From: "Matthew Nuzum" <cobalt@bearfruit.org>
To: "'Albrecht Berger'" <berger1517@gmx.ch>,
	"'pgsql'" <pgsql-sql@postgresql.org>
Subject: Re: trigger : emulate "instead of" with before ?
Date: Fri, 13 Jun 2003 09:09:52 -0400
Organization: Bearfruit.org
Message-ID: <001501c331ad$14207300$a322fea9@mattspc>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
In-Reply-To: <046801c331a2$0c483e70$a07ba8c0@wxp>
Importance: Normal

I'm not a postgres expert, and I certainly don't know the details of your
situation, but it seems to me you may want to use a rule instead of a
trigger.

Then, you can intercept the delete query and simply re-write it to be an
update query that sets your deleted flag.

--
Matthew Nuzum
www.bearfruit.org
cobalt@bearfruit.org
=20
> -----Original Message-----
> From: pgsql-sql-owner@postgresql.org [mailto:pgsql-sql-
> owner@postgresql.org] On Behalf Of Albrecht Berger
> Sent: Friday, June 13, 2003 7:51 AM
> To: pgsql
> Subject: [SQL] trigger : emulate "instead of" with before ?
>=20
> Hello,
> I need a trigger which is updating a delete flag of a row instead of
> deleting it physically.
>=20
> How do I implement a trigger which doesn't execute a delete without
> raising
> an exception
> in plsql ?
>=20
> CREATE TRIGGER trigger1 BEFORE DELETE ON table1
> FOR EACH ROW EXECUTE PROCEDURE setDeleteFlag ();
>=20
> If I use
> RAISE EXCEPTION "..."
> the delete statement isn't executed, but I think the transaction is rolled
> back too, am I right ?
>=20
> So what is the best way to implement something (Oracle like) like that :
> CREATE TRIGGER trigger1 INSTEAD OF DELETE ON table1
> FOR EACH ROW EXECUTE PROCEDURE setDeleteFlag ();
>=20
> thx
>=20
>=20
> ---------------------------(end of broadcast)---------------------------
> TIP 5: Have you checked our extensive FAQ?
>=20
> http://www.postgresql.org/docs/faqs/FAQ.html