Re: proposal: plpgsql, new check for extra_errors - strict_expr_check

ne 16. 6. 2024 v 16:11 odesílatel Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>
napsal:

> Hi,
>
> assigned patch try to solve issue reported by Mor Lehr (Missing semicolon
> in anonymous plpgsql block does not raise syntax error).
>
>
> https://www.postgresql.org/message-id/CALyvM2bp_CXMH_Gyq87pmHJRuZDEhV40u9VP8rX=CAnEt2wUXg@mail.gmail.com
>
> by introducing a new extra error check. With this check only a_expr exprs
> are allowed as plpgsql expressions. This is a small step to behaviour
> described in SQL/PSM standard (although the language is different, the
> expression syntax and features are almost similar. With this check the
> undocumented (but supported syntax)
>
> var := column FROM tab
>
> is disallowed. Only ANSI syntax for embedded queries (inside assignment
> statement) is allowed
>
> var := (SELECT column FROM tab);
>
> With this check, the reported issue (by Mor Lehr) is detected
>
> default setting
>
> CREATE TABLE foo3(id serial PRIMARY key, txt text);
> INSERT INTO foo3 (txt) VALUES ('aaa'),('bbb');
>
> DO $$
> DECLARE
> l_cnt int;
> BEGIN
> l_cnt := 1
> DELETE FROM foo3 WHERE id=1;
> END; $$
>
> -- without reaction - just don't work
>
> (2024-06-16 16:05:55) postgres=# set plpgsql.extra_errors to
> 'strict_expr_check';
> SET
> (2024-06-16 16:06:43) postgres=# DO $$
>
> DECLARE
> l_cnt int;
> BEGIN
> l_cnt := 1
> DELETE FROM foo3 WHERE id=1;
> END; $$;
> ERROR: syntax error at or near "DELETE"
> LINE 11: DELETE FROM foo3 WHERE id=1;
> ^
>
> This patch has three parts
>
> 1. Introduction strict_expr_check
> 2. set strict_expr_check as default, and impact on regress tests
> 3. revert @2
>
> I don't propose to be strict_expr_check active by default.
>
> Comments, notes?
>

fresh rebase

>
> Regards
>
> Pavel
>
>
>