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Overview
Comment: | Make sure sqlite3_value_bytes() does not reformat the content after a call to sqlite3_value_blob(). Add documentation to explain this hazard. Add many new tests. Ticket #2321. (CVS 3880) |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
e92bd97a3726bbb7978489e299474712 |
User & Date: | drh 2007-04-27 17:16:20.000 |
Context
2007-04-27
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21:02 | Refactor fts2 loadSegmentLeaf() in preparation for prefix-searching. Prefix-searching will want to accumulate data across multiple leaves in the segment, using LeavesReader instead of LeafReader is the first step in that direction. (CVS 3881) (check-in: 22ffdae4b6 user: shess tags: trunk) | |
17:16 | Make sure sqlite3_value_bytes() does not reformat the content after a call to sqlite3_value_blob(). Add documentation to explain this hazard. Add many new tests. Ticket #2321. (CVS 3880) (check-in: e92bd97a37 user: drh tags: trunk) | |
07:55 | Extra tests for incremental vacuum. (CVS 3879) (check-in: 40ba6493e9 user: danielk1977 tags: trunk) | |
Changes
Changes to src/func.c.
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12 13 14 15 16 17 18 | ** This file contains the C functions that implement various SQL ** functions of SQLite. ** ** There is only one exported symbol in this file - the function ** sqliteRegisterBuildinFunctions() found at the bottom of the file. ** All other code has file scope. ** | | | 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | ** This file contains the C functions that implement various SQL ** functions of SQLite. ** ** There is only one exported symbol in this file - the function ** sqliteRegisterBuildinFunctions() found at the bottom of the file. ** All other code has file scope. ** ** $Id: func.c,v 1.142 2007/04/27 17:16:20 drh Exp $ */ #include "sqliteInt.h" #include <ctype.h> /* #include <math.h> */ #include <stdlib.h> #include <assert.h> #include "vdbeInt.h" |
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211 212 213 214 215 216 217 | /* ** Implementation of the upper() and lower() SQL functions. */ static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){ char *z1; const char *z2; | | > | | > | | 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 | /* ** Implementation of the upper() and lower() SQL functions. */ static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){ char *z1; const char *z2; int i, n; if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return; n = sqlite3_value_bytes(argv[0]); z2 = (char*)sqlite3_value_text(argv[0]); if( z2 ){ z1 = sqlite3_malloc(n+1); if( z1 ){ strcpy(z1, z2); for(i=0; z1[i]; i++){ z1[i] = toupper(z1[i]); } sqlite3_result_text(context, z1, -1, sqlite3_free); } } } static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){ char *z1; const char *z2; int i, n; if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return; n = sqlite3_value_bytes(argv[0]); z2 = (char*)sqlite3_value_text(argv[0]); if( z2 ){ z1 = sqlite3_malloc(n+1); if( z1 ){ strcpy(z1, z2); for(i=0; z1[i]; i++){ z1[i] = tolower(z1[i]); } sqlite3_result_text(context, z1, -1, sqlite3_free); } |
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699 700 701 702 703 704 705 706 707 | int nPattern; /* Size of zPattern */ int nRep; /* Size of zRep */ int nOut; /* Maximum size of zOut */ int loopLimit; /* Last zStr[] that might match zPattern[] */ int i, j; /* Loop counters */ assert( argc==3 ); zStr = sqlite3_value_text(argv[0]); if( zStr==0 ) return; | > | | < | 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 | int nPattern; /* Size of zPattern */ int nRep; /* Size of zRep */ int nOut; /* Maximum size of zOut */ int loopLimit; /* Last zStr[] that might match zPattern[] */ int i, j; /* Loop counters */ assert( argc==3 ); nStr = sqlite3_value_bytes(argv[0]); zStr = sqlite3_value_text(argv[0]); if( zStr==0 ) return; nPattern = sqlite3_value_bytes(argv[1]); zPattern = sqlite3_value_text(argv[1]); if( zPattern==0 || zPattern[0]==0 ) return; nRep = sqlite3_value_bytes(argv[2]); zRep = sqlite3_value_text(argv[2]); if( zRep==0 ) return; if( nPattern>=nRep ){ nOut = nStr; }else{ nOut = (nStr/nPattern + 1)*nRep; } zOut = sqlite3_malloc(nOut+1); if( zOut==0 ) return; |
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750 751 752 753 754 755 756 757 758 | int nIn; /* Number of bytes in input */ int flags; int i; unsigned char cFirst, cNext; if( sqlite3_value_type(argv[0])==SQLITE_NULL ){ return; } zIn = sqlite3_value_text(argv[0]); if( zIn==0 ) return; | > < | 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 | int nIn; /* Number of bytes in input */ int flags; int i; unsigned char cFirst, cNext; if( sqlite3_value_type(argv[0])==SQLITE_NULL ){ return; } nIn = sqlite3_value_bytes(argv[0]); zIn = sqlite3_value_text(argv[0]); if( zIn==0 ) return; if( argc==1 ){ static const unsigned char zSpace[] = " "; zCharSet = zSpace; }else if( (zCharSet = sqlite3_value_text(argv[1]))==0 ){ return; } cFirst = zCharSet[0]; |
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Changes to src/test1.c.
