I think you want single table inheritance then.

On 8/17/07, Riccardo De Menna <[EMAIL PROTECTED]> wrote:
>
> Hi Guido,
>
> I might have badly explained my issue. I have successfully used EO
> inheritance in another context, but my aim here is exactly the
> opposite. I don't want to model my DB with all sort of empty tables
> for every possible domain ending (there are more than 200 different
> country codes and such).
> I'm perfectly fine with one single table holding domain info... I
> simply want to fetch from it and receive specific subclasses of the
> main "domain" class. These would simply differ from the common
> superclass in the custom logic in them and NOT in the fields they
> hold. Let's say for example that the DotCOM domain subclass would
> validate domains up to 63 chars in length while the DotEU would start
> bitching for anything longer than 25 or so, even though the table
> holds any length.
> That said I'm ordering Chuck's book anyway but it will take some time
> to get my hands on it since I'm traveling through Europe atm.
> If someone could simply tell me "you can't do it" or "you do it by
> subclassing this" or such it would speed me up a lot...
>
> Cheers,
> Ric
>
>
>
> On 17/ago/07, at 17:15, Guido Neitzer wrote:
>
> > On 17.08.2007, at 00:38, Riccardo De Menna wrote:
> >
> >> I was wondering if anyone could point me out in the right
> >> direction on this problem of mine.
> >> I'm writing a domain registration app and I have a model that
> >> holds an entity "domain".
> >> It's generic in nature as it will accomodate many different domain
> >> endings (com net org eu etc).
> >>
> >> Since I need to fit in a lot of custom behavior I was wondering if
> >> I can force my editing context to retrieve data from the database
> >> but then instantiate custom subclasses of a generic abstract
> >> "domain" class (ie DotComDomain, DotNetDomain) instead of what I
> >> provide in the model.
> >> Is there a way to decide on the fly what class gets used to
> >> generate fetched EO's?
> >
> > You can use EOF inheritance (get Chuck's book to really learn how
> > to do it).
> >
> > cug
>
>
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