[Middlegen-user] Middlegen and domain modelling

[a***@netcom.no]

Hi Joost,

I'm cc-ing to Middlegen's user list. Might be of general interest.

Am I correct in my understanding that the database
structure is always the source for your domain-model
when using middlegen?

Yes.

If so; it is often the case that the db structure is
leading of course but I thought it would conceptually
be more right to have an abstract domain model and use
that as the source for both db-schema and ejb-tier. That

It depends on the landscape. If you inherit a big legacy database,
you often don't have that luxury.

Besides, if you design your database with Middlegen in mind,
you have the possibility to make it look good in both object and
relational form.

way your ejb-structure is not constrained by the expressive
power of db-schema�s. For instance inheritance would be
difficult I guess.

If you're talking about EJB, inheritance isn't difficult. It's
impossible. EJB doesn't support inheritance.

You might be interested in UML2EJB. It is similar to Middlegen,
but it reads XMI (UML) and spits out XDoclet @nnotated beans.

http://uml2ejb.sourceforge.net/

Aslak