In the Persistence Unit window, select New to create a new persistence unit. In
the New Persistence Unit window, specify a Persistence Unit name ( em ). Specify
JTA DataSource Name as jdbc/OracleDBConnectionDS , which is the datasource
name corresponding to the OracleDBConnection connection. Select the settings for
Toplink ; Database Platform as Oracle and Server Platform as WebLogic 10 and
then click on OK .
The em Persistence Unit gets created. Click on OK in the Persistence Unit window.