/* ** 2015-06-08 ** ** 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 module contains C code that generates VDBE code used to process ** the WHERE clause of SQL statements. ** ** This file was originally part of where.c but was split out to improve ** readability and editability. This file contains utility routines for ** analyzing Expr objects in the WHERE clause. */ #include "sqliteInt.h" #include "whereInt.h" /* Forward declarations */ static void exprAnalyze(SrcList*, WhereClause*, int); /* ** Deallocate all memory associated with a WhereOrInfo object. */ static void whereOrInfoDelete(sqlite3 *db, WhereOrInfo *p){ sqlite3WhereClauseClear(&p->wc); sqlite3DbFree(db, p); } /* ** Deallocate all memory associated with a WhereAndInfo object. */ static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){ sqlite3WhereClauseClear(&p->wc); sqlite3DbFree(db, p); } /* ** 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 = sqlite3WhereMalloc(pWC->pWInfo, 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); pWC->nSlot = pWC->nSlot*2; } pTerm = &pWC->a[idx = pWC->nTerm++]; if( (wtFlags & TERM_VIRTUAL)==0 ) pWC->nBase = pWC->nTerm; if( p && ExprHasProperty(p, EP_Unlikely) ){ pTerm->truthProb = sqlite3LogEst(p->iTable) - 270; }else{ pTerm->truthProb = 1; } pTerm->pExpr = sqlite3ExprSkipCollateAndLikely(p); pTerm->wtFlags = wtFlags; pTerm->pWC = pWC; pTerm->iParent = -1; memset(&pTerm->eOperator, 0, sizeof(WhereTerm) - offsetof(WhereTerm,eOperator)); return idx; } /* ** Return TRUE if the given operator is one of the operators that is ** allowed for an indexable WHERE clause term. The allowed operators are ** "=", "<", ">", "<=", ">=", "IN", "IS", and "IS NULL" */ static int allowedOp(int op){ assert( TK_GT>TK_EQ && TK_GTTK_EQ && TK_LTTK_EQ && TK_LETK_GE ) return 0; if( op>=TK_EQ ) return 1; return op==TK_IN || op==TK_ISNULL || op==TK_IS; } /* ** Commute a comparison operator. Expressions of the form "X op Y" ** are converted into "Y op X". */ static u16 exprCommute(Parse *pParse, Expr *pExpr){ if( pExpr->pLeft->op==TK_VECTOR || pExpr->pRight->op==TK_VECTOR || sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight) != sqlite3BinaryCompareCollSeq(pParse, pExpr->pRight, pExpr->pLeft) ){ pExpr->flags ^= EP_Commuted; } SWAP(Expr*,pExpr->pRight,pExpr->pLeft); if( pExpr->op>=TK_GT ){ assert( TK_LT==TK_GT+2 ); assert( TK_GE==TK_LE+2 ); assert( TK_GT>TK_EQ ); assert( TK_GTop>=TK_GT && pExpr->op<=TK_GE ); pExpr->op = ((pExpr->op-TK_GT)^2)+TK_GT; } return 0; } /* ** Translate from TK_xx operator to WO_xx bitmask. */ static u16 operatorMask(int op){ u16 c; assert( allowedOp(op) ); if( op>=TK_EQ ){ assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff ); c = (u16)(WO_EQ<<(op-TK_EQ)); }else if( op==TK_IN ){ c = WO_IN; }else if( op==TK_ISNULL ){ c = WO_ISNULL; }else{ assert( op==TK_IS ); c = WO_IS; } assert( op!=TK_ISNULL || c==WO_ISNULL ); assert( op!=TK_IN || c==WO_IN ); assert( op!=TK_EQ || c==WO_EQ ); assert( op!=TK_LT || c==WO_LT ); assert( op!=TK_LE || c==WO_LE ); assert( op!=TK_GT || c==WO_GT ); assert( op!=TK_GE || c==WO_GE ); assert( op!=TK_IS || c==WO_IS ); return c; } #ifndef SQLITE_OMIT_LIKE_OPTIMIZATION /* ** 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 u8 *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 */ u8 c; /* One character in z[] */ int cnt; /* Number of non-wildcard prefix characters */ u8 wc[4]; /* Wildcard characters */ sqlite3 *db = pParse->db; /* Database connection */ sqlite3_value *pVal = 0; int op; /* Opcode of pRight */ int rc; /* Result code to return */ if( !sqlite3IsLikeFunction(db, pExpr, pnoCase, (char*)wc) ){ return 0; } #ifdef SQLITE_EBCDIC if( *pnoCase ) return 0; #endif assert( ExprUseXList(pExpr) ); pList = pExpr->x.pList; pLeft = pList->a[1].pExpr; pRight = sqlite3ExprSkipCollate(pList->a[0].pExpr); op = pRight->op; if( op==TK_VARIABLE && (db->flags & SQLITE_EnableQPSG)==0 ){ Vdbe *pReprepare = pParse->pReprepare; int iCol = pRight->iColumn; pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_BLOB); if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){ z = sqlite3_value_text(pVal); } sqlite3VdbeSetVarmask(pParse->pVdbe, iCol); assert( pRight->op==TK_VARIABLE || pRight->op==TK_REGISTER ); }else if( op==TK_STRING ){ assert( !ExprHasProperty(pRight, EP_IntValue) ); z = (u8*)pRight->u.zToken; } if( z ){ /* Count the number of prefix bytes prior to the first wildcard. ** or U+fffd character. If the underlying database has a UTF16LE ** encoding, then only consider ASCII characters. Note that the ** encoding of z[] is UTF8 - we are dealing with only UTF8 here in ** this code, but the database engine itself might be processing ** content using a different encoding. */ cnt = 0; while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){ cnt++; if( c==wc[3] && z[cnt]>0 && z[cnt]<0x80 ){ cnt++; }else if( c>=0x80 ){ const u8 *z2 = z+cnt-1; if( sqlite3Utf8Read(&z2)==0xfffd || ENC(db)==SQLITE_UTF16LE ){ cnt--; break; }else{ cnt = (int)(z2-z); } } } /* The optimization is possible only if (1) the pattern does not begin ** with a wildcard and if (2) the non-wildcard prefix does not end with ** an (illegal 0xff) character, or (3) the pattern does not consist of ** a single escape character. The second condition is necessary so ** that we can increment the prefix key to find an upper bound for the ** range search. The third is because the caller assumes that the pattern ** consists of at least one character after all escapes have been ** removed. */ if( (cnt>1 || (cnt>0 && z[0]!=wc[3])) && ALWAYS(255!=(u8)z[cnt-1]) ){ Expr *pPrefix; /* A "complete" match if the pattern ends with "*" or "%" */ *pisComplete = c==wc[0] && z[cnt+1]==0 && ENC(db)!=SQLITE_UTF16LE; /* Get the pattern prefix. Remove all escapes from the prefix. */ pPrefix = sqlite3Expr(db, TK_STRING, (char*)z); if( pPrefix ){ int iFrom, iTo; char *zNew; assert( !ExprHasProperty(pPrefix, EP_IntValue) ); zNew = pPrefix->u.zToken; zNew[cnt] = 0; for(iFrom=iTo=0; iFrom0 ); /* If the LHS is not an ordinary column with TEXT affinity, then the ** pattern prefix boundaries (both the start and end boundaries) must ** not look like a number. Otherwise the pattern might be treated as ** a number, which will invalidate the LIKE optimization. ** ** Getting this right has been a persistent source of bugs in the ** LIKE optimization. See, for example: ** 2018-09-10 https://sqlite.org/src/info/c94369cae9b561b1 ** 2019-05-02 https://sqlite.org/src/info/b043a54c3de54b28 ** 2019-06-10 https://sqlite.org/src/info/fd76310a5e843e07 ** 2019-06-14 https://sqlite.org/src/info/ce8717f0885af975 ** 2019-09-03 https://sqlite.org/src/info/0f0428096f17252a */ if( pLeft->op!