Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit29f7ce6

Browse files
committed
Fix deparsing FETCH FIRST <expr> ROWS WITH TIES
In the grammar, <expr> is a c_expr, which accepts only a limited setof integer literals and simple expressions without parens. Thedeparsing logic didn't quite match the grammar rule, and failed to useparens e.g. for "5::bigint".To fix, always surround the expression with parens. Would be nice toomit the parens in simple cases, but unfortunately it's non-trivial todetect such simple cases. Even if the expression is a simple literal123 in the original query, after parse analysis it becomes a FuncExprwith COERCE_IMPLICIT_CAST rather than a simple Const.Reported-by: yonghao leeBackpatch-through: 13Discussion:https://www.postgresql.org/message-id/18929-077d6b7093b176e2@postgresql.org
1 parentad5eaf3 commit29f7ce6

File tree

3 files changed

+31
-4
lines changed

3 files changed

+31
-4
lines changed

‎src/backend/utils/adt/ruleutils.c

Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -5956,9 +5956,19 @@ get_select_query_def(Query *query, deparse_context *context)
59565956
{
59575957
if (query->limitOption==LIMIT_OPTION_WITH_TIES)
59585958
{
5959+
/*
5960+
* The limitCount arg is a c_expr, so it needs parens. Simple
5961+
* literals and function expressions would not need parens, but
5962+
* unfortunately it's hard to tell if the expression will be
5963+
* printed as a simple literal like 123 or as a typecast
5964+
* expression, like '-123'::int4. The grammar accepts the former
5965+
* without quoting, but not the latter.
5966+
*/
59595967
appendContextKeyword(context," FETCH FIRST ",
59605968
-PRETTYINDENT_STD,PRETTYINDENT_STD,0);
5969+
appendStringInfoChar(buf,'(');
59615970
get_rule_expr(query->limitCount,context, false);
5971+
appendStringInfoChar(buf,')');
59625972
appendStringInfoString(buf," ROWS WITH TIES");
59635973
}
59645974
else

‎src/test/regress/expected/limit.out

Lines changed: 17 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -647,7 +647,7 @@ View definition:
647647
WHERE thousand < 995
648648
ORDER BY thousand
649649
OFFSET 10
650-
FETCH FIRST5 ROWS WITH TIES;
650+
FETCH FIRST(5) ROWS WITH TIES;
651651

652652
CREATE VIEW limit_thousand_v_2 AS SELECT thousand FROM onek WHERE thousand < 995
653653
ORDER BY thousand OFFSET 10 FETCH FIRST 5 ROWS ONLY;
@@ -679,15 +679,29 @@ View definition:
679679
FROM onek
680680
WHERE thousand < 995
681681
ORDER BY thousand
682-
FETCH FIRST (NULL::integer + 1) ROWS WITH TIES;
682+
FETCH FIRST ((NULL::integer + 1)) ROWS WITH TIES;
683683

684684
CREATE VIEW limit_thousand_v_4 AS SELECT thousand FROM onek WHERE thousand < 995
685-
ORDER BY thousand FETCH FIRSTNULL ROWSONLY;
685+
ORDER BY thousand FETCH FIRST(5::bigint) ROWSWITH TIES;
686686
\d+ limit_thousand_v_4
687687
View "public.limit_thousand_v_4"
688688
Column | Type | Collation | Nullable | Default | Storage | Description
689689
----------+---------+-----------+----------+---------+---------+-------------
690690
thousand | integer | | | | plain |
691+
View definition:
692+
SELECT thousand
693+
FROM onek
694+
WHERE thousand < 995
695+
ORDER BY thousand
696+
FETCH FIRST (5::bigint) ROWS WITH TIES;
697+
698+
CREATE VIEW limit_thousand_v_5 AS SELECT thousand FROM onek WHERE thousand < 995
699+
ORDER BY thousand FETCH FIRST NULL ROWS ONLY;
700+
\d+ limit_thousand_v_5
701+
View "public.limit_thousand_v_5"
702+
Column | Type | Collation | Nullable | Default | Storage | Description
703+
----------+---------+-----------+----------+---------+---------+-------------
704+
thousand | integer | | | | plain |
691705
View definition:
692706
SELECT thousand
693707
FROM onek

‎src/test/regress/sql/limit.sql

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -196,6 +196,9 @@ CREATE VIEW limit_thousand_v_3 AS SELECT thousand FROM onek WHERE thousand < 995
196196
ORDER BY thousand FETCH FIRST (NULL+1) ROWS WITH TIES;
197197
\d+ limit_thousand_v_3
198198
CREATEVIEWlimit_thousand_v_4ASSELECT thousandFROM onekWHERE thousand<995
199-
ORDER BY thousand FETCH FIRSTNULL ROWSONLY;
199+
ORDER BY thousand FETCH FIRST(5::bigint) ROWSWITH TIES;
200200
\d+ limit_thousand_v_4
201+
CREATEVIEWlimit_thousand_v_5ASSELECT thousandFROM onekWHERE thousand<995
202+
ORDER BY thousand FETCH FIRSTNULL ROWS ONLY;
203+
\d+ limit_thousand_v_5
201204
-- leave these views

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp