Re: catch an 'update where false' ? - Mailing list pgsql-sql

From Alvaro Herrera
Subject Re: catch an 'update where false' ?
Date
Msg-id 20050812152758.GA13246@alvh.no-ip.org
Whole thread Raw
In response to catch an 'update where false' ?  (santiago <chetzacoalt@free.fr>)
List pgsql-sql
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)


pgsql-sql by date:

Previous
From: santiago
Date:
Subject: catch an 'update where false' ?
Next
From: The One
Date:
Subject: Encrypting in Postgresql-8.0