"Ferguson, Jon" wrote:

> Assume I need to model a car as a course grained component. Since a car
> is rather complex I use aggregation to connect up all its parts. Then I
> say things like 'start' and 'stop'.  Assuming I'm using a relational
> database, my first instinct is that the car will have a data model using
> several tables, possibly with joins.  It appears that using Weblogic and
> CMP I can only model simple: attribute=field type relationships from a
> record of a single table.  Thus it seems like I therefore must model
> each simple component as a separate entity bean and then wrap the sum in
> a 'car' session bean.

One option is to design a database view that represents a Car, including
underlying joins as you've noted above.  You can then let the backend database
do the hard work.  However, you might then have to confront the classic "update
through views" problem that have until recently plagued DBMS vendors.  One
could use the underlying DB to its full potential and write stored procedure
triggers that enable view CRUD (Create, Read, Update, Delete).

Unfortunately, this approach would inhibit portability (stored procedure logic
is notoriously non-portable) and your choice of relational backend.

--
Don Herkimer
303-838-0639 (Home Office)
303-595-2548 (Denver Office)

 "What if the hokey-pokey really *is* what life is all about?"
 Ju Ju Horsepower

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