diff options
Diffstat (limited to 'src/backend/parser/parse_agg.c')
| -rw-r--r-- | src/backend/parser/parse_agg.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c index ab00040c654..19dd98dfbe8 100644 --- a/src/backend/parser/parse_agg.c +++ b/src/backend/parser/parse_agg.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/parser/parse_agg.c,v 1.19 1999/05/12 15:01:48 wieck Exp $ + * $Header: /cvsroot/pgsql/src/backend/parser/parse_agg.c,v 1.20 1999/05/23 21:41:14 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -173,28 +173,34 @@ tleIsAggOrGroupCol(TargetEntry *tle, List *groupClause, List *tlist) } /* - * parseCheckAggregates - - * this should really be done earlier but the current grammar - * cannot differentiate functions from aggregates. So we have do check - * here when the target list and the qualifications are finalized. + * parseCheckAggregates + * Check for aggregates where they shouldn't be and improper grouping. + * + * Ideally this should be done earlier, but it's difficult to distinguish + * aggregates from plain functions at the grammar level. So instead we + * check here. This function should be called after the target list and + * qualifications are finalized. */ void parseCheckAggregates(ParseState *pstate, Query *qry) { List *tl; - Assert(pstate->p_hasAggs); + /* This should only be called if we found aggregates or grouping */ + Assert(pstate->p_hasAggs || qry->groupClause); /* - * aggregates never appear in WHERE clauses. (we have to check where - * clause first because if there is an aggregate, the check for - * non-group column in target list may fail.) + * Aggregates must never appear in WHERE clauses. + * (Note this check should appear first to deliver an appropriate + * error message; otherwise we are likely to generate the generic + * "illegal use of aggregates in target list" message, which is + * outright misleading if the problem is in WHERE.) */ if (contain_agg_clause(qry->qual)) elog(ERROR, "Aggregates not allowed in WHERE clause"); /* - * the target list can only contain aggregates, group columns and + * The target list can only contain aggregates, group columns and * functions thereof. */ foreach(tl, qry->targetList) @@ -214,7 +220,6 @@ parseCheckAggregates(ParseState *pstate, Query *qry) if (!exprIsAggOrGroupCol(qry->havingQual, qry->groupClause, qry->targetList)) elog(ERROR, "Illegal use of aggregates or non-group column in HAVING clause"); - return; } |