The [xCreate] and [xConnect] methods of a |
|
4988 ** [virtual table module] call this interface |
|
4989 ** to declare the format (the names and datatypes of the columns) of |
|
4990 ** the virtual tables they implement. |
|
4991 */ |
|
4992 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL); |
|
4993 |
|
4994 /* |
|
4995 ** CAPI3REF: Overload A Function For A Virtual Table |
|
4996 ** |
|
4997 ** ^(Virtual tables can provide alternative implementations of functions |
|
4998 ** using the [xFindFunction] method of the [virtual table module]. |
|
4999 ** But global versions of those functions |
|
5000 ** must exist in order to be overloaded.)^ |
|
5001 ** |
|
5002 ** ^(This API makes sure a global version of a function with a particular |
|
5003 ** name and number of parameters exists. If no such function exists |
|
5004 ** before this API is called, a new function is created.)^ ^The implementation |
|
5005 ** of the new function always causes an exception to be thrown. So |
|
5006 ** the new function is not good for anything by itself. Its only |
|
5007 ** purpose is to be a placeholder function that can be overloaded |
|
5008 ** by a [virtual table]. |
|
5009 */ |
|
5010 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg); |
|
5011 |
|
5012 /* |
|
5013 ** The interface to the virtual-table mechanism defined above (back up |
|
5014 ** to a comment remarkably similar to this one) is currently considered |
|
5015 ** to be experimental. The interface might change in incompatible ways. |
|
5016 ** If this is a problem for you, do not use the interface at this time. |
|
5017 ** |
|
5018 ** When the virtual-table mechanism stabilizes, we will declare the |
|
5019 ** interface fixed, support it indefinitely, and remove this comment. |
|
5020 */ |
|
5021 |
|
5022 /* |
|
5023 ** CAPI3REF: A Handle To An Open BLOB |
|
5024 ** KEYWORDS: {BLOB handle} {BLOB handles} |
|
5025 ** |
|
5026 ** An instance of this object represents an open BLOB on which |
|
5027 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed. |
|
5028 ** ^Objects of this type are created by [sqlite3_blob_open()] |
|
5029 ** and destroyed by [sqlite3_blob_close()]. |
|
5030 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces |
|
5031 ** can be used to read or write small subsections of the BLOB. |
|
5032 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes. |
|
5033 */ |
|
5034 typedef struct sqlite3_blob sqlite3_blob; |
|
5035 |
|
5036 /* |
|
5037 ** CAPI3REF: Open A BLOB For Incremental I/O |
|
5038 ** |
|
5039 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located |
|
5040 ** in row iRow, column zColumn, table zTable in database zDb; |
|
5041 ** in other words, the same BLOB that would be selected by: |
|
5042 ** |
|
5043 ** <pre> |
|
5044 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow; |
|
5045 ** </pre>)^ |
|
5046 ** |
|
5047 ** ^If the flags parameter is non-zero, then the BLOB is opened for read |
|
5048 ** and write access. ^If it is zero, the BLOB is opened for read access. |
|
5049 ** ^It is not possible to open a column that is part of an index or primary |
|
5050 ** key for writing. ^If [foreign key constraints] are enabled, it is |
|
5051 ** not possible to open a column that is part of a [child key] for writing. |
|
5052 ** |
|
5053 ** ^Note that the database name is not the filename that contains |
|
5054 ** the database but rather the symbolic name of the database that |
|
5055 ** appears after the AS keyword when the database is connected using [ATTACH]. |
|
5056 ** ^For the main database file, the database name is "main". |
|
5057 ** ^For TEMP tables, the database name is "temp". |
|
5058 ** |
|
5059 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is written |
|
5060 ** to *ppBlob. Otherwise an [error code] is returned and *ppBlob is set |
|
5061 ** to be a null pointer.)^ |
|
5062 ** ^This function sets the [database connection] error code and message |
|
5063 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()] and related |
|
5064 ** functions. ^Note that the *ppBlob variable is always initialized in a |
|
5065 ** way that makes it safe to invoke [sqlite3_blob_close()] on *ppBlob |
|
5066 ** regardless of the success or failure of this routine. |
|
5067 ** |
|
5068 ** ^(If the row that a BLOB handle points to is modified by an |
|
5069 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects |
|
5070 ** then the BLOB handle is marked as "expired". |
|
5071 ** This is true if any column of the row is changed, even a column |
|
5072 ** other than the one the BLOB handle is open on.)^ |
|
5073 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for |
|
5074 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT]. |
|
5075 ** ^(Changes written into a BLOB prior to the BLOB expiring are not |
|
5076 ** rolled back by the expiration of the BLOB. Such changes will eventually |
|
5077 ** commit if the transaction continues to completion.)^ |
|
5078 ** |
|
5079 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of |
|
5080 ** the opened blob. ^The size of a blob may not be changed by this |
|
5081 ** interface. Use the [UPDATE] SQL command to change the size of a |
|
5082 ** blob. |
|
5083 ** |
|
5084 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces |
|
5085 ** and the built-in [zeroblob] SQL function can be used, if desired, |
|
5086 ** to create an empty, zero-filled blob in which to read or write using |
|
5087 ** this interface. |
|
5088 ** |
|
5089 ** To avoid a resource leak, every open [BLOB handle] should eventually |
|
5090 ** be released by a call to [sqlite3_blob_close()]. |
|
5091 */ |
|
5092 SQLITE_API int sqlite3_blob_open( |
|
5093 sqlite3*, |
|
5094 const char *zDb, |
|
5095 const char *zTable, |
|
5096 const char *zColumn, |
|
5097 sqlite3_int64 iRow, |
|
5098 int flags, |
|
5099 sqlite3_blob **ppBlob |
|
5100 ); |
|
5101 |
|
5102 /* |
|
5103 ** CAPI3REF: Move a BLOB Handle to a New Row |
|
5104 ** |
|
5105 ** ^This function is used to move an existing blob handle so that it points |
|
5106 ** to a different row of the same database table. ^The new row is identified |
|
5107 ** by the rowid value passed as the second argument. Only the row can be |
|
5108 ** changed. ^The database, table and column on which the blob handle is open |
|
5109 ** remain the same. Moving an existing blob handle to a new row can be |
|
5110 ** faster than closing the existing handle and opening a new one. |
|
5111 ** |
|
5112 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] - |
|
5113 ** it must exist and there must be either a blob or text value stored in |
|
5114 ** the nominated column.)^ ^If the new row is not present in the table, or if |
|
5115 ** it does not contain a blob or text value, or if another error occurs, an |
|
5116 ** SQLite error code is returned and the blob handle is considered aborted. |
|
5117 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or |
|
5118 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return |
|
5119 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle |
|
5120 ** always returns zero. |
|
5121 ** |
|
5122 ** ^This function sets the database handle error code and message. |
|
5123 */ |
|
5124 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64); |
|
5125 |
|
5126 /* |
|
5127 ** CAPI3REF: Close A BLOB Handle |
|
5128 ** |
|
5129 ** ^Closes an open [BLOB handle]. |
|
5130 ** |
|
5131 ** ^Closing a BLOB shall cause the current transaction to commit |
|
5132 ** if there are no other BLOBs, no pending prepared statements, and the |
|
5133 ** database connection is in [autocommit mode]. |
|
5134 ** ^If any writes were made to the BLOB, they might be held in cache |
|
5135 ** until the close operation if they will fit. |
|
5136 ** |
|
5137 ** ^(Closing the BLOB often forces the changes |
|
5138 ** out to disk and so if any I/O errors occur, they will likely occur |
|
5139 ** at the time when the BLOB is closed. Any errors that occur during |
|
5140 ** closing are reported as a non-zero return value.)^ |
|
5141 ** |
|
5142 ** ^(The BLOB is closed unconditionally. Even if this routine returns |
|
5143 ** an error code, the BLOB is still closed.)^ |
|
5144 ** |
|
5145 ** ^Calling this routine with a null pointer (such as would be returned |
|
5146 ** by a failed call to [sqlite3_blob_open()]) is a harmless no-op. |
|
5147 */ |
|
5148 SQLITE_API int sqlite3_blob_close(sqlite3_blob *); |
|
5149 |
|
5150 /* |
|
5151 ** CAPI3REF: Return The Size Of An Open BLOB |
|
5152 ** |
|
5153 ** ^Returns the size in bytes of the BLOB accessible via the |
|
5154 ** successfully opened [BLOB handle] in its only argument. ^The |
|
5155 ** incremental blob I/O routines can only read or overwriting existing |
|
5156 ** blob content; they cannot change the size of a blob. |
|
5157 ** |
|
5158 ** This routine only works on a [BLOB handle] which has been created |
|
5159 ** by a prior successful call to [sqlite3_blob_open()] and which has not |
|
5160 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
|
5161 ** to this routine results in undefined and probably undesirable behavior. |
|
5162 */ |
|
5163 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *); |
|
5164 |
|
5165 /* |
|
5166 ** CAPI3REF: Read Data From A BLOB Incrementally |
|
5167 ** |
|
5168 ** ^(This function is used to read data from an open [BLOB handle] into a |
|
5169 ** caller-supplied buffer. N bytes of data are copied into buffer Z |
|
5170 ** from the open BLOB, starting at offset iOffset.)^ |
|
5171 ** |
|
5172 ** ^If offset iOffset is less than N bytes from the end of the BLOB, |
|
5173 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is |
|
5174 ** less than zero, [SQLITE_ERROR] is returned and no data is read. |
|
5175 ** ^The size of the blob (and hence the maximum value of N+iOffset) |
|
5176 ** can be determined using the [sqlite3_blob_bytes()] interface. |
|
5177 ** |
|
5178 ** ^An attempt to read from an expired [BLOB handle] fails with an |
|
5179 ** error code of [SQLITE_ABORT]. |
|
5180 ** |
|
5181 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK. |
|
5182 ** Otherwise, an [error code] or an [extended error code] is returned.)^ |
|
5183 ** |
|
5184 ** This routine only works on a [BLOB handle] which has been created |
|
5185 ** by a prior successful call to [sqlite3_blob_open()] and which has not |
|
5186 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
|
5187 ** to this routine results in undefined and probably undesirable behavior. |
|
5188 ** |
|
5189 ** See also: [sqlite3_blob_write()]. |
|
5190 */ |
|
5191 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset); |
|
5192 |
|
5193 /* |
|
5194 ** CAPI3REF: Write Data Into A BLOB Incrementally |
|
5195 ** |
|
5196 ** ^This function is used to write data into an open [BLOB handle] from a |
|
5197 ** caller-supplied buffer. ^N bytes of data are copied from the buffer Z |
|
5198 ** into the open BLOB, starting at offset iOffset. |
|
5199 ** |
|
5200 ** ^If the [BLOB handle] passed as the first argument was not opened for |
|
5201 ** writing (the flags parameter to [sqlite3_blob_open()] was zero), |
|
5202 ** this function returns [SQLITE_READONLY]. |
|
5203 ** |
|
5204 ** ^This function may only modify the contents of the BLOB; it is |
|
5205 ** not possible to increase the size of a BLOB using this API. |
|
5206 ** ^If offset iOffset is less than N bytes from the end of the BLOB, |
|
5207 ** [SQLITE_ERROR] is returned and no data is written. ^If N is |
|
5208 ** less than zero [SQLITE_ERROR] is returned and no data is written. |
|
5209 ** The size of the BLOB (and hence the maximum value of N+iOffset) |
|
5210 ** can be determined using the [sqlite3_blob_bytes()] interface. |
|
5211 ** |
|
5212 ** ^An attempt to write to an expired [BLOB handle] fails with an |
|
5213 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred |
|
5214 ** before the [BLOB handle] expired are not rolled back by the |
|
