Re: abs() does not exists.. - Mailing list pgsql-general

From Peter Eisentraut
Subject Re: abs() does not exists..
Date
Msg-id Pine.LNX.4.30.0106130009150.756-100000@peter.localdomain
Whole thread Raw
In response to abs() does not exists..  ("mazzo" <jambo@aruba.it>)
Responses Re: abs() does not exists..  (Bruno Wolff III <bruno@wolff.to>)
List pgsql-general
mazzo writes:

> Hi all..i'm trying to create a trigger that fires before i insert a value into a column and if the value i insert is
negative,it will change it to positive... 
> I was trying with:
>
> create trigger postv before insert on my_table for each row execute procedure abs (column);
>
> But this doesn't seem to work and gives me the error i wrote in the subject...

Trigger procedures and regular functions cannot be mixed.  You need to
write a special procedure that takes the old value and alters it to your
liking.  See programmer's guide how to write trigger functions.  PL/pgSQL
is probably best.

> Sorry if i post here but i looked on deja.com but i didn't find anything..

There are mailing list archives on the postgresql.org site and at
geocrawler.com.

--
Peter Eisentraut   peter_e@gmx.net   http://funkturm.homeip.net/~peter


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