Implementation of [A]1---->*[B]

From: Loeffelholz (loeffelholz_at_gmx.net)
Date: 08/15/04 

Date: Sun, 15 Aug 2004 17:20:18 +0200

Hello,

concerning following kind of association:

[A]1----->*[B]

Concrete, for instance:

[Company]1---->*[Employee]*<----1[Project]

How can one prevent that an Employee is referenced more than one time by a
Project?

My thoughts so far are:

1. A Project holds its own copy of Employee. Dropped out, because Employee
is a reference object and there are other references to it.

2. Prevent it over the GUI. Okay, but it wouldn't prevent that I - as the
programmer - do this mistake accidently somewhere in the code.

3. Create a ProjectManager class which would check all Projects if one would
add a Employee to a Project. Okay, but seems to me as a too great efford
for all such kind of associations.

Are there other options? How do you implement this in daily work?

Thanks
L.

Relevant Pages

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