Hi,
> > Well, if you also have soundcard_products, in your example you could
have a
> > product which is both a networkcard AND a soundcard. No way to restrict
> > that a product can be only one 'subclass' at a time... If you can make
that
> > restriction using the relational model, you can do the same as with
> > subclasses. But afaict that is very hard to do...
>
> CREATE VIEW networkcard_v AS SELECT * FROM products, networkcard WHERE
> products.id = networkcard.prod_id;
I think I was not clear enough... You just demonstrated that it is possible
to have a card that is a soundcard and a networkcard at the same time. The
point I tried to make was that it is difficult to _prevent_ this. Ofcourse I
agree with you that your example fits the relational model perfectly!
I have this problem in a few real-life cases, so if you have a sollution to
this, I would realy appreciate it!
Sander.
