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Overview
Comment: | Add the sqlite_dbptr virtual table to the dbdata extension. For querying the links between b-tree pages. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | dbdata |
Files: | files | file ages | folders |
SHA3-256: |
3213a15f2133afbb0a4fec3b8f6e0eec |
User & Date: | dan 2019-04-18 21:14:11.260 |
Context
2019-04-20
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20:57 | Add the ".recovery" command to the shell tool. For recovering the maximum amount data from corrupt databases. Still needs work. (check-in: 7461d2e120 user: dan tags: dbdata) | |
2019-04-18
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21:14 | Add the sqlite_dbptr virtual table to the dbdata extension. For querying the links between b-tree pages. (check-in: 3213a15f21 user: dan tags: dbdata) | |
2019-04-17
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21:17 | Add the experimental dbdata extension. (check-in: a3ab588329 user: dan tags: dbdata) | |
Changes
Changes to ext/misc/dbdata.c.
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19 20 21 22 23 24 25 26 27 28 29 30 31 32 | ** pgno INTEGER, ** cell INTEGER, ** field INTEGER, ** value ANY, ** schema TEXT HIDDEN ** ); ** ** Each page of the database is inspected. If it cannot be interpreted as a ** b-tree page, or if it is a b-tree page containing 0 entries, the ** sqlite_dbdata table contains no rows for that page. Otherwise, the table ** contains one row for each field in the record associated with each ** cell on the page. For intkey b-trees, the key value is stored in field -1. ** ** For example, for the database: | > > > | 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 | ** pgno INTEGER, ** cell INTEGER, ** field INTEGER, ** value ANY, ** schema TEXT HIDDEN ** ); ** ** IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE ** FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND "schema". ** ** Each page of the database is inspected. If it cannot be interpreted as a ** b-tree page, or if it is a b-tree page containing 0 entries, the ** sqlite_dbdata table contains no rows for that page. Otherwise, the table ** contains one row for each field in the record associated with each ** cell on the page. For intkey b-trees, the key value is stored in field -1. ** ** For example, for the database: |
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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 | ** ** If database corruption is encountered, this module does not report an ** error. Instead, it attempts to extract as much data as possible and ** ignores the corruption. ** ** This module requires that the "sqlite_dbpage" eponymous virtual table be ** available. */ #if !defined(SQLITEINT_H) #include "sqlite3ext.h" typedef unsigned char u8; typedef unsigned int u32; #endif SQLITE_EXTENSION_INIT1 #include <string.h> #include <assert.h> typedef struct DbdataTable DbdataTable; typedef struct DbdataCursor DbdataCursor; /* A cursor for the sqlite_dbdata table */ struct DbdataCursor { sqlite3_vtab_cursor base; /* Base class. Must be first */ sqlite3_stmt *pStmt; /* For fetching database pages */ int iPgno; /* Current page number */ u8 *aPage; /* Buffer containing page */ int nPage; /* Size of aPage[] in bytes */ int nCell; /* Number of cells on aPage[] */ int iCell; /* Current cell number */ u8 *pRec; /* Buffer containing