To: Brian Blaha <bblaha@umr.edu>
Cc: pgsql-sql@postgresql.org
Subject: Re: SQL function triggers 
In-reply-to: <3DABB04B.8000104@umr.edu> 
References: <3DABB04B.8000104@umr.edu>
Comments: In-reply-to Brian Blaha <bblaha@umr.edu>
	message dated "Tue, 15 Oct 2002 06:06:03 -0000"
Date: Tue, 15 Oct 2002 10:07:14 -0400
Message-ID: <14677.1034690834@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Brian Blaha <bblaha@umr.edu> writes:
> I would like to write a function as a set of SQL statements, and then 
> use that function
> in a trigger. However, since triggers require a return type of opaque, 
> and SQL functions
> cannot return type opaque, this doesn't look possible.

You could call a SQL function from a trigger, but it can't be a trigger
itself; at present triggers have to be in C, plpgsql, or pltcl (maybe
plpython?  Not sure about that one).

For what you are doing (transferring info from one table to another)
I suspect a rule might work better than a trigger anyway.

			regards, tom lane