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JPA Primary Key

Explains how to define and use primary keys in JPA, including composite and embedded primary keys.... a primary key. Once assigned, the primary key cannot be modified. It represents the entity object as long as it exists in the ...


JPQL IN Operator

How can I use the standard JPQL IN operator with ObjectDB? This JPQL query works fine with EclipseLink / postgres but throws an exception in objectDB: select distinct dv.creationtime from DataValue dv where dv.capabilityId.capabilityId ==> in <== :capabilities and dv.creationtime >= :earliest and dv.creationtime <= :latest order by dv.creationtime ASC [ObjectDB 2.2.9] javax.persistence.PersistenceException Unexpected query token 'in' (error 752) ... thanks for suggestion, I modified the queries to read e.g. as follows: @NamedQuery ( name ...



Called before the values in the instance are cleared.(Method of javax.jdo.listener.ClearCallback)



This interface is used to notify instances of delete events.(Interface of JDO)



Specify the selection items that are to be returned in the query result.(Method of javax.persistence.criteria.CriteriaQuery)



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)



A persistence provider supplies an instance of this interface to the PersistenceUnitInfo.addTransformer method.(Interface of JPA)


Querys slower when execute a query after every persist

The test case of the java file attachment persists many entities and executes a query after every persist. The execution time amounts 2 sec when the test persists 1000 entities. The execution time amounts 100 sec when the test persists 10000 entities. We have been expected that the second case requires only 20 sec, but the test requires 100 sec. Why the querys will be more and more slower? In addition there are a cpu snapshot for visual vm and an image of cpu snapshot as attachment. ... to find which objects in the persistence context have been modified and should be flushed to the database. If you have more objects in the ...


Null returned by Persistence.createEntityManagerFactory

Hi, So I'm currently having an issue where createEntityManagerFactory returns null. When I run the application on the my local machine through Tomcat it works fine, the odb file is created.    #1 2014-06-12 18:11 Hi, So I'm currently having an issue where createEntityManagerFactory returns null. When I run the ap ...


makeDirty(pc, fieldName)

Explicitly mark the parameter instance and field dirty.(Method of javax.jdo.spi.StateInterrogation)