/* ** Add a single new WhereTerm entry to the WhereClause object pWC. ** The new WhereTerm object is constructed from Expr p and with wtFlags. ** The index in pWC->a[] of the new WhereTerm is returned on success. ** 0 is returned if the new WhereTerm could not be added due to a memory ** allocation error. The memory allocation failure will be recorded in ** the db->mallocFailed flag so that higher-level functions can detect it. ** ** This routine will increase the size of the pWC->a[] array as necessary. ** ** If the wtFlags argument includes TERM_DYNAMIC, then responsibility ** for freeing the expression p is assumed by the WhereClause object pWC. ** This is true even if this routine fails to allocate a new WhereTerm. ** ** WARNING: This routine might reallocate the space used to store ** WhereTerms. All pointers to WhereTerms should be invalidated after ** calling this routine. Such pointers may be reinitialized by referencing ** the pWC->a[] array. */ static int whereClauseInsert(WhereClause *pWC, Expr *p, u16 wtFlags){ WhereTerm *pTerm; int idx; testcase( wtFlags & TERM_VIRTUAL ); if( pWC->nTerm>=pWC->nSlot ){ WhereTerm *pOld = pWC->a; sqlite3 *db = pWC->pWInfo->pParse->db; pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 ); if( pWC->a==0 ){ if( wtFlags & TERM_DYNAMIC ){ sqlite3ExprDelete(db, p); } pWC->a = pOld; return 0; } memcpy(pWC->a, pOld, sizeof(pWC->a[0])*pWC->nTerm); if( pOld!=pWC->aStatic ){ sqlite3DbFree(db, pOld); } pWC->nSlot = sqlite3DbMallocSize(db, pWC->a)/sizeof(pWC->a[0]); memset(&pWC->a[pWC->nTerm], 0, sizeof(pWC->a[0])*(pWC->nSlot-pWC->nTerm)); } pTerm = &pWC->a[idx = pWC->nTerm++]; if( p && ExprHasProperty(p, EP_Unlikely) ){ pTerm->truthProb = sqlite3LogEst(p->iTable) - 270; }else{ pTerm->truthProb = 1; } pTerm->pExpr = sqlite3ExprSkipCollate(p); pTerm->wtFlags = wtFlags; pTerm->pWC = pWC; pTerm->iParent = -1; return idx; }
/* ** This function is used to allocate and populate UnpackedRecord ** structures intended to be compared against sample index keys stored ** in the sqlite_stat4 table. ** ** A single call to this function attempts to populates field iVal (leftmost ** is 0 etc.) of the unpacked record with a value extracted from expression ** pExpr. Extraction of values is possible if: ** ** * (pExpr==0). In this case the value is assumed to be an SQL NULL, ** ** * The expression is a bound variable, and this is a reprepare, or ** ** * The sqlite3ValueFromExpr() function is able to extract a value ** from the expression (i.e. the expression is a literal value). ** ** If a value can be extracted, the affinity passed as the 5th argument ** is applied to it before it is copied into the UnpackedRecord. Output ** parameter *pbOk is set to true if a value is extracted, or false ** otherwise. ** ** When this function is called, *ppRec must either point to an object ** allocated by an earlier call to this function, or must be NULL. If it ** is NULL and a value can be successfully extracted, a new UnpackedRecord ** is allocated (and *ppRec set to point to it) before returning. ** ** Unless an error is encountered, SQLITE_OK is returned. It is not an ** error if a value cannot be extracted from pExpr. If an error does ** occur, an SQLite error code is returned. */ SQLITE_PRIVATE int sqlite3Stat4ProbeSetValue( Parse *pParse, /* Parse context */ Index *pIdx, /* Index being probed */ UnpackedRecord **ppRec, /* IN/OUT: Probe record */ Expr *pExpr, /* The expression to extract a value from */ u8 affinity, /* Affinity to use */ int iVal, /* Array element to populate */ int *pbOk /* OUT: True if value was extracted */ ){ int rc = SQLITE_OK; sqlite3_value *pVal = 0; sqlite3 *db = pParse->db; struct ValueNewStat4Ctx alloc; alloc.pParse = pParse; alloc.pIdx = pIdx; alloc.ppRec = ppRec; alloc.iVal = iVal; /* Skip over any TK_COLLATE nodes */ pExpr = sqlite3ExprSkipCollate(pExpr); if( !pExpr ){ pVal = valueNew(db, &alloc); if( pVal ){ sqlite3VdbeMemSetNull((Mem*)pVal); *pbOk = 1; } }else if( pExpr->op==TK_VARIABLE || (pExpr->op==TK_REGISTER && pExpr->op2==TK_VARIABLE) ){ Vdbe *v; int iBindVar = pExpr->iColumn; sqlite3VdbeSetVarmask(pParse->pVdbe, iBindVar); if( (v = pParse->pReprepare)!=0 ){ pVal = valueNew(db, &alloc); if( pVal ){ rc = sqlite3VdbeMemCopy((Mem*)pVal, &v->aVar[iBindVar-1]); if( rc==SQLITE_OK ){ sqlite3ValueApplyAffinity(pVal, affinity, ENC(db)); } pVal->db = pParse->db; *pbOk = 1; sqlite3VdbeMemStoreType((Mem*)pVal); } }else{ *pbOk = 0; } }else{ rc = valueFromExpr(db, pExpr, ENC(db), affinity, &pVal, &alloc); *pbOk = (pVal!=0); } assert( pVal==0 || pVal->db==db ); return rc; }
/* ** This routine identifies subexpressions in the WHERE clause where ** each subexpression is separated by the AND operator or some other ** operator specified in the op parameter. The WhereClause structure ** is filled with pointers to subexpressions. For example: ** ** WHERE a=='hello' AND coalesce(b,11)<10 AND (c+12!=d OR c==22) ** \________/ \_______________/ \________________/ ** slot[0] slot[1] slot[2] ** ** The original WHERE clause in pExpr is unaltered. All this routine ** does is make slot[] entries point to substructure within pExpr. ** ** In the previous sentence and in the diagram, "slot[]" refers to ** the WhereClause.a[] array. The slot[] array grows as needed to contain ** all terms of the WHERE clause. */ void sqlite3WhereSplit(WhereClause *pWC, Expr *pExpr, u8 op){ Expr *pE2 = sqlite3ExprSkipCollate(pExpr); pWC->op = op; if( pE2==0 ) return; if( pE2->op!=op ){ whereClauseInsert(pWC, pExpr, 0); }else{ sqlite3WhereSplit(pWC, pE2->pLeft, op); sqlite3WhereSplit(pWC, pE2->pRight, op); } }
/* ** pOrderBy is an ORDER BY or GROUP BY clause in SELECT statement pSelect. ** The Name context of the SELECT statement is pNC. zType is either ** "ORDER" or "GROUP" depending on which type of clause pOrderBy is. ** ** This routine resolves each term of the clause into an expression. ** If the order-by term is an integer I between 1 and N (where N is the ** number of columns in the result set of the SELECT) then the expression ** in the resolution is a copy of the I-th result-set expression. If ** the order-by term is an identifier that corresponds to the AS-name of ** a result-set expression, then the term resolves to a copy of the ** result-set expression. Otherwise, the expression is resolved in ** the usual way - using sqlite3ResolveExprNames(). ** ** This routine returns the number of errors. If errors occur, then ** an appropriate error message might be left in pParse. (OOM errors ** excepted.) */ static int resolveOrderGroupBy( NameContext *pNC, /* The name context of the SELECT statement */ Select *pSelect, /* The SELECT statement holding pOrderBy */ ExprList *pOrderBy, /* An ORDER BY or GROUP BY clause to resolve */ const char *zType /* Either "ORDER" or "GROUP", as appropriate */ ){ int i, j; /* Loop counters */ int iCol; /* Column number */ struct ExprList_item *pItem; /* A term of the ORDER BY clause */ Parse *pParse; /* Parsing context */ int nResult; /* Number of terms in the result set */ if( pOrderBy==0 ) return 0; nResult = pSelect->pEList->nExpr; pParse = pNC->pParse; for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ Expr *pE = pItem->pExpr; Expr *pE2 = sqlite3ExprSkipCollate(pE); if( zType[0]!