Date: Fri, 12 Aug 2005 11:27:58 -0400
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: santiago <chetzacoalt@free.fr>
Cc: pgsql-sql@postgresql.org
Subject: Re: catch an 'update  where false' ?
Message-ID: <20050812152758.GA13246@alvh.no-ip.org>
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On Fri, Aug 12, 2005 at 05:13:24PM +0200, santiago wrote:
> hello
> 
> I' trying to catch un update that fails to update because no row matchs
> the where clause:
> 
> for instance:
> update t set c=1 where cc=2;
> --and no row with cc=2
> 
> I would like to perform a
> insert into t (c) values 1;
> before the update is resolved
> 
> I hoped a trigger before update could help me, but it seems
> that if where clause evals to false, triggers are not called..

Triggers FOR EACH ROW are called once for each updated row.  I think you
could try with a "FOR EACH STATEMENT" trigger.

-- 
Alvaro Herrera (<alvherre[a]alvh.no-ip.org>)
"There is evil in the world. There are dark, awful things. Occasionally, we get
a glimpse of them. But there are dark corners; horrors almost impossible to
imagine... even in our worst nightmares." (Van Helsing, Dracula A.D. 1972)