From: Tim Bates <tim@...>
Date: 2004-01-08T15:00:55+09:00
Subject: Re: Database applications and OOness

On Wed, Jan 07, 2004 at 10:16:42PM +0900, Martin DeMello wrote:
> > This really returns a salesperson-to-integer mapping of how many
> > customers a salesperson has dealt with. You can't represent this as a
> > plain list of objects, unless you created a special type of object just
> > for it (which is silly) and most OO-type database libraries won't let
> > you make that sort of query at all without going behind their backs,
> > which is really ugly.
> 
> What would you like it to return? Should it construct a class on the fly,
> with fields 'name' and 'customers'? And should it use its own query
> language to do so, or parse the sql query?

I don't know. Probably an array of arrays or an array of hashes - which,
I know, is exactly what DBI would return for such a query. The point I'm
trying to make is I'd like the system to be able to handle this sort of
query _as_well_as_ the "SELECT * FROM table WHERE property = ?" type
return-a-list-of-objects query. I don't know of any system that can do
that, or even if it could be done neatly. Possibly such a system would
have to accept two sorts of query and handle both separately, but that
introduces its own ugliness.

Tim Bates
-- 
tim@bates.id.au