From 29f7ce6fe78e3f8d520764b5870453d791a3ca65 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Mon, 19 May 2025 18:50:26 +0300 Subject: Fix deparsing FETCH FIRST ROWS WITH TIES In the grammar, is a c_expr, which accepts only a limited set of integer literals and simple expressions without parens. The deparsing logic didn't quite match the grammar rule, and failed to use parens e.g. for "5::bigint". To fix, always surround the expression with parens. Would be nice to omit the parens in simple cases, but unfortunately it's non-trivial to detect such simple cases. Even if the expression is a simple literal 123 in the original query, after parse analysis it becomes a FuncExpr with COERCE_IMPLICIT_CAST rather than a simple Const. Reported-by: yonghao lee Backpatch-through: 13 Discussion: https://www.postgresql.org/message-id/18929-077d6b7093b176e2@postgresql.org --- src/backend/utils/adt/ruleutils.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'src/backend/utils/adt/ruleutils.c') diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c index 467b08198b8..3d6e6bdbfd2 100644 --- a/src/backend/utils/adt/ruleutils.c +++ b/src/backend/utils/adt/ruleutils.c @@ -5956,9 +5956,19 @@ get_select_query_def(Query *query, deparse_context *context) { if (query->limitOption == LIMIT_OPTION_WITH_TIES) { + /* + * The limitCount arg is a c_expr, so it needs parens. Simple + * literals and function expressions would not need parens, but + * unfortunately it's hard to tell if the expression will be + * printed as a simple literal like 123 or as a typecast + * expression, like '-123'::int4. The grammar accepts the former + * without quoting, but not the latter. + */ appendContextKeyword(context, " FETCH FIRST ", -PRETTYINDENT_STD, PRETTYINDENT_STD, 0); + appendStringInfoChar(buf, '('); get_rule_expr(query->limitCount, context, false); + appendStringInfoChar(buf, ')'); appendStringInfoString(buf, " ROWS WITH TIES"); } else -- cgit v1.2.3