5215 ** expiration of the handle, though of course those changes might |
|
5216 ** have been overwritten by the statement that expired the BLOB handle |
|
5217 ** or by other independent statements. |
|
5218 ** |
|
5219 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK. |
|
5220 ** Otherwise, an [error code] or an [extended error code] is returned.)^ |
|
5221 ** |
|
5222 ** This routine only works on a [BLOB handle] which has been created |
|
5223 ** by a prior successful call to [sqlite3_blob_open()] and which has not |
|
5224 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in |
|
5225 ** to this routine results in undefined and probably undesirable behavior. |
|
5226 ** |
|
5227 ** See also: [sqlite3_blob_read()]. |
|
5228 */ |
|
5229 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset); |
|
5230 |
|
5231 /* |
|
5232 ** CAPI3REF: Virtual File System Objects |
|
5233 ** |
|
5234 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object |
|
5235 ** that SQLite uses to interact |
|
5236 ** with the underlying operating system. Most SQLite builds come with a |
|
5237 ** single default VFS that is appropriate for the host computer. |
|
5238 ** New VFSes can be registered and existing VFSes can be unregistered. |
|
5239 ** The following interfaces are provided. |
|
5240 ** |
|
5241 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name. |
|
5242 ** ^Names are case sensitive. |
|
5243 ** ^Names are zero-terminated UTF-8 strings. |
|
5244 ** ^If there is no match, a NULL pointer is returned. |
|
5245 ** ^If zVfsName is NULL then the default VFS is returned. |
|
5246 ** |
|
5247 ** ^New VFSes are registered with sqlite3_vfs_register(). |
|
5248 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set. |
|
5249 ** ^The same VFS can be registered multiple times without injury. |
|
5250 ** ^To make an existing VFS into the default VFS, register it again |
|
5251 ** with the makeDflt flag set. If two different VFSes with the |
|
5252 ** same name are registered, the behavior is undefined. If a |
|
5253 ** VFS is registered with a name that is NULL or an empty string, |
|
5254 ** then the behavior is undefined. |
|
5255 ** |
|
5256 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface. |
|
5257 ** ^(If the default VFS is unregistered, another VFS is chosen as |
|
5258 ** the default. The choice for the new VFS is arbitrary.)^ |
|
5259 */ |
|
5260 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName); |
|
5261 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt); |
|
5262 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*); |
|
5263 |
|
5264 /* |
|
5265 ** CAPI3REF: Mutexes |
|
5266 ** |
|
5267 ** The SQLite core uses these routines for thread |
|
5268 ** synchronization. Though they are intended for internal |
|
5269 ** use by SQLite, code that links against SQLite is |
|
5270 ** permitted to use any of these routines. |
|
5271 ** |
|
5272 ** The SQLite source code contains multiple implementations |
|
5273 ** of these mutex routines. An appropriate implementation |
|
5274 ** is selected automatically at compile-time. ^(The following |
|
5275 ** implementations are available in the SQLite core: |
|
5276 ** |
|
5277 ** <ul> |
|
5278 ** <li> SQLITE_MUTEX_OS2 |
|
5279 ** <li> SQLITE_MUTEX_PTHREAD |
|
5280 ** <li> SQLITE_MUTEX_W32 |
|
5281 ** <li> SQLITE_MUTEX_NOOP |
|
5282 ** </ul>)^ |
|
5283 ** |
|
5284 ** ^The SQLITE_MUTEX_NOOP implementation is a set of routines |
|
5285 ** that does no real locking and is appropriate for use in |
|
5286 ** a single-threaded application. ^The SQLITE_MUTEX_OS2, |
|
5287 ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations |
|
5288 ** are appropriate for use on OS/2, Unix, and Windows. |
|
5289 ** |
|
5290 ** ^(If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor |
|
5291 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex |
|
5292 ** implementation is included with the library. In this case the |
|
5293 ** application must supply a custom mutex implementation using the |
|
5294 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function |
|
5295 ** before calling sqlite3_initialize() or any other public sqlite3_ |
|
5296 ** function that calls sqlite3_initialize().)^ |
|
5297 ** |
|
5298 ** ^The sqlite3_mutex_alloc() routine allocates a new |
|
5299 ** mutex and returns a pointer to it. ^If it returns NULL |
|
5300 ** that means that a mutex could not be allocated. ^SQLite |
|
5301 ** will unwind its stack and return an error. ^(The argument |
|
5302 ** to sqlite3_mutex_alloc() is one of these integer constants: |
|
5303 ** |
|
5304 ** <ul> |
|
5305 ** <li> SQLITE_MUTEX_FAST |
|
5306 ** <li> SQLITE_MUTEX_RECURSIVE |
|
5307 ** <li> SQLITE_MUTEX_STATIC_MASTER |
|
5308 ** <li> SQLITE_MUTEX_STATIC_MEM |
|
5309 ** <li> SQLITE_MUTEX_STATIC_MEM2 |
|
5310 ** <li> SQLITE_MUTEX_STATIC_PRNG |
|
5311 ** <li> SQLITE_MUTEX_STATIC_LRU |
|
5312 ** <li> SQLITE_MUTEX_STATIC_LRU2 |
|
5313 ** </ul>)^ |
|
5314 ** |
|
5315 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) |
|
5316 ** cause sqlite3_mutex_alloc() to create |
|
5317 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE |
|
5318 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used. |
|
5319 ** The mutex implementation does not need to make a distinction |
|
5320 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does |
|
5321 ** not want to. ^SQLite will only request a recursive mutex in |
|
5322 ** cases where it really needs one. ^If a faster non-recursive mutex |
|
5323 ** implementation is available on the host platform, the mutex subsystem |
|
5324 ** might return such a mutex in response to SQLITE_MUTEX_FAST. |
|
5325 ** |
|
5326 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other |
|
5327 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return |
|
5328 ** a pointer to a static preexisting mutex. ^Six static mutexes are |
|
5329 ** used by the current version of SQLite. Future versions of SQLite |
|
5330 ** may add additional static mutexes. Static mutexes are for internal |
|
5331 ** use by SQLite only. Applications that use SQLite mutexes should |
|
5332 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or |
|
5333 ** SQLITE_MUTEX_RECURSIVE. |
|
5334 ** |
|
5335 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST |
|
5336 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc() |
|
5337 ** returns a different mutex on every call. ^But for the static |
|
5338 ** mutex types, the same mutex is returned on every call that has |
|
5339 ** the same type number. |
|
5340 ** |
|
5341 ** ^The sqlite3_mutex_free() routine deallocates a previously |
|
5342 ** allocated dynamic mutex. ^SQLite is careful to deallocate every |
|
5343 ** dynamic mutex that it allocates. The dynamic mutexes must not be in |
|
5344 ** use when they are deallocated. Attempting to deallocate a static |
|
5345 ** mutex results in undefined behavior. ^SQLite never deallocates |
|
5346 ** a static mutex. |
|
5347 ** |
|
5348 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt |
|
5349 ** to enter a mutex. ^If another thread is already within the mutex, |
|
5350 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return |
|
5351 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK] |
|
5352 ** upon successful entry. ^(Mutexes created using |
|
5353 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread. |
|
5354 ** In such cases the, |
|
5355 ** mutex must be exited an equal number of times before another thread |
|
5356 ** can enter.)^ ^(If the same thread tries to enter any other |
|
5357 ** kind of mutex more than once, the behavior is undefined. |
|
5358 ** SQLite will never exhibit |
|
5359 ** such behavior in its own use of mutexes.)^ |
|
5360 ** |
|
5361 ** ^(Some systems (for example, Windows 95) do not support the operation |
|
5362 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try() |
|
5363 ** will always return SQLITE_BUSY. The SQLite core only ever uses |
|
5364 ** sqlite3_mutex_try() as an optimization so this is acceptable behavior.)^ |
|
5365 ** |
|
5366 ** ^The sqlite3_mutex_leave() routine exits a mutex that was |
|
5367 ** previously entered by the same thread. ^(The behavior |
|
5368 ** is undefined if the mutex is not currently entered by the |
|
5369 ** calling thread or is not currently allocated. SQLite will |
|
5370 ** never do either.)^ |
|
5371 ** |
|
5372 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or |
|
5373 ** sqlite3_mutex_leave() is a NULL pointer, then all three routines |
|
5374 ** behave as no-ops. |
|
5375 ** |
|
5376 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()]. |
|
5377 */ |
|
5378 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int); |
|
5379 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*); |
|
5380 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*); |
|
5381 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*); |
|
5382 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*); |
|
5383 |
|
5384 /* |
|
5385 ** CAPI3REF: Mutex Methods Object |
|
5386 ** |
|
5387 ** An instance of this structure defines the low-level routines |
|
5388 ** used to allocate and use mutexes. |
|
5389 ** |
|
5390 ** Usually, the default mutex implementations provided by SQLite are |
|
5391 ** sufficient, however the user has the option of substituting a custom |
|
5392 ** implementation for specialized deployments or systems for which SQLite |
|
5393 ** does not provide a suitable implementation. In this case, the user |
|
5394 ** creates and populates an instance of this structure to pass |
|
5395 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option. |
|
5396 ** Additionally, an instance of this structure can be used as an |
|
5397 ** output variable when querying the system for the current mutex |
|
5398 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option. |
|
5399 ** |
|
5400 ** ^The xMutexInit method defined by this structure is invoked as |
|
5401 ** part of system initialization by the sqlite3_initialize() function. |
|
5402 ** ^The xMutexInit routine is called by SQLite exactly once for each |
|
5403 ** effective call to [sqlite3_initialize()]. |
|
5404 ** |
|
5405 ** ^The xMutexEnd method defined by this structure is invoked as |
|
5406 ** part of system shutdown by the sqlite3_shutdown() function. The |
|
5407 ** implementation of this method is expected to release all outstanding |
|
5408 ** resources obtained by the mutex methods implementation, especially |
|
5409 ** those obtained by the xMutexInit method. ^The xMutexEnd() |
|
5410 ** interface is invoked exactly once for each call to [sqlite3_shutdown()]. |
|
5411 ** |
|
5412 ** ^(The remaining seven methods defined by this structure (xMutexAlloc, |
|
5413 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and |
|
5414 ** xMutexNotheld) implement the following interfaces (respectively): |
|
5415 ** |
|
5416 ** <ul> |
|
5417 ** <li> [sqlite3_mutex_alloc()] </li> |
|
5418 ** <li> [sqlite3_mutex_free()] </li> |
|
5419 ** <li> [sqlite3_mutex_enter()] </li> |
|
5420 ** <li> [sqlite3_mutex_try()] </li> |
|
5421 ** <li> [sqlite3_mutex_leave()] </li> |
|
5422 ** <li> [sqlite3_mutex_held()] </li> |
|
5423 ** <li> [sqlite3_mutex_notheld()] </li> |
|
5424 ** </ul>)^ |
|
5425 ** |
|
5426 ** The only difference is that the public sqlite3_XXX functions enumerated |
|
5427 ** above silently ignore any invocations that pass a NULL pointer instead |
|
5428 ** of a valid mutex handle. The implementations of the methods defined |
|
5429 ** by this structure are not required to handle this case, the results |
|
5430 ** of passing a NULL pointer instead of a valid mutex handle are undefined |
|
5431 ** (i.e. it is acceptable to provide an implementation that segfaults if |
|
5432 ** it is passed a NULL pointer). |
|
5433 ** |
|
5434 ** The xMutexInit() method must be threadsafe. ^It must be harmless to |
|
5435 ** invoke xMutexInit() multiple times within the same process and without |
