Re: How to create a trigger

Thomas F.O'Connell <tfo@monsterlabs.com>

From: "Thomas F. O'Connell" <tfo@monsterlabs.com>
To: pgsql-general@postgresql.org
Date: 2001-05-11T14:56:39Z
Lists: pgsql-general
> create trigger date_update before update on mytable
>     for each statement execut procedure [procedure that inserts a date
> for me in the update_date column]
> 
> So what would I be doing for the portion in brackets?


at that point you need a function.

check out the CREATE FUNCTION syntax in the docs 
(http://www.postgresql.org/idocs/index.php?sql-createfunction.html).

for what you were talking about, it seems like something as simple as

create function trigger_before_update_mytable() returns opaque as '
begin
	new.update_date = now();
	return new;
end;
' as language 'plpgsql';

would work.

then your last line of the trigger statement would be:

for each statement execut procedure trigger_before_update_mytable();

good luck.

-tfo