Re: Employee modeling question

>
> > I could store the department and business attributes with the
>> > employee, but without proper constraints the referenced department
>> > could conceivably not correspond to the referenced business. Or I
>> > could ensure that all businesses have at least one department,
>> > defaulting to the business when the business has no department, but
>> > then I'd be storing duplicate data. The other alternative I've come up
>> > with is an exclusive constraint where the employee instance can only
>> > reference a department or a business, but not both.
>> >
>> > None of these solutions seems ideal, although the exclusivity solution
>> > seems like it would work the best, and I have had to create
>> > exclusivity constraints before. So, am I missing a more obvious
>> > solution, or am I even on track here?
>>
>> I’ve found this « Universal Person and Organization Data Model » very
>> useful to understand complex questions like that:
>> http://www.tdan.com/view-articles/5014
>>
>> Hope this helps,
>> François Beausoleil
>>
>>
> Thanks François. This is pretty generic stuff, but my first reading has
> got me thinking that I should at least pick up some ideas from it. I will
> give it a go. And I've got a new web site that I've now known about before,
> so thanks for that as well.
>
> Regards,
> Nelson
>
>
> I strongly suggest you read the writings of Joe Celko, he has been
> addressing this kind of problem for decades. Ultimately, it is very
> important not to confuse behaviour with entities (yes employment is
> behavioural)
>
> Cheers
>

Thanks Robin. Ironically enough, our little local library has three books
by Joe Celko, so looks like I may have a weekend of reading ahead of me.

Nelson