inserting values into arrays

(Message from Zoltan Kovacs; note to Zoltan: try subscribing to the
"pgsql-loophole" mailing list, which should let you post to any of the
other lists)

> ---------- Forwarded message ----------
> Date: Thu, 20 Jan 2000 09:16:48 +0100 (CET)
> From: Kovacs Zoltan <kovacsz(at)pc10(dot)radnoti-szeged(dot)sulinet(dot)hu>
> To: pgsql-sql(at)postgresql(dot)org
> Subject: inserting values into arrays
>
> I unsubscribed pgsql-sql for some days, so I don't know whether this
> problem is reported already or not.
>
> I am trying to write a function for making group and user creation
> easier. I would like to insert a new value after the existing ones in the
> field "grolist" in the table "pg_group".
>
> I tried a few solutions without success:
>
> a) Defining a variable in a plpgsql function with type _int4. But
> the command SELECT INTO refused to take the array up. Or, if I can do
> this, how can I append a row after the others?
>
> b) The other idea was to get the values step by step from the array,
> making a varchar type variable with the values and the other neccessary
> punctuation ("{", "'", ",", "}"), and then perform an update on the right
> row of pg_group. But I realized that there is no varchar->_int4 converter
> in Postgres yet, unfortunately.
>
> The strange thing is that I can do almost everything by typing the queries
> across the psql frontend, but from functions nothing (I think it is due to
> there is no varchar->_int4 conversion) .
>
> What should I do?
>
> Thanks in advice,
> Kovacs, Zoltan