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9 10 11 12 13 14 15 | ** May you share freely, never taking more than you give. ** ************************************************************************* ** Code for testing all sorts of SQLite interfaces. This code ** is not included in the SQLite library. It is used for automated ** testing of the SQLite library. ** | | | 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 | ** May you share freely, never taking more than you give. ** ************************************************************************* ** Code for testing all sorts of SQLite interfaces. This code ** is not included in the SQLite library. It is used for automated ** testing of the SQLite library. ** ** $Id: test1.c,v 1.240 2007/04/27 17:16:20 drh Exp $ */ #include "sqliteInt.h" #include "tcl.h" #include "os.h" #include <stdlib.h> #include <string.h> |
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553 554 555 556 557 558 559 560 | sqlite3_context *context, int argc, sqlite3_value **argv ){ int i; for(i=0; i<argc; i++){ if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){ sqlite3_result_text(context, (char*)sqlite3_value_text(argv[i]), | > | | 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 | sqlite3_context *context, int argc, sqlite3_value **argv ){ int i; for(i=0; i<argc; i++){ if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){ int n = sqlite3_value_bytes(argv[i]); sqlite3_result_text(context, (char*)sqlite3_value_text(argv[i]), n, SQLITE_TRANSIENT); break; } } } /* ** These are test functions. hex8() interprets its argument as |
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702 703 704 705 706 707 708 709 710 711 712 713 714 715 | sqlite3_result_error(context, "tkt2213 is not fixed", -1); }else{ char *zCopy = (char *)sqlite3_malloc(nText); memcpy(zCopy, zText1, nText); sqlite3_result_text(context, zCopy, nText, sqlite3_free); } } /* ** Usage: sqlite_test_create_function DB ** ** Call the sqlite3_create_function API on the given database in order ** to create a function named "x_coalesce". This function does the same thing ** as the "coalesce" function. This function also registers an SQL function | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 | sqlite3_result_error(context, "tkt2213 is not fixed", -1); }else{ char *zCopy = (char *)sqlite3_malloc(nText); memcpy(zCopy, zText1, nText); sqlite3_result_text(context, zCopy, nText, sqlite3_free); } } /* ** The following SQL function takes 4 arguments. The 2nd and ** 4th argument must be one of these strings: 'text', 'text16', ** or 'blob' corresponding to API functions ** ** sqlite3_value_text() ** sqlite3_value_text16() ** sqlite3_value_blob() ** ** The third argument is a string, either 'bytes' or 'bytes16' or 'noop', ** corresponding to APIs: ** ** sqlite3_value_bytes() ** sqlite3_value_bytes16() ** noop ** ** The APIs designated by the 2nd through 4th arguments are applied ** to the first argument in order. If the pointers returned by the ** second and fourth are different, this routine returns 1. Otherwise, ** this routine returns 0. ** ** This function is used to test to see when returned pointers from ** the _text(), _text16() and _blob() APIs become invalidated. */ static void ptrChngFunction( sqlite3_context *context, int argc, sqlite3_value **argv ){ const void *p1, *p2; const char *zCmd; if( argc!