Re: knowing which columns have beend UPDATEd inside a TRIGGER? - Mailing list pgsql-sql

From Louis-David Mitterrand
Subject Re: knowing which columns have beend UPDATEd inside a TRIGGER?
Date
Msg-id 20001025082320.A1941@styx
Whole thread Raw
In response to Re: knowing which columns have beend UPDATEd inside a TRIGGER?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-sql
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.


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