Re: many to many relationship

From: Bernard Peek <>
Date: Tue, 11 Mar 2003 15:35:01 +0000
Message-ID: <>

In message <b4b321$1vdtf6$>, Alan <> writes
>Enrollment is not hidden in an ERD (which is a conceptual model) - it shows
>as a diamond with M:N cardinality. Can't draw it here, but in text:

That depends on your notation. When I draw up an ERD the enrolment entity would appear just like any other entity. As I said earlier, link-entities sometimes evolve into important parts of the logical model. Enrolment might have other attributes that could be important. For instance is it necessary to record the enrolment date?

Bernard Peek SF & Computing book reviews and more.....

In search of cognoscenti
Received on Tue Mar 11 2003 - 16:35:01 CET

Original text of this message