=TK_COLUMN || sqlite3ExprAffinity(pLeft)!=SQLITE_AFF_TEXT || (ALWAYS( ExprUseYTab(pLeft) ) && ALWAYS(pLeft->y.pTab) && IsVirtual(pLeft->y.pTab)) /* Might be numeric */ ){ int isNum; double rDummy; isNum = sqlite3AtoF(zNew, &rDummy, iTo, SQLITE_UTF8); if( isNum<=0 ){ if( iTo==1 && zNew[0]=='-' ){ isNum = +1; }else{ zNew[iTo-1]++; isNum = sqlite3AtoF(zNew, &rDummy, iTo, SQLITE_UTF8); zNew[iTo-1]--; } } if( isNum>0 ){ sqlite3ExprDelete(db, pPrefix); sqlite3ValueFree(pVal); return 0; } } } *ppPrefix = pPrefix; /* If the RHS pattern is a bound parameter, make arrangements to ** reprepare the statement when that parameter is rebound */ if( op==TK_VARIABLE ){ Vdbe *v = pParse->pVdbe; sqlite3VdbeSetVarmask(v, pRight->iColumn); assert( !ExprHasProperty(pRight, EP_IntValue) ); 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; } } rc = (z!=0); sqlite3ValueFree(pVal); return rc; } #endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */ #ifndef SQLITE_OMIT_VIRTUALTABLE /* ** Check to see if the pExpr expression is a form that needs to be passed ** to the xBestIndex method of virtual tables. Forms of interest include: ** ** Expression Virtual Table Operator ** ----------------------- --------------------------------- ** 1. column MATCH expr SQLITE_INDEX_CONSTRAINT_MATCH ** 2. column GLOB expr SQLITE_INDEX_CONSTRAINT_GLOB ** 3. column LIKE expr SQLITE_INDEX_CONSTRAINT_LIKE ** 4. column REGEXP expr SQLITE_INDEX_CONSTRAINT_REGEXP ** 5. column != expr SQLITE_INDEX_CONSTRAINT_NE ** 6. expr != column SQLITE_INDEX_CONSTRAINT_NE ** 7. column IS NOT expr SQLITE_INDEX_CONSTRAINT_ISNOT ** 8. expr IS NOT column SQLITE_INDEX_CONSTRAINT_ISNOT ** 9. column IS NOT NULL SQLITE_INDEX_CONSTRAINT_ISNOTNULL ** ** In every case, "column" must be a column of a virtual table. If there ** is a match, set *ppLeft to the "column" expression, set *ppRight to the ** "expr" expression (even though in forms (6) and (8) the column is on the ** right and the expression is on the left). Also set *peOp2 to the ** appropriate virtual table operator. The return value is 1 or 2 if there ** is a match. The usual return is 1, but if the RHS is also a column ** of virtual table in forms (5) or (7) then return 2. ** ** If the expression matches none of the patterns above, return 0. */ static int isAuxiliaryVtabOperator( sqlite3 *db, /* Parsing context */ Expr *pExpr, /* Test this expression */ unsigned char *peOp2, /* OUT: 0 for MATCH, or else an op2 value */ Expr **ppLeft, /* Column expression to left of MATCH/op2 */ Expr **ppRight /* Expression to left of MATCH/op2 */ ){ if( pExpr->op==TK_FUNCTION ){ static const struct Op2 { const char *zOp; unsigned char eOp2; } aOp[] = { { "match", SQLITE_INDEX_CONSTRAINT_MATCH }, { "glob", SQLITE_INDEX_CONSTRAINT_GLOB }, { "like", SQLITE_INDEX_CONSTRAINT_LIKE }, { "regexp", SQLITE_INDEX_CONSTRAINT_REGEXP } }; ExprList *pList; Expr *pCol; /* Column reference */ int i; assert( ExprUseXList(pExpr) ); pList = pExpr->x.pList; if( pList==0 || pList->nExpr!=2 ){ return 0; } /* Built-in operators MATCH, GLOB, LIKE, and REGEXP attach to a ** virtual table on their second argument, which is the same as ** the left-hand side operand in their in-fix form. ** ** vtab_column MATCH expression ** MATCH(expression,vtab_column) */ pCol = pList->a[1].pExpr; assert( pCol->op!=TK_COLUMN || (ExprUseYTab(pCol) && pCol->y.pTab!=0) ); if( ExprIsVtab(pCol) ){ for(i=0; iu.zToken, aOp[i].zOp)==0 ){ *peOp2 = aOp[i].eOp2; *ppRight = pList->a[0].pExpr; *ppLeft = pCol; return 1; } } } /* We can also match against the first column of overloaded ** functions where xFindFunction returns a value of at least ** SQLITE_INDEX_CONSTRAINT_FUNCTION. ** ** OVERLOADED(vtab_column,expression) ** ** Historically, xFindFunction expected to see lower-case function ** names. But for this use case, xFindFunction is expected to deal ** with function names in an arbitrary case. */ pCol = pList->a[0].pExpr; assert( pCol->op!=TK_COLUMN || ExprUseYTab(pCol) ); assert( pCol->op!=TK_COLUMN || (ExprUseYTab(pCol) && pCol->y.pTab!=0) ); if( ExprIsVtab(pCol) ){ sqlite3_vtab *pVtab; sqlite3_module *pMod; void (*xNotUsed)(sqlite3_context*,int,sqlite3_value**); void *pNotUsed; pVtab = sqlite3GetVTable(db, pCol->y.pTab)->pVtab; assert( pVtab!=0 ); assert( pVtab->pModule!=0 ); assert( !ExprHasProperty(pExpr, EP_IntValue) ); pMod = (sqlite3_module *)pVtab->pModule; if( pMod->xFindFunction!=0 ){ i = pMod->xFindFunction(pVtab,2, pExpr->u.zToken, &xNotUsed, &pNotUsed); if( i>=SQLITE_INDEX_CONSTRAINT_FUNCTION ){ *peOp2 = i; *ppRight = pList->a[1].pExpr; *ppLeft = pCol; return 1; } } } }else if( pExpr->op>=TK_EQ ){ /* Comparison operators are a common case. Save a few comparisons for ** that common case by terminating early. */ assert( TK_NE < TK_EQ ); assert( TK_ISNOT < TK_EQ ); assert( TK_NOTNULL < TK_EQ ); return 0; }else if( pExpr->op==TK_NE || pExpr->op==TK_ISNOT || pExpr->op==TK_NOTNULL ){ int res = 0; Expr *pLeft = pExpr->pLeft; Expr *pRight = pExpr->pRight; assert( pLeft->op!=TK_COLUMN || (ExprUseYTab(pLeft) && pLeft->y.pTab!=0) ); if( ExprIsVtab(pLeft) ){ res++; } assert( pRight==0 || pRight->op!=TK_COLUMN || (ExprUseYTab(pRight) && pRight->y.pTab!=0) ); if( pRight && ExprIsVtab(pRight) ){ res++; SWAP(Expr*, pLeft, pRight); } *ppLeft = pLeft; *ppRight = pRight; if( pExpr->op==TK_NE ) *peOp2 = SQLITE_INDEX_CONSTRAINT_NE; if( pExpr->op==TK_ISNOT ) *peOp2 = SQLITE_INDEX_CONSTRAINT_ISNOT; if( pExpr->op==TK_NOTNULL ) *peOp2 = SQLITE_INDEX_CONSTRAINT_ISNOTNULL; return res; } return 0; } #endif /* SQLITE_OMIT_VIRTUALTABLE */ /* ** If the pBase expression originated in the ON or USING clause of ** a join, then transfer the appropriate markings over to derived. */ static void transferJoinMarkings(Expr *pDerived, Expr *pBase){ if( pDerived && ExprHasProperty(pBase, EP_OuterON|EP_InnerON) ){ pDerived->flags |= pBase->flags & (EP_OuterON|EP_InnerON); pDerived->w.iJoin = pBase->w.iJoin; } } /* ** Mark term iChild as being a child of term iParent */ static void markTermAsChild(WhereClause *pWC, int iChild, int iParent){ pWC->a[iChild].iParent = iParent; pWC->a[iChild].truthProb = pWC->a[iParent].truthProb; pWC->a[iParent].nChild++; } /* ** Return the N-th AND-connected subterm of pTerm. Or if pTerm is not ** a conjunction, then return just pTerm when N==0. If N is exceeds ** the number of available subterms, return NULL. */ static WhereTerm *whereNthSubterm(WhereTerm *pTerm, int N){ if( pTerm->eOperator!