|
5436 ** intervening calls to xMutexEnd(). Second and subsequent calls to |
|
5437 ** xMutexInit() must be no-ops. |
|
5438 ** |
|
5439 ** ^xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()] |
|
5440 ** and its associates). ^Similarly, xMutexAlloc() must not use SQLite memory |
|
5441 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite |
|
5442 ** memory allocation for a fast or recursive mutex. |
|
5443 ** |
|
5444 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is |
|
5445 ** called, but only if the prior call to xMutexInit returned SQLITE_OK. |
|
5446 ** If xMutexInit fails in any way, it is expected to clean up after itself |
|
5447 ** prior to returning. |
|
5448 */ |
|
5449 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods; |
|
5450 struct sqlite3_mutex_methods { |
|
5451 int (*xMutexInit)(void); |
|
5452 int (*xMutexEnd)(void); |
|
5453 sqlite3_mutex *(*xMutexAlloc)(int); |
|
5454 void (*xMutexFree)(sqlite3_mutex *); |
|
5455 void (*xMutexEnter)(sqlite3_mutex *); |
|
5456 int (*xMutexTry)(sqlite3_mutex *); |
|
5457 void (*xMutexLeave)(sqlite3_mutex *); |
|
5458 int (*xMutexHeld)(sqlite3_mutex *); |
|
5459 int (*xMutexNotheld)(sqlite3_mutex *); |
|
5460 }; |
|
5461 |
|
5462 /* |
|
5463 ** CAPI3REF: Mutex Verification Routines |
|
5464 ** |
|
5465 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines |
|
5466 ** are intended for use inside assert() statements. ^The SQLite core |
|
5467 ** never uses these routines except inside an assert() and applications |
|
5468 ** are advised to follow the lead of the core. ^The SQLite core only |
|
5469 ** provides implementations for these routines when it is compiled |
|
5470 ** with the SQLITE_DEBUG flag. ^External mutex implementations |
|
5471 ** are only required to provide these routines if SQLITE_DEBUG is |
|
5472 ** defined and if NDEBUG is not defined. |
|
5473 ** |
|
5474 ** ^These routines should return true if the mutex in their argument |
|
5475 ** is held or not held, respectively, by the calling thread. |
|
5476 ** |
|
5477 ** ^The implementation is not required to provided versions of these |
|
5478 ** routines that actually work. If the implementation does not provide working |
|
5479 ** versions of these routines, it should at least provide stubs that always |
|
5480 ** return true so that one does not get spurious assertion failures. |
|
5481 ** |
|
5482 ** ^If the argument to sqlite3_mutex_held() is a NULL pointer then |
|
5483 ** the routine should return 1. This seems counter-intuitive since |
|
5484 ** clearly the mutex cannot be held if it does not exist. But |
|
5485 ** the reason the mutex does not exist is because the build is not |
|
5486 ** using mutexes. And we do not want the assert() containing the |
|
5487 ** call to sqlite3_mutex_held() to fail, so a non-zero return is |
|
5488 ** the appropriate thing to do. ^The sqlite3_mutex_notheld() |
|
5489 ** interface should also return 1 when given a NULL pointer. |
|
5490 */ |
|
5491 #ifndef NDEBUG |
|
5492 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*); |
|
5493 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*); |
|
5494 #endif |
|
5495 |
|
5496 /* |
|
5497 ** CAPI3REF: Mutex Types |
|
5498 ** |
|
5499 ** The [sqlite3_mutex_alloc()] interface takes a single argument |
|
5500 ** which is one of these integer constants. |
|
5501 ** |
|
5502 ** The set of static mutexes may change from one SQLite release to the |
|
5503 ** next. Applications that override the built-in mutex logic must be |
|
5504 ** prepared to accommodate additional static mutexes. |
|
5505 */ |
|
5506 #define SQLITE_MUTEX_FAST 0 |
|
5507 #define SQLITE_MUTEX_RECURSIVE 1 |
|
5508 #define SQLITE_MUTEX_STATIC_MASTER 2 |
|
5509 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */ |
|
5510 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */ |
|
5511 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */ |
|
5512 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */ |
|
5513 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */ |
|
5514 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */ |
|
5515 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */ |
|
5516 |
|
5517 /* |
|
5518 ** CAPI3REF: Retrieve the mutex for a database connection |
|
5519 ** |
|
5520 ** ^This interface returns a pointer the [sqlite3_mutex] object that |
|
5521 ** serializes access to the [database connection] given in the argument |
|
5522 ** when the [threading mode] is Serialized. |
|
5523 ** ^If the [threading mode] is Single-thread or Multi-thread then this |
|
5524 ** routine returns a NULL pointer. |
|
5525 */ |
|
5526 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*); |
|
5527 |
|
5528 /* |
|
5529 ** CAPI3REF: Low-Level Control Of Database Files |
|
5530 ** |
|
5531 ** ^The [sqlite3_file_control()] interface makes a direct call to the |
|
5532 ** xFileControl method for the [sqlite3_io_methods] object associated |
|
5533 ** with a particular database identified by the second argument. ^The |
|
5534 ** name of the database is "main" for the main database or "temp" for the |
|
5535 ** TEMP database, or the name that appears after the AS keyword for |
|
5536 ** databases that are added using the [ATTACH] SQL command. |
|
5537 ** ^A NULL pointer can be used in place of "main" to refer to the |
|
5538 ** main database file. |
|
5539 ** ^The third and fourth parameters to this routine |
|
5540 ** are passed directly through to the second and third parameters of |
|
5541 ** the xFileControl method. ^The return value of the xFileControl |
|
5542 ** method becomes the return value of this routine. |
|
5543 ** |
|
5544 ** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes |
|
5545 ** a pointer to the underlying [sqlite3_file] object to be written into |
|
5546 ** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER |
|
5547 ** case is a short-circuit path which does not actually invoke the |
|
5548 ** underlying sqlite3_io_methods.xFileControl method. |
|
5549 ** |
|
5550 ** ^If the second parameter (zDbName) does not match the name of any |
|
5551 ** open database file, then SQLITE_ERROR is returned. ^This error |
|
5552 ** code is not remembered and will not be recalled by [sqlite3_errcode()] |
|
5553 ** or [sqlite3_errmsg()]. The underlying xFileControl method might |
|
5554 ** also return SQLITE_ERROR. There is no way to distinguish between |
|
5555 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying |
|
5556 ** xFileControl method. |
|
5557 ** |
|
5558 ** See also: [SQLITE_FCNTL_LOCKSTATE] |
|
5559 */ |
|
5560 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*); |
|
5561 |
|
5562 /* |
|
5563 ** CAPI3REF: Testing Interface |
|
5564 ** |
|
5565 ** ^The sqlite3_test_control() interface is used to read out internal |
|
5566 ** state of SQLite and to inject faults into SQLite for testing |
|
5567 ** purposes. ^The first parameter is an operation code that determines |
|
5568 ** the number, meaning, and operation of all subsequent parameters. |
|
5569 ** |
|
5570 ** This interface is not for use by applications. It exists solely |
|
5571 ** for verifying the correct operation of the SQLite library. Depending |
|
5572 ** on how the SQLite library is compiled, this interface might not exist. |
|
5573 ** |
|
5574 ** The details of the operation codes, their meanings, the parameters |
|
5575 ** they take, and what they do are all subject to change without notice. |
|
5576 ** Unlike most of the SQLite API, this function is not guaranteed to |
|
5577 ** operate consistently from one release to the next. |
|
5578 */ |
|
5579 SQLITE_API int sqlite3_test_control(int op, ...); |
|
5580 |
|
5581 /* |
|
5582 ** CAPI3REF: Testing Interface Operation Codes |
|
5583 ** |
|
5584 ** These constants are the valid operation code parameters used |
|
5585 ** as the first argument to [sqlite3_test_control()]. |
|
5586 ** |
|
5587 ** These parameters and their meanings are subject to change |
|
5588 ** without notice. These values are for testing purposes only. |
|
5589 ** Applications should not use any of these parameters or the |
|
5590 ** [sqlite3_test_control()] interface. |
|
5591 */ |
|
5592 #define SQLITE_TESTCTRL_FIRST 5 |
|
5593 #define SQLITE_TESTCTRL_PRNG_SAVE 5 |
|
5594 #define SQLITE_TESTCTRL_PRNG_RESTORE 6 |
|
5595 #define SQLITE_TESTCTRL_PRNG_RESET 7 |
|
5596 #define SQLITE_TESTCTRL_BITVEC_TEST 8 |
|
5597 #define SQLITE_TESTCTRL_FAULT_INSTALL 9 |
|
5598 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10 |
|
5599 #define SQLITE_TESTCTRL_PENDING_BYTE 11 |
|
5600 #define SQLITE_TESTCTRL_ASSERT 12 |
|
5601 #define SQLITE_TESTCTRL_ALWAYS 13 |
|
5602 #define SQLITE_TESTCTRL_RESERVE 14 |
|
5603 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15 |
|
5604 #define SQLITE_TESTCTRL_ISKEYWORD 16 |
|
5605 #define SQLITE_TESTCTRL_PGHDRSZ 17 |
|
5606 #define SQLITE_TESTCTRL_SCRATCHMALLOC 18 |
|
5607 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 19 |
|
5608 #define SQLITE_TESTCTRL_LAST 19 |
|
5609 |
|
5610 /* |
|
5611 ** CAPI3REF: SQLite Runtime Status |
|
5612 ** |
|
5613 ** ^This interface is used to retrieve runtime status information |
|
5614 ** about the performance of SQLite, and optionally to reset various |
|
5615 ** highwater marks. ^The first argument is an integer code for |
|
5616 ** the specific parameter to measure. ^(Recognized integer codes |
|
5617 ** are of the form [status parameters | SQLITE_STATUS_...].)^ |
|
5618 ** ^The current value of the parameter is returned into *pCurrent. |
|
5619 ** ^The highest recorded value is returned in *pHighwater. ^If the |
|
5620 ** resetFlag is true, then the highest record value is reset after |
|
5621 ** *pHighwater is written. ^(Some parameters do not record the highest |
|
5622 ** value. For those parameters |
|
5623 ** nothing is written into *pHighwater and the resetFlag is ignored.)^ |
|
5624 ** ^(Other parameters record only the highwater mark and not the current |
|
5625 ** value. For these latter parameters nothing is written into *pCurrent.)^ |
|
5626 ** |
|
5627 ** ^The sqlite3_status() routine returns SQLITE_OK on success and a |
|
5628 ** non-zero [error code] on failure. |
|
5629 ** |
|
5630 ** This routine is threadsafe but is not atomic. This routine can be |
|
5631 ** called while other threads are running the same or different SQLite |
|
5632 ** interfaces. However the values returned in *pCurrent and |
|
5633 ** *pHighwater reflect the status of SQLite at different points in time |
|
5634 ** and it is possible that another thread might change the parameter |
|
5635 ** in between the times when *pCurrent and *pHighwater are written. |
|
5636 ** |
|
5637 ** See also: [sqlite3_db_status()] |
|
5638 */ |
|
5639 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag); |
|
5640 |
|
5641 |
|
5642 /* |
|
5643 ** CAPI3REF: Status Parameters |
|
5644 ** KEYWORDS: {status parameters} |
|
5645 ** |
|
5646 ** These integer constants designate various run-time status parameters |
|
5647 ** that can be returned by [sqlite3_status()]. |
|
5648 ** |
|
5649 ** <dl> |
|
5650 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt> |
|
5651 ** <dd>This parameter is the current amount of memory checked out |
|
5652 ** using [sqlite3_malloc()], either directly or indirectly. The |
|
5653 ** figure includes calls made to [sqlite3_malloc()] by the application |
|
5654 ** and internal memory usage by the SQLite library. Scratch memory |
|
5655 ** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache |
|
5656 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in |
|
5657 ** this parameter. The amount returned is the sum of the allocation |
|
5658 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^ |
|
5659 ** |
|
5660 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt> |
|
5661 ** <dd>This parameter records the largest memory allocation request |
|
