Re: OO and relation "impedance mismatch"

From: Alfredo Novoa <alfredo_at_ncs.es>
Date: 3 Oct 2004 19:38:30 -0700
Message-ID: <e4330f45.0410031838.641e80b5@posting.google.com>

fredrik_bertilsson_at_passagen.se (Fredrik Bertilsson) wrote in message news:<31f7e57d.0410030636.52e3a21f_at_posting.google.com>...

> But non-OO languages support relations, or??

A few languages have a limited support like Prolog and Alloy.

D4 and Tutorial D have full support, although is not clear to me if they are OO languages or not.

> Please give an example.

grid.Expression = suppliers join parts;

button.ClickAction = delete suppliers where code = editBox.Text;

> Wouldn't it be possible to model a relation as a class?

It is not possible, but it is possible to represent a relation as an object.

> Overloaded
> operators could be used for expressing relational calculus. I think
> that OO languages is the most suited for this job.

They are not completely bad for this, but this is a poor solution.

Regards Received on Sun Oct 03 2004 - 21:38:30 CDT