diff options
Diffstat (limited to 'lib/libsqlite3/src/select.c')
| -rw-r--r-- | lib/libsqlite3/src/select.c | 505 |
1 files changed, 256 insertions, 249 deletions
diff --git a/lib/libsqlite3/src/select.c b/lib/libsqlite3/src/select.c index 90aaa842a62..8ac98f1759f 100644 --- a/lib/libsqlite3/src/select.c +++ b/lib/libsqlite3/src/select.c @@ -21,7 +21,8 @@ /***/ int sqlite3SelectTrace = 0; # define SELECTTRACE(K,P,S,X) \ if(sqlite3SelectTrace&(K)) \ - sqlite3DebugPrintf("%*s%s.%p: ",(P)->nSelectIndent*2-2,"",(S)->zSelName,(S)),\ + sqlite3DebugPrintf("%*s%s.%p: ",(P)->nSelectIndent*2-2,"",\ + (S)->zSelName,(S)),\ sqlite3DebugPrintf X #else # define SELECTTRACE(K,P,S,X) @@ -111,7 +112,6 @@ Select *sqlite3SelectNew( Select standin; sqlite3 *db = pParse->db; pNew = sqlite3DbMallocZero(db, sizeof(*pNew) ); - assert( db->mallocFailed || !pOffset || pLimit ); /* OFFSET implies LIMIT */ if( pNew==0 ){ assert( db->mallocFailed ); pNew = &standin; @@ -131,7 +131,7 @@ Select *sqlite3SelectNew( pNew->op = TK_SELECT; pNew->pLimit = pLimit; pNew->pOffset = pOffset; - assert( pOffset==0 || pLimit!=0 ); + assert( pOffset==0 || pLimit!=0 || pParse->nErr>0 || db->mallocFailed!=0 ); pNew->addrOpenEphm[0] = -1; pNew->addrOpenEphm[1] = -1; if( db->mallocFailed ) { @@ -366,6 +366,12 @@ static void setJoinExpr(Expr *p, int iTable){ assert( !ExprHasProperty(p, EP_TokenOnly|EP_Reduced) ); ExprSetVVAProperty(p, EP_NoReduce); p->iRightJoinTable = (i16)iTable; + if( p->op==TK_FUNCTION && p->x.pList ){ + int i; + for(i=0; i<p->x.pList->nExpr; i++){ + setJoinExpr(p->x.pList->a[i].pExpr, iTable); + } + } setJoinExpr(p->pLeft, iTable); p = p->pRight; } @@ -714,8 +720,13 @@ static void selectInnerLoop( /* If the destination is an EXISTS(...) expression, the actual ** values returned by the SELECT are not required. */ - sqlite3ExprCodeExprList(pParse, pEList, regResult, - (eDest==SRT_Output||eDest==SRT_Coroutine)?SQLITE_ECEL_DUP:0); + u8 ecelFlags; + if( eDest==SRT_Mem || eDest==SRT_Output || eDest==SRT_Coroutine ){ + ecelFlags = SQLITE_ECEL_DUP; + }else{ + ecelFlags = 0; + } + sqlite3ExprCodeExprList(pParse, pEList, regResult, ecelFlags); } /* If the DISTINCT keyword was present on the SELECT statement @@ -770,7 +781,8 @@ static void selectInnerLoop( default: { assert( pDistinct->eTnctType==WHERE_DISTINCT_UNORDERED ); - codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol, regResult); + codeDistinct(pParse, pDistinct->tabTnct, iContinue, nResultCol, + regResult); break; } } @@ -812,6 +824,8 @@ static void selectInnerLoop( int r1 = sqlite3GetTempRange(pParse, nPrefixReg+1); testcase( eDest==SRT_Table ); testcase( eDest==SRT_EphemTab ); + testcase( eDest==SRT_Fifo ); + testcase( eDest==SRT_DistFifo ); sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1+nPrefixReg); #ifndef SQLITE_OMIT_CTE if( eDest==SRT_DistFifo ){ @@ -821,7 +835,8 @@ static void selectInnerLoop( ** current row to the index and proceed with writing it to the ** output table as well. */ int addr = sqlite3VdbeCurrentAddr(v) + 4; - sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0); VdbeCoverage(v); + sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0); + VdbeCoverage(v); sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r1); assert( pSort==0 ); } @@ -1067,7 +1082,6 @@ static KeyInfo *keyInfoFromExprList( return pInfo; } -#ifndef SQLITE_OMIT_COMPOUND_SELECT /* ** Name of the connection operator, used for error messages. */ @@ -1081,7 +1095,6 @@ static const char *selectOpName(int id){ } return z; } -#endif /* SQLITE_OMIT_COMPOUND_SELECT */ #ifndef SQLITE_OMIT_EXPLAIN /* @@ -1227,10 +1240,7 @@ static void generateSortTail( VdbeComment((v, "%s", aOutEx[i].zName ? aOutEx[i].zName : aOutEx[i].zSpan)); } switch( eDest ){ - case SRT_Table: case SRT_EphemTab: { - testcase( eDest==SRT_Table ); - testcase( eDest==SRT_EphemTab ); sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, regRowid); sqlite3VdbeAddOp3(v, OP_Insert, iParm, regRow, regRowid); sqlite3VdbeChangeP5(v, OPFLAG_APPEND); @@ -1307,28 +1317,27 @@ static void generateSortTail( */ #ifdef SQLITE_ENABLE_COLUMN_METADATA # define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,C,D,E,F) +#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */ +# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,F) +#endif static const char *columnTypeImpl( NameContext *pNC, Expr *pExpr, +#ifdef SQLITE_ENABLE_COLUMN_METADATA const char **pzOrigDb, const char **pzOrigTab, const char **pzOrigCol, +#endif u8 *pEstWidth ){ - char const *zOrigDb = 0; - char const *zOrigTab = 0; - char const *zOrigCol = 0; -#else /* if !defined(SQLITE_ENABLE_COLUMN_METADATA) */ -# define columnType(A,B,C,D,E,F) columnTypeImpl(A,B,F) -static const char *columnTypeImpl( - NameContext *pNC, - Expr *pExpr, - u8 *pEstWidth -){ -#endif /* !defined(SQLITE_ENABLE_COLUMN_METADATA) */ char const *zType = 0; int j; u8 estWidth = 1; +#ifdef SQLITE_ENABLE_COLUMN_METADATA + char const *zOrigDb = 0; + char const *zOrigTab = 0; + char const *zOrigCol = 0; +#endif if( NEVER(pExpr==0) || pNC->pSrcList==0 ) return 0; switch( pExpr->op ){ @@ -1385,6 +1394,9 @@ static const char *columnTypeImpl( /* 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. + ** + ** The ALWAYS() is because iCol>=pS->pEList->nExpr will have been + ** caught already by name resolution. */ NameContext sNC; Expr *p = pS->pEList->a[iCol].pExpr; @@ -1701,12 +1713,15 @@ static void selectAddColumnTypeAndCollation( a = pSelect->pEList->a; for(i=0, pCol=pTab->aCol; i<pTab->nCol; i++, pCol++){ p = a[i].pExpr; - pCol->zType = sqlite3DbStrDup(db, columnType(&sNC, p,0,0,0, &pCol->szEst)); + if( pCol->zType==0 ){ + pCol->zType = sqlite3DbStrDup(db, + columnType(&sNC, p,0,0,0, &pCol->szEst)); + } szAll += pCol->szEst; pCol->affinity = sqlite3ExprAffinity(p); - if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_NONE; + if( pCol->affinity==0 ) pCol->affinity = SQLITE_AFF_BLOB; pColl = sqlite3ExprCollSeq(pParse, p); - if( pColl ){ + if( pColl && pCol->zColl==0 ){ pCol->zColl = sqlite3DbStrDup(db, pColl->zName); } } @@ -1860,7 +1875,10 @@ static CollSeq *multiSelectCollSeq(Parse *pParse, Select *p, int iCol){ pRet = 0; } assert( iCol>=0 ); - if( pRet==0 && iCol<p->pEList->nExpr ){ + /* iCol must be less than p->pEList->nExpr. Otherwise an error would + ** have been thrown during name resolution and we would not have gotten + ** this far */ + if( pRet==0 && ALWAYS(iCol<p->pEList->nExpr) ){ pRet = sqlite3ExprCollSeq(pParse, p->pEList->a[iCol].pExpr); } return pRet; @@ -2050,10 +2068,14 @@ static void generateWithRecursiveQuery( /* Execute the recursive SELECT taking the single row in Current as ** the value for the recursive-table. Store the results in the Queue. */ - p->pPrior = 0; - sqlite3Select(pParse, p, &destQueue); - assert( p->pPrior==0 ); - p->pPrior = pSetup; + if( p->selFlags & SF_Aggregate ){ + sqlite3ErrorMsg(pParse, "recursive aggregate queries not supported"); + }else{ + p->pPrior = 0; + sqlite3Select(pParse, p, &destQueue); + assert( p->pPrior==0 ); + p->pPrior = pSetup; + } /* Keep running the loop until the Queue is empty */ sqlite3VdbeAddOp2(v, OP_Goto, 0, addrTop); @@ -2076,19 +2098,6 @@ static int multiSelectOrderBy( ); /* -** Error message for when two or more terms of a compound select have different -** size result sets. -*/ -static void selectWrongNumTermsError(Parse *pParse, Select *p){ - if( p->selFlags & SF_Values ){ - sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms"); - }else{ - sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s" - " do not have the same number of result columns", selectOpName(p->op)); - } -} - -/* ** Handle the special case of a compound-select that originates from a ** VALUES clause. By handling this as a special case, we avoid deep ** recursion, and thus do not need to enforce the SQLITE_LIMIT_COMPOUND_SELECT @@ -2105,20 +2114,15 @@ static int multiSelectValues( SelectDest *pDest /* What to do with query results */ ){ Select *pPrior; - int nExpr = p->pEList->nExpr; int nRow = 1; int rc = 0; - assert( p->pNext==0 ); - assert( p->selFlags & SF_AllValues ); + assert( p->selFlags & SF_MultiValue ); do{ assert( p->selFlags & SF_Values ); assert( p->op==TK_ALL || (p->op==TK_SELECT && p->pPrior==0) ); assert( p->pLimit==0 ); assert( p->pOffset==0 ); - if( p->pEList->nExpr!