From: Heikki Linnakangas <heikki.linnakangas@iki.fi>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Fix deparsing FETCH FIRST <expr> ROWS WITH TIES
Date: Mon, 19 May 2025 15:52:20 +0000
Message-ID: <E1uH2mp-002Pp8-30@gemulon.postgresql.org> (raw)
Fix deparsing FETCH FIRST <expr> ROWS WITH TIES
In the grammar, <expr> 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
Branch
------
REL_17_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/54c05292b1ffc8d7ad9305d224225161e4d3d412
Modified Files
--------------
src/backend/utils/adt/ruleutils.c | 10 ++++++++++
src/test/regress/expected/limit.out | 20 +++++++++++++++++---
src/test/regress/sql/limit.sql | 5 ++++-
3 files changed, 31 insertions(+), 4 deletions(-)
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To: pgsql-committers@postgresql.org
Cc: heikki.linnakangas@iki.fi, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Fix deparsing FETCH FIRST <expr> ROWS WITH TIES
In-Reply-To: <E1uH2mp-002Pp8-30@gemulon.postgresql.org>
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