How about selecting an EJB server that stores Address as a related
table, and not as a blob?
The good EJB servers in the market do that for you. The rest are pretty
useless - CMP should allow you to read the address assuming you have a
database from before you bought the EJB server.
arkin
Jouni Juutinen wrote:
>
> Interesting question (again) is how one handles the persistence of dependent
> objects. I quess there are at least two options:
> 1. Make dependents as regular Java classes (e.g. Address). Then Person may
> be a entity bean with Adress attribute(s) or references. Using RDBMS you can
> persist this Java class in one blob (which seems to be to usual solution
> with CMP though Some CMP solutions may provide some custom mappers) or you
> can use BMP and write the required code to persist the class in appropriate
> table/columns. Blobs makes it difficult to figure out what's stored in your
> database if you are using some query tools.
> 2. Use the entity beans for Address too. For many cases this seems a pretty
> heavy-weight solution.
>
> You also have to decide what to do when the Person instance is deleted.
> Usually you want to delete the dependent objects too.
>
> Regards,
> Jouni
> > -----Original Message-----
> > From: A mailing list for Enterprise JavaBeans development
> > [mailto:[EMAIL PROTECTED]]On Behalf Of Richard Monson-Haefel
> > Sent: Tuesday, February 22, 2000 11:16 PM
> > To: [EMAIL PROTECTED]
> > Subject: Re: Dependent classes
> >
> >
> > That last post was difficult to read, so here it is again with
> > the line breaks
> > fixed:
> >
> > "Dependent objects are objects that only have meaning within the
> > context of
> > another business object. They typically represent fairly
> > fine-grained business
> > con-cepts, like an address, phone number, or order item. For example, an
> > address has little meaning when it is not associated with a
> > business object
> > like Person or Organization. It depends on the context of the
> > business object
> > to give it mean-ing. Such an object can be thought of as a
> > wrapper for related
> > data. The fields that make up an address (street, city, state,
> > and zip) should
> > be packaged together in a single object called Address. In turn,
> > the Address
> > object is usually an attribute or property of another business
> > object; in EJB,
> > we would typically see an Address or some other dependent object
> > as a property
> > of an entity bean."
> >
> > -- Richard
> > --
> > Author of Enterprise JavaBeans
> > Published by O'Reilly & Associates
> >
> > EJB FAQ
> > http://www.jguru.com/faq/EJB
> >
> > EJBNow.com
> > http://www.ejbnow.com
> >
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>
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--
----------------------------------------------------------------------
Assaf Arkin www.exoffice.com
CTO, Exoffice Technologies, Inc. www.exolab.org
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