='G' ){ iCol = resolveAsName(pParse, pSelect->pEList, pE2); if( iCol>0 ){ /* If an AS-name match is found, mark this ORDER BY column as being ** a copy of the iCol-th result-set column. The subsequent call to ** sqlite3ResolveOrderGroupBy() will convert the expression to a ** copy of the iCol-th result-set expression. */ pItem->u.x.iOrderByCol = (u16)iCol; continue; } } if( sqlite3ExprIsInteger(pE2, &iCol) ){ /* The ORDER BY term is an integer constant. Again, set the column ** number so that sqlite3ResolveOrderGroupBy() will convert the ** order-by term to a copy of the result-set expression */ if( iCol<1 || iCol>0xffff ){ resolveOutOfRangeError(pParse, zType, i+1, nResult); return 1; } pItem->u.x.iOrderByCol = (u16)iCol; continue; } /* Otherwise, treat the ORDER BY term as an ordinary expression */ pItem->u.x.iOrderByCol = 0; if( sqlite3ResolveExprNames(pNC, pE) ){ return 1; } for(j=0; j<pSelect->pEList->nExpr; j++){ if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr, -1)==0 ){ pItem->u.x.iOrderByCol = j+1; } } } return sqlite3ResolveOrderGroupBy(pParse, pSelect, pOrderBy, zType); }
/* ** The input to this routine is an WhereTerm structure with only the ** "pExpr" field filled in. The job of this routine is to analyze the ** subexpression and populate all the other fields of the WhereTerm ** structure. ** ** If the expression is of the form "<expr> <op> X" it gets commuted ** to the standard form of "X <op> <expr>". ** ** If the expression is of the form "X <op> Y" where both X and Y are ** columns, then the original expression is unchanged and a new virtual ** term of the form "Y <op> X" is added to the WHERE clause and ** analyzed separately. The original term is marked with TERM_COPIED ** and the new term is marked with TERM_DYNAMIC (because it's pExpr ** needs to be freed with the WhereClause) and TERM_VIRTUAL (because it ** is a commuted copy of a prior term.) The original term has nChild=1 ** and the copy has idxParent set to the index of the original term. */ static void exprAnalyze( SrcList *pSrc, /* the FROM clause */ WhereClause *pWC, /* the WHERE clause */ int idxTerm /* Index of the term to be analyzed */ ){ WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */ WhereTerm *pTerm; /* The term to be analyzed */ WhereMaskSet *pMaskSet; /* Set of table index masks */ Expr *pExpr; /* The expression to be analyzed */ Bitmask prereqLeft; /* Prerequesites of the pExpr->pLeft */ Bitmask prereqAll; /* Prerequesites of pExpr */ Bitmask extraRight = 0; /* Extra dependencies on LEFT JOIN */ Expr *pStr1 = 0; /* RHS of LIKE/GLOB operator */ int isComplete = 0; /* RHS of LIKE/GLOB ends with wildcard */ int noCase = 0; /* uppercase equivalent to lowercase */ int op; /* Top-level operator. pExpr->op */ Parse *pParse = pWInfo->pParse; /* Parsing context */ sqlite3 *db = pParse->db; /* Database connection */ if( db->mallocFailed ){ return; } pTerm = &pWC->a[idxTerm]; pMaskSet = &pWInfo->sMaskSet; pExpr = pTerm->pExpr; assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE ); prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft); op = pExpr->op; if( op==TK_IN ){ assert( pExpr->pRight==0 ); if( ExprHasProperty(pExpr, EP_xIsSelect) ){ pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect); }else{ pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList); } }else if( op==TK_ISNULL ){ pTerm->prereqRight = 0; }else{ pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight); } prereqAll = sqlite3WhereExprUsage(pMaskSet, pExpr); if( ExprHasProperty(pExpr, EP_FromJoin) ){ Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable); prereqAll |= x; extraRight = x-1; /* ON clause terms may not be used with an index ** on left table of a LEFT JOIN. Ticket #3015 */ } pTerm->prereqAll = prereqAll; pTerm->leftCursor = -1; pTerm->iParent = -1; pTerm->eOperator = 0; if( allowedOp(op) ){ Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft); Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight); u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV; if( pLeft->op==TK_COLUMN ){ pTerm->leftCursor = pLeft->iTable; pTerm->u.leftColumn = pLeft->iColumn; pTerm->eOperator = operatorMask(op) & opMask; } if( op==TK_IS ) pTerm->wtFlags |= TERM_IS; if( pRight && pRight->op==TK_COLUMN ){ WhereTerm *pNew; Expr *pDup; u16 eExtraOp = 0; /* Extra bits for pNew->eOperator */ if( pTerm->leftCursor>=0 ){ int idxNew; pDup = sqlite3ExprDup(db, pExpr, 0); if( db->mallocFailed ){ sqlite3ExprDelete(db, pDup); return; } idxNew = whereClauseInsert(pWC, pDup, TERM_VIRTUAL|TERM_DYNAMIC); if( idxNew==0 ) return; pNew = &pWC->a[idxNew]; markTermAsChild(pWC, idxNew, idxTerm); if( op==TK_IS ) pNew->wtFlags |= TERM_IS; pTerm = &pWC->a[idxTerm]; pTerm->wtFlags |= TERM_COPIED; if( termIsEquivalence(pParse, pDup) ){ pTerm->eOperator |= WO_EQUIV; eExtraOp = WO_EQUIV; } }else{ pDup = pExpr; pNew = pTerm; } exprCommute(pParse, pDup); pLeft = sqlite3ExprSkipCollate(pDup->pLeft); pNew->leftCursor = pLeft->iTable; pNew->u.leftColumn = pLeft->iColumn; testcase( (prereqLeft | extraRight) != prereqLeft ); pNew->prereqRight = prereqLeft | extraRight; pNew->prereqAll = prereqAll; pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask; } } #ifndef SQLITE_OMIT_BETWEEN_OPTIMIZATION /* If a term is the BETWEEN operator, create two new virtual terms ** that define the range that the BETWEEN implements. For example: ** ** a BETWEEN b AND c ** ** is converted into: ** ** (a BETWEEN b AND c) AND (a>=b) AND (a<=c) ** ** The two new terms are added onto the end of the WhereClause object. ** The new terms are "dynamic" and are children of the original BETWEEN ** term. That means that if the BETWEEN term is coded, the children are ** skipped. Or, if the children are satisfied by an index, the original ** BETWEEN term is skipped. */ else if( pExpr->op==TK_BETWEEN && pWC->op==TK_AND ){ ExprList *pList = pExpr->x.pList; int i; static const u8 ops[] = {TK_GE, TK_LE}; assert( pList!=0 ); assert( pList->nExpr==2 ); for(i=0; i<2; i++){ Expr *pNewExpr; int idxNew; pNewExpr = sqlite3PExpr(pParse, ops[i], sqlite3ExprDup(db, pExpr->pLeft, 0), sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0); transferJoinMarkings(pNewExpr, pExpr); idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC); testcase( idxNew==0 ); exprAnalyze(pSrc, pWC, idxNew); pTerm = &pWC->a[idxTerm]; markTermAsChild(pWC, idxNew, idxTerm); } } #endif /* SQLITE_OMIT_BETWEEN_OPTIMIZATION */ #if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY) /* Analyze a term that is composed of two or more subterms connected by ** an OR operator. */ else if( pExpr->op==TK_OR ){ assert( pWC->op==TK_AND ); exprAnalyzeOrTerm(pSrc, pWC, idxTerm); pTerm = &pWC->a[idxTerm]; } #endif /* SQLITE_OMIT_OR_OPTIMIZATION */ #ifndef SQLITE_OMIT_LIKE_OPTIMIZATION /* Add constraints to reduce the search space on a LIKE or GLOB ** operator. ** ** A like pattern of the form "x LIKE 'aBc%'" is changed into constraints ** ** x>='ABC' AND x<'abd' AND x LIKE 'aBc%' ** ** The last character of the prefix "abc" is incremented to form the ** termination condition "abd". If case is not significant (the default ** for LIKE) then the lower-bound is made all uppercase and the upper- ** bound