About between


mappedBy problem

If I put the mappedBy element to the @OneToMany, the owned side (the many side) will never persist ! for example @Entity public class Employee { @Id @GeneratedValue(strategy = GenerationType.IDENTITY) public Long id; public String name; @OneToMany(targetEntity=Address.class,mappedBy="employee") public List<Address> addresses; }   @Entity... can be persisted. But there is no relationship established between the two entities! Using the explorer I see the employee field in the ...


Custom collection types

Hi   In our project in few places there are used collections from emf framework eg EcoreEMap http://download.eclipse.org/modeling/emf/emf/javadoc/2.5.0/org/eclipse/emf/ecore/util/EcoreEMap.html This is strange map for me, it implements List interface but does not implement Map interface, nevertheless it causes some questions. ... I checked that i can easily change the type of collection between eg Vector, ArrayList, HashSet and all works fine, moreover Db-exploler ...


Detached Entity Objects

Explains detached entity objects and how to work with detached objects in JPA, including merging them into an EntityManager.... is not available and for transferring objects between different EntityManager instances. This page covers ...


Java 6/7 Performance Comparison

Hey, I've been using ObjectDB for a small scale home project to gain some familiarity before proposing it in a commercial project at work. What I've noticed though is that when using objectdb in embedded mode based on the console tutorial, there seems to be a bit of a performance gap running the same code between Java 6 & 7 Tracing it through I can see the bottle neck seems to be at the creation of the entity manager and I was wondering if there are any additional configuration options I may have missed while running under java 7. ... to be a bit of a performance gap running the same code between Java 6 & 7 Tracing it through I can see the bottle neck ...


Schema update: package, class and field

Hello, how can it be specified in the schema, that an entity is moved to another package? Package Structure (version 1) com |- btc |- impl |- Class1.java |- internal |- Class2.java |- Class3.java Now I want to move Class2   from com.btc.internal to com.btc.impl ... There should not be a difference between entity and embeddable classes regarding schema changes. Maybe you are ...


diff(x, y)

Create an expression that returns the difference between its arguments.(Method of javax.persistence.criteria.CriteriaBuilder)



This class is for identity with a single Object type field.(Class of JDO)



This method is called before the implementation calls the instance method ClearCallback.jdoPreClear and before it clears the values in the instance to their Java default values.(Method of javax.jdo.listener.ClearLifecycleListener)


Problem with merging / persisitng objects with @Embeddable field

Hi, After migration to version 2.4.2_01, I have noticed a strange problem with persisting object with field that contains @Embeddable object. Please check attached exception. Relation between entities looks like this: ... check attached exception. Relation between entities looks like this: @ Entity public class ...


Cannot find objectdb-jee.jar releases in the ObjectDB maven repository

Hi, I can only find objectdb.jar releases in the ObjectDB maven repository. If objectdb-jee.jar releases are there, can you let me know where they are, otherwise would it be possible to include objectdb-jee.jar in the current and future maven releases ? Thanks Andrew   ... was add now to the issue tracking. The difference between these jars is that  objectdb.jar includes JPA 2 ...