Re: Relation problem

Ok, Sorry I missed my own tread! I'm not used to actually getting feedback lately on my questions. Thank you very much for the enlightment, I feel like I'm back at school.

First clarification:
The primary problem is performance between addresses and (Organizations OR Individuals).
Individuals and Organizations can have more than 1 address. An address can exist by itself.

So, there will be addresses in the address table that are not assigned to anybody, but Individuals or Organization do require and Address.

Michel

Jan Hidders <hidders_at_REMOVE.THIS.win.tue.nl> wrote in message news:94dabm$i5s$2_at_news.tue.nl...
> wrote:
> > On 19 Jan 2001 17:06:00 GMT, hidders_at_REMOVE.THIS.win.tue.nl (Jan
> > Hidders) wrote:
> >
> > >That doesn't make the problem go away because then you have a "split"
> > >foreign key from Patries to Individuals and Organisations.
> >
> > Supertype. Supertype.
>
> I am afraid that these magic words also don't make the problem go
> away. :-)
>
> This supertype is a generalization of Individuals and Organizations.
> That means that every Party is either an Individual or an Organization.
> This constraint leads to a split foreign key. If you don't implement
> this constraint then you haven't solved the prolem that there may be
> addresses in the Address table that don't belong to any Individual or
> Organization. And that is what the original problem was.
>
> --
> Jan Hidders
Received on Mon Jan 29 2001 - 18:50:54 CET