5662 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their |
|
5663 ** internal equivalents). Only the value returned in the |
|
5664 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
|
5665 ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
|
5666 ** |
|
5667 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt> |
|
5668 ** <dd>This parameter records the number of separate memory allocations |
|
5669 ** currently checked out.</dd>)^ |
|
5670 ** |
|
5671 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt> |
|
5672 ** <dd>This parameter returns the number of pages used out of the |
|
5673 ** [pagecache memory allocator] that was configured using |
|
5674 ** [SQLITE_CONFIG_PAGECACHE]. The |
|
5675 ** value returned is in pages, not in bytes.</dd>)^ |
|
5676 ** |
|
5677 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]] |
|
5678 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt> |
|
5679 ** <dd>This parameter returns the number of bytes of page cache |
|
5680 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE] |
|
5681 ** buffer and where forced to overflow to [sqlite3_malloc()]. The |
|
5682 ** returned value includes allocations that overflowed because they |
|
5683 ** where too large (they were larger than the "sz" parameter to |
|
5684 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because |
|
5685 ** no space was left in the page cache.</dd>)^ |
|
5686 ** |
|
5687 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt> |
|
5688 ** <dd>This parameter records the largest memory allocation request |
|
5689 ** handed to [pagecache memory allocator]. Only the value returned in the |
|
5690 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
|
5691 ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
|
5692 ** |
|
5693 ** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt> |
|
5694 ** <dd>This parameter returns the number of allocations used out of the |
|
5695 ** [scratch memory allocator] configured using |
|
5696 ** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not |
|
5697 ** in bytes. Since a single thread may only have one scratch allocation |
|
5698 ** outstanding at time, this parameter also reports the number of threads |
|
5699 ** using scratch memory at the same time.</dd>)^ |
|
5700 ** |
|
5701 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt> |
|
5702 ** <dd>This parameter returns the number of bytes of scratch memory |
|
5703 ** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH] |
|
5704 ** buffer and where forced to overflow to [sqlite3_malloc()]. The values |
|
5705 ** returned include overflows because the requested allocation was too |
|
5706 ** larger (that is, because the requested allocation was larger than the |
|
5707 ** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer |
|
5708 ** slots were available. |
|
5709 ** </dd>)^ |
|
5710 ** |
|
5711 ** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt> |
|
5712 ** <dd>This parameter records the largest memory allocation request |
|
5713 ** handed to [scratch memory allocator]. Only the value returned in the |
|
5714 ** *pHighwater parameter to [sqlite3_status()] is of interest. |
|
5715 ** The value written into the *pCurrent parameter is undefined.</dd>)^ |
|
5716 ** |
|
5717 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt> |
|
5718 ** <dd>This parameter records the deepest parser stack. It is only |
|
5719 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^ |
|
5720 ** </dl> |
|
5721 ** |
|
5722 ** New status parameters may be added from time to time. |
|
5723 */ |
|
5724 #define SQLITE_STATUS_MEMORY_USED 0 |
|
5725 #define SQLITE_STATUS_PAGECACHE_USED 1 |
|
5726 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2 |
|
5727 #define SQLITE_STATUS_SCRATCH_USED 3 |
|
5728 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 |
|
5729 #define SQLITE_STATUS_MALLOC_SIZE 5 |
|
5730 #define SQLITE_STATUS_PARSER_STACK 6 |
|
5731 #define SQLITE_STATUS_PAGECACHE_SIZE 7 |
|
5732 #define SQLITE_STATUS_SCRATCH_SIZE 8 |
|
5733 #define SQLITE_STATUS_MALLOC_COUNT 9 |
|
5734 |
|
5735 /* |
|
5736 ** CAPI3REF: Database Connection Status |
|
5737 ** |
|
5738 ** ^This interface is used to retrieve runtime status information |
|
5739 ** about a single [database connection]. ^The first argument is the |
|
5740 ** database connection object to be interrogated. ^The second argument |
|
5741 ** is an integer constant, taken from the set of |
|
5742 ** [SQLITE_DBSTATUS options], that |
|
5743 ** determines the parameter to interrogate. The set of |
|
5744 ** [SQLITE_DBSTATUS options] is likely |
|
5745 ** to grow in future releases of SQLite. |
|
5746 ** |
|
5747 ** ^The current value of the requested parameter is written into *pCur |
|
5748 ** and the highest instantaneous value is written into *pHiwtr. ^If |
|
5749 ** the resetFlg is true, then the highest instantaneous value is |
|
5750 ** reset back down to the current value. |
|
5751 ** |
|
5752 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a |
|
5753 ** non-zero [error code] on failure. |
|
5754 ** |
|
5755 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()]. |
|
5756 */ |
|
5757 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg); |
|
5758 |
|
5759 /* |
|
5760 ** CAPI3REF: Status Parameters for database connections |
|
5761 ** KEYWORDS: {SQLITE_DBSTATUS options} |
|
5762 ** |
|
5763 ** These constants are the available integer "verbs" that can be passed as |
|
5764 ** the second argument to the [sqlite3_db_status()] interface. |
|
5765 ** |
|
5766 ** New verbs may be added in future releases of SQLite. Existing verbs |
|
5767 ** might be discontinued. Applications should check the return code from |
|
5768 ** [sqlite3_db_status()] to make sure that the call worked. |
|
5769 ** The [sqlite3_db_status()] interface will return a non-zero error code |
|
5770 ** if a discontinued or unsupported verb is invoked. |
|
5771 ** |
|
5772 ** <dl> |
|
5773 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt> |
|
5774 ** <dd>This parameter returns the number of lookaside memory slots currently |
|
5775 ** checked out.</dd>)^ |
|
5776 ** |
|
5777 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt> |
|
5778 ** <dd>This parameter returns the number malloc attempts that were |
|
5779 ** satisfied using lookaside memory. Only the high-water value is meaningful; |
|
5780 ** the current value is always zero.)^ |
|
5781 ** |
|
5782 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]] |
|
5783 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt> |
|
5784 ** <dd>This parameter returns the number malloc attempts that might have |
|
5785 ** been satisfied using lookaside memory but failed due to the amount of |
|
5786 ** memory requested being larger than the lookaside slot size. |
|
5787 ** Only the high-water value is meaningful; |
|
5788 ** the current value is always zero.)^ |
|
5789 ** |
|
5790 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]] |
|
5791 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt> |
|
5792 ** <dd>This parameter returns the number malloc attempts that might have |
|
5793 ** been satisfied using lookaside memory but failed due to all lookaside |
|
5794 ** memory already being in use. |
|
5795 ** Only the high-water value is meaningful; |
|
5796 ** the current value is always zero.)^ |
|
5797 ** |
|
5798 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt> |
|
5799 ** <dd>This parameter returns the approximate number of of bytes of heap |
|
5800 ** memory used by all pager caches associated with the database connection.)^ |
|
5801 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0. |
|
5802 ** |
|
5803 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt> |
|
5804 ** <dd>This parameter returns the approximate number of of bytes of heap |
|
5805 ** memory used to store the schema for all databases associated |
|
5806 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^ |
|
5807 ** ^The full amount of memory used by the schemas is reported, even if the |
|
5808 ** schema memory is shared with other database connections due to |
|
5809 ** [shared cache mode] being enabled. |
|
5810 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0. |
|
5811 ** |
|
5812 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt> |
|
5813 ** <dd>This parameter returns the approximate number of of bytes of heap |
|
5814 ** and lookaside memory used by all prepared statements associated with |
|
5815 ** the database connection.)^ |
|
5816 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0. |
|
5817 ** </dd> |
|
5818 ** </dl> |
|
5819 */ |
|
5820 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0 |
|
5821 #define SQLITE_DBSTATUS_CACHE_USED 1 |
|
5822 #define SQLITE_DBSTATUS_SCHEMA_USED 2 |
|
5823 #define SQLITE_DBSTATUS_STMT_USED 3 |
|
5824 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4 |
|
5825 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5 |
|
5826 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6 |
|
5827 #define SQLITE_DBSTATUS_MAX 6 /* Largest defined DBSTATUS */ |
|
5828 |
|
5829 |
|
5830 /* |
|
5831 ** CAPI3REF: Prepared Statement Status |
|
5832 ** |
|
5833 ** ^(Each prepared statement maintains various |
|
5834 ** [SQLITE_STMTSTATUS counters] that measure the number |
|
5835 ** of times it has performed specific operations.)^ These counters can |
|
5836 ** be used to monitor the performance characteristics of the prepared |
|
5837 ** statements. For example, if the number of table steps greatly exceeds |
|
5838 ** the number of table searches or result rows, that would tend to indicate |
|
5839 ** that the prepared statement is using a full table scan rather than |
|
5840 ** an index. |
|
5841 ** |
|
5842 ** ^(This interface is used to retrieve and reset counter values from |
|
5843 ** a [prepared statement]. The first argument is the prepared statement |
|
5844 ** object to be interrogated. The second argument |
|
5845 ** is an integer code for a specific [SQLITE_STMTSTATUS counter] |
|
5846 ** to be interrogated.)^ |
|
5847 ** ^The current value of the requested counter is returned. |
|
5848 ** ^If the resetFlg is true, then the counter is reset to zero after this |
|
5849 ** interface call returns. |
|
5850 ** |
|
5851 ** See also: [sqlite3_status()] and [sqlite3_db_status()]. |
|
5852 */ |
|
5853 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg); |
|
5854 |
|
5855 /* |
|
5856 ** CAPI3REF: Status Parameters for prepared statements |
|
5857 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters} |
|
5858 ** |
|
5859 ** These preprocessor macros define integer codes that name counter |
|
5860 ** values associated with the [sqlite3_stmt_status()] interface. |
|
5861 ** The meanings of the various counters are as follows: |
|
5862 ** |
|
5863 ** <dl> |
|
5864 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt> |
|
5865 ** <dd>^This is the number of times that SQLite has stepped forward in |
|
5866 ** a table as part of a full table scan. Large numbers for this counter |
|
5867 ** may indicate opportunities for performance improvement through |
|
5868 ** careful use of indices.</dd> |
|
5869 ** |
|
5870 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt> |
|
5871 ** <dd>^This is the number of sort operations that have occurred. |
|
5872 ** A non-zero value in this counter may indicate an opportunity to |
|
5873 ** improvement performance through careful use of indices.</dd> |
|
5874 ** |
|
5875 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt> |
|
5876 ** <dd>^This is the number of rows inserted into transient indices that |
|
5877 ** were created automatically in order to help joins run faster. |
|
5878 ** A non-zero value in this counter may indicate an opportunity to |
|
5879 ** improvement performance by adding permanent indices that do not |
|
5880 ** need to be reinitialized each time the statement is run.</dd> |
|
5881 ** |
|
5882 ** </dl> |
|
5883 */ |
|