=WO_AND ){ return N==0 ? pTerm : 0; } if( Nu.pAndInfo->wc.nTerm ){ return &pTerm->u.pAndInfo->wc.a[N]; } return 0; } /* ** Subterms pOne and pTwo are contained within WHERE clause pWC. The ** two subterms are in disjunction - they are OR-ed together. ** ** If these two terms are both of the form: "A op B" with the same ** A and B values but different operators and if the operators are ** compatible (if one is = and the other is <, for example) then ** add a new virtual AND term to pWC that is the combination of the ** two. ** ** Some examples: ** ** x x<=y ** x=y OR x=y --> x=y ** x<=y OR x x<=y ** ** The following is NOT generated: ** ** xy --> x!=y */ static void whereCombineDisjuncts( SrcList *pSrc, /* the FROM clause */ WhereClause *pWC, /* The complete WHERE clause */ WhereTerm *pOne, /* First disjunct */ WhereTerm *pTwo /* Second disjunct */ ){ u16 eOp = pOne->eOperator | pTwo->eOperator; sqlite3 *db; /* Database connection (for malloc) */ Expr *pNew; /* New virtual expression */ int op; /* Operator for the combined expression */ int idxNew; /* Index in pWC of the next virtual term */ if( (pOne->wtFlags | pTwo->wtFlags) & TERM_VNULL ) return; if( (pOne->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return; if( (pTwo->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE))==0 ) return; if( (eOp & (WO_EQ|WO_LT|WO_LE))!=eOp && (eOp & (WO_EQ|WO_GT|WO_GE))!=eOp ) return; assert( pOne->pExpr->pLeft!=0 && pOne->pExpr->pRight!=0 ); assert( pTwo->pExpr->pLeft!=0 && pTwo->pExpr->pRight!=0 ); if( sqlite3ExprCompare(0,pOne->pExpr->pLeft, pTwo->pExpr->pLeft, -1) ) return; if( sqlite3ExprCompare(0,pOne->pExpr->pRight, pTwo->pExpr->pRight,-1) )return; /* If we reach this point, it means the two subterms can be combined */ if( (eOp & (eOp-1))!=0 ){ if( eOp & (WO_LT|WO_LE) ){ eOp = WO_LE; }else{ assert( eOp & (WO_GT|WO_GE) ); eOp = WO_GE; } } db = pWC->pWInfo->pParse->db; pNew = sqlite3ExprDup(db, pOne->pExpr, 0); if( pNew==0 ) return; for(op=TK_EQ; eOp!=(WO_EQ<<(op-TK_EQ)); op++){ assert( opop = op; idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC); exprAnalyze(pSrc, pWC, idxNew); } #if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY) /* ** Analyze a term that consists of two or more OR-connected ** subterms. So in: ** ** ... WHERE (a=5) AND (b=7 OR c=9 OR d=13) AND (d=13) ** ^^^^^^^^^^^^^^^^^^^^ ** ** This routine analyzes terms such as the middle term in the above example. ** A WhereOrTerm object is computed and attached to the term under ** analysis, regardless of the outcome of the analysis. Hence: ** ** WhereTerm.wtFlags |= TERM_ORINFO ** WhereTerm.u.pOrInfo = a dynamically allocated WhereOrTerm object ** ** The term being analyzed must have two or more of OR-connected subterms. ** A single subterm might be a set of AND-connected sub-subterms. ** Examples of terms under analysis: ** ** (A) t1.x=t2.y OR t1.x=t2.z OR t1.y=15 OR t1.z=t3.a+5 ** (B) x=expr1 OR expr2=x OR x=expr3 ** (C) t1.x=t2.y OR (t1.x=t2.z AND t1.y=15) ** (D) x=expr1 OR (y>11 AND y<22 AND z LIKE '*hello*') ** (E) (p.a=1 AND q.b=2 AND r.c=3) OR (p.x=4 AND q.y=5 AND r.z=6) ** (F) x>A OR (x=A AND y>=B) ** ** CASE 1: ** ** If all subterms are of the form T.C=expr for some single column of C and ** a single table T (as shown in example B above) then create a new virtual ** term that is an equivalent IN expression. In other words, if the term ** being analyzed is: ** ** x = expr1 OR expr2 = x OR x = expr3 ** ** then create a new virtual term like this: ** ** x IN (expr1,expr2,expr3) ** ** CASE 2: ** ** If there are exactly two disjuncts and one side has x>A and the other side ** has x=A (for the same x and A) then add a new virtual conjunct term to the ** WHERE clause of the form "x>=A". Example: ** ** x>A OR (x=A AND y>B) adds: x>=A ** ** The added conjunct can sometimes be helpful in query planning. ** ** CASE 3: ** ** If all subterms are indexable by a single table T, then set ** ** WhereTerm.eOperator = WO_OR ** WhereTerm.u.pOrInfo->indexable |= the cursor number for table T ** ** A subterm is "indexable" if it is of the form ** "T.C " where C is any column of table T and ** is one of "=", "<", "<=", ">", ">=", "IS NULL", or "IN". ** A subterm is also indexable if it is an AND of two or more ** subsubterms at least one of which is indexable. Indexable AND ** subterms have their eOperator set to WO_AND and they have ** u.pAndInfo set to a dynamically allocated WhereAndTerm object. ** ** From another point of view, "indexable" means that the subterm could ** potentially be used with an index if an appropriate index exists. ** This analysis does not consider whether or not the index exists; that ** is decided elsewhere. This analysis only looks at whether subterms ** appropriate for indexing exist. ** ** All examples A through E above satisfy case 3. But if a term ** also satisfies case 1 (such as B) we know that the optimizer will ** always prefer case 1, so in that case we pretend that case 3 is not ** satisfied. ** ** It might be the case that multiple tables are indexable. For example, ** (E) above is indexable on tables P, Q, and R. ** ** Terms that satisfy case 3 are candidates for lookup by using ** separate indices to find rowids for each subterm and composing ** the union of all rowids using a RowSet object. This is similar ** to "bitmap indices" in other database engines. ** ** OTHERWISE: ** ** If none of cases 1, 2, or 3 apply, then leave the eOperator set to ** zero. This term is not useful for search. */ static void exprAnalyzeOrTerm( SrcList *pSrc, /* the FROM clause */ WhereClause *pWC, /* the complete WHERE clause */ int idxTerm /* Index of the OR-term to be analyzed */ ){ WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */ Parse *pParse = pWInfo->pParse; /* Parser context */ sqlite3 *db = pParse->db; /* Database connection */ WhereTerm *pTerm = &pWC->a[idxTerm]; /* The term to be analyzed */ Expr *pExpr = pTerm->pExpr; /* The expression of the term */ int i; /* Loop counters */ WhereClause *pOrWc; /* Breakup of pTerm into subterms */ WhereTerm *pOrTerm; /* A Sub-term within the pOrWc */ WhereOrInfo *pOrInfo; /* Additional information associated with pTerm */ Bitmask chngToIN; /* Tables that might satisfy case 1 */ Bitmask indexable; /* Tables that are indexable, satisfying case 2 */ /* ** Break the OR clause into its separate subterms. The subterms are ** stored in a WhereClause structure containing within the WhereOrInfo ** object that is attached to the original OR clause term. */ assert( (pTerm->wtFlags & (TERM_DYNAMIC|TERM_ORINFO|TERM_ANDINFO))==0 ); assert( pExpr->op==TK_OR ); pTerm->u.pOrInfo = pOrInfo = sqlite3DbMallocZero(db, sizeof(*pOrInfo)); if( pOrInfo==0 ) return; pTerm->wtFlags |= TERM_ORINFO; pOrWc = &pOrInfo->wc; memset(pOrWc->aStatic, 0, sizeof(pOrWc->aStatic)); sqlite3WhereClauseInit(pOrWc, pWInfo); sqlite3WhereSplit(pOrWc, pExpr, TK_OR); sqlite3WhereExprAnalyze(pSrc, pOrWc); if( db->mallocFailed ) return; assert( pOrWc->nTerm>=2 ); /* ** Compute the set of tables that might satisfy cases 1 or 3. */ indexable = ~(Bitmask)0; chngToIN = ~(Bitmask)0; for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0 && indexable; i--, pOrTerm++){ if( (pOrTerm->eOperator & WO_SINGLE)==0 ){ WhereAndInfo *pAndInfo; assert( (pOrTerm->wtFlags & (TERM_ANDINFO|TERM_ORINFO))==0 ); chngToIN = 0; pAndInfo = sqlite3DbMallocRawNN(db, sizeof(*pAndInfo)); if( pAndInfo ){ WhereClause *pAndWC; WhereTerm *pAndTerm; int j; Bitmask b = 0; pOrTerm->u.pAndInfo = pAndInfo; pOrTerm->wtFlags |= TERM_ANDINFO; pOrTerm->eOperator = WO_AND; pOrTerm->leftCursor = -1; pAndWC = &pAndInfo->wc; memset(pAndWC->aStatic, 0, sizeof(pAndWC->aStatic)); sqlite3WhereClauseInit(pAndWC, pWC->pWInfo); sqlite3WhereSplit(pAndWC, pOrTerm->pExpr, TK_AND); sqlite3WhereExprAnalyze(pSrc, pAndWC); pAndWC->pOuter = pWC; if( !db->mallocFailed ){ for(j=0, pAndTerm=pAndWC->a; jnTerm; j++, pAndTerm++){ assert( pAndTerm->pExpr ); if( allowedOp(pAndTerm->pExpr->op) || pAndTerm->eOperator==WO_AUX ){ b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pAndTerm->leftCursor); } } } indexable &= b; } }else if( pOrTerm->wtFlags & TERM_COPIED ){ /* Skip this term for now. We revisit it when we process the ** corresponding TERM_VIRTUAL term */ }else{ Bitmask b; b = sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor); if( pOrTerm->wtFlags & TERM_VIRTUAL ){ WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent]; b |= sqlite3WhereGetMask(&pWInfo->sMaskSet, pOther->leftCursor); } indexable &= b; if( (pOrTerm->eOperator & WO_EQ)==0 ){ chngToIN = 0; }else{ chngToIN &= b; } } } /* ** Record the set of tables that satisfy case 3. The set might be ** empty. */ pOrInfo->indexable = indexable; pTerm->eOperator = WO_OR; pTerm->leftCursor = -1; if( indexable ){ pWC->hasOr = 1; } /* For a two-way OR, attempt to implementation case 2. */ if( indexable && pOrWc->nTerm==2 ){ int iOne = 0; WhereTerm *pOne; while( (pOne = whereNthSubterm(&pOrWc->a[0],iOne++))!=0 ){ int iTwo = 0; WhereTerm *pTwo; while( (pTwo = whereNthSubterm(&pOrWc->a[1],iTwo++))!=0 ){ whereCombineDisjuncts(pSrc, pWC, pOne, pTwo); } } } /* ** chngToIN holds a set of tables that *might* satisfy case 1. But ** we have to do some additional checking to see if case 1 really ** is satisfied. ** ** chngToIN will hold either 0, 1, or 2 bits. The 0-bit case means ** that there is no possibility of transforming the OR clause into an ** IN operator because one or more terms in the OR clause contain ** something other than == on a column in the single table. The 1-bit ** case means that every term of the OR clause is of the form ** "table.column=expr" for some single table. The one bit that is set ** will correspond to the common table. We still need to check to make ** sure the same column is used on all terms. The 2-bit case is when ** the all terms are of the form "table1.column=table2.column". It ** might be possible to form an IN operator with either table1.column ** or table2.column as the LHS if either is common to every term of ** the OR clause. ** ** Note that terms of the form "table.column1=table.column2" (the ** same table on both sizes of the ==) cannot be optimized. */ if( chngToIN ){ int okToChngToIN = 0; /* True if the conversion to IN is valid */ int iColumn = -1; /* Column index on lhs of IN operator */ int iCursor = -1; /* Table cursor common to all terms */ int j = 0; /* Loop counter */ /* Search for a table and column that appears on one side or the ** other of the == operator in every subterm. That table and column ** will be recorded in iCursor and iColumn. There might not be any ** such table and column. Set okToChngToIN if an appropriate table ** and column is found but leave okToChngToIN false if not found. */ for(j=0; j<2 && !okToChngToIN; j++){ Expr *pLeft = 0; pOrTerm = pOrWc->a; for(i=pOrWc->nTerm-1; i>=0; i--, pOrTerm++){ assert( pOrTerm->eOperator & WO_EQ ); pOrTerm->wtFlags &= ~TERM_OK; if( pOrTerm->leftCursor==iCursor ){ /* This is the 2-bit case and we are on the second iteration and ** current term is from the first iteration. So skip this term. */ assert( j==1 ); continue; } if( (chngToIN & sqlite3WhereGetMask(&pWInfo->sMaskSet, pOrTerm->leftCursor))==0 ){ /* This term must be of the form t1.a==t2.b where t2 is in the ** chngToIN set but t1 is not. This term will be either preceded ** or followed by an inverted copy (t2.b==t1.a). Skip this term ** and use its inversion. */ testcase( pOrTerm->wtFlags & TERM_COPIED ); testcase( pOrTerm->wtFlags & TERM_VIRTUAL ); assert( pOrTerm->wtFlags & (TERM_COPIED|TERM_VIRTUAL) ); continue; } assert( (pOrTerm->eOperator & (WO_OR|WO_AND))==0 ); iColumn = pOrTerm->u.x.leftColumn; iCursor = pOrTerm->leftCursor; pLeft = pOrTerm->pExpr->pLeft; break; } if( i<0 ){ /* No candidate table+column was found. This can only occur ** on the second iteration */ assert( j==1 ); assert( IsPowerOfTwo(chngToIN) ); assert( chngToIN==sqlite3WhereGetMask(&pWInfo->sMaskSet, iCursor) ); break; } testcase( j==1 ); /* We have found a candidate table and column. Check to see if that ** table and column is common to every term in the OR clause */ okToChngToIN = 1; for(; i>=0 && okToChngToIN; i--, pOrTerm++){ assert( pOrTerm->eOperator & WO_EQ ); assert( (pOrTerm->eOperator & (WO_OR|WO_AND))==0 ); if( pOrTerm->leftCursor!=iCursor ){ pOrTerm->wtFlags &= ~TERM_OK; }else if( pOrTerm->u.x.leftColumn!=iColumn || (iColumn==XN_EXPR && sqlite3ExprCompare(pParse, pOrTerm->pExpr->pLeft, pLeft, -1) )){ okToChngToIN = 0; }else{ int affLeft, affRight; /* If the right-hand side is also a column, then the affinities ** of both right and left sides must be such that no type ** conversions are required on the right. (Ticket #2249) */ affRight = sqlite3ExprAffinity(pOrTerm->pExpr->pRight); affLeft = sqlite3ExprAffinity(pOrTerm->pExpr->pLeft); if( affRight!=0 && affRight!=affLeft ){ okToChngToIN = 0; }else{ pOrTerm->wtFlags |= TERM_OK; } } } } /* At this point, okToChngToIN is true if original pTerm satisfies ** case 1. In that case, construct a new virtual term that is ** pTerm converted into an IN operator. */ if( okToChngToIN ){ Expr *pDup; /* A transient duplicate expression */ ExprList *pList = 0; /* The RHS of the IN operator */ Expr *pLeft = 0; /* The LHS of the IN operator */ Expr *pNew; /* The complete IN operator */ for(i=pOrWc->nTerm-1, pOrTerm=pOrWc->a; i>=0; i--, pOrTerm++){ if( (pOrTerm->wtFlags & TERM_OK)==0 ) continue; assert( pOrTerm->eOperator & WO_EQ ); assert( (pOrTerm->eOperator & (WO_OR|WO_AND))==0 ); assert( pOrTerm->leftCursor==iCursor ); assert( pOrTerm->u.x.leftColumn==iColumn ); pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0); pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup); pLeft = pOrTerm->pExpr->pLeft; } assert( pLeft!