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-rw-r--r--lib/libsqlite3/src/resolve.c157
1 files changed, 122 insertions, 35 deletions
diff --git a/lib/libsqlite3/src/resolve.c b/lib/libsqlite3/src/resolve.c
index 91efcaa1a16..43a3870e23e 100644
--- a/lib/libsqlite3/src/resolve.c
+++ b/lib/libsqlite3/src/resolve.c
@@ -55,7 +55,7 @@ static void incrAggFunctionDepth(Expr *pExpr, int N){
** column reference is so that the column reference will be recognized as
** usable by indices within the WHERE clause processing logic.
**
-** Hack: The TK_AS operator is inhibited if zType[0]=='G'. This means
+** The TK_AS operator is inhibited if zType[0]=='G'. This means
** that in a GROUP BY clause, the expression is evaluated twice. Hence:
**
** SELECT random()%5 AS x, count(*) FROM tab GROUP BY x
@@ -65,8 +65,9 @@ static void incrAggFunctionDepth(Expr *pExpr, int N){
** SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5
**
** The result of random()%5 in the GROUP BY clause is probably different
-** from the result in the result-set. We might fix this someday. Or
-** then again, we might not...
+** from the result in the result-set. On the other hand Standard SQL does
+** not allow the GROUP BY clause to contain references to result-set columns.
+** So this should never come up in well-formed queries.
**
** If the reference is followed by a COLLATE operator, then make sure
** the COLLATE operator is preserved. For example:
@@ -240,11 +241,20 @@ static int lookupName(
** resulting in an appropriate error message toward the end of this routine
*/
if( zDb ){
- for(i=0; i<db->nDb; i++){
- assert( db->aDb[i].zName );
- if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){
- pSchema = db->aDb[i].pSchema;
- break;
+ testcase( pNC->ncFlags & NC_PartIdx );
+ testcase( pNC->ncFlags & NC_IsCheck );
+ if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){
+ /* Silently ignore database qualifiers inside CHECK constraints and partial
+ ** indices. Do not raise errors because that might break legacy and
+ ** because it does not hurt anything to just ignore the database name. */
+ zDb = 0;
+ }else{
+ for(i=0; i<db->nDb; i++){
+ assert( db->aDb[i].zName );
+ if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){
+ pSchema = db->aDb[i].pSchema;
+ break;
+ }
}
}
}
@@ -387,10 +397,16 @@ static int lookupName(
** forms the result set entry ("a+b" in the example) and return immediately.
** Note that the expression in the result set should have already been
** resolved by the time the WHERE clause is resolved.
+ **
+ ** The ability to use an output result-set column in the WHERE, GROUP BY,
+ ** or HAVING clauses, or as part of a larger expression in the ORDRE BY
+ ** clause is not standard SQL. This is a (goofy) SQLite extension, that
+ ** is supported for backwards compatibility only. TO DO: Issue a warning
+ ** on sqlite3_log() whenever the capability is used.
*/
if( (pEList = pNC->pEList)!=0
&& zTab==0
- && ((pNC->ncFlags & NC_AsMaybe)==0 || cnt==0)
+ && cnt==0
){
for(j=0; j<pEList->nExpr; j++){
char *zAs = pEList->a[j].zName;
@@ -523,6 +539,39 @@ Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){
}
/*
+** Report an error that an expression is not valid for a partial index WHERE
+** clause.
+*/
+static void notValidPartIdxWhere(
+ Parse *pParse, /* Leave error message here */
+ NameContext *pNC, /* The name context */
+ const char *zMsg /* Type of error */
+){
+ if( (pNC->ncFlags & NC_PartIdx)!=0 ){
+ sqlite3ErrorMsg(pParse, "%s prohibited in partial index WHERE clauses",
+ zMsg);
+ }
+}
+
+#ifndef SQLITE_OMIT_CHECK
+/*
+** Report an error that an expression is not valid for a CHECK constraint.
+*/
+static void notValidCheckConstraint(
+ Parse *pParse, /* Leave error message here */
+ NameContext *pNC, /* The name context */
+ const char *zMsg /* Type of error */
+){
+ if( (pNC->ncFlags & NC_IsCheck)!=0 ){
+ sqlite3ErrorMsg(pParse,"%s prohibited in CHECK constraints", zMsg);
+ }
+}
+#else
+# define notValidCheckConstraint(P,N,M)
+#endif
+
+
+/*
** This routine is callback for sqlite3WalkExpr().
**
** Resolve symbolic names into TK_COLUMN operators for the current
@@ -621,6 +670,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
testcase( pExpr->op==TK_CONST_FUNC );
assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
+ notValidPartIdxWhere(pParse, pNC, "functions");
zId = pExpr->u.zToken;
nId = sqlite3Strlen30(zId);
pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
@@ -686,11 +736,8 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
testcase( pExpr->op==TK_IN );
if( ExprHasProperty(pExpr, EP_xIsSelect) ){
int nRef = pNC->nRef;
-#ifndef SQLITE_OMIT_CHECK
- if( (pNC->ncFlags & NC_IsCheck)!=0 ){
- sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
- }
-#endif
+ notValidCheckConstraint(pParse, pNC, "subqueries");
+ notValidPartIdxWhere(pParse, pNC, "subqueries");
sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
assert( pNC->nRef>=nRef );
if( nRef!=pNC->nRef ){
@@ -699,14 +746,11 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
}
break;
}
-#ifndef SQLITE_OMIT_CHECK
case TK_VARIABLE: {
- if( (pNC->ncFlags & NC_IsCheck)!=0 ){
- sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints");
- }
+ notValidCheckConstraint(pParse, pNC, "parameters");
+ notValidPartIdxWhere(pParse, pNC, "parameters");
break;
