Re: Unexpected Return from Function - Mailing list pgsql-sql

From Anthony Bouvier
Subject Re: Unexpected Return from Function
Date
Msg-id CBEBKIKGCCOCPDEMKBBJMEPKCAAA.anthony@developware.com
Whole thread Raw
In response to Re: Unexpected Return from Function  (Stephan Szabo <sszabo@megazone23.bigpanda.com>)
List pgsql-sql
That was the exact problem.  Your help is much appreciated.

Of course, after getting this solution working in respect to the
concatenation, I realise I was going about this whole thing all wrong.
I spent 6 hours trying to do the original with no luck, then came in
today and created an AGGREGATE that does -exactly- what I wanted to do
in the first place, and in a much simpler fashion.

-----Original Message-----
From: pgsql-sql-owner@postgresql.org
[mailto:pgsql-sql-owner@postgresql.org]On Behalf Of Stephan Szabo
Sent: Saturday, December 01, 2001 9:23 PM
To: Anthony Bouvier
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] Unexpected Return from Function


On Sat, 1 Dec 2001, Anthony Bouvier wrote:

> I have a FUNCTION:
>
> CREATE FUNCTION get_responsible(text)
> RETURNS TEXT AS '
> DECLARE
>   responsible_list text;
>   my_record RECORD;
> BEGIN
>   FOR my_record IN SELECT login FROM employee WHERE id IN (1,2) LOOP
>     responsible_list := responsible_list || '', '' my_record.login;
>   END LOOP;
>   RETURN responsible_list;
> END;
> ' LANGUAGE 'plpgsql';
>
> The employee table is such:
>
> id | login
> -------------
> 1  | anthony
> 2  | mary
> -------------
>
> I expect the SQL statement "SELECT get_responsible('1,2')" to return
> something like so:
>
> get_responsible
> ---------------
> anthony, mary
> ---------------
>
> But instead I receive:
>
> get_responsible
> ---------------
>
> ---------------

You probably need to initialize responsible_list to an empty string.
My guess is that it starts NULL and NULL concatenated with anything
is still NULL.


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