On Wed, 3 Mar 2004, [UTF-8] PauloviÄ Michal wrote:
> Yes I know,
>
> But how you do this at PgSQL????
OK, I just read the response where someone showed me how to make such a
table in mysql. What an odd, and non-intuitive behaviour that is.
Anyway, first off, upgrade your version of postgresql to 7.4.x . 7.1 is
VERY old, and is no longer maintained. IT would suck to develop all this
for 7.1 only to find out some minor bug fix gets in your way of upgrading.
Next, what you need is a before trigger that will take any row being
inserted, select the max(id2) where id1 = whatwereinserting adds one to it
and makes that the new id2.
Look up before triggers. plpgsql is a good language to do this in. Note
that on large tables it WILL BE SLOW.