=nExpr ){ - selectWrongNumTermsError(pParse, p); - return 1; - } + assert( p->pNext==0 || p->pEList->nExpr==p->pNext->pEList->nExpr ); if( p->pPrior==0 ) break; assert( p->pPrior->pNext==p ); p = p->pPrior; @@ -2218,7 +2222,7 @@ static int multiSelect( /* Special handling for a compound-select that originates as a VALUES clause. */ - if( p->selFlags & SF_AllValues ){ + if( p->selFlags & SF_MultiValue ){ rc = multiSelectValues(pParse, p, &dest); goto multi_select_end; } @@ -2227,11 +2231,7 @@ static int multiSelect( ** in their result sets. */ assert( p->pEList && pPrior->pEList ); - if( p->pEList->nExpr!=pPrior->pEList->nExpr ){ - selectWrongNumTermsError(pParse, p); - rc = 1; - goto multi_select_end; - } + assert( p->pEList->nExpr==pPrior->pEList->nExpr ); #ifndef SQLITE_OMIT_CTE if( p->selFlags & SF_Recursive ){ @@ -2524,6 +2524,19 @@ multi_select_end: #endif /* SQLITE_OMIT_COMPOUND_SELECT */ /* +** Error message for when two or more terms of a compound select have different +** size result sets. +*/ +void sqlite3SelectWrongNumTermsError(Parse *pParse, Select *p){ + if( p->selFlags & SF_Values ){ + sqlite3ErrorMsg(pParse, "all VALUES must have the same number of terms"); + }else{ + sqlite3ErrorMsg(pParse, "SELECTs to the left and right of %s" + " do not have the same number of result columns", selectOpName(p->op)); + } +} + +/* ** Code an output subroutine for a coroutine implementation of a ** SELECT statment. ** @@ -2578,15 +2591,14 @@ static int generateOutputSubroutine( */ codeOffset(v, p->iOffset, iContinue); + assert( pDest->eDest!=SRT_Exists ); + assert( pDest->eDest!=SRT_Table ); switch( pDest->eDest ){ /* Store the result as data using a unique key. */ - case SRT_Table: case SRT_EphemTab: { int r1 = sqlite3GetTempReg(pParse); int r2 = sqlite3GetTempReg(pParse); - testcase( pDest->eDest==SRT_Table ); - testcase( pDest->eDest==SRT_EphemTab ); sqlite3VdbeAddOp3(v, OP_MakeRecord, pIn->iSdst, pIn->nSdst, r1); sqlite3VdbeAddOp2(v, OP_NewRowid, pDest->iSDParm, r2); sqlite3VdbeAddOp3(v, OP_Insert, pDest->iSDParm, r1, r2); @@ -2603,7 +2615,7 @@ static int generateOutputSubroutine( */ case SRT_Set: { int r1; - assert( pIn->nSdst==1 ); + assert( pIn->nSdst==1 || pParse->nErr>0 ); pDest->affSdst = sqlite3CompareAffinity(p->pEList->a[0].pExpr, pDest->affSdst); r1 = sqlite3GetTempReg(pParse); @@ -2614,22 +2626,12 @@ static int generateOutputSubroutine( break; } -#if 0 /* Never occurs on an ORDER BY query */ - /* If any row exist in the result set, record that fact and abort. - */ - case SRT_Exists: { - sqlite3VdbeAddOp2(v, OP_Integer, 1, pDest->iSDParm); - /* The LIMIT clause will terminate the loop for us */ - break; - } -#endif - /* If this is a scalar select that is part of an expression, then ** store the results in the appropriate memory cell and break out ** of the scan loop. */ case SRT_Mem: { - assert( pIn->nSdst==1 ); + assert( pIn->nSdst==1 || pParse->nErr>0 ); testcase( pIn->nSdst!