From: "Josh Berkus" <josh@agliodbs.com>
Subject: Re: [SQL] Copying a rowtype variable.
To: "Rison, Stuart" <srison@rvc.ac.uk>,
	"'pgsql-general@postgresql.org'" <pgsql-general@postgresql.org>,
	"'pgsql-sql@postgresql.org'" <pgsql-sql@postgresql.org>
Date: Tue, 05 Nov 2002 08:55:27 -0800
Message-ID: <web-1813013@davinci.ethosmedia.com>
In-Reply-To: <6BD8CE460CC6EE40B83DDFCED609F84B964D33@cmnt4008.rvc.ac.uk>
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Stuart,

> Just doing a bit of PL/PGSQL so my first question is:
> 
> 1) should PL/PGSQL questions be posted to the general mailing list,
> the sql
> mailing list or both?

The SQL list is the best place.

> 2) I am looking for an elegant way of copying a rowtype variable:
> 
> eg.
> 
> DECLARE
>  current_row orf%ROWTYPE;
>  previous_row orf%ROWTYPE;
> BEGIN
> 
>  LOOP
>  -- use cursors or FOR SELECT to get values into current_row
>  -- now try this:
> 
>  previous_row = current_row;
>  END LOOP;
> END;
> 
> Now, as I anticipated, this fails because a rowtype variable is a
> composite
> variable.  One working alternative is to do:

I haven't tried this.  One thing I notice above is that you're using
the equality operator "=" instead of the assignment operator ":="  .
  Usually Postgres lets you slack on this, but it would be worth trying
to see whether that has an effect on the problem.

Another thing to try is, instead of a simple variable assignment,

SELECT current_row INTO previous_row;

... and see if that works.   I'll tinker later today; there has to be a
way to do it.

-Josh Berkus