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Re: Erm Modelling

From: karl wettin <wettin_at_users.sourceforge.net>
Date: Sat, 1 Mar 2003 19:30:32 +0100
Message-ID: <20030301193032.59ef613a.wettin@users.sourceforge.net>


On 1 Mar 2003 05:55:56 -0800
kellizer_at_hotmail.com (Ian) wrote:

> Hi,
>
> Little query, as i'am interested in variation of possible
> implementations. Basically "A Child can apply many times to a school,
> but may or may not be sucessful. If the child is sucessful, then the
> child's information is then stored in a student table. Applicants who
> are refused are also stored in the application table" A relationship
> must exsist between the student and the application. But my
> implemenation ends up being a mandatory 1 to 1, which is nearly always
> worng.
>
> Also tried going down the "ApplicationRequests", ie 1 application can
> have many request, still no joy.
>
> Anyone have any guidence? is there a name for this modelling problem?

I would model it this way: (UML class diagram)

[Student]-{*} --[School]-- {*}-[Application]-{*} --[Human]<|----[Student]

I suppose you want to store this in an RDBMS? There are quite a few ways of implementing the [Human]<|----[Student] generalization.

karl Received on Sat Mar 01 2003 - 12:30:32 CST

Original text of this message

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