=4 ) return; zCmd = (const char*)sqlite3_value_text(argv[1]); if( zCmd==0 ) return; if( strcmp(zCmd,"text")==0 ){ p1 = (const void*)sqlite3_value_text(argv[0]); #ifndef SQLITE_OMIT_UTF16 }else if( strcmp(zCmd, "text16")==0 ){ p1 = (const void*)sqlite3_value_text16(argv[0]); #endif }else if( strcmp(zCmd, "blob")==0 ){ p1 = (const void*)sqlite3_value_blob(argv[0]); }else{ return; } zCmd = (const char*)sqlite3_value_text(argv[2]); if( zCmd==0 ) return; if( strcmp(zCmd,"bytes")==0 ){ sqlite3_value_bytes(argv[0]); #ifndef SQLITE_OMIT_UTF16 }else if( strcmp(zCmd, "bytes16")==0 ){ sqlite3_value_bytes16(argv[0]); #endif }else if( strcmp(zCmd, "noop")==0 ){ /* do nothing */ }else{ return; } zCmd = (const char*)sqlite3_value_text(argv[3]); if( zCmd==0 ) return; if( strcmp(zCmd,"text")==0 ){ p2 = (const void*)sqlite3_value_text(argv[0]); #ifndef SQLITE_OMIT_UTF16 }else if( strcmp(zCmd, "text16")==0 ){ p2 = (const void*)sqlite3_value_text16(argv[0]); #endif }else if( strcmp(zCmd, "blob")==0 ){ p2 = (const void*)sqlite3_value_blob(argv[0]); }else{ return; } sqlite3_result_int(context, p1!=p2); } /* ** Usage: sqlite_test_create_function DB ** ** Call the sqlite3_create_function API on the given database in order ** to create a function named "x_coalesce". This function does the same thing ** as the "coalesce" function. This function also registers an SQL function |
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750 751 752 753 754 755 756 757 758 759 760 761 762 763 | hex16Func, 0, 0); } #endif if( rc==SQLITE_OK ){ rc = sqlite3_create_function(db, "tkt2213func", 1, SQLITE_ANY, 0, tkt2213Function, 0, 0); } #ifndef SQLITE_OMIT_UTF16 /* Use the sqlite3_create_function16() API here. Mainly for fun, but also ** because it is not tested anywhere else. */ if( rc==SQLITE_OK ){ sqlite3_value *pVal; #ifdef SQLITE_MEMDEBUG | > > > > | 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 | hex16Func, 0, 0); } #endif if( rc==SQLITE_OK ){ rc = sqlite3_create_function(db, "tkt2213func", 1, SQLITE_ANY, 0, tkt2213Function, 0, 0); } if( rc==SQLITE_OK ){ rc = sqlite3_create_function(db, "pointer_change", 4, SQLITE_ANY, 0, ptrChngFunction, 0, 0); } #ifndef SQLITE_OMIT_UTF16 /* Use the sqlite3_create_function16() API here. Mainly for fun, but also ** because it is not tested anywhere else. */ if( rc==SQLITE_OK ){ sqlite3_value *pVal; #ifdef SQLITE_MEMDEBUG |
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3125 3126 3127 3128 3129 3130 3131 | Tcl_GetString(objv[0]), " STMT column", 0); return TCL_ERROR; } if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR; if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR; | < > | 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 | Tcl_GetString(objv[0]), " STMT column", 0); return TCL_ERROR; } if( getStmtPointer(interp, Tcl_GetString(objv[1]), &pStmt) ) return TCL_ERROR; if( Tcl_GetIntFromObj(interp, objv[2], &col) ) return TCL_ERROR; len = sqlite3_column_bytes(pStmt, col); pBlob = sqlite3_column_blob(pStmt, col); Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(pBlob, len)); return TCL_OK; } /* ** Usage: sqlite3_column_double STMT column ** |
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Changes to src/vdbeapi.c.
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33 34 35 36 37 38 39 40 41 42 43 44 45 46 | /**************************** sqlite3_value_ ******************************* ** The following routines extract information from a Mem or sqlite3_value ** structure. */ const void *sqlite3_value_blob(sqlite3_value *pVal){ Mem *p = (Mem*)pVal; if( p->flags & (MEM_Blob|MEM_Str) ){ return p->z; }else{ return sqlite3_value_text(pVal); } } int sqlite3_value_bytes(sqlite3_value *pVal){ return sqlite3ValueBytes(pVal, SQLITE_UTF8); | > > > | 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 | /**************************** sqlite3_value_ ******************************* ** The following routines extract information from a Mem or sqlite3_value ** structure. */ const void *sqlite3_value_blob(sqlite3_value *pVal){ Mem *p = (Mem*)pVal; if( p->flags & (MEM_Blob|MEM_Str) ){ if( (p->flags & MEM_Term)==0 ){ p->flags &= ~MEM_Str; } return p->z; }else{ return sqlite3_value_text(pVal); } } int sqlite3_value_bytes(sqlite3_value *pVal){ return sqlite3ValueBytes(pVal, SQLITE_UTF8); |
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Added test/ptrchng.test.
> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 | # 2007 April 27 # # The author disclaims copyright to this source code. In place of # a legal notice, here is a blessing: # # May you do good and not evil. # May you find forgiveness for yourself and forgive others. # May you share freely, never taking more than you give. # #*********************************************************************** # This file implements regression tests for SQLite library. # # The focus of the tests in this file are to verify that the # underlying TEXT or BLOB representation of an sqlite3_value # changes appropriately when APIs from the following set are # called: # # sqlite3_value_text() # sqlite3_value_text16() # sqlite3_value_blob() # sqlite3_value_bytes() # sqlite3_value_bytes16() # # $Id: ptrchng.test,v 1.1 2007/04/27 17:16:22 drh Exp $ set testdir [file dirname $argv0] source $testdir/tester.tcl # Register the "pointer_change" SQL function. # sqlite3_create_function db do_test ptrchng-1.1 { execsql { CREATE TABLE t1(x INTEGER PRIMARY KEY, y BLOB); INSERT INTO t1 VALUES(1, 'abc'); INSERT INTO t1 VALUES(2, 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234356789'); INSERT INTO t1 VALUES(3, x'626c6f62'); INSERT INTO t1 VALUES(4, x'000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f2021222324' ); SELECT count(*) FROM t1; } } {4} # For the short entries that fit in the Mem.zBuf[], the pointer should # never change regardless of what type conversions occur. # do_test ptrchng-2.1 { execsql { SELECT pointer_change(y, 'text', 'noop', 'blob') FROM t1 WHERE x=1 } } {0} do_test ptrchng-2.2 { execsql { SELECT pointer_change(y, 'blob', 'noop', 'text') FROM t1 WHERE x=1 } } {0} ifcapable utf16 { do_test ptrchng-2.3 { execsql { SELECT pointer_change(y, 'text', 'noop', 'text16') FROM t1 WHERE x=1 } } {0} do_test ptrchng-2.4 { execsql { SELECT pointer_change(y, 'blob', 'noop', 'text16') FROM t1 WHERE x=1 } } {0} do_test ptrchng-2.5 { execsql { SELECT pointer_change(y, 'text16', 'noop', 'blob') FROM t1 WHERE x=1 } } {0} do_test ptrchng-2.6 { execsql { SELECT pointer_change(y, 'text16', 'noop', 'text') FROM t1 WHERE x=1 } } {0} } do_test ptrchng-2.11 { execsql { SELECT pointer_change(y, 'text', 'noop', 'blob') FROM t1 WHERE x=3 } } {0} do_test ptrchng-2.12 { execsql { SELECT pointer_change(y, 'blob', 'noop', 'text') FROM t1 WHERE x=3 } } {0} ifcapable utf16 { do_test ptrchng-2.13 { execsql { SELECT pointer_change(y, 'text', 'noop', 'text16') FROM t1 WHERE x=3 } } {0} do_test ptrchng-2.14 { execsql { SELECT pointer_change(y, 'blob', 'noop', 'text16') FROM t1 WHERE x=3 } } {0} do_test ptrchng-2.15 { execsql { SELECT pointer_change(y, 'text16', 'noop', 'blob') FROM t1 WHERE x=3 } } {0} do_test ptrchng-2.16 { btree_breakpoint execsql { SELECT pointer_change(y, 'text16', 'noop', 'text') FROM t1 WHERE x=3 } } {0} } # For the long entries that do not fit in the Mem.zBuf[], the pointer # should change sometimes. # do_test ptrchng-3.1 { execsql { SELECT pointer_change(y, 'text', 'noop', 'blob') FROM t1 WHERE x=2 } } {0} do_test ptrchng-3.2 { execsql { SELECT pointer_change(y, 'blob', 'noop', 'text') FROM t1 WHERE x=2 } } {0} ifcapable utf16 { do_test ptrchng-3.3 { execsql { SELECT pointer_change(y, 'text', 'noop', 'text16') FROM t1 WHERE x=2 } } {1} do_test ptrchng-3.4 { execsql { SELECT pointer_change(y, 'blob', 'noop', 'text16') FROM t1 WHERE x=2 } } {1} do_test ptrchng-3.5 { execsql { SELECT pointer_change(y, 'text16', 'noop', 'blob') FROM t1 WHERE x=2 } } {0} do_test ptrchng-3.6 { execsql { SELECT pointer_change(y, 'text16', 'noop', 'text') FROM t1 WHERE x=2 } } {1} } do_test ptrchng-3.11 { execsql { SELECT pointer_change(y, 'text', 'noop', 'blob') FROM t1 WHERE x=4 } } {0} do_test ptrchng-3.12 { execsql { SELECT pointer_change(y, 'blob', 'noop', 'text') FROM t1 WHERE x=4 } } {0} ifcapable utf16 { do_test ptrchng-3.13 { execsql { SELECT pointer_change(y, 'text', 'noop', 