I've found the following pages helpful in getting CVS EJB3 Entity beans to use MySQL and Postgres for persistence.


http://docs.jboss.org/ejb3/reference/hibernate.html

http://www.hibernate.org/hib_docs/reference/en/html/session-configuration.html

From the hibernate page I learnt you can either set up a database source in JBoss and point hibernate to that (I think this is the prefered way)

Or you point hibernate directly to the database (this is what I did for development)

This is what my hibernate.properties looks like...

hibernate.connection.driver_class=com.mysql.jdbc.Driver
hibernate.connection.url=jdbc:mysql://localhost:3306/database
hibernate.connection.username=username
hibernate.connection.password=password
hibernate.cache.provider_class=org.hibernate.cache.HashtableCacheProvider
hibernate.dialect=org.hibernate.dialect.MySQLDialect
#hibernate.hbm2ddl.auto=create-drop
hibernate.hbm2ddl.auto=update

(the commented out create-drop line will kill everything in your database every time your ejb3 deploys, changed to update to stop this)