current record */ int nRec; /* Size of pRec[] in bytes */ int nField; /* Number of fields in pRec */ int iField; /* Current field number */ sqlite3_int64 iIntkey; /* Integer key value */ | > > > > > > > > > > > > < < > > > > > > > > > > > > | > | 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 | ** ** If database corruption is encountered, this module does not report an ** error. Instead, it attempts to extract as much data as possible and ** ignores the corruption. ** ** This module requires that the "sqlite_dbpage" eponymous virtual table be ** available. ** ** ** CREATE TABLE sqlite_dbptr( ** pgno INTEGER, ** child INTEGER, ** schema TEXT HIDDEN ** ); */ #if !defined(SQLITEINT_H) #include "sqlite3ext.h" typedef unsigned char u8; typedef unsigned int u32; #endif SQLITE_EXTENSION_INIT1 #include <string.h> #include <assert.h> typedef struct DbdataTable DbdataTable; typedef struct DbdataCursor DbdataCursor; /* A cursor for the sqlite_dbdata table */ struct DbdataCursor { sqlite3_vtab_cursor base; /* Base class. Must be first */ sqlite3_stmt *pStmt; /* For fetching database pages */ int iPgno; /* Current page number */ u8 *aPage; /* Buffer containing page */ int nPage; /* Size of aPage[] in bytes */ int nCell; /* Number of cells on aPage[] */ int iCell; /* Current cell number */ int bOnePage; /* True to stop after one page */ sqlite3_int64 iRowid; /* Only for the sqlite_dbdata table */ u8 *pRec; /* Buffer containing current record */ int nRec; /* Size of pRec[] in bytes */ int nField; /* Number of fields in pRec */ int iField; /* Current field number */ sqlite3_int64 iIntkey; /* Integer key value */ }; /* The sqlite_dbdata table */ struct DbdataTable { sqlite3_vtab base; /* Base class. Must be first */ sqlite3 *db; /* The database connection */ int bPtr; /* True for sqlite3_dbptr table */ }; #define DBDATA_COLUMN_PGNO 0 #define DBDATA_COLUMN_CELL 1 #define DBDATA_COLUMN_FIELD 2 #define DBDATA_COLUMN_VALUE 3 #define DBDATA_COLUMN_SCHEMA 4 #define DBPTR_COLUMN_PGNO 0 #define DBPTR_COLUMN_CHILD 1 #define DBPTR_COLUMN_SCHEMA 2 #define DBDATA_SCHEMA \ "CREATE TABLE x(" \ " pgno INTEGER," \ " cell INTEGER," \ " field INTEGER," \ " value ANY," \ " schema TEXT HIDDEN" \ ")" #define DBPTR_SCHEMA \ "CREATE TABLE x(" \ " pgno INTEGER," \ " child INTEGER," \ " schema TEXT HIDDEN" \ ")" /* ** Connect to the sqlite_dbdata virtual table. */ static int dbdataConnect( sqlite3 *db, void *pAux, int argc, const char *const*argv, sqlite3_vtab **ppVtab, char **pzErr ){ DbdataTable *pTab = 0; int rc = sqlite3_declare_vtab(db, pAux ? DBPTR_SCHEMA : DBDATA_SCHEMA); if( rc==SQLITE_OK ){ pTab = (DbdataTable*)sqlite3_malloc64(sizeof(DbdataTable)); if( pTab==0 ){ rc = SQLITE_NOMEM; }else{ memset(pTab, 0, sizeof(DbdataTable)); pTab->db = db; pTab->bPtr = (pAux!=0); } } *ppVtab = (sqlite3_vtab*)pTab; return rc; } |
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153 154 155 156 157 158 159 160 161 162 163 164 165 166 | ** the 0x01 bit in idxNum is set. If pgno=? is present, the 0x02 bit ** in idxNum is set. ** ** If both parameters are present, schema is in position 0 and pgno in ** position 1. */ static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ int i; int iSchema = -1; int iPgno = -1; for(i=0; i<pIdxInfo->nConstraint; i++){ struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i]; if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){ | > > | | 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 | ** the 0x01 bit in idxNum is set. If pgno=? is present, the 0x02 bit ** in idxNum is set. ** ** If both parameters are present, schema is in position 0 and pgno in ** position 1. */ static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){ DbdataTable *pTab = (DbdataTable*)tab; int i; int iSchema = -1; int iPgno = -1; int colSchema = (pTab->bPtr ? DBPTR_COLUMN_SCHEMA : DBDATA_COLUMN_SCHEMA); for(i=0; i<pIdxInfo->nConstraint; i++){ struct sqlite3_index_constraint *p = &pIdxInfo->aConstraint[i]; if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){ if( p->iColumn==colSchema ){ if( p->usable==0 ) return SQLITE_CONSTRAINT; iSchema = i; } if( p->iColumn==DBDATA_COLUMN_PGNO && p->usable ){ iPgno = i; } } |
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206 207 208 209 210 211 212 213 214 215 216 217 218 219 | static void dbdataResetCursor(DbdataCursor *pCsr){ sqlite3_finalize(pCsr->pStmt); pCsr->pStmt = 0; pCsr->iPgno = 1; pCsr->iCell = 0; pCsr->iField = 0; } /* ** Close a dbdata cursor. */ static int dbdataClose(sqlite3_vtab_cursor *pCursor){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; | > | 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 | static void dbdataResetCursor(DbdataCursor *pCsr){ sqlite3_finalize(pCsr->pStmt); pCsr->pStmt = 0; pCsr->iPgno = 1; pCsr->iCell = 0; pCsr->iField = 0; pCsr->bOnePage = 0; } /* ** Close a dbdata cursor. */ static int dbdataClose(sqlite3_vtab_cursor *pCursor){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; |
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277 278 279 280 281 282 283 | return 9; } /* ** Move a dbdata cursor to the next entry in the file. */ static int dbdataNext(sqlite3_vtab_cursor *pCursor){ | | > > | | | < < < < < < < < < < | | < < < < < < < < < | < > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | > | 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 | return 9; } /* ** Move a dbdata cursor to the next entry in the file. */ static int dbdataNext(sqlite3_vtab_cursor *pCursor){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; DbdataTable *pTab = (DbdataTable*)pCursor->pVtab; pCsr->iRowid++; while( 1 ){ int rc; int iOff = (pCsr->iPgno==1 ? 100 : 0); if( pCsr->aPage==0 ){ rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage); if( rc!=SQLITE_OK || pCsr->aPage==0 ) return rc; pCsr->iCell = pTab->bPtr ? -2 : 0; pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]); } if( pTab->bPtr ){ if( pCsr->aPage[iOff]!=0x02 && pCsr->aPage[iOff]!=0x05 ){ pCsr->iCell = pCsr->nCell; } pCsr->iCell++; if( pCsr->iCell>=pCsr->nCell ){ sqlite3_free(pCsr->aPage); pCsr->aPage = 0; if( pCsr->bOnePage ) return SQLITE_OK; pCsr->iPgno++; }else{ return SQLITE_OK; } }else{ /* If there is no record loaded, load it now. */ if( pCsr->pRec==0 ){ int bHasRowid = 0; int nPointer = 0; sqlite3_int64 nPayload = 0; sqlite3_int64 nHdr = 0; int iHdr; int U, X; int nLocal; switch( pCsr->aPage[iOff] ){ case 0x02: nPointer = 4; break; case 0x0a: break; case 0x0d: bHasRowid = 1; break; default: /* This is not a b-tree page with records on it. Continue. */ pCsr->iCell = pCsr->nCell; break; } if( pCsr->iCell>=pCsr->nCell ){ sqlite3_free(pCsr->aPage); pCsr->aPage = 0; if( pCsr->bOnePage ) return SQLITE_OK; pCsr->iPgno++; continue; } iOff += 8 + nPointer + pCsr->iCell*2; iOff = get_uint16(&pCsr->aPage[iOff]); /* For