Re: need trigger help - Mailing list pgsql-general

From Mike Nolan
Subject Re: need trigger help
Date
Msg-id 200505091903.j49J3xDv031377@gw.tssi.com
Whole thread Raw
In response to need trigger help  (Abdul-Wahid Paterson <abdulwahid@gmail.com>)
Responses Re: need trigger help  (Abdul-Wahid Paterson <abdulwahid@gmail.com>)
List pgsql-general
> So how can I create a trigger to automatically update the hash fields
> on updates and inserts?

Something like the following works for me:

create or replace function public.my_trigger()
returns trigger as '

NEW.hashfield = hashfunction(NEW.data1,NEW.data2);

RETURN NEW;
END;
' language 'plpgsql';

--------
create trigger my_trig
before insert or update on my_tablename
for each row
execute procedure public.my_trigger();

The 'RETURN NEW' part is very important, without it your hash field won't
get updated at all.
--
Mike Nolan



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