5884 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1 |
|
5885 #define SQLITE_STMTSTATUS_SORT 2 |
|
5886 #define SQLITE_STMTSTATUS_AUTOINDEX 3 |
|
5887 |
|
5888 /* |
|
5889 ** CAPI3REF: Custom Page Cache Object |
|
5890 ** |
|
5891 ** The sqlite3_pcache type is opaque. It is implemented by |
|
5892 ** the pluggable module. The SQLite core has no knowledge of |
|
5893 ** its size or internal structure and never deals with the |
|
5894 ** sqlite3_pcache object except by holding and passing pointers |
|
5895 ** to the object. |
|
5896 ** |
|
5897 ** See [sqlite3_pcache_methods] for additional information. |
|
5898 */ |
|
5899 typedef struct sqlite3_pcache sqlite3_pcache; |
|
5900 |
|
5901 /* |
|
5902 ** CAPI3REF: Application Defined Page Cache. |
|
5903 ** KEYWORDS: {page cache} |
|
5904 ** |
|
5905 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE], ...) interface can |
|
5906 ** register an alternative page cache implementation by passing in an |
|
5907 ** instance of the sqlite3_pcache_methods structure.)^ |
|
5908 ** In many applications, most of the heap memory allocated by |
|
5909 ** SQLite is used for the page cache. |
|
5910 ** By implementing a |
|
5911 ** custom page cache using this API, an application can better control |
|
5912 ** the amount of memory consumed by SQLite, the way in which |
|
5913 ** that memory is allocated and released, and the policies used to |
|
5914 ** determine exactly which parts of a database file are cached and for |
|
5915 ** how long. |
|
5916 ** |
|
5917 ** The alternative page cache mechanism is an |
|
5918 ** extreme measure that is only needed by the most demanding applications. |
|
5919 ** The built-in page cache is recommended for most uses. |
|
5920 ** |
|
5921 ** ^(The contents of the sqlite3_pcache_methods structure are copied to an |
|
5922 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence |
|
5923 ** the application may discard the parameter after the call to |
|
5924 ** [sqlite3_config()] returns.)^ |
|
5925 ** |
|
5926 ** [[the xInit() page cache method]] |
|
5927 ** ^(The xInit() method is called once for each effective |
|
5928 ** call to [sqlite3_initialize()])^ |
|
5929 ** (usually only once during the lifetime of the process). ^(The xInit() |
|
5930 ** method is passed a copy of the sqlite3_pcache_methods.pArg value.)^ |
|
5931 ** The intent of the xInit() method is to set up global data structures |
|
5932 ** required by the custom page cache implementation. |
|
5933 ** ^(If the xInit() method is NULL, then the |
|
5934 ** built-in default page cache is used instead of the application defined |
|
5935 ** page cache.)^ |
|
5936 ** |
|
5937 ** [[the xShutdown() page cache method]] |
|
5938 ** ^The xShutdown() method is called by [sqlite3_shutdown()]. |
|
5939 ** It can be used to clean up |
|
5940 ** any outstanding resources before process shutdown, if required. |
|
5941 ** ^The xShutdown() method may be NULL. |
|
5942 ** |
|
5943 ** ^SQLite automatically serializes calls to the xInit method, |
|
5944 ** so the xInit method need not be threadsafe. ^The |
|
5945 ** xShutdown method is only called from [sqlite3_shutdown()] so it does |
|
5946 ** not need to be threadsafe either. All other methods must be threadsafe |
|
5947 ** in multithreaded applications. |
|
5948 ** |
|
5949 ** ^SQLite will never invoke xInit() more than once without an intervening |
|
5950 ** call to xShutdown(). |
|
5951 ** |
|
5952 ** [[the xCreate() page cache methods]] |
|
5953 ** ^SQLite invokes the xCreate() method to construct a new cache instance. |
|
5954 ** SQLite will typically create one cache instance for each open database file, |
|
5955 ** though this is not guaranteed. ^The |
|
5956 ** first parameter, szPage, is the size in bytes of the pages that must |
|
5957 ** be allocated by the cache. ^szPage will not be a power of two. ^szPage |
|
5958 ** will the page size of the database file that is to be cached plus an |
|
5959 ** increment (here called "R") of less than 250. SQLite will use the |
|
5960 ** extra R bytes on each page to store metadata about the underlying |
|
5961 ** database page on disk. The value of R depends |
|
5962 ** on the SQLite version, the target platform, and how SQLite was compiled. |
|
5963 ** ^(R is constant for a particular build of SQLite. Except, there are two |
|
5964 ** distinct values of R when SQLite is compiled with the proprietary |
|
5965 ** ZIPVFS extension.)^ ^The second argument to |
|
5966 ** xCreate(), bPurgeable, is true if the cache being created will |
|
5967 ** be used to cache database pages of a file stored on disk, or |
|
5968 ** false if it is used for an in-memory database. The cache implementation |
|
5969 ** does not have to do anything special based with the value of bPurgeable; |
|
5970 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will |
|
5971 ** never invoke xUnpin() except to deliberately delete a page. |
|
5972 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to |
|
5973 ** false will always have the "discard" flag set to true. |
|
5974 ** ^Hence, a cache created with bPurgeable false will |
|
5975 ** never contain any unpinned pages. |
|
5976 ** |
|
5977 ** [[the xCachesize() page cache method]] |
|
5978 ** ^(The xCachesize() method may be called at any time by SQLite to set the |
|
5979 ** suggested maximum cache-size (number of pages stored by) the cache |
|
5980 ** instance passed as the first argument. This is the value configured using |
|
5981 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable |
|
5982 ** parameter, the implementation is not required to do anything with this |
|
5983 ** value; it is advisory only. |
|
5984 ** |
|
5985 ** [[the xPagecount() page cache methods]] |
|
5986 ** The xPagecount() method must return the number of pages currently |
|
5987 ** stored in the cache, both pinned and unpinned. |
|
5988 ** |
|
5989 ** [[the xFetch() page cache methods]] |
|
5990 ** The xFetch() method locates a page in the cache and returns a pointer to |
|
5991 ** the page, or a NULL pointer. |
|
5992 ** A "page", in this context, means a buffer of szPage bytes aligned at an |
|
5993 ** 8-byte boundary. The page to be fetched is determined by the key. ^The |
|
5994 ** minimum key value is 1. After it has been retrieved using xFetch, the page |
|
5995 ** is considered to be "pinned". |
|
5996 ** |
|
5997 ** If the requested page is already in the page cache, then the page cache |
|
5998 ** implementation must return a pointer to the page buffer with its content |
|
5999 ** intact. If the requested page is not already in the cache, then the |
|
6000 ** cache implementation should use the value of the createFlag |
|
6001 ** parameter to help it determined what action to take: |
|
6002 ** |
|
6003 ** <table border=1 width=85% align=center> |
|
6004 ** <tr><th> createFlag <th> Behaviour when page is not already in cache |
|
6005 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL. |
|
6006 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so. |
|
6007 ** Otherwise return NULL. |
|
6008 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return |
|
6009 ** NULL if allocating a new page is effectively impossible. |
|
6010 ** </table> |
|
6011 ** |
|
6012 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite |
|
6013 ** will only use a createFlag of 2 after a prior call with a createFlag of 1 |
|
6014 ** failed.)^ In between the to xFetch() calls, SQLite may |
|
6015 ** attempt to unpin one or more cache pages by spilling the content of |
|
6016 ** pinned pages to disk and synching the operating system disk cache. |
|
6017 ** |
|
6018 ** [[the xUnpin() page cache method]] |
|
6019 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page |
|
6020 ** as its second argument. If the third parameter, discard, is non-zero, |
|
6021 ** then the page must be evicted from the cache. |
|
6022 ** ^If the discard parameter is |
|
6023 ** zero, then the page may be discarded or retained at the discretion of |
|
6024 ** page cache implementation. ^The page cache implementation |
|
6025 ** may choose to evict unpinned pages at any time. |
|
6026 ** |
|
6027 ** The cache must not perform any reference counting. A single |
|
6028 ** call to xUnpin() unpins the page regardless of the number of prior calls |
|
6029 ** to xFetch(). |
|
6030 ** |
|
6031 ** [[the xRekey() page cache methods]] |
|
6032 ** The xRekey() method is used to change the key value associated with the |
|
6033 ** page passed as the second argument. If the cache |
|
6034 ** previously contains an entry associated with newKey, it must be |
|
6035 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not |
|
6036 ** to be pinned. |
|
6037 ** |
|
6038 ** When SQLite calls the xTruncate() method, the cache must discard all |
|
6039 ** existing cache entries with page numbers (keys) greater than or equal |
|
6040 ** to the value of the iLimit parameter passed to xTruncate(). If any |
|
6041 ** of these pages are pinned, they are implicitly unpinned, meaning that |
|
6042 ** they can be safely discarded. |
|
6043 ** |
|
6044 ** [[the xDestroy() page cache method]] |
|
6045 ** ^The xDestroy() method is used to delete a cache allocated by xCreate(). |
|
6046 ** All resources associated with the specified cache should be freed. ^After |
|
6047 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*] |
|
6048 ** handle invalid, and will not use it with any other sqlite3_pcache_methods |
|
6049 ** functions. |
|
6050 */ |
|
6051 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods; |
|
6052 struct sqlite3_pcache_methods { |
|
6053 void *pArg; |
|
6054 int (*xInit)(void*); |
|
6055 void (*xShutdown)(void*); |
|
6056 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable); |
|
6057 void (*xCachesize)(sqlite3_pcache*, int nCachesize); |
|
6058 int (*xPagecount)(sqlite3_pcache*); |
|
6059 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag); |
|
6060 void (*xUnpin)(sqlite3_pcache*, void*, int discard); |
|
6061 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey); |
|
6062 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit); |
|
6063 void (*xDestroy)(sqlite3_pcache*); |
|
6064 }; |
|
6065 |
|
6066 /* |
|
6067 ** CAPI3REF: Online Backup Object |
|
6068 ** |
|
6069 ** The sqlite3_backup object records state information about an ongoing |
|
6070 ** online backup operation. ^The sqlite3_backup object is created by |
|
6071 ** a call to [sqlite3_backup_init()] and is destroyed by a call to |
|
6072 ** [sqlite3_backup_finish()]. |
|
6073 ** |
|
6074 ** See Also: [Using the SQLite Online Backup API] |
|
6075 */ |
|
6076 typedef struct sqlite3_backup sqlite3_backup; |
|
6077 |
|
6078 /* |
|
6079 ** CAPI3REF: Online Backup API. |
|
6080 ** |
|
6081 ** The backup API copies the content of one database into another. |
|
6082 ** It is useful either for creating backups of databases or |
|
6083 ** for copying in-memory databases to or from persistent files. |
|
6084 ** |
|
6085 ** See Also: [Using the SQLite Online Backup API] |
|
6086 ** |
|
6087 ** ^SQLite holds a write transaction open on the destination database file |
|
6088 ** for the duration of the backup operation. |
|
6089 ** ^The source database is read-locked only while it is being read; |
|
6090 ** it is not locked continuously for the entire backup operation. |
|
6091 ** ^Thus, the backup may be performed on a live source database without |
|
6092 ** preventing other database connections from |
|
6093 ** reading or writing to the source database while the backup is underway. |
|
6094 ** |
|
6095 ** ^(To perform a backup operation: |
|
6096 ** <ol> |
|
6097 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the |
|
6098 ** backup, |
|
6099 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer |
|
6100 ** the data between the two databases, and finally |
|
6101 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources |
|
6102 ** associated with the backup operation. |