=1 ); sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSDParm, 1); /* The LIMIT clause will jump out of the loop for us */ break; @@ -2644,7 +2646,7 @@ static int generateOutputSubroutine( pDest->iSdst = sqlite3GetTempRange(pParse, pIn->nSdst); pDest->nSdst = pIn->nSdst; } - sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pDest->nSdst); + sqlite3ExprCodeMove(pParse, pIn->iSdst, pDest->iSdst, pIn->nSdst); sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm); break; } @@ -2860,8 +2862,8 @@ static int multiSelectOrderBy( if( aPermute ){ struct ExprList_item *pItem; for(i=0, pItem=pOrderBy->a; i<nOrderBy; i++, pItem++){ - assert( pItem->u.x.iOrderByCol>0 - && pItem->u.x.iOrderByCol<=p->pEList->nExpr ); + assert( pItem->u.x.iOrderByCol>0 ); + assert( pItem->u.x.iOrderByCol<=p->pEList->nExpr ); aPermute[i] = pItem->u.x.iOrderByCol - 1; } pKeyMerge = multiSelectOrderByKeyInfo(pParse, p, 1); @@ -3071,7 +3073,7 @@ static int multiSelectOrderBy( /*** TBD: Insert subroutine calls to close cursors on incomplete **** subqueries ****/ explainComposite(pParse, p->op, iSub1, iSub2, 0); - return SQLITE_OK; + return pParse->nErr!=0; } #endif @@ -3220,8 +3222,8 @@ static void substSelect( ** ** (**) Restriction (10) was removed from the code on 2005-02-05 but we ** accidently carried the comment forward until 2014-09-15. Original -** text: "The subquery does not use aggregates or the outer query does not -** use LIMIT." +** text: "The subquery does not use aggregates or the outer query +** does not use LIMIT." ** ** (11) The subquery and the outer query do not both have ORDER BY clauses. ** @@ -3431,10 +3433,10 @@ static int flattenSubquery( testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct ); testcase( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))==SF_Aggregate ); assert( pSub->pSrc!=0 ); + assert( pSub->pEList->nExpr==pSub1->pEList->nExpr ); if( (pSub1->selFlags & (SF_Distinct|SF_Aggregate))!=0 || (pSub1->pPrior && pSub1->op!=TK_ALL) || pSub1->pSrc->nSrc<1 - || pSub->pEList->nExpr!=pSub1->pEList->nExpr ){ return 0; } @@ -3714,7 +3716,7 @@ static int flattenSubquery( #if SELECTTRACE_ENABLED if( sqlite3SelectTrace & 0x100 ){ - sqlite3DebugPrintf("After flattening:\n"); + SELECTTRACE(0x100,pParse,p,("After flattening:\n")); sqlite3TreeViewSelect(0, p, 0); } #endif @@ -3723,6 +3725,73 @@ static int flattenSubquery( } #endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */ + + +#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) +/* +** Make copies of relevant WHERE clause terms of the outer query into +** the WHERE clause of subquery. Example: +** +** SELECT * FROM (SELECT a AS x, c-d AS y FROM t1) WHERE x=5 AND y=10; +** +** Transformed into: +** +** SELECT * FROM (SELECT a AS x, c-d AS y FROM t1 WHERE a=5 AND c-d=10) +** WHERE x=5 AND y=10; +** +** The hope is that the terms added to the inner query will make it more +** efficient. +** +** Do not attempt this optimization if: +** +** (1) The inner query is an aggregate. (In that case, we'd really want +** to copy the outer WHERE-clause terms onto the HAVING clause of the +** inner query. But they probably won't help there so do not bother.) +** +** (2) The inner query is the recursive part of a common table expression. +** +** (3) The inner query has a LIMIT clause (since the changes to the WHERE +** close would change the meaning of the LIMIT). +** +** (4) The inner query is the right operand of a LEFT JOIN. (The caller +** enforces this restriction since this routine does not have enough +** information to know.) +** +** Return 0 if no changes are made and non-zero if one or more WHERE clause +** terms are duplicated into the subquery. +*/ +static int pushDownWhereTerms( + sqlite3 *db, /* The database connection (for malloc()) */ + Select *pSubq, /* The subquery whose WHERE clause is to be augmented */ + Expr *pWhere, /* The WHERE clause of the outer query */ + int iCursor /* Cursor number of the subquery */ +){ + Expr *pNew; + int nChng = 0; + if( pWhere==0 ) return 0; + if( (pSubq->selFlags & (SF_Aggregate|SF_Recursive))!=0 ){ + return 0; /* restrictions (1) and (2) */ + } + if( pSubq->pLimit!