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Make GROUP BY work with aliases, ORDER BY with column numbers

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This commit is contained in:
Bruce Momjian
1996-12-17 01:53:43 +00:00
parent ec105b6026
commit db7a90f1d9
4 changed files with 111 additions and 66 deletions
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98
src/backend/parser/analyze.c
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@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.18 1996/11/30 18:06:20 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/analyze.c,v 1.19 1996/12/17 01:53:26 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -63,7 +63,8 @@ static TargetEntry *make_targetlist_expr(ParseState *pstate,
char *colname, Node *expr,
List *arrayRef);
static Node *transformWhereClause(ParseState *pstate, Node *a_expr);
static List *transformGroupClause(ParseState *pstate, List *grouplist);
static List *transformGroupClause(ParseState *pstate, List *grouplist,
List *targetlist);
static List *transformSortClause(ParseState *pstate,
List *orderlist, List *targetlist,
char* uniqueFlag);
@ -422,13 +423,14 @@ transformSelectStmt(ParseState *pstate, RetrieveStmt *stmt)
/* fix order clause */
qry->sortClause = transformSortClause(pstate,
stmt->orderClause,
stmt->sortClause,
qry->targetList,
qry->uniqueFlag);
/* fix group by clause */
qry->groupClause = transformGroupClause(pstate,
stmt->groupClause);
stmt->groupClause,
qry->targetList);
qry->rtable = pstate->p_rtable;
if (pstate->p_numAgg > 0)
@ -505,12 +507,13 @@ transformCursorStmt(ParseState *pstate, CursorStmt *stmt)
/* fix order clause */
qry->sortClause = transformSortClause(pstate,
stmt->orderClause,
stmt->sortClause,
qry->targetList,
qry->uniqueFlag);
/* fix group by clause */
qry->groupClause = transformGroupClause(pstate,
stmt->groupClause);
stmt->groupClause,
qry->targetList);
qry->rtable = pstate->p_rtable;
@ -1426,19 +1429,21 @@ transformWhereClause(ParseState *pstate, Node *a_expr)
*****************************************************************************/
/*
* find_tl_elt -
* find_targetlist_entry -
* returns the Resdom in the target list matching the specified varname
* and range
*
*/
static Resdom *
find_tl_elt(ParseState *pstate, char *refname, char *colname, List *tlist)
static TargetEntry *
find_targetlist_entry(ParseState *pstate, SortGroupBy *sortgroupby, List *tlist)
{
List *i;
int real_rtable_pos = 0;
if(refname)
real_rtable_pos = refnameRangeTablePosn(pstate->p_rtable, refname);
int real_rtable_pos = 0, target_pos = 0;
TargetEntry *target_result = NULL;
if(sortgroupby->range)
real_rtable_pos = refnameRangeTablePosn(pstate->p_rtable,
sortgroupby->range);
foreach(i, tlist) {
TargetEntry *target = (TargetEntry *)lfirst(i);
@ -1447,17 +1452,30 @@ find_tl_elt(ParseState *pstate, char *refname, char *colname, List *tlist)
char *resname = resnode->resname;
int test_rtable_pos = var->varno;
if (!strcmp(resname, colname)) {
if(refname) {
if(real_rtable_pos == test_rtable_pos) {
return (resnode);
}
} else {
return (resnode);
if (!sortgroupby->name) {
if (sortgroupby->resno == ++target_pos) {
target_result = target;
break;
}
}
else {
if (!strcmp(resname, sortgroupby->name)) {
if(sortgroupby->range) {
if(real_rtable_pos == test_rtable_pos) {
if (target_result != NULL)
elog(WARN, "Order/Group By %s is ambiguous", sortgroupby->name);
else target_result = target;
}
}
else {
if (target_result != NULL)
elog(WARN, "Order/Group By %s is ambiguous", sortgroupby->name);
else target_result = target;
}
}
}
}
return ((Resdom *)NULL);
return target_result;
}
static Oid
@ -1478,22 +1496,27 @@ any_ordering_op(int restype)
*
*/
static List *
transformGroupClause(ParseState *pstate, List *grouplist)
transformGroupClause(ParseState *pstate, List *grouplist, List *targetlist)
{
List *glist = NIL, *gl = NIL;
while (grouplist != NIL) {
GroupClause *grpcl = makeNode(GroupClause);
Var *groupAttr = (Var*)transformExpr(pstate, (Node*)lfirst(grouplist));
TargetEntry *restarget;
if (nodeTag(groupAttr) != T_Var) {
elog(WARN, "parser: can only specify attribute in group by");
}
grpcl->grpAttr = groupAttr;
grpcl->grpOpoid = any_ordering_op(groupAttr->vartype);
if (glist == NIL) {
restarget = find_targetlist_entry(pstate, lfirst(grouplist), targetlist);
if (restarget == NULL)
elog(WARN,"The field being grouped by must appear in the target list");
if (nodeTag(restarget->expr) != T_Var) {
elog(WARN, "parser: can only specify attribute in group by");
}
grpcl->grpAttr = (Var *)restarget->expr;
grpcl->grpOpoid = any_ordering_op(grpcl->grpAttr->vartype);
if (glist == NIL)
gl = glist = lcons(grpcl, NIL);
} else {
else {
lnext(gl) = lcons(grpcl, NIL);
gl = lnext(gl);
}
@ -1517,15 +1540,16 @@ transformSortClause(ParseState *pstate,
List *s = NIL, *i;
while(orderlist != NIL) {
SortBy *sortby = lfirst(orderlist);
SortGroupBy *sortby = lfirst(orderlist);
SortClause *sortcl = makeNode(SortClause);
TargetEntry *restarget;
Resdom *resdom;
resdom = find_tl_elt(pstate, sortby->range, sortby->name, targetlist);
if (resdom == NULL)
elog(WARN,"The field being sorted by must appear in the target list");
sortcl->resdom = resdom;
restarget = find_targetlist_entry(pstate, sortby, targetlist);
if (restarget == NULL)
elog(WARN,"The field being ordered by must appear in the target list");
sortcl->resdom = resdom = restarget->resdom;
sortcl->opoid = oprid(oper(sortby->useOp,
resdom->restype,
resdom->restype));