Re: How to ensure data consistency?

On 8 Sep 2004 09:26:06 -0700 Lennart Jonsson wrote:
> > I have a similar problem, although mine is about enforcing "complete
> > disjoint specialization", whereas yours is about enforcing "incomplete
> > disjoint specialization" (terminology is from the article that you
> > pointed to).
> >
>
> Not sure whether or not you found an answer to your question (I seem
> to miss some posts in this thread). Any how, here is how I would model
> it:
>
> [...]

That's a very nice solution. Thanks. The underlying concept seems to be identical to that presented in a post by Joe Celko [1] to which Dan pointed in this thread.

> As someone already mentioned it doesnt protect against a PERSORG
> having 0 persons and 0 organisations. For that we would need defered
> constraints or something similar.

I wonder if PostgreSQL allows this.

Felix

[1]
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&selm=OEYKH2bbEHA.368%40TK2MSFTNGP10.phx.gbl&rnum=5 Received on Thu Sep 09 2004 - 01:32:34 CEST