=0 ){ + return 0; /* restriction (3) */ + } + while( pWhere->op==TK_AND ){ + nChng += pushDownWhereTerms(db, pSubq, pWhere->pRight, iCursor); + pWhere = pWhere->pLeft; + } + if( sqlite3ExprIsTableConstant(pWhere, iCursor) ){ + nChng++; + while( pSubq ){ + pNew = sqlite3ExprDup(db, pWhere, 0); + pNew = substExpr(db, pNew, iCursor, pSubq->pEList); + pSubq->pWhere = sqlite3ExprAnd(db, pSubq->pWhere, pNew); + pSubq = pSubq->pPrior; + } + } + return nChng; +} +#endif /* !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) */ + /* ** Based on the contents of the AggInfo structure indicated by the first ** argument, this function checks if the following are true: @@ -3806,16 +3875,16 @@ static Table *isSimpleCount(Select *p, AggInfo *pAggInfo){ ** pFrom->pIndex and return SQLITE_OK. */ int sqlite3IndexedByLookup(Parse *pParse, struct SrcList_item *pFrom){ - if( pFrom->pTab && pFrom->zIndex ){ + if( pFrom->pTab && pFrom->zIndexedBy ){ Table *pTab = pFrom->pTab; - char *zIndex = pFrom->zIndex; + char *zIndexedBy = pFrom->zIndexedBy; Index *pIdx; for(pIdx=pTab->pIndex; - pIdx && sqlite3StrICmp(pIdx->zName, zIndex); + pIdx && sqlite3StrICmp(pIdx->zName, zIndexedBy); pIdx=pIdx->pNext ); if( !pIdx ){ - sqlite3ErrorMsg(pParse, "no such index: %s", zIndex, 0); + sqlite3ErrorMsg(pParse, "no such index: %s", zIndexedBy, 0); pParse->checkSchema = 1; return SQLITE_ERROR; } @@ -3883,6 +3952,7 @@ static int convertCompoundSelectToSubquery(Walker *pWalker, Select *p){ pNew->pOrderBy = 0; p->pPrior = 0; p->pNext = 0; + p->pWith = 0; p->selFlags &= ~SF_Compound; assert( (p->selFlags & SF_Converted)==0 ); p->selFlags |= SF_Converted; @@ -3995,7 +4065,7 @@ static int withExpand( pTab->zName = sqlite3DbStrDup(db, pCte->zName); pTab->iPKey = -1; pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) ); - pTab->tabFlags |= TF_Ephemeral; + pTab->tabFlags |= TF_Ephemeral | TF_NoVisibleRowid; pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0); if( db->mallocFailed ) return SQLITE_NOMEM; assert( pFrom->pSelect ); @@ -4240,13 +4310,6 @@ static int selectExpander(Walker *pWalker, Select *p){ int longNames = (flags & SQLITE_FullColNames)!=0 && (flags & SQLITE_ShortColNames)==0; - /* When processing FROM-clause subqueries, it is always the case - ** that full_column_names=OFF and short_column_names=ON. The - ** sqlite3ResultSetOfSelect() routine makes it so. */ - assert( (p->selFlags & SF_NestedFrom)==0 - || ((flags & SQLITE_FullColNames)==0 && - (flags & SQLITE_ShortColNames)!=0) ); - for(k=0; k<pEList->nExpr; k++){ pE = a[k].pExpr; pRight = pE->pRight; @@ -4421,7 +4484,7 @@ static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){ sqlite3WalkSelect(&w, pSelect); } w.xSelectCallback = selectExpander; - if( (pSelect->selFlags & SF_AllValues)==0 ){ + if( (pSelect->selFlags & SF_MultiValue)==0 ){ w.xSelectCallback2 = selectPopWith; } sqlite3WalkSelect(&w, pSelect); @@ -4607,7 +4670,8 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){ } if( pF->iDistinct>=0 ){ addrNext = sqlite3VdbeMakeLabel(v); - assert( nArg==1 ); + testcase( nArg==0 ); /* Error condition */ + testcase( nArg>1 ); /* Also an error */ codeDistinct(pParse, pF->iDistinct, addrNext, 1, regAgg); } if( pF->pFunc->funcFlags & SQLITE_FUNC_NEEDCOLL ){ @@ -4624,7 +4688,7 @@ static void updateAccumulator(Parse *pParse, AggInfo *pAggInfo){ if( regHit==0 && pAggInfo->nAccumulator ) regHit = ++pParse->nMem; sqlite3VdbeAddOp4(v, OP_CollSeq, regHit, 0, 0, (char *)pColl, P4_COLLSEQ); } - sqlite3VdbeAddOp4(v, OP_AggStep, 0, regAgg, pF->iMem, + sqlite3VdbeAddOp4(v, OP_AggStep0, 0, regAgg, pF->iMem, (void*)pF->pFunc, P4_FUNCDEF); sqlite3VdbeChangeP5(v, (u8)nArg); sqlite3ExprCacheAffinityChange(pParse, regAgg, nArg); @@ -4707,7 +4771,7 @@ int sqlite3Select( WhereInfo *pWInfo; /* Return from sqlite3WhereBegin() */ Vdbe *v; /* The virtual machine under construction */ int isAgg; /* True for select lists like "count(*)" */ - ExprList *pEList; /* List of columns to extract. */ + ExprList *pEList = 0; /* List of columns to extract. */ SrcList *pTabList; /* List of tables to select from */ Expr *pWhere; /* The WHERE clause. May be NULL */ ExprList *pGroupBy; /* The GROUP BY clause. May be NULL */ @@ -4757,12 +4821,11 @@ int sqlite3Select( memset(&sSort, 0, sizeof(sSort)); sSort.pOrderBy = p->pOrderBy; pTabList = p->pSrc; - pEList = p->pEList; if( pParse->nErr || db->mallocFailed ){ goto select_end; } + assert( p->pEList!