is made all lowercase so that the bounds also work when comparing ** BLOBs. */ if( pWC->op==TK_AND && isLikeOrGlob(pParse, pExpr, &pStr1, &isComplete, &noCase) ){ Expr *pLeft; /* LHS of LIKE/GLOB operator */ Expr *pStr2; /* Copy of pStr1 - RHS of LIKE/GLOB operator */ Expr *pNewExpr1; Expr *pNewExpr2; int idxNew1; int idxNew2; const char *zCollSeqName; /* Name of collating sequence */ const u16 wtFlags = TERM_LIKEOPT | TERM_VIRTUAL | TERM_DYNAMIC; pLeft = pExpr->x.pList->a[1].pExpr; pStr2 = sqlite3ExprDup(db, pStr1, 0); /* Convert the lower bound to upper-case and the upper bound to ** lower-case (upper-case is less than lower-case in ASCII) so that ** the range constraints also work for BLOBs */ if( noCase && !pParse->db->mallocFailed ){ int i; char c; pTerm->wtFlags |= TERM_LIKE; for(i=0; (c = pStr1->u.zToken[i])!=0; i++){ pStr1->u.zToken[i] = sqlite3Toupper(c); pStr2->u.zToken[i] = sqlite3Tolower(c); } } if( !db->mallocFailed ){ u8 c, *pC; /* Last character before the first wildcard */ pC = (u8*)&pStr2->u.zToken[sqlite3Strlen30(pStr2->u.zToken)-1]; c = *pC; if( noCase ){ /* The point is to increment the last character before the first ** wildcard. But if we increment '@', that will push it into the ** alphabetic range where case conversions will mess up the ** inequality. To avoid this, make sure to also run the full ** LIKE on all candidate expressions by clearing the isComplete flag */ if( c=='A'-1 ) isComplete = 0; c = sqlite3UpperToLower[c]; } *pC = c + 1; } zCollSeqName = noCase ? "NOCASE" : "BINARY"; pNewExpr1 = sqlite3ExprDup(db, pLeft, 0); pNewExpr1 = sqlite3PExpr(pParse, TK_GE, sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName), pStr1, 0); transferJoinMarkings(pNewExpr1, pExpr); idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags); testcase( idxNew1==0 ); exprAnalyze(pSrc, pWC, idxNew1); pNewExpr2 = sqlite3ExprDup(db, pLeft, 0); pNewExpr2 = sqlite3PExpr(pParse, TK_LT, sqlite3ExprAddCollateString(pParse,pNewExpr2,zCollSeqName), pStr2, 0); transferJoinMarkings(pNewExpr2, pExpr); idxNew2 = whereClauseInsert(pWC, pNewExpr2, wtFlags); testcase( idxNew2==0 ); exprAnalyze(pSrc, pWC, idxNew2); pTerm = &pWC->a[idxTerm]; if( isComplete ){ markTermAsChild(pWC, idxNew1, idxTerm); markTermAsChild(pWC, idxNew2, idxTerm); } } #endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */ #ifndef SQLITE_OMIT_VIRTUALTABLE /* Add a WO_MATCH auxiliary term to the constraint set if the ** current expression is of the form: column MATCH expr. ** This information is used by the xBestIndex methods of ** virtual tables. The native query optimizer does not attempt ** to do anything with MATCH functions. */ if( isMatchOfColumn(pExpr) ){ int idxNew; Expr *pRight, *pLeft; WhereTerm *pNewTerm; Bitmask prereqColumn, prereqExpr; pRight = pExpr->x.pList->a[0].pExpr; pLeft = pExpr->x.pList->a[1].pExpr; prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight); prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft); if( (prereqExpr & prereqColumn)==0 ){ Expr *pNewExpr; pNewExpr = sqlite3PExpr(pParse, TK_MATCH, 0, sqlite3ExprDup(db, pRight, 0), 0); idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC); testcase( idxNew==0 ); pNewTerm = &pWC->a[idxNew]; pNewTerm->prereqRight = prereqExpr; pNewTerm->leftCursor = pLeft->iTable; pNewTerm->u.leftColumn = pLeft->iColumn; pNewTerm->eOperator = WO_MATCH; markTermAsChild(pWC, idxNew, idxTerm); pTerm = &pWC->a[idxTerm]; pTerm->wtFlags |= TERM_COPIED; pNewTerm->prereqAll = pTerm->prereqAll; } } #endif /* SQLITE_OMIT_VIRTUALTABLE */ #ifdef SQLITE_ENABLE_STAT3_OR_STAT4 /* When sqlite_stat3 histogram data