Date: Tue, 11 Mar 2003 09:45:32 +0530
From: Aspire Something <sank89@sancharnet.in>
Subject: Re: How to notice column changes in trigger
To: Christoph Haller <ch@rodos.fzk.de>, pgsql-sql@postgresql.org
Cc: Andreas.Pflug@web.de
Reply-To: Aspire Something <aspire420@hotpop.com>
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References: <3E6CA287.2EE21BFB@rodos.fzk.de>

Hello Christoph Haller ,


> >
> > >So you want the trigger executed only if assignments to b and/or c do

Do sime thing like this  use if /then /esle s block for the problem

In the first if blick check that b and c is null by the declaration of 
IS NULL after that you run the update command as required 

The program code will show as

create function 
CREATE FUNCTION BLAH_FUNCTION() RETURNS "trigger"
    AS ' 
usual blah blah of declre and all ,


IF NEW.b IS NULL and NEW.C IS NULL THEN
ROCK BABY
ELSE
Do OTHERWISE
END IF;
more blah blah plpgsql';


CREATE TRIGGER BLAH
    BEFORE  UPDATE ON BLAH_TABLE
    FOR EACH ROW
    EXECUTE PROCEDURE BLAH_FUNCTION


Please revert back if this helps .


Regards
V Kashyap

> > >not appear within the update command. Right?
> > >
> >
> > Right, that's what I want.
> >
> I'm afraid I have no idea how to accomplish that.
> 
> Regards, Christoph
> 
> 
> 
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