an interior node cell, skip past the child-page number */ iOff += nPointer; /* Load the "byte of payload including overflow" field */ iOff += dbdataGetVarint(&pCsr->aPage[iOff], &nPayload); /* If this is a leaf intkey cell, load the rowid */ if( bHasRowid ){ iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey); } /* Allocate space for payload */ pCsr->pRec = (u8*)sqlite3_malloc64(nPayload); if( pCsr->pRec==0 ) return SQLITE_NOMEM; pCsr->nRec = nPayload; U = pCsr->nPage; if( bHasRowid ){ X = U-35; }else{ X = ((U-12)*64/255)-23; } if( nPayload<=X ){ nLocal = nPayload; }else{ int M, K; M = ((U-12)*32/255)-23; K = M+((nPayload-M)%(U-4)); if( K<=X ){ nLocal = K; }else{ nLocal = M; } } /* Load the nLocal bytes of payload */ memcpy(pCsr->pRec, &pCsr->aPage[iOff], nLocal); iOff += nLocal; /* Load content from overflow pages */ if( nPayload>nLocal ){ sqlite3_int64 nRem = nPayload - nLocal; u32 pgnoOvfl = get_uint32(&pCsr->aPage[iOff]); while( nRem>0 ){ u8 *aOvfl = 0; int nOvfl = 0; int nCopy; rc = dbdataLoadPage(pCsr, pgnoOvfl, &aOvfl, &nOvfl); assert( rc!=SQLITE_OK || nOvfl==pCsr->nPage ); if( rc!=SQLITE_OK ) return rc; nCopy = U-4; if( nCopy>nRem ) nCopy = nRem; memcpy(&pCsr->pRec[nPayload-nRem], &aOvfl[4], nCopy); nRem -= nCopy; sqlite3_free(aOvfl); } } /* Figure out how many fields in the record */ pCsr->nField = 0; iHdr = dbdataGetVarint(pCsr->pRec, &nHdr); while( iHdr<nHdr ){ sqlite3_int64 iDummy; iHdr += dbdataGetVarint(&pCsr->pRec[iHdr], &iDummy); pCsr->nField++; } pCsr->iField = (bHasRowid ? -2 : -1); } pCsr->iField++; if( pCsr->iField<pCsr->nField ) return SQLITE_OK; /* Advance to the next cell. The next iteration of the loop will load ** the record and so on. */ sqlite3_free(pCsr->pRec); pCsr->pRec = 0; pCsr->iCell++; } } assert( !"can't get here" ); return SQLITE_OK; } /* We have reached EOF if previous sqlite3_step() returned |
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436 437 438 439 440 441 442 443 444 445 446 447 448 449 | dbdataResetCursor(pCsr); assert( pCsr->iPgno==1 ); if( idxNum & 0x01 ){ zSchema = sqlite3_value_text(argv[0]); } if( idxNum & 0x02 ){ pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]); } rc = sqlite3_prepare_v2(pTab->db, "SELECT data FROM sqlite_dbpage(?) WHERE pgno=?", -1, &pCsr->pStmt, 0 ); if( rc==SQLITE_OK ){ | > | 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 | dbdataResetCursor(pCsr); assert( pCsr->iPgno==1 ); if( idxNum & 0x01 ){ zSchema = sqlite3_value_text(argv[0]); } if( idxNum & 0x02 ){ pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]); pCsr->bOnePage = 1; } rc = sqlite3_prepare_v2(pTab->db, "SELECT data FROM sqlite_dbpage(?) WHERE pgno=?", -1, &pCsr->pStmt, 0 ); if( rc==SQLITE_OK ){ |
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529 530 531 532 533 534 535 | /* Return a column for the sqlite_dbdata table */ static int dbdataColumn( sqlite3_vtab_cursor *pCursor, sqlite3_context *ctx, int i ){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; | > > > > > > > > > > > > > > > > > > > | | | | | | | | | | | | | | | | | | | | | | | | | | | > | 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 | /* Return a column for the sqlite_dbdata table */ static int dbdataColumn( sqlite3_vtab_cursor *pCursor, sqlite3_context *ctx, int i ){ DbdataCursor *pCsr = (DbdataCursor*)pCursor; DbdataTable *pTab = (DbdataTable*)pCursor->pVtab; if( pTab->bPtr ){ switch( i ){ case DBPTR_COLUMN_PGNO: sqlite3_result_int64(ctx, pCsr->iPgno); break; case DBPTR_COLUMN_CHILD: { int iOff = pCsr->iPgno==1 ? 