With a sample query such as
SELECT x, avg(x)
FROM (VALUES (1), (2), (3)) AS v (x);
We give the error message "column "v.x" must appear in the GROUP BY
clause or be used in an aggregate function".
This is correct but incomplete. Attached is a trivial patch to also
suggest that the user might have been trying to use a window function.
--
Vik Fearing +33 6 46 75 15 36
http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support
diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c
index c745fcdd2b..52d9a3d00e 100644
--- a/src/backend/parser/parse_agg.c
+++ b/src/backend/parser/parse_agg.c
@@ -1402,7 +1402,7 @@ check_ungrouped_columns_walker(Node *node,
if (context->sublevels_up == 0)
ereport(ERROR,
(errcode(ERRCODE_GROUPING_ERROR),
- errmsg("column \"%s.%s\" must appear in the GROUP BY clause or be used in an aggregate function",
+ errmsg("column \"%s.%s\" must appear in the GROUP BY clause or be used in an aggregate or window function",
rte->eref->aliasname, attname),
context->in_agg_direct_args ?
errdetail("Direct arguments of an ordered-set aggregate must use only grouped columns.") : 0,