}
-#endif
}
return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
}
@@ -797,7 +841,7 @@ static int resolveOrderByTermToExprList(
** result-set entry.
*/
for(i=0; i<pEList->nExpr; i++){
- if( sqlite3ExprCompare(pEList->a[i].pExpr, pE)<2 ){
+ if( sqlite3ExprCompare(pEList->a[i].pExpr, pE, -1)<2 ){
return i+1;
}
}
@@ -924,7 +968,7 @@ static int resolveCompoundOrderBy(
/*
** Check every term in the ORDER BY or GROUP BY clause pOrderBy of
** the SELECT statement pSelect. If any term is reference to a
-** result set expression (as determined by the ExprList.a.iCol field)
+** result set expression (as determined by the ExprList.a.iOrderByCol field)
** then convert that term into a copy of the corresponding result set
** column.
**
@@ -972,7 +1016,7 @@ int sqlite3ResolveOrderGroupBy(
** If the order-by term is an integer I between 1 and N (where N is the
** number of columns in the result set of the SELECT) then the expression
** in the resolution is a copy of the I-th result-set expression. If
-** the order-by term is an identify that corresponds to the AS-name of
+** the order-by term is an identifier that corresponds to the AS-name of
** a result-set expression, then the term resolves to a copy of the
** result-set expression. Otherwise, the expression is resolved in
** the usual way - using sqlite3ResolveExprNames().
@@ -998,16 +1042,19 @@ static int resolveOrderGroupBy(
pParse = pNC->pParse;
for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
Expr *pE = pItem->pExpr;
- iCol = resolveAsName(pParse, pSelect->pEList, pE);
- if( iCol>0 ){
- /* If an AS-name match is found, mark this ORDER BY column as being
- ** a copy of the iCol-th result-set column. The subsequent call to
- ** sqlite3ResolveOrderGroupBy() will convert the expression to a
- ** copy of the iCol-th result-set expression. */
- pItem->iOrderByCol = (u16)iCol;
- continue;
+ Expr *pE2 = sqlite3ExprSkipCollate(pE);
+ if( zType[0]!='G' ){
+ iCol = resolveAsName(pParse, pSelect->pEList, pE2);
+ if( iCol>0 ){
+ /* If an AS-name match is found, mark this ORDER BY column as being
+ ** a copy of the iCol-th result-set column. The subsequent call to
+ ** sqlite3ResolveOrderGroupBy() will convert the expression to a
+ ** copy of the iCol-th result-set expression. */
+ pItem->iOrderByCol = (u16)iCol;
+ continue;
+ }
}
- if( sqlite3ExprIsInteger(sqlite3ExprSkipCollate(pE), &iCol) ){
+ if( sqlite3ExprIsInteger(pE2, &iCol) ){
/* The ORDER BY term is an integer constant. Again, set the column
** number so that sqlite3ResolveOrderGroupBy() will convert the
** order-by term to a copy of the result-set expression */
@@ -1025,7 +1072,7 @@ static int resolveOrderGroupBy(
return 1;
}
for(j=0; j<pSelect->pEList->nExpr; j++){
- if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr)==0 ){
+ if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr, -1)==0 ){
pItem->iOrderByCol = j+1;
}
}
@@ -1150,7 +1197,7 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
return WRC_Abort;
}
- /* Add the expression list to the name-context before parsing the
+ /* Add the output column list to the name-context before parsing the
** other expressions in the SELECT statement. This is so that
** expressions in the WHERE clause (etc.) can refer to expressions by
** aliases in the result set.
@@ -1159,10 +1206,8 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
** re-evaluated for each reference to it.
*/
sNC.pEList = p->pEList;
- sNC.ncFlags |= NC_AsMaybe;
if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort;
if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort;
- sNC.ncFlags &= ~NC_AsMaybe;
/* The ORDER BY and GROUP BY clauses may not refer to terms in
** outer queries
@@ -1331,3 +1376,45 @@ void sqlite3ResolveSelectNames(
w.u.pNC = pOuterNC;
sqlite3WalkSelect(&w, p);
}
+
+/*
+** Resolve names in expressions that can only reference a single table:
+**
+** * CHECK constraints
+** * WHERE clauses on partial indices
+**
+** The Expr.iTable value for Expr.op==TK_COLUMN nodes of the expression
+** is set to -1 and the Expr.iColumn value is set to the column number.
+**
+** Any errors cause an error message to be set in pParse.
+*/
+void sqlite3ResolveSelfReference(
+ Parse *pParse, /* Parsing context */
+ Table *pTab, /* The table being referenced */
+ int type, /* NC_IsCheck or NC_PartIdx */
+ Expr *pExpr, /* Expression to resolve. May be NULL. */
+ ExprList *pList /* Expression list to resolve. May be NUL. */
+){
+ SrcList sSrc; /* Fake SrcList for pParse->pNewTable */
+ NameContext sNC; /* Name context for pParse->pNewTable */
+ int i; /* Loop counter */
+
+ assert( type==NC_IsCheck || type==NC_PartIdx );
+ memset(&sNC, 0, sizeof(sNC));
+ memset(&sSrc, 0, sizeof(sSrc));
+ sSrc.nSrc = 1;
+ sSrc.a[0].zName = pTab->zName;
+ sSrc.a[0].pTab = pTab;
+ sSrc.a[0].iCursor = -1;
+ sNC.pParse = pParse;
+ sNC.pSrcList = &sSrc;
+ sNC.ncFlags = type;
+ if( sqlite3ResolveExprNames(&sNC, pExpr) ) return;
+ if( pList ){
+ for(i=0; i<pList->nExpr; i++){
+ if( sqlite3ResolveExprNames(&sNC, pList->a[i].pExpr) ){
+ return;
+ }
+ }
+ }
+}
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