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Re: many to many relationship

From: Bernard Peek <bap_at_shrdlu.com>
Date: Tue, 11 Mar 2003 15:35:01 +0000
Message-ID: <v4RLRR+lIgb+EweJ@shrdlu.co.uk>


In message <b4b321$1vdtf6$1_at_ID-114862.news.dfncis.de>, Alan <alan_at_erols.com> 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
bap_at_shrdlu.com
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Received on Tue Mar 11 2003 - 09:35:01 CST

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