ForeignGenerator does not handle transient entities with an entity-name properly -------------------------------------------------------------------------------- Key: HHH-1336 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1336 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.1 Environment: Hibernate 3.1, any platform/database Reporter: Paul Andrews Assignee: Steve Ebersole Priority: Minor Fix For: 3.1.1 I have an entity that has a one-to-one relationship with another entity, i.e. (ommitting a bunch of mandatory stuff for the sake of brevity): <class entity-name="AnEntity"> <id name="primaryKey"> <generator class="foreign"> <param name="property">aProperty</param> </generator> </id> <one-to-one name="aProperty" entity-name="AnotherEntity"/> </class> I then create a detached (aka transient) instance of AnEntity with an embedded detached instance of AnotherEntity with both of their id's set to null and then do a saveOrUpdate(). Hibernate then throws an 'unknown entity mapping' exception with the classname of the instance of AnotherEntity. In other words it is looking for a mapping for the actual class name of the associated entity when it should be looking for a mapping for the entity-name of the associated entity. Tracing into the code ForeignGenerator.generate() calls session.save as follows: Serializable id; try { id = ForeignKeys.getEntityIdentifierIfNotUnsaved( type.getAssociatedEntityName(), associatedObject, sessionImplementor); } catch (TransientObjectException toe) { id = session.save(associatedObject); } Modifying the session.save() call as follows seems to fix the problem: Serializable id; try { id = ForeignKeys.getEntityIdentifierIfNotUnsaved( type.getAssociatedEntityName(), associatedObject, sessionImplementor); } catch (TransientObjectException toe) { id = session.save(type.getAssociatedEntityName(), associatedObject); }