DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com;
	h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding;
	b=llQuHp3AddRcsCznaDu0uk4yGukHxKDYPBnLmQSXicTfkjtOi16HxMNWo1HqdeyHvcxUk06FFAy4/eGf6GizZ8scwAoQ0FV3hSEjtHsXxtyZWqWvEgy+dXt2QpXFNQFYzT64+LKD7tjvpBRf38gwrEXqqJktIko5NXy2dX9v324=
	;
Message-ID: <20061023190433.66796.qmail@web31806.mail.mud.yahoo.com>
Date: Mon, 23 Oct 2006 12:04:33 -0700 (PDT)
From: Richard Broersma Jr <rabroersma@yahoo.com>
Subject: Re: delete on cascade
To: Richard Broersma Jr <rabroersma@yahoo.com>,
	Luca Ferrari <fluca1978@infinito.it>, pgsql-sql@postgresql.org
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: 8bit

i guess my first attempt to send a reply failed.

--- Richard Broersma Jr <rabroersma@yahoo.com> wrote:

> > Hi all,
> > I guess this is an already asked question, but I didn't found an answer, so 
> > apologize me. Imagine I've got two tables:
> > skill(id,description)		// primary key => id
> > family(id,description)	// primary key => id
> > and I want to associate skills to families:
> > ass_sf(id_skill,id_family)	// appropriate foreign keys
> > 
> > Tables are already created and the database is running. Now I'd like to 
> > implement a delete cascade, thus when I delete a skill also its association 
> > with the family must be deleted. I gues I should have declared the skill 
> > table as follows:
> > CREATE TABLE skill
> > (
> > 	id varchar(20) on delete cascade,
> > 	description varchar(50),
> > 	primary key(id)
> > );
> > 
> > right? The problem is: how can I alter the table to add the column constraint 
> > now, without redeclaring the table?
> > Thanks very much for helping me.
> 
> This link has one line that is very similar to what you want to do.  You will probably have to
> start a transaction, drop the foriegn key contraint and then add a new foriegn key contraint
> with
> the on drop cascade .
> 
> http://archives.postgresql.org/pgsql-general/2006-10/msg00467.php
> 
> Regards,
> 
> Richard Broersma Jr.
> 
>