=0 ); isAgg = (p->selFlags & SF_Aggregate)!=0; - assert( pEList!=0 ); #if SELECTTRACE_ENABLED if( sqlite3SelectTrace & 0x100 ){ SELECTTRACE(0x100,pParse,p, ("after name resolution:\n")); @@ -4771,29 +4834,67 @@ int sqlite3Select( #endif - /* Begin generating code. - */ - v = sqlite3GetVdbe(pParse); - if( v==0 ) goto select_end; - /* If writing to memory or generating a set ** only a single column may be output. */ #ifndef SQLITE_OMIT_SUBQUERY - if( checkForMultiColumnSelectError(pParse, pDest, pEList->nExpr) ){ + if( checkForMultiColumnSelectError(pParse, pDest, p->pEList->nExpr) ){ goto select_end; } #endif - /* Generate code for all sub-queries in the FROM clause + /* 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]; - SelectDest dest; Select *pSub = pItem->pSelect; int isAggSub; + if( pSub==0 ) continue; + isAggSub = (pSub->selFlags & SF_Aggregate)!=0; + if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){ + /* This subquery can be absorbed into its parent. */ + if( isAggSub ){ + isAgg = 1; + p->selFlags |= SF_Aggregate; + } + i = -1; + } + pTabList = p->pSrc; + if( db->mallocFailed ) goto select_end; + if( !IgnorableOrderby(pDest) ){ + sSort.pOrderBy = p->pOrderBy; + } + } +#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; + +#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); +#if SELECTTRACE_ENABLED + SELECTTRACE(1,pParse,p,("end compound-select processing\n")); + pParse->nSelectIndent--; +#endif + return rc; + } +#endif + + /* Generate code for all sub-queries in the FROM clause + */ +#if !defined(SQLITE_OMIT_SUBQUERY) || !defined(SQLITE_OMIT_VIEW) + for(i=0; i<pTabList->nSrc; i++){ + struct SrcList_item *pItem = &pTabList->a[i]; + SelectDest dest; + Select *pSub = pItem->pSelect; if( pSub==0 ) continue; /* Sometimes the code for a subquery will be generated more than @@ -4818,16 +4919,25 @@ int sqlite3Select( */ pParse->nHeight += sqlite3SelectExprHeight(p); - isAggSub = (pSub->selFlags & SF_Aggregate)!=0; - if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){ - /* This subquery can be absorbed into its parent. */ - if( isAggSub ){ - isAgg = 1; - p->selFlags |= SF_Aggregate; + /* Make copies of constant WHERE-clause terms in the outer query down + ** inside the subquery. This can help the subquery to run more efficiently. + */ + if( (pItem->jointype & JT_OUTER)==0 + && pushDownWhereTerms(db, pSub, p->pWhere, pItem->iCursor) + ){ +#if SELECTTRACE_ENABLED + if( sqlite3SelectTrace & 0x100 ){ + SELECTTRACE(0x100,pParse,p,("After WHERE-clause push-down:\n")); + sqlite3TreeViewSelect(0, p, 0); } - i = -1; - }else if( pTabList->nSrc==1 - && OptimizationEnabled(db, SQLITE_SubqCoroutine) +#endif + } + + /* Generate code to implement the subquery + */ + if( pTabList->nSrc==1 + && (p->selFlags & SF_All)==0 + && OptimizationEnabled(db, SQLITE_SubqCoroutine) ){ /* Implement a co-routine that will return a single row of the result ** set on each invocation. @@ -4878,33 +4988,23 @@ int sqlite3Select( sqlite3VdbeChangeP1(v, topAddr, retAddr); sqlite3ClearTempRegCache(pParse); } - if( /*pParse->nErr ||*/ db->mallocFailed ){ - goto select_end; - } + if( db->mallocFailed ) goto select_end; pParse->nHeight -= sqlite3SelectExprHeight(p); - pTabList = p->pSrc; - if( !IgnorableOrderby(pDest) ){ - sSort.pOrderBy = p->pOrderBy; - } } - pEList = p->pEList; #endif + + /* Various elements of the SELECT copied into local variables for + ** convenience */ + pEList = p->pEList; pWhere = p->pWhere; pGroupBy = p->pGroupBy; pHaving = p->pHaving; sDistinct.isTnct = (p->selFlags & SF_Distinct)!