'text16') FROM t1 WHERE x=4 } } {1} do_test ptrchng-3.14 { execsql { SELECT pointer_change(y, 'blob', 'noop', 'text16') FROM t1 WHERE x=4 } } {1} do_test ptrchng-3.15 { execsql { SELECT pointer_change(y, 'text16', 'noop', 'blob') FROM t1 WHERE x=4 } } {0} do_test ptrchng-3.16 { execsql { SELECT pointer_change(y, 'text16', 'noop', 'text') FROM t1 WHERE x=4 } } {1} } # A call to _bytes() should never reformat a _text() or _blob(). # do_test ptrchng-4.1 { execsql { SELECT pointer_change(y, 'text', 'bytes', 'text') FROM t1 } } {0 0 0 0} do_test ptrchng-4.2 { execsql { SELECT pointer_change(y, 'blob', 'bytes', 'blob') FROM t1 } } {0 0 0 0} # A call to _blob() should never trigger a reformat # do_test ptrchng-5.1 { execsql { SELECT pointer_change(y, 'text', 'bytes', 'blob') FROM t1 } } {0 0 0 0} ifcapable utf16 { do_test ptrchng-5.2 { execsql { SELECT pointer_change(y, 'text16', 'noop', 'blob') FROM t1 } } {0 0 0 0} do_test ptrchng-5.3 { execsql { SELECT pointer_change(y, 'text16', 'bytes16', 'blob') FROM t1 } } {0 0 0 0} } finish_test |
Changes to www/capi3.tcl.
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| | | 1 2 3 4 5 6 7 8 | set rcsid {$Id: capi3.tcl,v 1.10 2007/04/27 17:16:22 drh Exp $} source common.tcl header {C/C++ Interface For SQLite Version 3} proc AddHyperlinks {txt} { regsub -all {([^:alnum:>])(sqlite3_\w+)(\([^\)]*\))} $txt \ {\1<a href="capi3ref.html#\2">\2</a>\3} t2 puts $t2 |
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320 321 322 323 324 325 326 327 328 329 330 331 332 333 | <p> It is not necessary to retrieve data in the format specify by sqlite3_column_type(). If a different format is requested, the data is converted automatically. </p> <h4>2.3 User-defined functions</h4> <p> User defined functions can be created using the following routine: </p> <blockquote><pre> | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 | <p> It is not necessary to retrieve data in the format specify by sqlite3_column_type(). If a different format is requested, the data is converted automatically. </p> <p> Data format conversions can invalidate the pointer returned by prior calls to sqlite3_column_blob(), sqlite3_column_text(), and/or sqlite3_column_text16(). Pointers might be invalided in the following cases: </p> <ul> <li><p> The initial content is a BLOB and sqlite3_column_text() or sqlite3_column_text16() is called. A zero-terminator might need to be added to the string. </p></li> <li><p> The initial content is UTF-8 text and sqlite3_column_bytes16() or sqlite3_column_text16() is called. The content must be converted to UTF-16. </p></li> <li><p> The initial content is UTF-16 text and sqlite3_column_bytes() or sqlite3_column_text() is called. The content must be converted to UTF-8. </p></li> </ul> <p> Note that conversions between UTF-16be and UTF-16le are always done in place and do not invalidate a prior pointer, though of course the content of the buffer that the prior pointer points to will have been modified. Other kinds of conversion are done in place when it is possible, but sometime it is not possible and in those cases prior pointers are invalidated. </p> <p> The safest and easiest to remember policy is this: assume that any result from <ul> <li>sqlite3_column_blob(),</li> <li>sqlite3_column_text(), or</li> <li>sqlite3_column_text16()</li> </ul> is invalided by subsequent calls to <ul> <li>sqlite3_column_bytes(),</li> <li>sqlite3_column_bytes16(),</li> <li>sqlite3_column_text(), or</li> <li>sqlite3_column_text16().</li> </ul> This means that you should always call sqlite3_column_bytes() or sqlite3_column_bytes16() <u>before</u> calling sqlite3_column_blob(), sqlite3_column_text(), or sqlite3_column_text16(). </p> <h4>2.3 User-defined functions</h4> <p> User defined functions can be created using the following routine: </p> <blockquote><pre> |
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Changes to www/capi3ref.tcl.
