Re: Howto prevent write based on date

You could write a trigger like this:

CREATE OR REPLACE FUNCTION checkDate() RETURNS TRIGGER LANGUAGE 'plpgsql' AS '
DECLARE
limitDate DATE DEFAULT current_date-''1 year''::INTERVAL;
BEGIN
IF (OLD.date<=limitDate) THEN
RAISE EXCEPTION ''Cannot change record.'';
END IF;

RETURN NEW;
END;
';

CREATE TRIGGER xxxx_tg1 BEFORE UPDATE OR DELETE ON xxxx FOR EACH ROW
EXECUTE PROCEDURE checkDate();

This should do the job :)

2005/5/4, Fmiser <fmiser(at)gmail(dot)com>:
>
> I'm a newbie to database admin, but I'm not afraid to try - but this one
> has me stumped.
>
> I'm using SQL-Ledger as a front end to postgresql 7.4.2. on (mostly)
> Debian Testing, i386.
>
> My fiscal year is over and I would _like_ to prevent any changes to the
> data from last year.
>
> I looked/searched in the manual, but I don't even know what to call what
> it is that I'm trying to do!
>
> "lock" has another meaning for databases. :)
>
> "Write" seems to bring up lots of user-related stuff.
>
> So, I'm hoping one of you geniuses can tell me where to look, what to
> look for, or how to do it. *smile*
>
> Thanks!
>
> Philip, wanabe-admin
>
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