|
6103 ** </ol>)^ |
|
6104 ** There should be exactly one call to sqlite3_backup_finish() for each |
|
6105 ** successful call to sqlite3_backup_init(). |
|
6106 ** |
|
6107 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b> |
|
6108 ** |
|
6109 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the |
|
6110 ** [database connection] associated with the destination database |
|
6111 ** and the database name, respectively. |
|
6112 ** ^The database name is "main" for the main database, "temp" for the |
|
6113 ** temporary database, or the name specified after the AS keyword in |
|
6114 ** an [ATTACH] statement for an attached database. |
|
6115 ** ^The S and M arguments passed to |
|
6116 ** sqlite3_backup_init(D,N,S,M) identify the [database connection] |
|
6117 ** and database name of the source database, respectively. |
|
6118 ** ^The source and destination [database connections] (parameters S and D) |
|
6119 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with |
|
6120 ** an error. |
|
6121 ** |
|
6122 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is |
|
6123 ** returned and an error code and error message are stored in the |
|
6124 ** destination [database connection] D. |
|
6125 ** ^The error code and message for the failed call to sqlite3_backup_init() |
|
6126 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or |
|
6127 ** [sqlite3_errmsg16()] functions. |
|
6128 ** ^A successful call to sqlite3_backup_init() returns a pointer to an |
|
6129 ** [sqlite3_backup] object. |
|
6130 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and |
|
6131 ** sqlite3_backup_finish() functions to perform the specified backup |
|
6132 ** operation. |
|
6133 ** |
|
6134 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b> |
|
6135 ** |
|
6136 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between |
|
6137 ** the source and destination databases specified by [sqlite3_backup] object B. |
|
6138 ** ^If N is negative, all remaining source pages are copied. |
|
6139 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there |
|
6140 ** are still more pages to be copied, then the function returns [SQLITE_OK]. |
|
6141 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages |
|
6142 ** from source to destination, then it returns [SQLITE_DONE]. |
|
6143 ** ^If an error occurs while running sqlite3_backup_step(B,N), |
|
6144 ** then an [error code] is returned. ^As well as [SQLITE_OK] and |
|
6145 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY], |
|
6146 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an |
|
6147 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code. |
|
6148 ** |
|
6149 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if |
|
6150 ** <ol> |
|
6151 ** <li> the destination database was opened read-only, or |
|
6152 ** <li> the destination database is using write-ahead-log journaling |
|
6153 ** and the destination and source page sizes differ, or |
|
6154 ** <li> the destination database is an in-memory database and the |
|
6155 ** destination and source page sizes differ. |
|
6156 ** </ol>)^ |
|
6157 ** |
|
6158 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then |
|
6159 ** the [sqlite3_busy_handler | busy-handler function] |
|
6160 ** is invoked (if one is specified). ^If the |
|
6161 ** busy-handler returns non-zero before the lock is available, then |
|
6162 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to |
|
6163 ** sqlite3_backup_step() can be retried later. ^If the source |
|
6164 ** [database connection] |
|
6165 ** is being used to write to the source database when sqlite3_backup_step() |
|
6166 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this |
|
6167 ** case the call to sqlite3_backup_step() can be retried later on. ^(If |
|
6168 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or |
|
6169 ** [SQLITE_READONLY] is returned, then |
|
6170 ** there is no point in retrying the call to sqlite3_backup_step(). These |
|
6171 ** errors are considered fatal.)^ The application must accept |
|
6172 ** that the backup operation has failed and pass the backup operation handle |
|
6173 ** to the sqlite3_backup_finish() to release associated resources. |
|
6174 ** |
|
6175 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock |
|
6176 ** on the destination file. ^The exclusive lock is not released until either |
|
6177 ** sqlite3_backup_finish() is called or the backup operation is complete |
|
6178 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to |
|
6179 ** sqlite3_backup_step() obtains a [shared lock] on the source database that |
|
6180 ** lasts for the duration of the sqlite3_backup_step() call. |
|
6181 ** ^Because the source database is not locked between calls to |
|
6182 ** sqlite3_backup_step(), the source database may be modified mid-way |
|
6183 ** through the backup process. ^If the source database is modified by an |
|
6184 ** external process or via a database connection other than the one being |
|
6185 ** used by the backup operation, then the backup will be automatically |
|
6186 ** restarted by the next call to sqlite3_backup_step(). ^If the source |
|
6187 ** database is modified by the using the same database connection as is used |
|
6188 ** by the backup operation, then the backup database is automatically |
|
6189 ** updated at the same time. |
|
6190 ** |
|
6191 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b> |
|
6192 ** |
|
6193 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the |
|
6194 ** application wishes to abandon the backup operation, the application |
|
6195 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish(). |
|
6196 ** ^The sqlite3_backup_finish() interfaces releases all |
|
6197 ** resources associated with the [sqlite3_backup] object. |
|
6198 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any |
|
6199 ** active write-transaction on the destination database is rolled back. |
|
6200 ** The [sqlite3_backup] object is invalid |
|
6201 ** and may not be used following a call to sqlite3_backup_finish(). |
|
6202 ** |
|
6203 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no |
|
6204 ** sqlite3_backup_step() errors occurred, regardless or whether or not |
|
6205 ** sqlite3_backup_step() completed. |
|
6206 ** ^If an out-of-memory condition or IO error occurred during any prior |
|
6207 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then |
|
6208 ** sqlite3_backup_finish() returns the corresponding [error code]. |
|
6209 ** |
|
6210 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step() |
|
6211 ** is not a permanent error and does not affect the return value of |
|
6212 ** sqlite3_backup_finish(). |
|
6213 ** |
|
6214 ** [[sqlite3_backup__remaining()]] [[sqlite3_backup_pagecount()]] |
|
6215 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b> |
|
6216 ** |
|
6217 ** ^Each call to sqlite3_backup_step() sets two values inside |
|
6218 ** the [sqlite3_backup] object: the number of pages still to be backed |
|
6219 ** up and the total number of pages in the source database file. |
|
6220 ** The sqlite3_backup_remaining() and sqlite3_backup_pagecount() interfaces |
|
6221 ** retrieve these two values, respectively. |
|
6222 ** |
|
6223 ** ^The values returned by these functions are only updated by |
|
6224 ** sqlite3_backup_step(). ^If the source database is modified during a backup |
|
6225 ** operation, then the values are not updated to account for any extra |
|
6226 ** pages that need to be updated or the size of the source database file |
|
6227 ** changing. |
|
6228 ** |
|
6229 ** <b>Concurrent Usage of Database Handles</b> |
|
6230 ** |
|
6231 ** ^The source [database connection] may be used by the application for other |
|
6232 ** purposes while a backup operation is underway or being initialized. |
|
6233 ** ^If SQLite is compiled and configured to support threadsafe database |
|
6234 ** connections, then the source database connection may be used concurrently |
|
6235 ** from within other threads. |
|
6236 ** |
|
6237 ** However, the application must guarantee that the destination |
|
6238 ** [database connection] is not passed to any other API (by any thread) after |
|
6239 ** sqlite3_backup_init() is called and before the corresponding call to |
|
6240 ** sqlite3_backup_finish(). SQLite does not currently check to see |
|
6241 ** if the application incorrectly accesses the destination [database connection] |
|
6242 ** and so no error code is reported, but the operations may malfunction |
|
6243 ** nevertheless. Use of the destination database connection while a |
|
6244 ** backup is in progress might also also cause a mutex deadlock. |
|
6245 ** |
|
6246 ** If running in [shared cache mode], the application must |
|
6247 ** guarantee that the shared cache used by the destination database |
|
6248 ** is not accessed while the backup is running. In practice this means |
|
6249 ** that the application must guarantee that the disk file being |
|
6250 ** backed up to is not accessed by any connection within the process, |
|
6251 ** not just the specific connection that was passed to sqlite3_backup_init(). |
|
6252 ** |
|
6253 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple |
|
6254 ** threads may safely make multiple concurrent calls to sqlite3_backup_step(). |
|
6255 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount() |
|
6256 ** APIs are not strictly speaking threadsafe. If they are invoked at the |
|
6257 ** same time as another thread is invoking sqlite3_backup_step() it is |
|
6258 ** possible that they return invalid values. |
|
6259 */ |
|
6260 SQLITE_API sqlite3_backup *sqlite3_backup_init( |
|
6261 sqlite3 *pDest, /* Destination database handle */ |
|
6262 const char *zDestName, /* Destination database name */ |
|
6263 sqlite3 *pSource, /* Source database handle */ |
|
6264 const char *zSourceName /* Source database name */ |
|
6265 ); |
|
6266 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage); |
|
6267 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p); |
|
6268 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p); |
|
6269 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p); |
|
6270 |
|
6271 /* |
|
6272 ** CAPI3REF: Unlock Notification |
|
6273 ** |
|
6274 ** ^When running in shared-cache mode, a database operation may fail with |
|
6275 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or |
|
6276 ** individual tables within the shared-cache cannot be obtained. See |
|
6277 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking. |
|
6278 ** ^This API may be used to register a callback that SQLite will invoke |
|
6279 ** when the connection currently holding the required lock relinquishes it. |
|
6280 ** ^This API is only available if the library was compiled with the |
|
6281 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined. |
|
6282 ** |
|
6283 ** See Also: [Using the SQLite Unlock Notification Feature]. |
|
6284 ** |
|
6285 ** ^Shared-cache locks are released when a database connection concludes |
|
6286 ** its current transaction, either by committing it or rolling it back. |
|
6287 ** |
|
6288 ** ^When a connection (known as the blocked connection) fails to obtain a |
|
6289 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the |
|
6290 ** identity of the database connection (the blocking connection) that |
|
6291 ** has locked the required resource is stored internally. ^After an |
|
6292 ** application receives an SQLITE_LOCKED error, it may call the |
|
6293 ** sqlite3_unlock_notify() method with the blocked connection handle as |
|
6294 ** the first argument to register for a callback that will be invoked |
|
6295 ** when the blocking connections current transaction is concluded. ^The |
|
6296 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close] |
|
6297 ** call that concludes the blocking connections transaction. |
|
6298 ** |
|
