Re: trigger : emulate "instead of" with before ?

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(at)bearfruit(dot)org

> -----Original Message-----
> From: pgsql-sql-owner(at)postgresql(dot)org [mailto:pgsql-sql-
> owner(at)postgresql(dot)org] On Behalf Of Albrecht Berger
> Sent: Friday, June 13, 2003 7:51 AM
> To: pgsql
> Subject: [SQL] trigger : emulate "instead of" with before ?
>
> Hello,
> I need a trigger which is updating a delete flag of a row instead of
> deleting it physically.
>
> How do I implement a trigger which doesn't execute a delete without
> raising
> an exception
> in plsql ?
>
> CREATE TRIGGER trigger1 BEFORE DELETE ON table1
> FOR EACH ROW EXECUTE PROCEDURE setDeleteFlag ();
>
> If I use
> RAISE EXCEPTION "..."
> the delete statement isn't executed, but I think the transaction is rolled
> back too, am I right ?
>
> 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 ();
>
> thx
>
>
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