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Overview
| Comment: | Add new routines to simplify dealing with collating sequences in expressions: sqlite3ExprNNCollSeq() and sqlite3ExprCollSeqMatch(). |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: |
490e488ea963fe725b16212822c8608f |
| User & Date: | drh 2017-09-28 01:58:23 |
Context
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2017-09-28
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| 13:47 | Fix an issue introduced by check-in [4cd2a9672c59] (2017-03-03) that could allow a negative value in the 3rd parameter to memmove() when defragmentPage() is called on a btree page with a corrupted freeblock list. The corruption is now detected early and results in an SQLITE_CORRUPT return before the memmove() is reached. check-in: 5b9ae693 user: drh tags: trunk | |
| 01:58 | Add new routines to simplify dealing with collating sequences in expressions: sqlite3ExprNNCollSeq() and sqlite3ExprCollSeqMatch(). check-in: 490e488e user: drh tags: trunk | |
| 01:09 | Indexes on expressions with a COLLATE clause are able to satisfy an ORDER BY with the same COLLATE clause. check-in: 04130018 user: drh tags: trunk | |
Changes
Changes to src/expr.c.
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return pExpr;
}
/*
** Return the collation sequence for the expression pExpr. If
** there is no defined collating sequence, return NULL.
**
** The collating sequence might be determined by a COLLATE operator
** or by the presence of a column with a defined collating sequence.
** COLLATE operators take first precedence. Left operands take
** precedence over right operands.
*/
CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
sqlite3 *db = pParse->db;
................................................................................
}
}
if( sqlite3CheckCollSeq(pParse, pColl) ){
pColl = 0;
}
return pColl;
}
/*
** pExpr is an operand of a comparison operator. aff2 is the
** type affinity of the other operand. This routine returns the
** type affinity that should be used for the comparison operator.
*/
char sqlite3CompareAffinity(Expr *pExpr, char aff2){
................................................................................
int i;
/* Check if pExpr is identical to any GROUP BY term. If so, consider
** it constant. */
for(i=0; i<pGroupBy->nExpr; i++){
Expr *p = pGroupBy->a[i].pExpr;
if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){
CollSeq *pColl = sqlite3ExprCollSeq(pWalker->pParse, p);
if( pColl==0 || sqlite3_stricmp("BINARY", pColl->zName)==0 ){
return WRC_Prune;
}
}
}
/* Check if pExpr is a sub-select. If so, consider it variable. */
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
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return pExpr; } /* ** Return the collation sequence for the expression pExpr. If ** there is no defined collating sequence, return NULL. ** ** See also: sqlite3ExprNNCollSeq() ** ** The sqlite3ExprNNCollSeq() works the same exact that it returns the ** default collation if pExpr has no defined collation. ** ** The collating sequence might be determined by a COLLATE operator ** or by the presence of a column with a defined collating sequence. ** COLLATE operators take first precedence. Left operands take ** precedence over right operands. */ CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){ sqlite3 *db = pParse->db; ................................................................................ } } if( sqlite3CheckCollSeq(pParse, pColl) ){ pColl = 0; } return pColl; } /* ** Return the collation sequence for the expression pExpr. If ** there is no defined collating sequence, return a pointer to the ** defautl collation sequence. ** ** See also: sqlite3ExprCollSeq() ** ** The sqlite3ExprCollSeq() routine works the same except that it ** returns NULL if there is no defined collation. */ CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr){ CollSeq *p = sqlite3ExprCollSeq(pParse, pExpr); if( p==0 ) p = pParse->db->pDfltColl; assert( p!=0 ); return p; } /* ** Return TRUE if the two expressions have equivalent collating sequences. */ int sqlite3ExprCollSeqMatch(Parse *pParse, Expr *pE1, Expr *pE2){ CollSeq *pColl1 = sqlite3ExprNNCollSeq(pParse, pE1); CollSeq *pColl2 = sqlite3ExprNNCollSeq(pParse, pE2); return sqlite3StrICmp(pColl1->zName, pColl2->zName)==0; } /* ** pExpr is an operand of a comparison operator. aff2 is the ** type affinity of the other operand. This routine returns the ** type affinity that should be used for the comparison operator. */ char sqlite3CompareAffinity(Expr *pExpr, char aff2){ ................................................................................ int i; /* Check if pExpr is identical to any GROUP BY term. If so, consider ** it constant. */ for(i=0; i<pGroupBy->nExpr; i++){ Expr *p = pGroupBy->a[i].pExpr; if( sqlite3ExprCompare(0, pExpr, p, -1)<2 ){ CollSeq *pColl = sqlite3ExprNNCollSeq(pWalker->pParse, p); if( sqlite3_stricmp("BINARY", pColl->zName)==0 ){ return WRC_Prune; } } } /* Check if pExpr is a sub-select. If so, consider it variable. */ if( ExprHasProperty(pExpr, EP_xIsSelect) ){ |
Changes to src/select.c.
