Re: PERFORM bug with FOUND?

Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> david(at)fetter(dot)org (David Fetter) writes:
>> I've written a little hack, here included, which is supposed to find
>> whether a user is in a group. I'd intended to do a PERFORM instead of
>> SELECT INTO, but PERFORM appears to set FOUND to true no matter what.
>
> What version are you using? It seems to work per spec in 7.4.
>
> regression=# create function foo(name) returns bool as '
> regression'# begin
> regression'# perform * from pg_user where usename = $1;
> regression'# return found;
> regression'# end' language plpgsql;
> CREATE FUNCTION
> regression=# select foo('postgres');
> foo
> -----
> t
> (1 row)
>
> regression=# select foo('not');
> foo
> -----
> f
> (1 row)
>
> regression=#
>
> regards, tom lane

Tom,

Thanks for staying on top of this. This was 7.4 on Linux i686,
compiling from source with just the defaults except port. Here's a
working version.

CREATE OR REPLACE FUNCTION in_group (text, text) RETURNS BOOLEAN AS '
BEGIN
PERFORM u.usename
FROM
pg_user u
, pg_group g
WHERE
u.usename = $1
AND g.groname = $2
AND u.usesysid = ANY (g.grolist);

RETURN FOUND;
END;
' LANGUAGE 'plpgsql' STRICT IMMUTABLE;

BTW, I'd like to lobby for an example in the docs of how to do a
PERFORM instead of a SELECT, 'cause that syntax wasn't right away
obvious.

Cheers,
D
--
David Fetter david(at)fetter(dot)org http://fetter.org/
phone: +1 510 893 6100 cell: +1 415 235 3778

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