How to represent types of people

From: Kev <kevin.porter_at_fastsearch.com>
Date: Wed, 06 Dec 2000 11:51:11 +0000
Message-ID: <3A2E282F.EE503743_at_fastsearch.com>


Hi,

I have a design question I hope someone can help me with...

I'm designing a database, a part of which needs to represent different types of people, 'different types of people' meaning 'people with different jobs'. So, I have made a 'Job' entity on my ERM and a 'Person' entity. I have
a third entity called 'Person_Job' which represents an instance of a person's employment. Person_Job stores
a start and end date too.

The problem I'm having is that different types of people need to have different relationships with other
entities in the system. For example, I cannot simply add a relationship labelled 'Plays for' between
Person_Job and the Team entity, because although that would be correct for a player it would not be
correct for a manager, and there are other relationships which are true for a manager but not for a player.

What is the correct way of dealing with this situation on an ERM? And, what is the correct way of
implementing it?

thanks,

Received on Wed Dec 06 2000 - 12:51:11 CET

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