Re: many to many relationship
From: Paul Vernon <paul.vernon_at_ukk.ibmm.comm>
Date: Fri, 7 Mar 2003 15:20:34 -0000
Message-ID: <b4adf6$emg$1_at_sp15at20.hursley.ibm.com>
Date: Fri, 7 Mar 2003 15:20:34 -0000
Message-ID: <b4adf6$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
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