6299 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application, |
|
6300 ** there is a chance that the blocking connection will have already |
|
6301 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked. |
|
6302 ** If this happens, then the specified callback is invoked immediately, |
|
6303 ** from within the call to sqlite3_unlock_notify().)^ |
|
6304 ** |
|
6305 ** ^If the blocked connection is attempting to obtain a write-lock on a |
|
6306 ** shared-cache table, and more than one other connection currently holds |
|
6307 ** a read-lock on the same table, then SQLite arbitrarily selects one of |
|
6308 ** the other connections to use as the blocking connection. |
|
6309 ** |
|
6310 ** ^(There may be at most one unlock-notify callback registered by a |
|
6311 ** blocked connection. If sqlite3_unlock_notify() is called when the |
|
6312 ** blocked connection already has a registered unlock-notify callback, |
|
6313 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is |
|
6314 ** called with a NULL pointer as its second argument, then any existing |
|
6315 ** unlock-notify callback is canceled. ^The blocked connections |
|
6316 ** unlock-notify callback may also be canceled by closing the blocked |
|
6317 ** connection using [sqlite3_close()]. |
|
6318 ** |
|
6319 ** The unlock-notify callback is not reentrant. If an application invokes |
|
6320 ** any sqlite3_xxx API functions from within an unlock-notify callback, a |
|
6321 ** crash or deadlock may be the result. |
|
6322 ** |
|
6323 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always |
|
6324 ** returns SQLITE_OK. |
|
6325 ** |
|
6326 ** <b>Callback Invocation Details</b> |
|
6327 ** |
|
6328 ** When an unlock-notify callback is registered, the application provides a |
|
6329 ** single void* pointer that is passed to the callback when it is invoked. |
|
6330 ** However, the signature of the callback function allows SQLite to pass |
|
6331 ** it an array of void* context pointers. The first argument passed to |
|
6332 ** an unlock-notify callback is a pointer to an array of void* pointers, |
|
6333 ** and the second is the number of entries in the array. |
|
6334 ** |
|
6335 ** When a blocking connections transaction is concluded, there may be |
|
6336 ** more than one blocked connection that has registered for an unlock-notify |
|
6337 ** callback. ^If two or more such blocked connections have specified the |
|
6338 ** same callback function, then instead of invoking the callback function |
|
6339 ** multiple times, it is invoked once with the set of void* context pointers |
|
6340 ** specified by the blocked connections bundled together into an array. |
|
6341 ** This gives the application an opportunity to prioritize any actions |
|
6342 ** related to the set of unblocked database connections. |
|
6343 ** |
|
6344 ** <b>Deadlock Detection</b> |
|
6345 ** |
|
6346 ** Assuming that after registering for an unlock-notify callback a |
|
6347 ** database waits for the callback to be issued before taking any further |
|
6348 ** action (a reasonable assumption), then using this API may cause the |
|
6349 ** application to deadlock. For example, if connection X is waiting for |
|
6350 ** connection Y's transaction to be concluded, and similarly connection |
|
6351 ** Y is waiting on connection X's transaction, then neither connection |
|
6352 ** will proceed and the system may remain deadlocked indefinitely. |
|
6353 ** |
|
6354 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock |
|
6355 ** detection. ^If a given call to sqlite3_unlock_notify() would put the |
|
6356 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no |
|
6357 ** unlock-notify callback is registered. The system is said to be in |
|
6358 ** a deadlocked state if connection A has registered for an unlock-notify |
|
6359 ** callback on the conclusion of connection B's transaction, and connection |
|
6360 ** B has itself registered for an unlock-notify callback when connection |
|
6361 ** A's transaction is concluded. ^Indirect deadlock is also detected, so |
|
6362 ** the system is also considered to be deadlocked if connection B has |
|
6363 ** registered for an unlock-notify callback on the conclusion of connection |
|
6364 ** C's transaction, where connection C is waiting on connection A. ^Any |
|
6365 ** number of levels of indirection are allowed. |
|
6366 ** |
|
6367 ** <b>The "DROP TABLE" Exception</b> |
|
6368 ** |
|
6369 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost |
|
6370 ** always appropriate to call sqlite3_unlock_notify(). There is however, |
|
6371 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement, |
|
6372 ** SQLite checks if there are any currently executing SELECT statements |
|
6373 ** that belong to the same connection. If there are, SQLITE_LOCKED is |
|
6374 ** returned. In this case there is no "blocking connection", so invoking |
|
6375 ** sqlite3_unlock_notify() results in the unlock-notify callback being |
|
6376 ** invoked immediately. If the application then re-attempts the "DROP TABLE" |
|
6377 ** or "DROP INDEX" query, an infinite loop might be the result. |
|
6378 ** |
|
6379 ** One way around this problem is to check the extended error code returned |
|
6380 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the |
|
6381 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in |
|
6382 ** the special "DROP TABLE/INDEX" case, the extended error code is just |
|
6383 ** SQLITE_LOCKED.)^ |
|
6384 */ |
|
6385 SQLITE_API int sqlite3_unlock_notify( |
|
6386 sqlite3 *pBlocked, /* Waiting connection */ |
|
6387 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */ |
|
6388 void *pNotifyArg /* Argument to pass to xNotify */ |
|
6389 ); |
|
6390 |
|
6391 |
|
6392 /* |
|
6393 ** CAPI3REF: String Comparison |
|
6394 ** |
|
6395 ** ^The [sqlite3_strnicmp()] API allows applications and extensions to |
|
6396 ** compare the contents of two buffers containing UTF-8 strings in a |
|
6397 ** case-independent fashion, using the same definition of case independence |
|
6398 ** that SQLite uses internally when comparing identifiers. |
|
6399 */ |
|
6400 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int); |
|
6401 |
|
6402 /* |
|
6403 ** CAPI3REF: Error Logging Interface |
|
6404 ** |
|
6405 ** ^The [sqlite3_log()] interface writes a message into the error log |
|
6406 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()]. |
|
6407 ** ^If logging is enabled, the zFormat string and subsequent arguments are |
|
6408 ** used with [sqlite3_snprintf()] to generate the final output string. |
|
6409 ** |
|
6410 ** The sqlite3_log() interface is intended for use by extensions such as |
|
6411 ** virtual tables, collating functions, and SQL functions. While there is |
|
6412 ** nothing to prevent an application from calling sqlite3_log(), doing so |
|
6413 ** is considered bad form. |
|
6414 ** |
|
6415 ** The zFormat string must not be NULL. |
|
6416 ** |
|
6417 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine |
|
6418 ** will not use dynamically allocated memory. The log message is stored in |
|
6419 ** a fixed-length buffer on the stack. If the log message is longer than |
|
6420 ** a few hundred characters, it will be truncated to the length of the |
|
6421 ** buffer. |
|
6422 */ |
|
6423 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...); |
|
6424 |
|
6425 /* |
|
6426 ** CAPI3REF: Write-Ahead Log Commit Hook |
|
6427 ** |
|
6428 ** ^The [sqlite3_wal_hook()] function is used to register a callback that |
|
6429 ** will be invoked each time a database connection commits data to a |
|
6430 ** [write-ahead log] (i.e. whenever a transaction is committed in |
|
6431 ** [journal_mode | journal_mode=WAL mode]). |
|
6432 ** |
|
6433 ** ^The callback is invoked by SQLite after the commit has taken place and |
|
6434 ** the associated write-lock on the database released, so the implementation |
|
6435 ** may read, write or [checkpoint] the database as required. |
|
6436 ** |
|
6437 ** ^The first parameter passed to the callback function when it is invoked |
|
6438 ** is a copy of the third parameter passed to sqlite3_wal_hook() when |
|
6439 ** registering the callback. ^The second is a copy of the database handle. |
|
6440 ** ^The third parameter is the name of the database that was written to - |
|
6441 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter |
|
6442 ** is the number of pages currently in the write-ahead log file, |
|
6443 ** including those that were just committed. |
|
6444 ** |
|
6445 ** The callback function should normally return [SQLITE_OK]. ^If an error |
|
6446 ** code is returned, that error will propagate back up through the |
|
6447 ** SQLite code base to cause the statement that provoked the callback |
|
6448 ** to report an error, though the commit will have still occurred. If the |
|
6449 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value |
|
6450 ** that does not correspond to any valid SQLite error code, the results |
|
6451 ** are undefined. |
|
6452 ** |
|
6453 ** A single database handle may have at most a single write-ahead log callback |
|
6454 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any |
|
6455 ** previously registered write-ahead log callback. ^Note that the |
|
6456 ** [sqlite3_wal_autocheckpoint()] interface and the |
|
6457 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will |
|
6458 ** those overwrite any prior [sqlite3_wal_hook()] settings. |
|
6459 */ |
|
6460 SQLITE_API void *sqlite3_wal_hook( |
|
6461 sqlite3*, |
|
6462 int(*)(void *,sqlite3*,const char*,int), |
|
6463 void* |
|
6464 ); |
|
6465 |
|
6466 /* |
|
6467 ** CAPI3REF: Configure an auto-checkpoint |
|
6468 ** |
|
6469 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around |
|
6470 ** [sqlite3_wal_hook()] that causes any database on [database connection] D |
|
6471 ** to automatically [checkpoint] |
|
6472 ** after committing a transaction if there are N or |
|
6473 ** more frames in the [write-ahead log] file. ^Passing zero or |
|
6474 ** a negative value as the nFrame parameter disables automatic |
|
6475 ** checkpoints entirely. |
|
6476 ** |
|
6477 ** ^The callback registered by this function replaces any existing callback |
|
6478 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback |
|
6479 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism |
|
6480 ** configured by this function. |
|
6481 ** |
|
6482 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface |
|
6483 ** from SQL. |
|
6484 ** |
|
6485 ** ^Every new [database connection] defaults to having the auto-checkpoint |
|
6486 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT] |
|
6487 ** pages. The use of this interface |
|
6488 ** is only necessary if the default setting is found to be suboptimal |
|
6489 ** for a particular application. |
|
6490 */ |
|
6491 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N); |
|
6492 |
|
6493 /* |
|
6494 ** CAPI3REF: Checkpoint a database |
|
6495 ** |
|
6496 ** ^The [sqlite3_wal_checkpoint(D,X)] interface causes database named X |
|
6497 ** on [database connection] D to be [checkpointed]. ^If X is NULL or an |
|
6498 ** empty string, then a checkpoint is run on all databases of |
|
6499 ** connection D. ^If the database connection D is not in |
|
6500 ** [WAL | write-ahead log mode] then this interface is a harmless no-op. |
|
6501 ** |
|
6502 ** ^The [wal_checkpoint pragma] can be used to invoke this interface |
|
6503 ** from SQL. ^The [sqlite3_wal_autocheckpoint()] interface and the |
|
6504 ** [wal_autocheckpoint pragma] can be used to cause this interface to be |
|
6505 ** run whenever the WAL reaches a certain size threshold. |
|
6506 ** |
|
6507 ** See also: [sqlite3_wal_checkpoint_v2()] |
|
6508 */ |
|
6509 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb); |
|
6510 |
|
6511 /* |
|
6512 ** CAPI3REF: Checkpoint a database |
|
6513 ** |
|