1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 |
int i;
nExpr = pList->nExpr;
pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);
if( pInfo ){
assert( sqlite3KeyInfoIsWriteable(pInfo) );
for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){
CollSeq *pColl;
pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
if( !pColl ) pColl = db->pDfltColl;
pInfo->aColl[i-iStart] = pColl;
pInfo->aSortOrder[i-iStart] = pItem->sortOrder;
}
}
return pInfo;
}
/*
|
< < < | |
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int i;
nExpr = pList->nExpr;
pInfo = sqlite3KeyInfoAlloc(db, nExpr-iStart, nExtra+1);
if( pInfo ){
assert( sqlite3KeyInfoIsWriteable(pInfo) );
for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){
pInfo->aColl[i-iStart] = sqlite3ExprNNCollSeq(pParse, pItem->pExpr);
pInfo->aSortOrder[i-iStart] = pItem->sortOrder;
}
}
return pInfo;
}
/*
|
Changes to src/sqliteInt.h.
4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 |
#endif const char *sqlite3ErrStr(int); int sqlite3ReadSchema(Parse *pParse); CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int); CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName); CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr); Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int); Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*); Expr *sqlite3ExprSkipCollate(Expr*); int sqlite3CheckCollSeq(Parse *, CollSeq *); int sqlite3CheckObjectName(Parse *, const char *); void sqlite3VdbeSetChanges(sqlite3 *, int); int sqlite3AddInt64(i64*,i64); |
> > |
4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 |
#endif const char *sqlite3ErrStr(int); int sqlite3ReadSchema(Parse *pParse); CollSeq *sqlite3FindCollSeq(sqlite3*,u8 enc, const char*,int); CollSeq *sqlite3LocateCollSeq(Parse *pParse, const char*zName); CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr); CollSeq *sqlite3ExprNNCollSeq(Parse *pParse, Expr *pExpr); int sqlite3ExprCollSeqMatch(Parse*,Expr*,Expr*); Expr *sqlite3ExprAddCollateToken(Parse *pParse, Expr*, const Token*, int); Expr *sqlite3ExprAddCollateString(Parse*,Expr*,const char*); Expr *sqlite3ExprSkipCollate(Expr*); int sqlite3CheckCollSeq(Parse *, CollSeq *); int sqlite3CheckObjectName(Parse *, const char *); void sqlite3VdbeSetChanges(sqlite3 *, int); int sqlite3AddInt64(i64*,i64); |
Changes to src/where.c.
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for(i=0; i<pList->nExpr; i++){
Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);
if( p->op==TK_COLUMN
&& p->iColumn==pIdx->aiColumn[iCol]
&& p->iTable==iBase
){
CollSeq *pColl = sqlite3ExprCollSeq(pParse, pList->a[i].pExpr);
if( pColl && 0==sqlite3StrICmp(pColl->zName, zColl) ){
return i;
}
}
}
return -1;
}
................................................................................
** optimization, and then only if they are actually used
** by the query plan */
assert( wctrlFlags & WHERE_ORDERBY_LIMIT );
for(j=0; j<pLoop->nLTerm && pTerm!=pLoop->aLTerm[j]; j++){}
if( j>=pLoop->nLTerm ) continue;
}
if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
const char *z1, *z2;
pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
if( !pColl ) pColl = db->pDfltColl;
z1 = pColl->zName;
pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
if( !pColl ) pColl = db->pDfltColl;
z2 = pColl->zName;
if( sqlite3StrICmp(z1, z2)!=0 ) continue;
testcase( pTerm->pExpr->op==TK_IS );
}
obSat |= MASKBIT(i);
}
if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
if( pLoop->wsFlags & WHERE_IPK ){
................................................................................