=0 ); pDup = sqlite3ExprDup(db, pLeft, 0); pNew = sqlite3PExpr(pParse, TK_IN, pDup, 0); if( pNew ){ int idxNew; transferJoinMarkings(pNew, pExpr); assert( ExprUseXList(pNew) ); pNew->x.pList = pList; idxNew = whereClauseInsert(pWC, pNew, TERM_VIRTUAL|TERM_DYNAMIC); testcase( idxNew==0 ); exprAnalyze(pSrc, pWC, idxNew); /* pTerm = &pWC->a[idxTerm]; // would be needed if pTerm where reused */ markTermAsChild(pWC, idxNew, idxTerm); }else{ sqlite3ExprListDelete(db, pList); } } } } #endif /* !SQLITE_OMIT_OR_OPTIMIZATION && !SQLITE_OMIT_SUBQUERY */ /* ** We already know that pExpr is a binary operator where both operands are ** column references. This routine checks to see if pExpr is an equivalence ** relation: ** 1. The SQLITE_Transitive optimization must be enabled ** 2. Must be either an == or an IS operator ** 3. Not originating in the ON clause of an OUTER JOIN ** 4. The affinities of A and B must be compatible ** 5a. Both operands use the same collating sequence OR ** 5b. The overall collating sequence is BINARY ** If this routine returns TRUE, that means that the RHS can be substituted ** for the LHS anyplace else in the WHERE clause where the LHS column occurs. ** This is an optimization. No harm comes from returning 0. But if 1 is ** returned when it should not be, then incorrect answers might result. */ static int termIsEquivalence(Parse *pParse, Expr *pExpr){ char aff1, aff2; CollSeq *pColl; if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0; if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0; if( ExprHasProperty(pExpr, EP_OuterON) ) return 0; aff1 = sqlite3ExprAffinity(pExpr->pLeft); aff2 = sqlite3ExprAffinity(pExpr->pRight); if( aff1!=aff2 && (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2)) ){ return 0; } pColl = sqlite3ExprCompareCollSeq(pParse, pExpr); if( sqlite3IsBinary(pColl) ) return 1; return sqlite3ExprCollSeqMatch(pParse, pExpr->pLeft, pExpr->pRight); } /* ** Recursively walk the expressions of a SELECT statement and generate ** a bitmask indicating which tables are used in that expression ** tree. */ static Bitmask exprSelectUsage(WhereMaskSet *pMaskSet, Select *pS){ Bitmask mask = 0; while( pS ){ SrcList *pSrc = pS->pSrc; mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pEList); mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pGroupBy); mask |= sqlite3WhereExprListUsage(pMaskSet, pS->pOrderBy); mask |= sqlite3WhereExprUsage(pMaskSet, pS->pWhere); mask |= sqlite3WhereExprUsage(pMaskSet, pS->pHaving); if( ALWAYS(pSrc!=0) ){ int i; for(i=0; inSrc; i++){ if( pSrc->a[i].fg.isSubquery ){ mask |= exprSelectUsage(pMaskSet, pSrc->a[i].u4.pSubq->pSelect); } if( pSrc->a[i].fg.isUsing==0 ){ mask |= sqlite3WhereExprUsage(pMaskSet, pSrc->a[i].u3.pOn); } if( pSrc->a[i].fg.isTabFunc ){ mask |= sqlite3WhereExprListUsage(pMaskSet, pSrc->a[i].u1.pFuncArg); } } } pS = pS->pPrior; } return mask; } /* ** Expression pExpr is one operand of a comparison operator that might ** be useful for indexing. This routine checks to see if pExpr appears ** in any index. Return TRUE (1) if pExpr is an indexed term and return ** FALSE (0) if not. If TRUE is returned, also set aiCurCol[0] to the cursor ** number of the table that is indexed and aiCurCol[1] to the column number ** of the column that is indexed, or XN_EXPR (-2) if an expression is being ** indexed. ** ** If pExpr is a TK_COLUMN column reference, then this routine always returns ** true even if that particular column is not indexed, because the column ** might be added to an automatic index later. */ static SQLITE_NOINLINE int exprMightBeIndexed2( SrcList *pFrom, /* The FROM clause */ int *aiCurCol, /* Write the referenced table cursor and column here */ Expr *pExpr, /* An operand of a comparison operator */ int j /* Start looking with the j-th pFrom entry */ ){ Index *pIdx; int i; int iCur; do{ iCur = pFrom->a[j].iCursor; for(pIdx=pFrom->a[j].pSTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->aColExpr==0 ) continue; for(i=0; inKeyCol; i++){ if( pIdx->aiColumn[i]!=XN_EXPR ) continue; assert( pIdx->bHasExpr ); if( sqlite3ExprCompareSkip(pExpr,pIdx->aColExpr->a[i].pExpr,iCur)==0 && !sqlite3ExprIsConstant(0,pIdx->aColExpr->a[i].pExpr) ){ aiCurCol[0] = iCur; aiCurCol[1] = XN_EXPR; return 1; } } } }while( ++j < pFrom->nSrc ); return 0; } static int exprMightBeIndexed( SrcList *pFrom, /* The FROM clause */ int *aiCurCol, /* Write the referenced table cursor & column here */ Expr *pExpr, /* An operand of a comparison operator */ int op /* The specific comparison operator */ ){ int i; /* If this expression is a vector to the left or right of a ** inequality constraint (>, <, >= or <=), perform the processing ** on the first element of the vector. */ assert( TK_GT+1==TK_LE && TK_GT+2==TK_LT && TK_GT+3==TK_GE ); assert( TK_ISop==TK_VECTOR && (op>=TK_GT && ALWAYS(op<=TK_GE)) ){ assert( ExprUseXList(pExpr) ); pExpr = pExpr->x.pList->a[0].pExpr; } if( pExpr->op==TK_COLUMN ){ aiCurCol[0] = pExpr->iTable; aiCurCol[1] = pExpr->iColumn; return 1; } for(i=0; inSrc; i++){ Index *pIdx; for(pIdx=pFrom->a[i].pSTab->pIndex; pIdx; pIdx=pIdx->pNext){ if( pIdx->aColExpr ){ return exprMightBeIndexed2(pFrom,aiCurCol,pExpr,i); } } } return 0; } /* ** 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 " X" it gets commuted ** to the standard form of "X ". ** ** If the expression is of the form "X Y" where both X and Y are ** columns, then the original expression is unchanged and a new virtual ** term of the form "Y 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; /* Prerequisites of the pExpr->pLeft */ Bitmask prereqAll; /* Prerequisites 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 */ unsigned char eOp2 = 0; /* op2 value for LIKE/REGEXP/GLOB */ int nLeft; /* Number of elements on left side vector */ if( db->mallocFailed ){ return; } assert( pWC->nTerm > idxTerm ); pTerm = &pWC->a[idxTerm]; pMaskSet = &pWInfo->sMaskSet; pExpr = pTerm->pExpr; assert( pExpr!=0 ); /* Because malloc() has not failed */ assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE ); pMaskSet->bVarSelect = 0; prereqLeft = sqlite3WhereExprUsage(pMaskSet, pExpr->pLeft); op = pExpr->op; if( op==TK_IN ){ assert( pExpr->pRight==0 ); if( sqlite3ExprCheckIN(pParse, pExpr) ) return; if( ExprUseXSelect(pExpr) ){ pTerm->prereqRight = exprSelectUsage(pMaskSet, pExpr->x.pSelect); }else{ pTerm->prereqRight = sqlite3WhereExprListUsage(pMaskSet, pExpr->x.pList); } prereqAll = prereqLeft | pTerm->prereqRight; }else{ pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight); if( pExpr->pLeft==0 || ExprHasProperty(pExpr, EP_xIsSelect|EP_IfNullRow) || pExpr->x.pList!