6514 ** Run a checkpoint operation on WAL database zDb attached to database |
|
6515 ** handle db. The specific operation is determined by the value of the |
|
6516 ** eMode parameter: |
|
6517 ** |
|
6518 ** <dl> |
|
6519 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd> |
|
6520 ** Checkpoint as many frames as possible without waiting for any database |
|
6521 ** readers or writers to finish. Sync the db file if all frames in the log |
|
6522 ** are checkpointed. This mode is the same as calling |
|
6523 ** sqlite3_wal_checkpoint(). The busy-handler callback is never invoked. |
|
6524 ** |
|
6525 ** <dt>SQLITE_CHECKPOINT_FULL<dd> |
|
6526 ** This mode blocks (calls the busy-handler callback) until there is no |
|
6527 ** database writer and all readers are reading from the most recent database |
|
6528 ** snapshot. It then checkpoints all frames in the log file and syncs the |
|
6529 ** database file. This call blocks database writers while it is running, |
|
6530 ** but not database readers. |
|
6531 ** |
|
6532 ** <dt>SQLITE_CHECKPOINT_RESTART<dd> |
|
6533 ** This mode works the same way as SQLITE_CHECKPOINT_FULL, except after |
|
6534 ** checkpointing the log file it blocks (calls the busy-handler callback) |
|
6535 ** until all readers are reading from the database file only. This ensures |
|
6536 ** that the next client to write to the database file restarts the log file |
|
6537 ** from the beginning. This call blocks database writers while it is running, |
|
6538 ** but not database readers. |
|
6539 ** </dl> |
|
6540 ** |
|
6541 ** If pnLog is not NULL, then *pnLog is set to the total number of frames in |
|
6542 ** the log file before returning. If pnCkpt is not NULL, then *pnCkpt is set to |
|
6543 ** the total number of checkpointed frames (including any that were already |
|
6544 ** checkpointed when this function is called). *pnLog and *pnCkpt may be |
|
6545 ** populated even if sqlite3_wal_checkpoint_v2() returns other than SQLITE_OK. |
|
6546 ** If no values are available because of an error, they are both set to -1 |
|
6547 ** before returning to communicate this to the caller. |
|
6548 ** |
|
6549 ** All calls obtain an exclusive "checkpoint" lock on the database file. If |
|
6550 ** any other process is running a checkpoint operation at the same time, the |
|
6551 ** lock cannot be obtained and SQLITE_BUSY is returned. Even if there is a |
|
6552 ** busy-handler configured, it will not be invoked in this case. |
|
6553 ** |
|
6554 ** The SQLITE_CHECKPOINT_FULL and RESTART modes also obtain the exclusive |
|
6555 ** "writer" lock on the database file. If the writer lock cannot be obtained |
|
6556 ** immediately, and a busy-handler is configured, it is invoked and the writer |
|
6557 ** lock retried until either the busy-handler returns 0 or the lock is |
|
6558 ** successfully obtained. The busy-handler is also invoked while waiting for |
|
6559 ** database readers as described above. If the busy-handler returns 0 before |
|
6560 ** the writer lock is obtained or while waiting for database readers, the |
|
6561 ** checkpoint operation proceeds from that point in the same way as |
|
6562 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible |
|
6563 ** without blocking any further. SQLITE_BUSY is returned in this case. |
|
6564 ** |
|
6565 ** If parameter zDb is NULL or points to a zero length string, then the |
|
6566 ** specified operation is attempted on all WAL databases. In this case the |
|
6567 ** values written to output parameters *pnLog and *pnCkpt are undefined. If |
|
6568 ** an SQLITE_BUSY error is encountered when processing one or more of the |
|
6569 ** attached WAL databases, the operation is still attempted on any remaining |
|
6570 ** attached databases and SQLITE_BUSY is returned to the caller. If any other |
|
6571 ** error occurs while processing an attached database, processing is abandoned |
|
6572 ** and the error code returned to the caller immediately. If no error |
|
6573 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached |
|
6574 ** databases, SQLITE_OK is returned. |
|
6575 ** |
|
6576 ** If database zDb is the name of an attached database that is not in WAL |
|
6577 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. If |
|
6578 ** zDb is not NULL (or a zero length string) and is not the name of any |
|
6579 ** attached database, SQLITE_ERROR is returned to the caller. |
|
6580 */ |
|
6581 SQLITE_API int sqlite3_wal_checkpoint_v2( |
|
6582 sqlite3 *db, /* Database handle */ |
|
6583 const char *zDb, /* Name of attached database (or NULL) */ |
|
6584 int eMode, /* SQLITE_CHECKPOINT_* value */ |
|
6585 int *pnLog, /* OUT: Size of WAL log in frames */ |
|
6586 int *pnCkpt /* OUT: Total number of frames checkpointed */ |
|
6587 ); |
|
6588 |
|
6589 /* |
|
6590 ** CAPI3REF: Checkpoint operation parameters |
|
6591 ** |
|
6592 ** These constants can be used as the 3rd parameter to |
|
6593 ** [sqlite3_wal_checkpoint_v2()]. See the [sqlite3_wal_checkpoint_v2()] |
|
6594 ** documentation for additional information about the meaning and use of |
|
6595 ** each of these values. |
|
6596 */ |
|
6597 #define SQLITE_CHECKPOINT_PASSIVE 0 |
|
6598 #define SQLITE_CHECKPOINT_FULL 1 |
|
6599 #define SQLITE_CHECKPOINT_RESTART 2 |
|
6600 |
|
6601 /* |
|
6602 ** CAPI3REF: Virtual Table Interface Configuration |
|
6603 ** |
|
6604 ** This function may be called by either the [xConnect] or [xCreate] method |
|
6605 ** of a [virtual table] implementation to configure |
|
6606 ** various facets of the virtual table interface. |
|
6607 ** |
|
6608 ** If this interface is invoked outside the context of an xConnect or |
|
6609 ** xCreate virtual table method then the behavior is undefined. |
|
6610 ** |
|
6611 ** At present, there is only one option that may be configured using |
|
6612 ** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options |
|
6613 ** may be added in the future. |
|
6614 */ |
|
6615 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...); |
|
6616 |
|
6617 /* |
|
6618 ** CAPI3REF: Virtual Table Configuration Options |
|
6619 ** |
|
6620 ** These macros define the various options to the |
|
6621 ** [sqlite3_vtab_config()] interface that [virtual table] implementations |
|
6622 ** can use to customize and optimize their behavior. |
|
6623 ** |
|
6624 ** <dl> |
|
6625 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT |
|
6626 ** <dd>Calls of the form |
|
6627 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported, |
|
6628 ** where X is an integer. If X is zero, then the [virtual table] whose |
|
6629 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not |
|
6630 ** support constraints. In this configuration (which is the default) if |
|
6631 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire |
|
6632 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been |
|
6633 ** specified as part of the users SQL statement, regardless of the actual |
|
6634 ** ON CONFLICT mode specified. |
|
6635 ** |
|
6636 ** If X is non-zero, then the virtual table implementation guarantees |
|
6637 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before |
|
6638 ** any modifications to internal or persistent data structures have been made. |
|
6639 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite |
|
6640 ** is able to roll back a statement or database transaction, and abandon |
|
6641 ** or continue processing the current SQL statement as appropriate. |
|
6642 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns |
|
6643 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode |
|
6644 ** had been ABORT. |
|
6645 ** |
|
6646 ** Virtual table implementations that are required to handle OR REPLACE |
|
6647 ** must do so within the [xUpdate] method. If a call to the |
|
6648 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON |
|
6649 ** CONFLICT policy is REPLACE, the virtual table implementation should |
|
6650 ** silently replace the appropriate rows within the xUpdate callback and |
|
6651 ** return SQLITE_OK. Or, if this is not possible, it may return |
|
6652 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT |
|
6653 ** constraint handling. |
|
6654 ** </dl> |
|
6655 */ |
|
6656 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1 |
|
6657 |
|
6658 /* |
|
6659 ** CAPI3REF: Determine The Virtual Table Conflict Policy |
|
6660 ** |
|
6661 ** This function may only be called from within a call to the [xUpdate] method |
|
6662 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The |
|
6663 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL], |
|
6664 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode |
|
6665 ** of the SQL statement that triggered the call to the [xUpdate] method of the |
|
6666 ** [virtual table]. |
|
6667 */ |
|
6668 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *); |
|
6669 |
|
6670 /* |
|
6671 ** CAPI3REF: Conflict resolution modes |
|
6672 ** |
|
6673 ** These constants are returned by [sqlite3_vtab_on_conflict()] to |
|
6674 ** inform a [virtual table] implementation what the [ON CONFLICT] mode |
|
6675 ** is for the SQL statement being evaluated. |
|
6676 ** |
|
6677 ** Note that the [SQLITE_IGNORE] constant is also used as a potential |
|
6678 ** return value from the [sqlite3_set_authorizer()] callback and that |
|
6679 ** [SQLITE_ABORT] is also a [result code]. |
|
6680 */ |
|
6681 #define SQLITE_ROLLBACK 1 |
|
6682 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ |
|
6683 #define SQLITE_FAIL 3 |
|
6684 /* #define SQLITE_ABORT 4 // Also an error code */ |
|
6685 #define SQLITE_REPLACE 5 |
|
6686 |
|
6687 |
|
6688 |
|
6689 /* |
|
6690 ** Undo the hack that converts floating point types to integer for |
|
6691 ** builds on processors without floating point support. |
|
6692 */ |
|
6693 #ifdef SQLITE_OMIT_FLOATING_POINT |
|
6694 # undef double |
|
6695 #endif |
|
6696 |
|
6697 #ifdef __cplusplus |
|
6698 } /* End of the 'extern "C"' block */ |
|
6699 #endif |
|
6700 #endif |
|
6701 |
|
6702 /* |
|
6703 ** 2010 August 30 |
|
6704 ** |
|
6705 ** The author disclaims copyright to this source code. In place of |
|
6706 ** a legal notice, here is a blessing: |
|
6707 ** |
|
6708 ** May you do good and not evil. |
|
6709 ** May you find forgiveness for yourself and forgive others. |
|
6710 ** May you share freely, never taking more than you give. |
|
6711 ** |
|
6712 ************************************************************************* |
|
6713 */ |
|
6714 |
|
6715 #ifndef _SQLITE3RTREE_H_ |
|
6716 #define _SQLITE3RTREE_H_ |
|
6717 |
|
6718 |
|
6719 #ifdef __cplusplus |
|
6720 extern "C" { |
|
6721 #endif |
|
6722 |
|
6723 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry; |
|
6724 |
|
6725 /* |
|
6726 ** Register a geometry callback named zGeom that can be used as part of an |
|
6727 ** R-Tree geometry query as follows: |
|
6728 ** |
|
6729 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...) |
|
6730 */ |
|
6731 SQLITE_API int sqlite3_rtree_geometry_callback( |
|
6732 sqlite3 *db, |
|
6733 const char *zGeom, |
|
6734 int (*xGeom)(sqlite3_rtree_geometry *, int nCoord, double *aCoord, int *pRes), |
|
6735 void *pContext |
|
6736 ); |
|
6737 |
|
6738 |
|
6739 /* |
|
6740 ** A pointer to a structure of the following type is passed as the first |
|
6741 ** argument to callbacks registered using rtree_geometry_callback(). |
|
6742 */ |
|
6743 struct sqlite3_rtree_geometry { |
|
6744 void *pContext; /* Copy of pContext passed to s_r_g_c() */ |
|
6745 int nParam; /* Size of array aParam[] */ |
|
6746 double *aParam; /* Parameters passed to SQL geom function */ |
|
6747 void *pUser; /* Callback implementation user data */ |
|
6748 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */ |
|
6749 }; |
|
6750 |
|
6751 |
|
6752 #ifdef __cplusplus |
|
6753 } /* end of the 'extern "C"' block */ |
|
6754 #endif |
|
6755 |
|
6756 #endif /* ifndef _SQLITE3RTREE_H_ */ |
|
6757 |