=0; -#ifndef SQLITE_OMIT_COMPOUND_SELECT - /* If there is are a sequence of queries, do the earlier ones first. - */ - if( p->pPrior ){ - rc = multiSelect(pParse, p, pDest); - explainSetInteger(pParse->iSelectId, iRestoreSelectId); #if SELECTTRACE_ENABLED - SELECTTRACE(1,pParse,p,("end compound-select processing\n")); - pParse->nSelectIndent--; -#endif - return rc; + if( sqlite3SelectTrace & 0x400 ){ + SELECTTRACE(0x400,pParse,p,("After all FROM-clause analysis:\n")); + sqlite3TreeViewSelect(0, p, 0); } #endif @@ -4924,23 +5024,23 @@ int sqlite3Select( ** BY and DISTINCT, and an index or separate temp-table for the other. */ if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct - && sqlite3ExprListCompare(sSort.pOrderBy, p->pEList, -1)==0 + && sqlite3ExprListCompare(sSort.pOrderBy, pEList, -1)==0 ){ p->selFlags &= ~SF_Distinct; - p->pGroupBy = sqlite3ExprListDup(db, p->pEList, 0); - pGroupBy = p->pGroupBy; + pGroupBy = p->pGroupBy = sqlite3ExprListDup(db, pEList, 0); /* Notice that even thought SF_Distinct has been cleared from p->selFlags, ** the sDistinct.isTnct is still set. Hence, isTnct represents the ** original setting of the SF_Distinct flag, not the current setting */ assert( sDistinct.isTnct ); } - /* If there is an ORDER BY clause, then this sorting - ** index might end up being unused if the data can be - ** extracted in pre-sorted order. If that is the case, then the - ** OP_OpenEphemeral instruction will be changed to an OP_Noop once - ** we figure out that the sorting index is not needed. The addrSortIndex - ** variable is used to facilitate that change. + /* If there is an ORDER BY clause, then create an ephemeral index to + ** do the sorting. But this sorting ephemeral index might end up + ** being unused if the data can be extracted in pre-sorted order. + ** If that is the case, then the OP_OpenEphemeral instruction will be + ** changed to an OP_Noop once we figure out that the sorting index is + ** not needed. The sSort.addrSortIndex variable is used to facilitate + ** that change. */ if( sSort.pOrderBy ){ KeyInfo *pKeyInfo; @@ -4971,14 +5071,14 @@ int sqlite3Select( sSort.sortFlags |= SORTFLAG_UseSorter; } - /* Open a virtual index to use for the distinct set. + /* Open an ephemeral index to use for the distinct set. */ if( p->selFlags & SF_Distinct ){ sDistinct.tabTnct = pParse->nTab++; sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral, - sDistinct.tabTnct, 0, 0, - (char*)keyInfoFromExprList(pParse, p->pEList,0,0), - P4_KEYINFO); + sDistinct.tabTnct, 0, 0, + (char*)keyInfoFromExprList(pParse, p->pEList,0,0), + P4_KEYINFO); sqlite3VdbeChangeP5(v, BTREE_UNORDERED); sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED; }else{ @@ -5056,11 +5156,10 @@ int sqlite3Select( p->nSelectRow = 1; } - /* If there is both a GROUP BY and an ORDER BY clause and they are ** identical, then it may be possible to disable the ORDER BY clause ** on the grounds that the GROUP BY will cause elements to come out - ** in the correct order. It also may not - the GROUP BY may use a + ** in the correct order. It also may not - the GROUP BY might use a ** database index that causes rows to be grouped together as required ** but not actually sorted. Either way, record the fact that the ** ORDER BY and GROUP BY clauses are the same by setting the orderByGrp @@ -5238,7 +5337,8 @@ int sqlite3Select( addrTopOfLoop = sqlite3VdbeCurrentAddr(v); sqlite3ExprCacheClear(pParse); if( groupBySort ){ - sqlite3VdbeAddOp3(v, OP_SorterData, sAggInfo.sortingIdx, sortOut,sortPTab); + sqlite3VdbeAddOp3(v, OP_SorterData, sAggInfo.sortingIdx, + sortOut, sortPTab); } for(j=0; j<pGroupBy->nExpr; j++){ if( groupBySort ){ @@ -5310,7 +5410,8 @@ int sqlite3Select( sqlite3VdbeAddOp1(v, OP_Return, regOutputRow); sqlite3VdbeResolveLabel(v, addrOutputRow); addrOutputRow = sqlite3VdbeCurrentAddr(v); - sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2); VdbeCoverage(v); + sqlite3VdbeAddOp2(v, OP_IfPos, iUseFlag, addrOutputRow+2); + VdbeCoverage(v); VdbeComment((v, "Groupby result generator entry point")); sqlite3VdbeAddOp1(v, OP_Return, regOutputRow); finalizeAggFunctions(pParse, &sAggInfo); @@ -5474,7 +5575,8 @@ int sqlite3Select( ** and send them to the callback one by one. */ if( sSort.pOrderBy ){ - explainTempTable(pParse, sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY"); + explainTempTable(pParse, + sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY"); generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest); } @@ -5482,10 +5584,9 @@ int sqlite3Select( */ sqlite3VdbeResolveLabel(v, iEnd); - /* The SELECT was successfully coded. Set the return code to 0 - ** to indicate no errors. - */ - rc = 0; + /* The SELECT has been coded. If there is an error in the Parse structure, + ** set the return code to 1. Otherwise 0. */ + rc = (pParse->nErr>0); /* Control jumps to here if an error is encountered above, or upon ** successful coding of the SELECT. @@ -5507,97 +5608,3 @@ select_end: #endif return rc; } - -#ifdef SQLITE_DEBUG -/* -** Generate a human-readable description of a the Select object. -*/ -void sqlite3TreeViewSelect(TreeView *pView, const Select *p, u8 moreToFollow){ - int n = 0; - pView = sqlite3TreeViewPush(pView, moreToFollow); - sqlite3TreeViewLine(pView, "SELECT%s%s (0x%p)", - ((p->selFlags & SF_Distinct) ? " DISTINCT" : ""), - ((p->selFlags & SF_Aggregate) ? " agg_flag" : ""), p - ); - if( p->pSrc && p->pSrc->nSrc ) n++; - if( p->pWhere ) n++; - if( p->pGroupBy ) n++; - if( p->pHaving ) n++; - if( p->pOrderBy ) n++; - if( p->pLimit ) n++; - if( p->pOffset ) n++; - if( p->pPrior ) n++; - sqlite3TreeViewExprList(pView, p->pEList, (n--)>0, "result-set"); - if( p->pSrc && p->pSrc->nSrc ){ - int i; - pView = sqlite3TreeViewPush(pView, (n--)>0); - sqlite3TreeViewLine(pView, "FROM"); - for(i=0; i<p->pSrc->nSrc; i++){ - struct SrcList_item *pItem = &p->pSrc->a[i]; - StrAccum x; - char zLine[100]; - sqlite3StrAccumInit(&x, zLine, sizeof(zLine), 0); - sqlite3XPrintf(&x, 0, "{%d,*}", pItem->iCursor); - if( pItem->zDatabase ){ - sqlite3XPrintf(&x, 0, " %s.%s", pItem->zDatabase, pItem->zName); - }else if( pItem->zName ){ - sqlite3XPrintf(&x, 0, " %s", pItem->zName); - } - if( pItem->pTab ){ - sqlite3XPrintf(&x, 0, " tabname=%Q", pItem->pTab->zName); - } - if( pItem->zAlias ){ - sqlite3XPrintf(&x, 0, " (AS %s)", pItem->zAlias); - } - if( pItem->jointype & JT_LEFT ){ - sqlite3XPrintf(&x, 0, " LEFT-JOIN"); - } - sqlite3StrAccumFinish(&x); - sqlite3TreeViewItem(pView, zLine, i<p->pSrc->nSrc-1); - if( pItem->pSelect ){ - sqlite3TreeViewSelect(pView, pItem->pSelect, 0); - } - sqlite3TreeViewPop(pView); - } - sqlite3TreeViewPop(pView); - } - if( p->pWhere ){ - sqlite3TreeViewItem(pView, "WHERE", (n--)>0); - sqlite3TreeViewExpr(pView, p->pWhere, 0); - sqlite3TreeViewPop(pView); - } - if( p->pGroupBy ){ - sqlite3TreeViewExprList(pView, p->pGroupBy, (n--)>0, "GROUPBY"); - } - if( p->pHaving ){ - sqlite3TreeViewItem(pView, "HAVING", (n--)>0); - sqlite3TreeViewExpr(pView, p->pHaving, 0); - sqlite3TreeViewPop(pView); - } - if( p->pOrderBy ){ - sqlite3TreeViewExprList(pView, p->pOrderBy, (n--)>0, "ORDERBY"); - } - if( p->pLimit ){ - sqlite3TreeViewItem(pView, "LIMIT", (n--)>0); - sqlite3TreeViewExpr(pView, p->pLimit, 0); - sqlite3TreeViewPop(pView); - } - if( p->pOffset ){ - sqlite3TreeViewItem(pView, "OFFSET", (n--)>0); - sqlite3TreeViewExpr(pView, p->pOffset, 0); - sqlite3TreeViewPop(pView); - } - if( p->pPrior ){ - const char *zOp = "UNION"; - switch( p->op ){ - case TK_ALL: zOp = "UNION ALL"; break; - case TK_INTERSECT: zOp = "INTERSECT"; break; - case TK_EXCEPT: zOp = "EXCEPT"; break; - } - sqlite3TreeViewItem(pView, zOp, (n--)>0); - sqlite3TreeViewSelect(pView, p->pPrior, 0); - sqlite3TreeViewPop(pView); - } - sqlite3TreeViewPop(pView); -} -#endif /* SQLITE_DEBUG */ |