Re: many to many relationship

So you use ORM to model your databases at IBM as opposed to ER?

I'm at college at the moment learning ORM and Z. I was just wondering how much these techniques are used in the 'real world'.

Cheers
Ivan

"Paul Vernon" <paul.vernon_at_ukk.ibmm.comm> wrote in message news:b4adf6$emg$1_at_sp15at20.hursley.ibm.com...
> "Alan" <alan_at_erols.com> wrote in message
> news:b4a9p3$1tdad9$1_at_ID-114862.news.dfncis.de...
> > Don't confuse the conceptual model with the physical model
>
> As if I would
>
> > An ERD models the business.
>
> My point is that classic Entity Relationship Diagrams are *not* a great
way to
> model a business if they encourage you to hide entities such as 'enrolment
> from your conceptual model.
>
> In fact as many common constraints (aka business rules) are not
representable
> graphically in Entity Relationship Diagrams, I don't find they make good
> conceptual models at all. ORM is generally much better.
>
> Regards
> Paul Vernon
> Business Intelligence, IBM Global Services
>
>
Received on Tue Mar 11 2003 - 01:12:16 CET