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Overview
Comment: | Move the generation of output column names earlier, to right after name resolution and before query transformations such as flattening. This prevents the names from getting mangled by query transformations, and obviates hacks in the query flattener that attempt to work around the name mangling. The resulting code is smaller and faster and gives more consistent output. This is a fix for ticket [de3403bf5ae5f72ed] and a cherry-pick of check-in [09834279aeca3bda] |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | branch-3.19 |
Files: | files | file ages | folders |
SHA3-256: |
499942b3eece097a6b1695ebe60d7eb3 |
User & Date: | drh 2017-07-31 13:11:26.773 |
Context
2017-07-31
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13:22 | Use batch atomic writes when running on a recent F2FS filesystem, if compiled with SQLITE_ENABLE_BATCH_ATOMIC_WRITE. (check-in: 2dd0c77d54 user: drh tags: branch-3.19) | |
13:11 | Move the generation of output column names earlier, to right after name resolution and before query transformations such as flattening. This prevents the names from getting mangled by query transformations, and obviates hacks in the query flattener that attempt to work around the name mangling. The resulting code is smaller and faster and gives more consistent output. This is a fix for ticket [de3403bf5ae5f72ed] and a cherry-pick of check-in [09834279aeca3bda] (check-in: 499942b3ee user: drh tags: branch-3.19) | |
12:19 | Correctly handle an "INTEGER PRIMARY KEY UNIQUE" column in a WITHOUT ROWID table. This is a fix for ticket [bc115541132dad136], cherry-picked from check-in [5216bfb73f1a49bdd8] (check-in: 322a2ede6d user: drh tags: branch-3.19) | |
2017-07-29
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16:01 | Move the generation of output column names earlier, to right after name resolution and before query transformations such as flattening. This prevents the names from getting mangled by query transformations, and obviates hacks in the query flattener that attempt to work around the name mangling. The resulting code is smaller and faster and gives more consistent output. This is an alternative fix to ticket [de3403bf5ae5f72ed]. (check-in: 09834279ae user: drh tags: early-column-names) | |
Changes
Changes to src/select.c.
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1434 1435 1436 1437 1438 1439 1440 | assert( pTab && pExpr->pTab==pTab ); if( pS ){ /* The "table" is actually a sub-select or a view in the FROM clause ** of the SELECT statement. Return the declaration type and origin ** data for the result-set column of the sub-select. */ | | < < < | 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 | assert( pTab && pExpr->pTab==pTab ); if( pS ){ /* The "table" is actually a sub-select or a view in the FROM clause ** of the SELECT statement. Return the declaration type and origin ** data for the result-set column of the sub-select. */ if( iCol>=0 && iCol<pS->pEList->nExpr ){ /* If iCol is less than zero, then the expression requests the ** rowid of the sub-select or view. This expression is legal (see ** test case misc2.2.2) - it always evaluates to NULL. */ NameContext sNC; Expr *p = pS->pEList->a[iCol].pExpr; sNC.pSrcList = pS->pSrc; sNC.pNext = pNC; sNC.pParse = pNC->pParse; zType = columnType(&sNC, p,&zOrigDb,&zOrigTab,&zOrigCol, &estWidth); |
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1550 1551 1552 1553 1554 1555 1556 | zType = columnType(&sNC, p, 0, 0, 0, 0); #endif sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT); } #endif /* !defined(SQLITE_OMIT_DECLTYPE) */ } | < < < < < < < < < < < < | < > > | > > > > > | | < | | > > | < < > > < < < | | 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 | zType = columnType(&sNC, p, 0, 0, 0, 0); #endif sqlite3VdbeSetColName(v, i, COLNAME_DECLTYPE, zType, SQLITE_TRANSIENT); } #endif /* !defined(SQLITE_OMIT_DECLTYPE) */ } /* ** Generate code that will tell the VDBE the names of columns ** in the result set. This information is used to provide the ** azCol[] values in the callback. */ static void generateColumnNames( Parse *pParse, /* Parser context */ Select *pSelect /* Generate column names for this SELECT statement */ ){ Vdbe *v = pParse->pVdbe; int i; Table *pTab; SrcList *pTabList; ExprList *pEList; sqlite3 *db = pParse->db; int fullName; /* TABLE.COLUMN if no AS clause and is a direct table ref */ int srcName; /* COLUMN or TABLE.COLUMN if no AS clause and is direct */ #ifndef SQLITE_OMIT_EXPLAIN /* If this is an EXPLAIN, skip this step */ if( pParse->explain ){ return; } #endif if( pParse->colNamesSet || db->mallocFailed ) return; /* Column names are determined by the left-most term of a compound select */ while( pSelect->pPrior ) pSelect = pSelect->pPrior; pTabList = pSelect->pSrc; pEList = pSelect->pEList; assert( v!