100 : 0; if( pCsr->iCell<0 ){ iOff += 8; }else{ iOff += 12 + pCsr->iCell*2; iOff = get_uint16(&pCsr->aPage[iOff]); } sqlite3_result_int64(ctx, get_uint32(&pCsr->aPage[iOff])); break; } } }else{ switch( i ){ case DBDATA_COLUMN_PGNO: sqlite3_result_int64(ctx, pCsr->iPgno); break; case DBDATA_COLUMN_CELL: sqlite3_result_int(ctx, pCsr->iCell); break; case DBDATA_COLUMN_FIELD: sqlite3_result_int(ctx, pCsr->iField); break; case DBDATA_COLUMN_VALUE: { if( pCsr->iField<0 ){ sqlite3_result_int64(ctx, pCsr->iIntkey); }else{ int iHdr; sqlite3_int64 iType; sqlite3_int64 iOff; int i; iHdr = dbdataGetVarint(pCsr->pRec, &iOff); for(i=0; i<pCsr->iField; i++){ iHdr += dbdataGetVarint(&pCsr->pRec[iHdr], &iType); iOff += dbdataValueBytes(iType); } dbdataGetVarint(&pCsr->pRec[iHdr], &iType); dbdataValue(ctx, iType, &pCsr->pRec[iOff]); } break; } } } return SQLITE_OK; } /* Return the ROWID for the sqlite_dbdata table */ static int dbdataRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){ |
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600 601 602 603 604 605 606 | 0, /* xFindMethod */ 0, /* xRename */ 0, /* xSavepoint */ 0, /* xRelease */ 0, /* xRollbackTo */ 0 /* xShadowName */ }; | > | > > > > | 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 | 0, /* xFindMethod */ 0, /* xRename */ 0, /* xSavepoint */ 0, /* xRelease */ 0, /* xRollbackTo */ 0 /* xShadowName */ }; int rc = sqlite3_create_module(db, "sqlite_dbdata", &dbdata_module, 0); if( rc==SQLITE_OK ){ rc = sqlite3_create_module(db, "sqlite_dbptr", &dbdata_module, (void*)1); } return rc; } #ifdef _WIN32 __declspec(dllexport) #endif int sqlite3_dbdata_init( sqlite3 *db, char **pzErrMsg, const sqlite3_api_routines *pApi ){ SQLITE_EXTENSION_INIT2(pApi); return sqlite3DbdataRegister(db); } |
Changes to test/dbdata.test.
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39 40 41 42 43 44 45 46 | 2 0 0 'v' 2 0 1 'five' 2 1 -1 10 2 1 0 'x' 2 1 1 'ten' } set big [string repeat big 2000] | > > > > > > > > > > > > > > > > > > | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | 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 | 2 0 0 'v' 2 0 1 'five' 2 1 -1 10 2 1 0 'x' 2 1 1 'ten' } breakpoint do_execsql_test 1.2 { SELECT pgno, cell, field, quote(value) FROM sqlite_dbdata; } { 1 0 -1 1 1 0 0 'table' 1 0 1 'T1' 1 0 2 'T1' 1 0 3 2 1 0 4 {'CREATE TABLE T1(a, b)'} 2 0 -1 5 2 0 0 'v' 2 0 1 'five' 2 1 -1 10 2 1 0 'x' 2 1 1 'ten' } set big [string repeat big 2000] do_execsql_test 1.3 { INSERT INTO t1 VALUES(NULL, $big); SELECT value FROM sqlite_dbdata WHERE pgno=2 AND cell=2 AND field=1; } $big #------------------------------------------------------------------------- reset_db db enable_load_extension 1 db eval { SELECT load_extension('../dbdata') } do_execsql_test 2.0 { CREATE TABLE t1(a); CREATE INDEX i1 ON t1(a); WITH s(i) AS ( SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<10 ) INSERT INTO t1 SELECT randomblob(900) FROM s; } do_execsql_test 2.1 { SELECT * FROM sqlite_dbptr WHERE pgno=2; } { 2 25 2 6 2 7 2 9 2 11 2 13 2 15 2 17 2 19 2 21 } do_execsql_test 2.2 { SELECT * FROM sqlite_dbptr WHERE pgno=3; } { 3 24 3 23 } do_execsql_test 2.3 { SELECT * FROM sqlite_dbptr } { 2 25 2 6 2 7 2 9 2 11 2 13 2 15 2 17 2 19 2 21 3 24 3 23 } finish_test |