}else{
Expr *pIdxExpr = pIndex->aColExpr->a[j].pExpr;
if( sqlite3ExprCompareSkip(pOBExpr, pIdxExpr, iCur) ){
continue;
}
}
if( iColumn!=XN_ROWID ){
pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
if( !pColl ) pColl = db->pDfltColl;
if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
}
pLoop->u.btree.nIdxCol = j+1;
isMatch = 1;
break;
}
if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){
|
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for(i=0; i<pList->nExpr; i++){
Expr *p = sqlite3ExprSkipCollate(pList->a[i].pExpr);
if( p->op==TK_COLUMN
&& p->iColumn==pIdx->aiColumn[iCol]
&& p->iTable==iBase
){
CollSeq *pColl = sqlite3ExprNNCollSeq(pParse, pList->a[i].pExpr);
if( 0==sqlite3StrICmp(pColl->zName, zColl) ){
return i;
}
}
}
return -1;
}
................................................................................
** optimization, and then only if they are actually used
** by the query plan */
assert( wctrlFlags & WHERE_ORDERBY_LIMIT );
for(j=0; j<pLoop->nLTerm && pTerm!=pLoop->aLTerm[j]; j++){}
if( j>=pLoop->nLTerm ) continue;
}
if( (pTerm->eOperator&(WO_EQ|WO_IS))!=0 && pOBExpr->iColumn>=0 ){
if( sqlite3ExprCollSeqMatch(pWInfo->pParse,
pOrderBy->a[i].pExpr, pTerm->pExpr)==0 ){
continue;
}
testcase( pTerm->pExpr->op==TK_IS );
}
obSat |= MASKBIT(i);
}
if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
if( pLoop->wsFlags & WHERE_IPK ){
................................................................................
}else{
Expr *pIdxExpr = pIndex->aColExpr->a[j].pExpr;
if( sqlite3ExprCompareSkip(pOBExpr, pIdxExpr, iCur) ){
continue;
}
}
if( iColumn!=XN_ROWID ){
pColl = sqlite3ExprNNCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
}
pLoop->u.btree.nIdxCol = j+1;
isMatch = 1;
break;
}
if( isMatch && (wctrlFlags & WHERE_GROUPBY)==0 ){
|
Changes to src/whereexpr.c.
838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 |
** 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;
const char *zColl1, *zColl2;
if( !OptimizationEnabled(pParse->db, SQLITE_Transitive) ) return 0;
if( pExpr->op!=TK_EQ && pExpr->op!=TK_IS ) return 0;
if( ExprHasProperty(pExpr, EP_FromJoin) ) return 0;
aff1 = sqlite3ExprAffinity(pExpr->pLeft);
aff2 = sqlite3ExprAffinity(pExpr->pRight);
if( aff1!=aff2
&& (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))
){
return 0;
}
pColl = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
if( pColl==0 || sqlite3StrICmp(pColl->zName, "BINARY")==0 ) return 1;
pColl = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
zColl1 = pColl ? pColl->zName : 0;
pColl = sqlite3ExprCollSeq(pParse, pExpr->pRight);
zColl2 = pColl ? pColl->zName : 0;
return sqlite3_stricmp(zColl1, zColl2)==0;
}
/*
** Recursively walk the expressions of a SELECT statement and generate
** a bitmask indicating which tables are used in that expression
** tree.
*/
|
< | < < < < |
838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 |
** 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_FromJoin) ) return 0;
aff1 = sqlite3ExprAffinity(pExpr->pLeft);
aff2 = sqlite3ExprAffinity(pExpr->pRight);
if( aff1!=aff2
&& (!sqlite3IsNumericAffinity(aff1) || !sqlite3IsNumericAffinity(aff2))
){
return 0;
}
pColl = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft, pExpr->pRight);
if( pColl==0 || sqlite3StrICmp(pColl->zName, "BINARY")==0 ) 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.
*/
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