is available an operator of the ** form "x IS NOT NULL" can sometimes be evaluated more efficiently ** as "x>NULL" if x is not an INTEGER PRIMARY KEY. So construct a ** virtual term of that form. ** ** Note that the virtual term must be tagged with TERM_VNULL. */ if( pExpr->op==TK_NOTNULL && pExpr->pLeft->op==TK_COLUMN && pExpr->pLeft->iColumn>=0 && OptimizationEnabled(db, SQLITE_Stat34) ){ Expr *pNewExpr; Expr *pLeft = pExpr->pLeft; int idxNew; WhereTerm *pNewTerm; pNewExpr = sqlite3PExpr(pParse, TK_GT, sqlite3ExprDup(db, pLeft, 0), sqlite3PExpr(pParse, TK_NULL, 0, 0, 0), 0); idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC|TERM_VNULL); if( idxNew ){ pNewTerm = &pWC->a[idxNew]; pNewTerm->prereqRight = 0; pNewTerm->leftCursor = pLeft->iTable; pNewTerm->u.leftColumn = pLeft->iColumn; pNewTerm->eOperator = WO_GT; markTermAsChild(pWC, idxNew, idxTerm); pTerm = &pWC->a[idxTerm]; pTerm->wtFlags |= TERM_COPIED; pNewTerm->prereqAll = pTerm->prereqAll; } } #endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ /* Prevent ON clause terms of a LEFT JOIN from being used to drive ** an index for tables to the left of the join. */ pTerm->prereqRight |= extraRight; }
/* ** Check to see if the given expression is a LIKE or GLOB operator that ** can be optimized using inequality constraints. Return TRUE if it is ** so and false if not. ** ** In order for the operator to be optimizible, the RHS must be a string ** literal that does not begin with a wildcard. The LHS must be a column ** that may only be NULL, a string, or a BLOB, never a number. (This means ** that virtual tables cannot participate in the LIKE optimization.) The ** collating sequence for the column on the LHS must be appropriate for ** the operator. */ static int isLikeOrGlob( Parse *pParse, /* Parsing and code generating context */ Expr *pExpr, /* Test this expression */ Expr **ppPrefix, /* Pointer to TK_STRING expression with pattern prefix */ int *pisComplete, /* True if the only wildcard is % in the last character */ int *pnoCase /* True if uppercase is equivalent to lowercase */ ){ const char *z = 0; /* String on RHS of LIKE operator */ Expr *pRight, *pLeft; /* Right and left size of LIKE operator */ ExprList *pList; /* List of operands to the LIKE operator */ int c; /* One character in z[] */ int cnt; /* Number of non-wildcard prefix characters */ char wc[3]; /* Wildcard characters */ sqlite3 *db = pParse->db; /* Database connection */ sqlite3_value *pVal = 0; int op; /* Opcode of pRight */ if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, wc) ){ return 0; } #ifdef SQLITE_EBCDIC if( *pnoCase ) return 0; #endif pList = pExpr->x.pList; pLeft = pList->a[1].pExpr; if( pLeft->op!=TK_COLUMN || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT || IsVirtual(pLeft->pTab) /* Value might be numeric */ ){ /* IMP: R-02065-49465 The left-hand side of the LIKE or GLOB operator must ** be the name of an indexed column with TEXT affinity. */ return 0; } assert( pLeft->iColumn!=(-1) ); /* Because IPK never has AFF_TEXT */ pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr); op = pRight->op; if( op==TK_VARIABLE ){ Vdbe *pReprepare = pParse->pReprepare; int iCol = pRight->iColumn; pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_BLOB); if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){ z = (char *)sqlite3_value_text(pVal); } sqlite3VdbeSetVarmask(pParse->pVdbe, iCol); assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER ); }else if( op==TK_STRING ){ z = pRight->u.zToken; } if( z ){ cnt = 0; while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){ cnt++; } if( cnt!