Re: PERFORM bug with FOUND?

Tom Lane <tgl@sss.pgh.pa.us> wrote:
> david@fetter.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@fetter.org http://fetter.org/
phone: +1 510 893 6100    cell: +1 415 235 3778

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      An Inquiry Into the Nature and Causes of the Wealth of Nations