=0 ){ prereqAll = sqlite3WhereExprUsageNN(pMaskSet, pExpr); }else{ prereqAll = prereqLeft | pTerm->prereqRight; } } if( pMaskSet->bVarSelect ) pTerm->wtFlags |= TERM_VARSELECT; #ifdef SQLITE_DEBUG if( prereqAll!=sqlite3WhereExprUsageNN(pMaskSet, pExpr) ){ printf("\n*** Incorrect prereqAll computed for:\n"); sqlite3TreeViewExpr(0,pExpr,0); assert( 0 ); } #endif if( ExprHasProperty(pExpr, EP_OuterON|EP_InnerON) ){ Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->w.iJoin); if( ExprHasProperty(pExpr, EP_OuterON) ){ prereqAll |= x; extraRight = x-1; /* ON clause terms may not be used with an index ** on left table of a LEFT JOIN. Ticket #3015 */ if( (prereqAll>>1)>=x ){ sqlite3ErrorMsg(pParse, "ON clause references tables to its right"); return; } }else if( (prereqAll>>1)>=x ){ /* The ON clause of an INNER JOIN references a table to its right. ** Most other SQL database engines raise an error. But SQLite versions ** 3.0 through 3.38 just put the ON clause constraint into the WHERE ** clause and carried on. Beginning with 3.39, raise an error only ** if there is a RIGHT or FULL JOIN in the query. This makes SQLite ** more like other systems, and also preserves legacy. */ if( ALWAYS(pSrc->nSrc>0) && (pSrc->a[0].fg.jointype & JT_LTORJ)!=0 ){ sqlite3ErrorMsg(pParse, "ON clause references tables to its right"); return; } ExprClearProperty(pExpr, EP_InnerON); } } pTerm->prereqAll = prereqAll; pTerm->leftCursor = -1; pTerm->iParent = -1; pTerm->eOperator = 0; if( allowedOp(op) ){ int aiCurCol[2]; Expr *pLeft = sqlite3ExprSkipCollate(pExpr->pLeft); Expr *pRight = sqlite3ExprSkipCollate(pExpr->pRight); u16 opMask = (pTerm->prereqRight & prereqLeft)==0 ? WO_ALL : WO_EQUIV; if( pTerm->u.x.iField>0 ){ assert( op==TK_IN ); assert( pLeft->op==TK_VECTOR ); assert( ExprUseXList(pLeft) ); pLeft = pLeft->x.pList->a[pTerm->u.x.iField-1].pExpr; } if( exprMightBeIndexed(pSrc, aiCurCol, pLeft, op) ){ pTerm->leftCursor = aiCurCol[0]; assert( (pTerm->eOperator & (WO_OR|WO_AND))==0 ); pTerm->u.x.leftColumn = aiCurCol[1]; pTerm->eOperator = operatorMask(op) & opMask; } if( op==TK_IS ) pTerm->wtFlags |= TERM_IS; if( pRight && exprMightBeIndexed(pSrc, aiCurCol, pRight, op) && !ExprHasProperty(pRight, EP_FixedCol) ){ WhereTerm *pNew; Expr *pDup; u16 eExtraOp = 0; /* Extra bits for pNew->eOperator */ assert( pTerm->u.x.iField==0 ); 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; } pNew->wtFlags |= exprCommute(pParse, pDup); pNew->leftCursor = aiCurCol[0]; assert( (pTerm->eOperator & (WO_OR|WO_AND))==0 ); pNew->u.x.leftColumn = aiCurCol[1]; testcase( (prereqLeft | extraRight) != prereqLeft ); pNew->prereqRight = prereqLeft | extraRight; pNew->prereqAll = prereqAll; pNew->eOperator = (operatorMask(pDup->op) + eExtraOp) & opMask; }else if( op==TK_ISNULL && !ExprHasProperty(pExpr,EP_OuterON) && 0==sqlite3ExprCanBeNull(pLeft) ){ assert( !ExprHasProperty(pExpr, EP_IntValue) ); pExpr->op = TK_TRUEFALSE; /* See tag-20230504-1 */ pExpr->u.zToken = "false"; ExprSetProperty(pExpr, EP_IsFalse); pTerm->prereqAll = 0; pTerm->eOperator = 0; } } #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; int i; static const u8 ops[] = {TK_GE, TK_LE}; assert( ExprUseXList(pExpr) ); pList = pExpr->x.pList; 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)); 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 */ /* 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. ** ** The virtual term must be tagged with TERM_VNULL. */ else if( pExpr->op==TK_NOTNULL ){ if( pExpr->pLeft->op==TK_COLUMN && pExpr->pLeft->iColumn>=0 && !ExprHasProperty(pExpr, EP_OuterON) ){ Expr *pNewExpr; Expr *pLeft = pExpr->pLeft; int idxNew; WhereTerm *pNewTerm; pNewExpr = sqlite3PExpr(pParse, TK_GT, sqlite3ExprDup(db, pLeft, 0), sqlite3ExprAlloc(db, TK_NULL, 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.x.leftColumn = pLeft->iColumn; pNewTerm->eOperator = WO_GT; markTermAsChild(pWC, idxNew, idxTerm); pTerm = &pWC->a[idxTerm]; pTerm->wtFlags |= TERM_COPIED; pNewTerm->prereqAll = pTerm->prereqAll; } } } #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. */ else if( pExpr->op==TK_FUNCTION && 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; assert( ExprUseXList(pExpr) ); pLeft = pExpr->x.pList->a[1].pExpr; pStr2 = sqlite3ExprDup(db, pStr1, 0); assert( pStr1==0 || !ExprHasProperty(pStr1, EP_IntValue) ); assert( pStr2==0 || !ExprHasProperty(pStr2, EP_IntValue) ); /* 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" : sqlite3StrBINARY; pNewExpr1 = sqlite3ExprDup(db, pLeft, 0); pNewExpr1 = sqlite3PExpr(pParse, TK_GE, sqlite3ExprAddCollateString(pParse,pNewExpr1,zCollSeqName), pStr1); transferJoinMarkings(pNewExpr1, pExpr); idxNew1 = whereClauseInsert(pWC, pNewExpr1, wtFlags); testcase( idxNew1==0 ); pNewExpr2 = sqlite3ExprDup(db, pLeft, 0); pNewExpr2 = sqlite3PExpr(pParse, TK_LT, sqlite3ExprAddCollateString(pParse,pNewExpr2,zCollSeqName), pStr2); transferJoinMarkings(pNewExpr2, pExpr); idxNew2 = whereClauseInsert(pWC, pNewExpr2, wtFlags); testcase( idxNew2==0 ); exprAnalyze(pSrc, pWC, idxNew1); exprAnalyze(pSrc, pWC, idxNew2); pTerm = &pWC->a[idxTerm]; if( isComplete ){ markTermAsChild(pWC, idxNew1, idxTerm); markTermAsChild(pWC, idxNew2, idxTerm); } } #endif /* SQLITE_OMIT_LIKE_OPTIMIZATION */ /* If there is a vector == or IS term - e.g. "(a, b) == (?, ?)" - create ** new terms for each component comparison - "a = ?" and "b = ?". The ** new terms completely replace the original vector comparison, which is ** no longer used. ** ** This is only required if at least one side of the comparison operation ** is not a sub-select. ** ** tag-20220128a */ if( (pExpr->op==TK_EQ || pExpr->op==TK_IS) && (nLeft = sqlite3ExprVectorSize(pExpr->pLeft))>1 && sqlite3ExprVectorSize(pExpr->pRight)==nLeft && ( (pExpr->pLeft->flags & EP_xIsSelect)==0 || (pExpr->pRight->flags & EP_xIsSelect)==0) && pWC->op==TK_AND ){ int i; for(i=0; ipLeft, i, nLeft); Expr *pRight = sqlite3ExprForVectorField(pParse, pExpr->pRight, i, nLeft); pNew = sqlite3PExpr(pParse, pExpr->op, pLeft, pRight); transferJoinMarkings(pNew, pExpr); idxNew = whereClauseInsert(pWC, pNew, TERM_DYNAMIC|TERM_SLICE); exprAnalyze(pSrc, pWC, idxNew); } pTerm = &pWC->a[idxTerm]; pTerm->wtFlags |= TERM_CODED|TERM_VIRTUAL; /* Disable the original */ pTerm->eOperator = WO_ROWVAL; } /* If there is a vector IN term - e.g. "(a, b) IN (SELECT ...)" - create ** a virtual term for each vector component. The expression object ** used by each such virtual term is pExpr (the full vector IN(...) ** expression). The WhereTerm.u.x.iField