Date: Wed, 25 Oct 2000 08:23:20 +0200
From: Louis-David Mitterrand <cunctator@apartia.ch>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-sql@hub.org
Subject: Re: knowing which columns have beend UPDATEd inside a TRIGGER?
Message-ID: <20001025082320.A1941@styx>
Reply-To: ldm@apartia.ch
Mail-Followup-To: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-sql@hub.org
References: <20001024155506.A775@styx> <26414.972427863@sss.pgh.pa.us>
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	from tgl@sss.pgh.pa.us on Tue, Oct 24, 2000 at 06:51:03PM -0400

On Tue, Oct 24, 2000 at 06:51:03PM -0400, Tom Lane wrote:
> Louis-David Mitterrand <cunctator@apartia.ch> writes:
> > Is there a way to know which columns are being UPDATEd or INSERTEd from
> > inside a trigger, either in C or pl/pgsql?
> 
> Huh?  An INSERT always inserts all columns, by definition.  Some of them
> might be null and/or equal to their default values, but they're all
> there.

*slap* Doh! Thanks for clearing up my mind about this ;-)

> For an UPDATE, you could check to see whether old.col = new.col.
> This would miss the case where an UPDATE command is explicitly setting
> a column to the same value it already had; dunno if you care or not.

That is so obvious I didn't think about it, and it's exactly what I
need.

Thanks a lot,

-- 
Louis-David Mitterrand - ldm@apartia.org - http://www.apartia.org

 Hi. This is my friend, Jack Shit, and you don't know him.