=0 ); assert( pTabList!=0 ); pParse->colNamesSet = 1; fullName = (db->flags & SQLITE_FullColNames)!=0; srcName = (db->flags & SQLITE_ShortColNames)!=0 || fullName; sqlite3VdbeSetNumCols(v, pEList->nExpr); for(i=0; i<pEList->nExpr; i++){ Expr *p = pEList->a[i].pExpr; assert( p!=0 ); if( pEList->a[i].zName ){ /* An AS clause always takes first priority */ char *zName = pEList->a[i].zName; sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_TRANSIENT); }else if( srcName && p->op==TK_COLUMN ){ char *zCol; int iCol = p->iColumn; pTab = p->pTab; assert( pTab!=0 ); if( iCol<0 ) iCol = pTab->iPKey; assert( iCol==-1 || (iCol>=0 && iCol<pTab->nCol) ); if( iCol<0 ){ zCol = "rowid"; }else{ zCol = pTab->aCol[iCol].zName; } if( fullName ){ char *zName = 0; zName = sqlite3MPrintf(db, "%s.%s", pTab->zName, zCol); sqlite3VdbeSetColName(v, i, COLNAME_NAME, zName, SQLITE_DYNAMIC); }else{ sqlite3VdbeSetColName(v, i, COLNAME_NAME, zCol, SQLITE_TRANSIENT); } }else{ |
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2429 2430 2431 2432 2433 2434 2435 | /* Convert the data in the temporary table into whatever form ** it is that we currently need. */ assert( unionTab==dest.iSDParm || dest.eDest!=priorOp ); if( dest.eDest!=priorOp ){ int iCont, iBreak, iStart; assert( p->pEList ); | < < < < < | 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 | /* Convert the data in the temporary table into whatever form ** it is that we currently need. */ assert( unionTab==dest.iSDParm || dest.eDest!=priorOp ); if( dest.eDest!=priorOp ){ int iCont, iBreak, iStart; assert( p->pEList ); iBreak = sqlite3VdbeMakeLabel(v); iCont = sqlite3VdbeMakeLabel(v); computeLimitRegisters(pParse, p, iBreak); sqlite3VdbeAddOp2(v, OP_Rewind, unionTab, iBreak); VdbeCoverage(v); iStart = sqlite3VdbeCurrentAddr(v); selectInnerLoop(pParse, p, p->pEList, unionTab, 0, 0, &dest, iCont, iBreak); |
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2504 2505 2506 2507 2508 2509 2510 | p->pLimit = pLimit; p->pOffset = pOffset; /* Generate code to take the intersection of the two temporary ** tables. */ assert( p->pEList ); | < < < < < | 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 | p->pLimit = pLimit; p->pOffset = pOffset; /* Generate code to take the intersection of the two temporary ** tables. */ assert( p->pEList ); iBreak = sqlite3VdbeMakeLabel(v); iCont = sqlite3VdbeMakeLabel(v); computeLimitRegisters(pParse, p, iBreak); sqlite3VdbeAddOp2(v, OP_Rewind, tab1, iBreak); VdbeCoverage(v); r1 = sqlite3GetTempReg(pParse); iStart = sqlite3VdbeAddOp2(v, OP_RowData, tab1, r1); sqlite3VdbeAddOp4Int(v, OP_NotFound, tab2, iCont, r1, 0); VdbeCoverage(v); |
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3116 3117 3118 3119 3120 3121 3122 | sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE); sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v); /* Jump to the this point in order to terminate the query. */ sqlite3VdbeResolveLabel(v, labelEnd); | < < < < < < < < | 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 | sqlite3VdbeChangeP5(v, OPFLAG_PERMUTE); sqlite3VdbeAddOp3(v, OP_Jump, addrAltB, addrAeqB, addrAgtB); VdbeCoverage(v); /* Jump to the this point in order to terminate the query. */ sqlite3VdbeResolveLabel(v, labelEnd); /* Reassembly the compound query so that it will be freed correctly ** by the calling function */ if( p->pPrior ){ sqlite3SelectDelete(db, p->pPrior); } p->pPrior = pPrior; pPrior->pNext = p; |
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3414 3415 3416 3417 3418 3419 3420 | ){ const char *zSavedAuthContext = pParse->zAuthContext; Select *pParent; /* Current UNION ALL term of the other query */ Select *pSub; /* The inner query or "subquery" */ Select *pSub1; /* Pointer to the rightmost select in sub-query */ SrcList *pSrc; /* The FROM clause of the outer query */ SrcList *pSubSrc; /* The FROM clause of the subquery */ | < | 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 | ){ const char *zSavedAuthContext = pParse->zAuthContext; Select *pParent; /* Current UNION ALL term of the other query */ Select *pSub; /* The inner query or "subquery" */ Select *pSub1; /* Pointer to the rightmost select in sub-query */ SrcList *pSrc; /* The FROM clause of the outer query */ SrcList *pSubSrc; /* The FROM clause of the subquery */ int iParent; /* VDBE cursor number of the pSub result set temp table */ int iNewParent = -1;/* Replacement table for iParent */ int isLeftJoin = 0; /* True if pSub is the right side of a LEFT JOIN */ int i; /* Loop counter */ Expr *pWhere; /* The WHERE clause */ struct SrcList_item *pSubitem; /* The subquery */ sqlite3 *db = pParse->db; |
