Entities and relationships

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Tegiri Nenashi - 12 Oct 2007 19:35 GMT

I never really took any effort to bother to know what these are until
they got in my way in otherwise fine paper:
http://arxiv.org/PS_cache/arxiv/pdf/0710/0710.2083v1.pdf
It defines an entity as a relation (aka table:-) with a single
noncomposite key, and relationship as a table with composite key. Does
this definition pretty much exhausts the entity-relationship theory?

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Bob Badour - 12 Oct 2007 20:33 GMT

> I never really took any effort to bother to know what these are until
> they got in my way in otherwise fine paper:
> http://arxiv.org/PS_cache/arxiv/pdf/0710/0710.2083v1.pdf
> It defines an entity as a relation (aka table:-) with a single
> noncomposite key, and relationship as a table with composite key. Does
> this definition pretty much exhausts the entity-relationship theory?

Um, no, because an order line item is generally an entity--albeit a weak
one. If I recall correctly.

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