Re: View updating in practice?
Date: Mon, 11 Nov 2002 16:41:13 GMT
Jens Lechtenb÷rger wrote:
> 71062.1056_at_compuserve.com (--CELKO--) writes:
> > >> I would be delighted if anybody out there was willing to share
> > their experiences with me. <<
> > The SQL-92 standard is actually very conservative about what VIEWs are
> > updatable. They have to be based on:
> > (1) a SELECT statement on one and only one table; this can go thru
> > several layers of VIEWs on top of VIEWs, however.
> > (2) The VIEW must include all the columns of a key (i.e. a UNIQUE or
> > PRIMARY KEY constraint) in the base table
> > (3) All columns not shown in the VIEW must have default values or be
> > NULL-able (if you think about it for a minute, this lets you construct
> > and insert a complete row into the base table).
> I don't even agree with this. If wouldn't want a user to delete
> from a projection that includes the key if s/he is not allowed to
> select from the underlying table. Just because s/he doesn't know
> what exactly is being deleted.
Daniel Morgan Received on Mon Nov 11 2002 - 17:41:13 CET