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| | | 1 2 3 4 5 6 7 8 | set rcsid {$Id: capi3ref.tcl,v 1.56 2007/04/27 17:16:22 drh Exp $} source common.tcl header {C/C++ Interface For SQLite Version 3} puts { <h2 class=pdf_section>C/C++ Interface For SQLite Version 3</h2> } proc api {name prototype desc {notused x}} { |
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428 429 430 431 432 433 434 | <tr><td> BLOB </td><td> FLOAT </td><td> Convert to TEXT then use atof()</td></tr> <tr><td> BLOB </td><td> TEXT </td><td> Add a \\000 terminator if needed</td></tr> </table> </blockquote> Note that when type conversions occur, pointers returned by prior calls to sqlite3_column_blob(), sqlite3_column_text(), and/or | | > > | > > > | > > > > | > > > > > > | > > > > > > | > > > > > > > > > | | > > > > > > | | 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 | <tr><td> BLOB </td><td> FLOAT </td><td> Convert to TEXT then use atof()</td></tr> <tr><td> BLOB </td><td> TEXT </td><td> Add a \\000 terminator if needed</td></tr> </table> </blockquote> Note that when type conversions occur, pointers returned by prior calls to sqlite3_column_blob(), sqlite3_column_text(), and/or sqlite3_column_text16() may be invalidated. Type conversions and pointer invalidations might occur in the following cases: <ul> <li><p> The initial content is a BLOB and sqlite3_column_text() or sqlite3_column_text16() is called. A zero-terminator might need to be added to the string. </p></li> <li><p> The initial content is UTF-8 text and sqlite3_column_bytes16() or sqlite3_column_text16() is called. The content must be converted to UTF-16. </p></li> <li><p> The initial content is UTF-16 text and sqlite3_column_bytes() or sqlite3_column_text() is called. The content must be converted to UTF-8. </p></li> </ul> Conversions between UTF-16be and UTF-16le are always done in place and do not invalidate a prior pointer, though of course the content of the buffer that the prior pointer points to will have been modified. Other kinds of conversion are done in place when it is possible, but sometime it is not possible and in those cases prior pointers are invalidated. The safest and easiest to remember policy is this: assume that any result from <ul> <li>sqlite3_column_blob(),</li> <li>sqlite3_column_text(), or</li> <li>sqlite3_column_text16()</li> </ul> is invalided by subsequent calls to <ul> <li>sqlite3_column_bytes(),</li> <li>sqlite3_column_bytes16(),</li> <li>sqlite3_column_text(), or</li> <li>sqlite3_column_text16().</li> </ul> This means that you should always call sqlite3_column_bytes() or sqlite3_column_bytes16() <u>before</u> calling sqlite3_column_blob(), sqlite3_column_text(), or sqlite3_column_text16(). } api {} { int sqlite3_column_count(sqlite3_stmt *pStmt); } { Return the number of columns in the result set returned by the prepared SQL statement. This routine returns 0 if pStmt is an SQL statement |
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1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 | to access their arguments. These routines are the same as the sqlite3_column_... routines except that these routines take a single sqlite3_value* pointer instead of an sqlite3_stmt* and an integer column number. See the documentation under sqlite3_column_blob for additional information. } api {} { int sqlite3_sleep(int); } { Sleep for a little while. The second parameter is the number of miliseconds to sleep for. | > > > > > > | 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 | to access their arguments. These routines are the same as the sqlite3_column_... routines except that these routines take a single sqlite3_value* pointer instead of an sqlite3_stmt* and an integer column number. See the documentation under sqlite3_column_blob for additional information. Please pay particular attention to the fact that the pointer that is returned from sqlite3_value_blob(), sqlite3_value_text(), or sqlite3_value_text16() can be invalidated by a subsequent call to sqlite3_value_bytes(), sqlite3_value_bytes16(), sqlite_value_text(), or sqlite3_value_text16(). } api {} { int sqlite3_sleep(int); } { Sleep for a little while. The second parameter is the number of miliseconds to sleep for. |
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