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Constant expressions that appear in ORDER BY, GROUP BY, DISTINCT ON 

lists should be reverse-compiled into targetlist index numbers, because
that's the only interpretation the parser allows for a constant in these
clauses.  (Ergo, the only way they could have gotten into the list in
the first place is to have come from the targetlist; so this should always
work.)  Per problem report from Peter E.
This commit is contained in:
Tom Lane 2001-04-15 03:14:18 +00:00
parent 7f2de4937a
commit ffbeafb19a
1 changed files with 39 additions and 19 deletions
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58
src/backend/utils/adt/ruleutils.c
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@ -3,7 +3,7 @@
* back to source text
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.75 2001/03/22 06:16:18 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/utils/adt/ruleutils.c,v 1.76 2001/04/15 03:14:18 tgl Exp $
*
* This software is copyrighted by Jan Wieck - Hamburg.
*
@ -120,6 +120,9 @@ static void get_basic_select_query(Query *query, deparse_context *context);
static void get_setop_query(Node *setOp, Query *query,
deparse_context *context, bool toplevel);
static bool simple_distinct(List *distinctClause, List *targetList);
static void get_rule_sortgroupclause(SortClause *srt, List *tlist,
bool force_colno,
deparse_context *context);
static void get_names_for_var(Var *var, deparse_context *context,
char **refname, char **attname);
static bool get_alias_for_case(CaseExpr *caseexpr, deparse_context *context,
@ -925,7 +928,7 @@ static void
get_select_query_def(Query *query, deparse_context *context)
{
StringInfo buf = context->buf;
bool shortform_orderby;
bool force_colno;
char *sep;
List *l;
@ -938,12 +941,12 @@ get_select_query_def(Query *query, deparse_context *context)
{
get_setop_query(query->setOperations, query, context, true);
/* ORDER BY clauses must be simple in this case */
shortform_orderby = true;
force_colno = true;
}
else
{
get_basic_select_query(query, context);
shortform_orderby = false;
force_colno = false;
}
/* Add the ORDER BY clause if given */
@ -954,16 +957,11 @@ get_select_query_def(Query *query, deparse_context *context)
foreach(l, query->sortClause)
{
SortClause *srt = (SortClause *) lfirst(l);
TargetEntry *sorttle;
char *opname;
sorttle = get_sortgroupclause_tle(srt,
query->targetList);
appendStringInfo(buf, sep);
if (shortform_orderby)
appendStringInfo(buf, "%d", sorttle->resdom->resno);
else
get_rule_expr(sorttle->expr, context);
get_rule_sortgroupclause(srt, query->targetList,
force_colno, context);
opname = get_opname(srt->sortop);
if (strcmp(opname, "<") != 0)
{
@ -1017,12 +1015,10 @@ get_basic_select_query(Query *query, deparse_context *context)
foreach(l, query->distinctClause)
{
SortClause *srt = (SortClause *) lfirst(l);
Node *sortexpr;
sortexpr = get_sortgroupclause_expr(srt,
query->targetList);
appendStringInfo(buf, sep);
get_rule_expr(sortexpr, context);
get_rule_sortgroupclause(srt, query->targetList,
false, context);
sep = ", ";
}
appendStringInfo(buf, ")");
@ -1082,12 +1078,10 @@ get_basic_select_query(Query *query, deparse_context *context)
foreach(l, query->groupClause)
{
GroupClause *grp = (GroupClause *) lfirst(l);
Node *groupexpr;
groupexpr = get_sortgroupclause_expr(grp,
query->targetList);
appendStringInfo(buf, sep);
get_rule_expr(groupexpr, context);
get_rule_sortgroupclause(grp, query->targetList,
false, context);
sep = ", ";
}
}
@ -1182,6 +1176,32 @@ simple_distinct(List *distinctClause, List *targetList)
return true;
}
/*
* Display a sort/group clause.
*/
static void
get_rule_sortgroupclause(SortClause *srt, List *tlist, bool force_colno,
deparse_context *context)
{
StringInfo buf = context->buf;
TargetEntry *tle;
Node *expr;
tle = get_sortgroupclause_tle(srt, tlist);
expr = tle->expr;
/*
* Use column-number form if requested by caller or if expression is a
* constant --- a constant is ambiguous (and will be misinterpreted
* by findTargetlistEntry()) if we dump it explicitly.
*/
if (force_colno || (expr && IsA(expr, Const)))
{
Assert(!tle->resdom->resjunk);
appendStringInfo(buf, "%d", tle->resdom->resno);
}
else
get_rule_expr(expr, context);
}
/* ----------
* get_insert_query_def - Parse back an INSERT parsetree