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Diffstat (limited to '')
| -rw-r--r-- | src/whereexpr.c | 1870 |
1 files changed, 1870 insertions, 0 deletions
diff --git a/src/whereexpr.c b/src/whereexpr.c new file mode 100644 index 0000000..daf3d5d --- /dev/null +++ b/src/whereexpr.c @@ -0,0 +1,1870 @@ +/* +** 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_GT<TK_GE ); + assert( TK_LT>TK_EQ && TK_LT<TK_GE ); + assert( TK_LE>TK_EQ && TK_LE<TK_GE ); + assert( TK_GE==TK_EQ+4 ); + return op==TK_IN || (op>=TK_EQ && op<=TK_GE) || 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_GT<TK_LE ); + assert( pExpr->op>=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_IN ){ + c = WO_IN; + }else if( op==TK_ISNULL ){ + c = WO_ISNULL; + }else if( op==TK_IS ){ + c = WO_IS; + }else{ + assert( (WO_EQ<<(op-TK_EQ)) < 0x7fff ); + c = (u16)(WO_EQ<<(op-TK_EQ)); + } + 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 characters prior to the first wildcard */ + cnt = 0; + while( (c=z[cnt])!=0 && c!=wc[0] && c!=wc[1] && c!=wc[2] ){ + cnt++; + if( c==wc[3] && z[cnt]!=0 ) cnt++; + } + + /* 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])) && 255!=(u8)z[cnt-1] ){ + Expr *pPrefix; + + /* A "complete" match if the pattern ends with "*" or "%" */ + *pisComplete = c==wc[0] && z[cnt+1]==0; + + /* 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; iFrom<cnt; iFrom++){ + if( zNew[iFrom]==wc[3] ) iFrom++; + zNew[iTo++] = zNew[iFrom]; + } + zNew[iTo] = 0; + assert( iTo>0 ); + + /* 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; i<ArraySize(aOp); i++){ + assert( !ExprHasProperty(pExpr, EP_IntValue) ); + if( sqlite3StrICmp(pExpr->u.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_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( N<pTerm->u.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<y OR x=y --> x<=y +** x=y OR x=y --> x=y +** x<=y OR x<y --> x<=y +** +** The following is NOT generated: +** +** x<y OR x>y --> 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( op<TK_GE ); } + pNew->op = 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 <op> <expr>" where C is any column of table T and +** <op> 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; j<pAndWC->nTerm; 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; i<pSrc->nSrc; i++){ + mask |= exprSelectUsage(pMaskSet, pSrc->a[i].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].pTab->pIndex; pIdx; pIdx=pIdx->pNext){ + if( pIdx->aColExpr==0 ) continue; + for(i=0; i<pIdx->nKeyCol; i++){ + if( pIdx->aiColumn[i]!=XN_EXPR ) continue; + assert( pIdx->bHasExpr ); + if( sqlite3ExprCompareSkip(pExpr,pIdx->aColExpr->a[i].pExpr,iCur)==0 + && pExpr->op!=TK_STRING + ){ + 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_IS<TK_GE && TK_ISNULL<TK_GE && TK_IN<TK_GE ); + assert( op<=TK_GE ); + if( pExpr->op==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; i<pFrom->nSrc; i++){ + Index *pIdx; + for(pIdx=pFrom->a[i].pTab->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 "<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; /* 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; i<nLeft; i++){ + int idxNew; + Expr *pNew; + Expr *pLeft = sqlite3ExprForVectorField(pParse, pExpr->pLeft, 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; i<sqlite3ExprVectorSize(pExpr->pLeft); 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) && 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].pTab)) /* 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; ii<pWC->nTerm; 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; + } + + /* Check condition (5). Return early if it is not met. */ + if( pOrderBy ){ + for(ii=0; ii<pOrderBy->nExpr; 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 ); + whereAddLimitExpr(pWC, p->iLimit, p->pLimit->pLeft, + iCsr, SQLITE_INDEX_CONSTRAINT_LIMIT); + if( p->iOffset>0 ){ + whereAddLimitExpr(pWC, p->iOffset, p->pLimit->pRight, + iCsr, SQLITE_INDEX_CONSTRAINT_OFFSET); + } + } +} + +/* +** 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; i<pWC->nTerm; 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; i<pList->nExpr; 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->pTab; + assert( pTab!=0 ); + pArgs = pItem->u1.pFuncArg; + if( pArgs==0 ) return; + for(j=k=0; j<pArgs->nExpr; j++){ + Expr *pRhs; + u32 joinType; + while( k<pTab->nCol && (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); + } +} |