From: | hubert depesz lubaczewski <depesz(at)depesz(dot)com> |
---|---|
To: | Christian Rengstl <Christian(dot)Rengstl(at)klinik(dot)uni-regensburg(dot)de> |
Cc: | pgsql-general(at)postgresql(dot)org |
Subject: | Re: Questions concerning check constraints |
Date: | 2007-11-02 11:30:44 |
Message-ID: | 20071102113044.GA20336@depesz.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
On Fri, Nov 02, 2007 at 10:04:06AM +0100, Christian Rengstl wrote:
> 1) Is it possible to refer to a column in a different table, ie
> entering a value in mytable.x should only be allowed if mytable2.y=1 for
> example? I know that it is possible to use triggers to do that, but I
> think adding a simple check constraint might be simpler.
you would need to make a wrapper function for the actual checking, and
then add check (function(column) = true) or something like this.
> 2) Is it possible to issue custom error messages in case a constraint
> is violated?
if you have function based checks - sure, "raise exception"
depesz
--
quicksil1er: "postgres is excellent, but like any DB it requires a
highly paid DBA. here's my CV!" :)
http://www.depesz.com/ - blog dla ciebie (i moje CV)
From | Date | Subject | |
---|---|---|---|
Next Message | Filip Rembiałkowski | 2007-11-02 11:53:59 | Re: Calculation for Max_FSM_pages : Any rules of thumb? |
Previous Message | Oleg Bartunov | 2007-11-02 10:08:58 | Re: Improve Search |