Actually, Oracle doesn't support container managed persistence. Oracle
recommends using only stateless session beans, and the O4BC tool generates
all of the data manipulation code for you.
The mechanisms of container managed persistence are not defined by the
specification. Therefore each vendor implements the service in its own way.
The capabilities of the various implementations can be dramatically
different.
<I apologize up front if I offend any vendors here. My comments are purely
to demonstrate the differences between the implementations.>
For example, WebLogic provides relatively primitive CMP services. The native
service allows you to map a single object to a single row in a table. You
define the mappings while deploying the bean using WebLogic's deployment
tools. WebLogic also allows you to plug in alternate CMP mechanisms such as
an O/R Mapping tool (TOPlink) or an object database (Versant or ODI). The
mapping mechanism depends on the CMP mechanism used.
At the other extreme, Persistence PowerTier provides exceptionally
comprehensive CMP services. You use the Persistence development environment
to generate objects from your database or the generate a database from your
objects. Persistence supports very complex mappings of object data to
relational tables. The downside to the Persistence approach is that the
entity beans that you develop with PowerTier are not portable to other EJB
implementations.
Anne
-----Original Message-----
From: Robert Nicholson [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, November 09, 1999 12:30 AM
Subject: Container supported persistence... mapping?
With the EJB projects that currently support container supported
persistance. I assume sybase's and oracle's do. How is the mapping
b/w the persistence properties of the bean and the schema of the database
specified?
Is schema generated from class definitions of the bean?
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