Date: Sun, 11 Dec 2005 10:22:18 -0700
From: Michael Fuhr <mike@fuhr.org>
To: Douglas McNaught <doug@mcnaught.org>
Cc: "Foster, Stephen" <stephenlfoster@comcast.net>,
	pgsql-general@postgresql.org, pgsql-sql@postgresql.org
Subject: Re: [SQL] Looking for information on PostgreSQL Stored Procedures
Message-ID: <20051211172218.GA87286@winnie.fuhr.org>
References: <000001c5fe70$f5e51330$2101a8c0@cfgod>
	<m2bqznh9m0.fsf@Douglas-McNaughts-Powerbook.local>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <m2bqznh9m0.fsf@Douglas-McNaughts-Powerbook.local>

On Sun, Dec 11, 2005 at 11:38:47AM -0500, Douglas McNaught wrote:
> "Foster, Stephen" <stephenlfoster@comcast.net> writes:
> 
> > WHILE (--Lost on variable name for end of query; EmptyQueryResponse <>
> > 0? --)
> > 	BEGIN
> > 		IF LastName = fname THEN
> > 			DELETE FROM MailingList WHERE id = id;
> > 		END IF;
> > 		LastName := fname;
> > 		FETCH NEXT FROM NewListCursor INTO fname, id;
> > 	END;
> > CLOSE NewListCursor;
> > $BODY$
> > LANGUAGE 'sql' VOLATILE;
> 
> You can't do any looping or other control structures in an SQL
> function.  Use PL/pgSQL instead.

And as I mentioned in my previous post, you can loop through query
results without messing around with an explicit cursor.

CREATE FUNCTION testfunc() RETURNS void AS $$
DECLARE
    row  record;
BEGIN
    FOR row IN SELECT * FROM tablename ORDER BY whatever LOOP
	-- do stuff that refers to row.column_name
    END LOOP;

    RETURN;
END;
$$ LANGUAGE plpgsql;

-- 
Michael Fuhr