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3739 3740 3741 3742 3743 3744 3745 | ** SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b; ** \ \_____________ subquery __________/ / ** \_____________________ outer query ______________________________/ ** ** We look at every expression in the outer query and every place we see ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10". */ | < < < < < < < < | 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 | ** SELECT a+5, b*10 FROM (SELECT x*3 AS a, y+10 AS b FROM t1) WHERE a>b; ** \ \_____________ subquery __________/ / ** \_____________________ outer query ______________________________/ ** ** We look at every expression in the outer query and every place we see ** "a" we substitute "x*3" and every place we see "b" we substitute "y+10". */ if( pSub->pOrderBy ){ /* At this point, any non-zero iOrderByCol values indicate that the ** ORDER BY column expression is identical to the iOrderByCol'th ** expression returned by SELECT statement pSub. Since these values ** do not necessarily correspond to columns in SELECT statement pParent, ** zero them before transfering the ORDER BY clause. ** |
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5072 5073 5074 5075 5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 | isAgg = (p->selFlags & SF_Aggregate)!=0; #if SELECTTRACE_ENABLED if( sqlite3SelectTrace & 0x100 ){ SELECTTRACE(0x100,pParse,p, ("after name resolution:\n")); sqlite3TreeViewSelect(0, p, 0); } #endif /* Try to flatten subqueries in the FROM clause up into the main query */ #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) for(i=0; !p->pPrior && i<pTabList->nSrc; i++){ struct SrcList_item *pItem = &pTabList->a[i]; Select *pSub = pItem->pSelect; | > > > > > > > > | 5034 5035 5036 5037 5038 5039 5040 5041 5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055 | isAgg = (p->selFlags & SF_Aggregate)!=0; #if SELECTTRACE_ENABLED if( sqlite3SelectTrace & 0x100 ){ SELECTTRACE(0x100,pParse,p, ("after name resolution:\n")); sqlite3TreeViewSelect(0, p, 0); } #endif /* Get a pointer the VDBE under construction, allocating a new VDBE if one ** does not already exist */ v = sqlite3GetVdbe(pParse); if( v==0 ) goto select_end; if( pDest->eDest==SRT_Output ){ generateColumnNames(pParse, p); } /* Try to flatten subqueries in the FROM clause up into the main query */ #if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) for(i=0; !p->pPrior && i<pTabList->nSrc; i++){ struct SrcList_item *pItem = &pTabList->a[i]; Select *pSub = pItem->pSelect; |
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5108 5109 5110 5111 5112 5113 5114 | if( db->mallocFailed ) goto select_end; if( !IgnorableOrderby(pDest) ){ sSort.pOrderBy = p->pOrderBy; } } #endif | < < < < < | 5078 5079 5080 5081 5082 5083 5084 5085 5086 5087 5088 5089 5090 5091 | if( db->mallocFailed ) goto select_end; if( !IgnorableOrderby(pDest) ){ sSort.pOrderBy = p->pOrderBy; } } #endif #ifndef SQLITE_OMIT_COMPOUND_SELECT /* Handle compound SELECT statements using the separate multiSelect() ** procedure. */ if( p->pPrior ){ rc = multiSelect(pParse, p, pDest); explainSetInteger(pParse->iSelectId, iRestoreSelectId); |
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5899 5900 5901 5902 5903 5904 5905 | /* Control jumps to here if an error is encountered above, or upon ** successful coding of the SELECT. */ select_end: explainSetInteger(pParse->iSelectId, iRestoreSelectId); | < < < < < < | 5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875 5876 5877 5878 | /* Control jumps to here if an error is encountered above, or upon ** successful coding of the SELECT. */ select_end: explainSetInteger(pParse->iSelectId, iRestoreSelectId); sqlite3DbFree(db, sAggInfo.aCol); sqlite3DbFree(db, sAggInfo.aFunc); #if SELECTTRACE_ENABLED SELECTTRACE(1,pParse,p,("end processing\n")); pParse->nSelectIndent--; #endif return rc; } |