Re: Triggers

O Leif B. Kristensen έγραψε στις Nov 22, 2005 :

> On Tuesday 22 November 2005 17:25, Achilleus Mantzios wrote:
> >O Leif B. Kristensen έγραψε στις Nov 22, 2005 :
> >> I'm trying to understand triggers. I have read the documentation in
> >> the manual as well as the few pages in the Douglas book about the
> >> subject, but I don't see how to implement a trigger that simply
> >> updates a 'last_edit' date field in my 'persons' table whenever I do
> >> an insert or update into my 'participants' table; that is a trigger
> >> that basically does an "UPDATE persons SET 'last_edit' = NOW() WHERE
> >> persons.person_id = participants.person_fk". Is that even possible?
> >
> >smth like:
> >foodb=# CREATE or REPLACE FUNCTION upd_dad() RETURNS "trigger" AS '
> >foodb'# BEGIN
> >foodb'# UPDATE dad set lastedit=now() where id=new.dadid;
> >foodb'# RETURN new;
> >foodb'# END;
> >foodb'# '
> >foodb-# LANGUAGE plpgsql;
> >CREATE FUNCTION
> >foodb=# CREATE TRIGGER upd_dad_tg AFTER INSERT OR UPDATE ON kid FOR
> > EACH ROW EXECUTE PROCEDURE upd_dad();
> 
> leif=> create or replace function update_last_edit() returns trigger as 
> $$
> leif$> begin
> leif$> update persons set last_edit=now() where person_id=new.person_fk;
> leif$> return new;
> leif$> end;
> leif$> $$ language plpgsql;
> CREATE FUNCTION
> leif=> create trigger update_last_edit after insert or update on 
> participants
> leif-> for each row execute procedure update_last_edit();
> CREATE TRIGGER
> leif=> insert into participants (participant_id,person_fk) values (1,1);
> ERROR:  record "new" has no field "last_edit"
> CONTEXT:  PL/pgSQL function "process_last_edited" line 2 at assignment
^^^^^^^^^^^^^^^^^^^^^

> leif=> 
> 
> What am I missing?
> 

apparently some forgotten process_last_edited() function.

-- 
-Achilleus