[news.eclipse.rt.eclipselink] Re: Cache Refresh Problem

[james.sutherland@xxxxxxxxxx (James )]

In JPA you must always add to both sides of the relationship, otherwise 
the objects will be out of synch.

Technically you could refresh the object, or disable caching, and see the 
relationship from the database, as the ManyToOne does the writing, but 
best to ensure your object model is not corrupt.

Hibernate does not cache by default, so if you created a new EntityManager 
you would read from the database.  EclipseLink does cache by default, so 
you read from the cache.  If you use the same EntityManager, even in 
Hibernate or without caching your relationship would be empty.

To disable caching see,
http://www.eclipse.org/eclipselink/api/1.1.2/org/eclipse/persistence/config/PersistenceUnitProperties.html#CACHE_SHARED_DEFAULT

---
James