variable identifies the index within ** the vector on the LHS that the virtual term represents. ** ** This only works if the RHS is a simple SELECT (not a compound) that does ** not use window functions. */ else if( pExpr->op==TK_IN && pTerm->u.x.iField==0 && pExpr->pLeft->op==TK_VECTOR && ALWAYS( ExprUseXSelect(pExpr) ) && (pExpr->x.pSelect->pPrior==0 || (pExpr->x.pSelect->selFlags & SF_Values)) #ifndef SQLITE_OMIT_WINDOWFUNC && pExpr->x.pSelect->pWin==0 #endif && pWC->op==TK_AND ){ int i; for(i=0; ipLeft); i++){ int idxNew; idxNew = whereClauseInsert(pWC, pExpr, TERM_VIRTUAL|TERM_SLICE); pWC->a[idxNew].u.x.iField = i+1; exprAnalyze(pSrc, pWC, idxNew); markTermAsChild(pWC, idxNew, idxTerm); } } #ifndef SQLITE_OMIT_VIRTUALTABLE /* Add a WO_AUX auxiliary term to the constraint set if the ** current expression is of the form "column OP expr" where OP ** is an operator that gets passed into virtual tables but which is ** not normally optimized for ordinary tables. In other words, OP ** is one of MATCH, LIKE, GLOB, REGEXP, !=, IS, IS NOT, or NOT NULL. ** This information is used by the xBestIndex methods of ** virtual tables. The native query optimizer does not attempt ** to do anything with MATCH functions. */ else if( pWC->op==TK_AND ){ Expr *pRight = 0, *pLeft = 0; int res = isAuxiliaryVtabOperator(db, pExpr, &eOp2, &pLeft, &pRight); while( res-- > 0 ){ int idxNew; WhereTerm *pNewTerm; Bitmask prereqColumn, prereqExpr; prereqExpr = sqlite3WhereExprUsage(pMaskSet, pRight); prereqColumn = sqlite3WhereExprUsage(pMaskSet, pLeft); if( (prereqExpr & prereqColumn)==0 ){ Expr *pNewExpr; pNewExpr = sqlite3PExpr(pParse, TK_MATCH, 0, sqlite3ExprDup(db, pRight, 0)); if( ExprHasProperty(pExpr, EP_OuterON) && pNewExpr ){ ExprSetProperty(pNewExpr, EP_OuterON); pNewExpr->w.iJoin = pExpr->w.iJoin; } idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC); testcase( idxNew==0 ); pNewTerm = &pWC->a[idxNew]; pNewTerm->prereqRight = prereqExpr; pNewTerm->leftCursor = pLeft->iTable; pNewTerm->u.x.leftColumn = pLeft->iColumn; pNewTerm->eOperator = WO_AUX; pNewTerm->eMatchOp = eOp2; markTermAsChild(pWC, idxNew, idxTerm); pTerm = &pWC->a[idxTerm]; pTerm->wtFlags |= TERM_COPIED; pNewTerm->prereqAll = pTerm->prereqAll; } SWAP(Expr*, pLeft, pRight); } } #endif /* SQLITE_OMIT_VIRTUALTABLE */ /* Prevent ON clause terms of a LEFT JOIN from being used to drive ** an index for tables to the left of the join. */ testcase( pTerm!=&pWC->a[idxTerm] ); pTerm = &pWC->a[idxTerm]; pTerm->prereqRight |= extraRight; } /*************************************************************************** ** Routines with file scope above. Interface to the rest of the where.c ** subsystem follows. ***************************************************************************/ /* ** 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 = sqlite3ExprSkipCollateAndLikely(pExpr); pWC->op = op; assert( pE2!=0 || pExpr==0 ); if( pE2==0 ) return; if( pE2->op!=op ){ whereClauseInsert(pWC, pExpr, 0); }else{ sqlite3WhereSplit(pWC, pE2->pLeft, op); sqlite3WhereSplit(pWC, pE2->pRight, op); } } /* ** Add either a LIMIT (if eMatchOp==SQLITE_INDEX_CONSTRAINT_LIMIT) or ** OFFSET (if eMatchOp==SQLITE_INDEX_CONSTRAINT_OFFSET) term to the ** where-clause passed as the first argument. The value for the term ** is found in register iReg. ** ** In the common case where the value is a simple integer ** (example: "LIMIT 5 OFFSET 10") then the expression codes as a ** TK_INTEGER so that it will be available to sqlite3_vtab_rhs_value(). ** If not, then it codes as a TK_REGISTER expression. */ static void whereAddLimitExpr( WhereClause *pWC, /* Add the constraint to this WHERE clause */ int iReg, /* Register that will hold value of the limit/offset */ Expr *pExpr, /* Expression that defines the limit/offset */ int iCsr, /* Cursor to which the constraint applies */ int eMatchOp /* SQLITE_INDEX_CONSTRAINT_LIMIT or _OFFSET */ ){ Parse *pParse = pWC->pWInfo->pParse; sqlite3 *db = pParse->db; Expr *pNew; int iVal = 0; if( sqlite3ExprIsInteger(pExpr, &iVal, pParse) && iVal>=0 ){ Expr *pVal = sqlite3Expr(db, TK_INTEGER, 0); if( pVal==0 ) return; ExprSetProperty(pVal, EP_IntValue); pVal->u.iValue = iVal; pNew = sqlite3PExpr(pParse, TK_MATCH, 0, pVal); }else{ Expr *pVal = sqlite3Expr(db, TK_REGISTER, 0); if( pVal==0 ) return; pVal->iTable = iReg; pNew = sqlite3PExpr(pParse, TK_MATCH, 0, pVal); } if( pNew ){ WhereTerm *pTerm; int idx; idx = whereClauseInsert(pWC, pNew, TERM_DYNAMIC|TERM_VIRTUAL); pTerm = &pWC->a[idx]; pTerm->leftCursor = iCsr; pTerm->eOperator = WO_AUX; pTerm->eMatchOp = eMatchOp; } } /* ** Possibly add terms corresponding to the LIMIT and OFFSET clauses of the ** SELECT statement passed as the second argument. These terms are only ** added if: ** ** 1. The SELECT statement has a LIMIT clause, and ** 2. The SELECT statement is not an aggregate or DISTINCT query, and ** 3. The SELECT statement has exactly one object in its from clause, and ** that object is a virtual table, and ** 4. There are no terms in the WHERE clause that will not be passed ** to the virtual table xBestIndex method. ** 5. The ORDER BY clause, if any, will be made available to the xBestIndex ** method. ** ** LIMIT and OFFSET terms are ignored by most of the planner code. They ** exist only so that they may be passed to the xBestIndex method of the ** single virtual table in the FROM clause of the SELECT. */ void SQLITE_NOINLINE sqlite3WhereAddLimit(WhereClause *pWC, Select *p){ assert( p!=0 && p->pLimit!=0 ); /* 1 -- checked by caller */ if( p->pGroupBy==0 && (p->selFlags & (SF_Distinct|SF_Aggregate))==0 /* 2 */ && (p->pSrc->nSrc==1 && IsVirtual(p->pSrc->a[0].pSTab)) /* 3 */ ){ ExprList *pOrderBy = p->pOrderBy; int iCsr = p->pSrc->a[0].iCursor; int ii; /* Check condition (4). Return early if it is not met. */ for(ii=0; iinTerm; ii++){ if( pWC->a[ii].wtFlags & TERM_CODED ){ /* This term is a vector operation that has been decomposed into ** other, subsequent terms. It can be ignored. See tag-20220128a */ assert( pWC->a[ii].wtFlags & TERM_VIRTUAL ); assert( pWC->a[ii].eOperator==WO_ROWVAL ); continue; } if( pWC->a[ii].nChild ){ /* If this term has child terms, then they are also part of the ** pWC->a[] array. So this term can be ignored, as a LIMIT clause ** will only be added if each of the child terms passes the ** (leftCursor==iCsr) test below. */ continue; } if( pWC->a[ii].leftCursor!=iCsr ) return; if( pWC->a[ii].prereqRight!=0 ) return; } /* Check condition (5). Return early if it is not met. */ if( pOrderBy ){ for(ii=0; iinExpr; ii++){ Expr *pExpr = pOrderBy->a[ii].pExpr; if( pExpr->op!=TK_COLUMN ) return; if( pExpr->iTable!