=0 && 255!=(u8)z[cnt-1] ){ Expr *pPrefix; *pisComplete = c==wc[0] && z[cnt+1]==0; pPrefix = sqlite3Expr(db, TK_STRING, z); if( pPrefix ) pPrefix->u.zToken[cnt] = 0; *ppPrefix = pPrefix; if( op==TK_VARIABLE ){ Vdbe *v = pParse->pVdbe; sqlite3VdbeSetVarmask(v, pRight->iColumn); if( *pisComplete && pRight->u.zToken[1] ){ /* If the rhs of the LIKE expression is a variable, and the current ** value of the variable means there is no need to invoke the LIKE ** function, then no OP_Variable will be added to the program. ** This causes problems for the sqlite3_bind_parameter_name() ** API. To work around them, add a dummy OP_Variable here. */ int r1 = sqlite3GetTempReg(pParse); sqlite3ExprCodeTarget(pParse, pRight, r1); sqlite3VdbeChangeP3(v, sqlite3VdbeCurrentAddr(v)-1, 0); sqlite3ReleaseTempReg(pParse, r1); } } }else{ z = 0; } } sqlite3ValueFree(pVal); return (z!=0); }
/* ** Analyze the ORDER BY clause in a compound SELECT statement. Modify ** each term of the ORDER BY clause is a constant integer between 1 ** and N where N is the number of columns in the compound SELECT. ** ** ORDER BY terms that are already an integer between 1 and N are ** unmodified. ORDER BY terms that are integers outside the range of ** 1 through N generate an error. ORDER BY terms that are expressions ** are matched against result set expressions of compound SELECT ** beginning with the left-most SELECT and working toward the right. ** At the first match, the ORDER BY expression is transformed into ** the integer column number. ** ** Return the number of errors seen. */ static int resolveCompoundOrderBy( Parse *pParse, /* Parsing context. Leave error messages here */ Select *pSelect /* The SELECT statement containing the ORDER BY */ ){ int i; ExprList *pOrderBy; ExprList *pEList; sqlite3 *db; int moreToDo = 1; pOrderBy = pSelect->pOrderBy; if( pOrderBy==0 ) return 0; db = pParse->db; #if SQLITE_MAX_COLUMN if( pOrderBy->nExpr>db->aLimit[SQLITE_LIMIT_COLUMN] ){ sqlite3ErrorMsg(pParse, "too many terms in ORDER BY clause"); return 1; } #endif for(i=0; i<pOrderBy->nExpr; i++){ pOrderBy->a[i].done = 0; } pSelect->pNext = 0; while( pSelect->pPrior ){ pSelect->pPrior->pNext = pSelect; pSelect = pSelect->pPrior; } while( pSelect && moreToDo ){ struct ExprList_item *pItem; moreToDo = 0; pEList = pSelect->pEList; assert( pEList!=0 ); for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){ int iCol = -1; Expr *pE, *pDup; if( pItem->done ) continue; pE = sqlite3ExprSkipCollate(pItem->pExpr); if( sqlite3ExprIsInteger(pE, &iCol) ){ if( iCol<=0 || iCol>pEList->nExpr ){ resolveOutOfRangeError(pParse, "ORDER", i+1, pEList->nExpr); return 1; } }else{ iCol = resolveAsName(pParse, pEList, pE); if( iCol==0 ){ pDup = sqlite3ExprDup(db, pE, 0); if( !db->mallocFailed ){ assert(pDup); iCol = resolveOrderByTermToExprList(pParse, pSelect, pDup); } sqlite3ExprDelete(db, pDup); } } if( iCol>0 ){ /* Convert the ORDER BY term into an integer column number iCol, ** taking care to preserve the COLLATE clause if it exists */ Expr *pNew = sqlite3Expr(db, TK_INTEGER, 0); if( pNew==0 ) return 1; pNew->flags |= EP_IntValue; pNew->u.iValue = iCol; if( pItem->pExpr==pE ){ pItem->pExpr = pNew; }else{ assert( pItem->pExpr->op==TK_COLLATE ); assert( pItem->pExpr->pLeft==pE ); pItem->pExpr->pLeft = pNew; } sqlite3ExprDelete(db, pE); pItem->u.x.iOrderByCol = (u16)iCol; pItem->done = 1; }else{ moreToDo = 1; } } pSelect = pSelect->pNext; } for(i=0; i<pOrderBy->nExpr; i++){ if( pOrderBy->a[i].done==0 ){ sqlite3ErrorMsg(pParse, "%r ORDER BY term does not match any " "column in the result set", i+1); return 1; } } return 0; }