Re: Help with trigger

Michael,

>>> I'm new to PostgreSQL, but have worked with other databases. I'm trying
>>> to write a trigger to default a timestamp column to a fixed interval
>>> before another. The test setup is as follows:

Try this pg_dump of a working example:

CREATE FUNCTION t_listing_startdate() RETURNS trigger
LANGUAGE plpgsql
AS $$
begin
if new.d2 is null then
new.d2 := new.d1 - interval '7 day';
end if;
return new;
end;
$$;

CREATE TABLE t (
d1 timestamp without time zone,
d2 timestamp without time zone
);

CREATE TRIGGER t_listing_startdate
BEFORE INSERT OR UPDATE ON t
FOR EACH ROW
EXECUTE PROCEDURE t_listing_startdate();

-- Gary Chambers