=iCsr ) return; if( pOrderBy->a[ii].fg.sortFlags & KEYINFO_ORDER_BIGNULL ) return; } } /* All conditions are met. Add the terms to the where-clause object. */ assert( p->pLimit->op==TK_LIMIT ); if( p->iOffset!=0 && (p->selFlags & SF_Compound)==0 ){ whereAddLimitExpr(pWC, p->iOffset, p->pLimit->pRight, iCsr, SQLITE_INDEX_CONSTRAINT_OFFSET); } if( p->iOffset==0 || (p->selFlags & SF_Compound)==0 ){ whereAddLimitExpr(pWC, p->iLimit, p->pLimit->pLeft, iCsr, SQLITE_INDEX_CONSTRAINT_LIMIT); } } } /* ** Initialize a preallocated WhereClause structure. */ void sqlite3WhereClauseInit( WhereClause *pWC, /* The WhereClause to be initialized */ WhereInfo *pWInfo /* The WHERE processing context */ ){ pWC->pWInfo = pWInfo; pWC->hasOr = 0; pWC->pOuter = 0; pWC->nTerm = 0; pWC->nBase = 0; pWC->nSlot = ArraySize(pWC->aStatic); pWC->a = pWC->aStatic; } /* ** Deallocate a WhereClause structure. The WhereClause structure ** itself is not freed. This routine is the inverse of ** sqlite3WhereClauseInit(). */ void sqlite3WhereClauseClear(WhereClause *pWC){ sqlite3 *db = pWC->pWInfo->pParse->db; assert( pWC->nTerm>=pWC->nBase ); if( pWC->nTerm>0 ){ WhereTerm *a = pWC->a; WhereTerm *aLast = &pWC->a[pWC->nTerm-1]; #ifdef SQLITE_DEBUG int i; /* Verify that every term past pWC->nBase is virtual */ for(i=pWC->nBase; inTerm; i++){ assert( (pWC->a[i].wtFlags & TERM_VIRTUAL)!=0 ); } #endif while(1){ assert( a->eMatchOp==0 || a->eOperator==WO_AUX ); if( a->wtFlags & TERM_DYNAMIC ){ sqlite3ExprDelete(db, a->pExpr); } if( a->wtFlags & (TERM_ORINFO|TERM_ANDINFO) ){ if( a->wtFlags & TERM_ORINFO ){ assert( (a->wtFlags & TERM_ANDINFO)==0 ); whereOrInfoDelete(db, a->u.pOrInfo); }else{ assert( (a->wtFlags & TERM_ANDINFO)!=0 ); whereAndInfoDelete(db, a->u.pAndInfo); } } if( a==aLast ) break; a++; } } } /* ** These routines walk (recursively) an expression tree and generate ** a bitmask indicating which tables are used in that expression ** tree. ** ** sqlite3WhereExprUsage(MaskSet, Expr) -> ** ** Return a Bitmask of all tables referenced by Expr. Expr can be ** be NULL, in which case 0 is returned. ** ** sqlite3WhereExprUsageNN(MaskSet, Expr) -> ** ** Same as sqlite3WhereExprUsage() except that Expr must not be ** NULL. The "NN" suffix on the name stands for "Not Null". ** ** sqlite3WhereExprListUsage(MaskSet, ExprList) -> ** ** Return a Bitmask of all tables referenced by every expression ** in the expression list ExprList. ExprList can be NULL, in which ** case 0 is returned. ** ** sqlite3WhereExprUsageFull(MaskSet, ExprList) -> ** ** Internal use only. Called only by sqlite3WhereExprUsageNN() for ** complex expressions that require pushing register values onto ** the stack. Many calls to sqlite3WhereExprUsageNN() do not need ** the more complex analysis done by this routine. Hence, the ** computations done by this routine are broken out into a separate ** "no-inline" function to avoid the stack push overhead in the ** common case where it is not needed. */ static SQLITE_NOINLINE Bitmask sqlite3WhereExprUsageFull( WhereMaskSet *pMaskSet, Expr *p ){ Bitmask mask; mask = (p->op==TK_IF_NULL_ROW) ? sqlite3WhereGetMask(pMaskSet, p->iTable) : 0; if( p->pLeft ) mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pLeft); if( p->pRight ){ mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pRight); assert( p->x.pList==0 ); }else if( ExprUseXSelect(p) ){ if( ExprHasProperty(p, EP_VarSelect) ) pMaskSet->bVarSelect = 1; mask |= exprSelectUsage(pMaskSet, p->x.pSelect); }else if( p->x.pList ){ mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList); } #ifndef SQLITE_OMIT_WINDOWFUNC if( (p->op==TK_FUNCTION || p->op==TK_AGG_FUNCTION) && ExprUseYWin(p) ){ assert( p->y.pWin!=0 ); mask |= sqlite3WhereExprListUsage(pMaskSet, p->y.pWin->pPartition); mask |= sqlite3WhereExprListUsage(pMaskSet, p->y.pWin->pOrderBy); mask |= sqlite3WhereExprUsage(pMaskSet, p->y.pWin->pFilter); } #endif return mask; } Bitmask sqlite3WhereExprUsageNN(WhereMaskSet *pMaskSet, Expr *p){ if( p->op==TK_COLUMN && !ExprHasProperty(p, EP_FixedCol) ){ return sqlite3WhereGetMask(pMaskSet, p->iTable); }else if( ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){ assert( p->op!=TK_IF_NULL_ROW ); return 0; } return sqlite3WhereExprUsageFull(pMaskSet, p); } Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){ return p ? sqlite3WhereExprUsageNN(pMaskSet,p) : 0; } Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){ int i; Bitmask mask = 0; if( pList ){ for(i=0; inExpr; i++){ mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr); } } return mask; } /* ** Call exprAnalyze on all terms in a WHERE clause. ** ** Note that exprAnalyze() might add new virtual terms onto the ** end of the WHERE clause. We do not want to analyze these new ** virtual terms, so start analyzing at the end and work forward ** so that the added virtual terms are never processed. */ void sqlite3WhereExprAnalyze( SrcList *pTabList, /* the FROM clause */ WhereClause *pWC /* the WHERE clause to be analyzed */ ){ int i; for(i=pWC->nTerm-1; i>=0; i--){ exprAnalyze(pTabList, pWC, i); } } /* ** For table-valued-functions, transform the function arguments into ** new WHERE clause terms. ** ** Each function argument translates into an equality constraint against ** a HIDDEN column in the table. */ void sqlite3WhereTabFuncArgs( Parse *pParse, /* Parsing context */ SrcItem *pItem, /* The FROM clause term to process */ WhereClause *pWC /* Xfer function arguments to here */ ){ Table *pTab; int j, k; ExprList *pArgs; Expr *pColRef; Expr *pTerm; if( pItem->fg.isTabFunc==0 ) return; pTab = pItem->pSTab; assert( pTab!=0 ); pArgs = pItem->u1.pFuncArg; if( pArgs==0 ) return; for(j=k=0; jnExpr; j++){ Expr *pRhs; u32 joinType; while( knCol && (pTab->aCol[k].colFlags & COLFLAG_HIDDEN)==0 ){k++;} if( k>=pTab->nCol ){ sqlite3ErrorMsg(pParse, "too many arguments on %s() - max %d", pTab->zName, j); return; } pColRef = sqlite3ExprAlloc(pParse->db, TK_COLUMN, 0, 0); if( pColRef==0 ) return; pColRef->iTable = pItem->iCursor; pColRef->iColumn = k++; assert( ExprUseYTab(pColRef) ); pColRef->y.pTab = pTab; pItem->colUsed |= sqlite3ExprColUsed(pColRef); pRhs = sqlite3PExpr(pParse, TK_UPLUS, sqlite3ExprDup(pParse->db, pArgs->a[j].pExpr, 0), 0); pTerm = sqlite3PExpr(pParse, TK_EQ, pColRef, pRhs); if( pItem->fg.jointype & (JT_LEFT|JT_RIGHT) ){ testcase( pItem->fg.jointype & JT_LEFT ); /* testtag-20230227a */ testcase( pItem->fg.jointype & JT_RIGHT ); /* testtag-20230227b */ joinType = EP_OuterON; }else{ testcase( pItem->fg.jointype & JT_LTORJ ); /* testtag-20230227c */ joinType = EP_InnerON; } sqlite3SetJoinExpr(pTerm, pItem->iCursor, joinType); whereClauseInsert(pWC, pTerm, TERM_DYNAMIC); } }