About persistence

forum_thread

ODB lost?

I'm new to ObjectDB. While debugging small programs in single-step mode in NetBeans, the ODB appears to get corrupted or lost if I don't invoke close on EntityManager. If I re-run my program and get a new EntityManager, the instance behaves as if the data that was persisting is somehow gone. I noticed in the file system, indeed, the .odb file is gone, but there are <name>_<v>.odb files where <name> is the name of my odb and <v> is apparently a version number. Is there any way to recover <name>.odb? #1 2011-03-18 23:11 I'm new to ObjectDB. While debugging small programs in single-step mode in NetBeans, the ODB appears to get corru ...

 
forum_thread

LDAP and ObjectDB

Hello, Is there any advantage in using LDAP with ObjectDB? I notice that I would still have to query the config for the credential, as well as query LDAP, a doubling of the work.   Thanks #1 2011-11-14 18:43 Hello, Is there any advantage in using LDAP with ObjectDB? I notice that I would still have ...

 
forum_thread

Optimistic Locking

We are having problems with optimistic locking.  I made a simple test case to try to induce an optimistic lock. #1 2010-08-11 16:03 We are having problems with optimistic locking. I made a simple test case to try to induce an optimistic lock. ...

 
api-jdo

JDO External Listeners

... Listener objects can be bound to one or more persistence capable classes by invoking the addInstanceLifecycleListner ...

 
forum_thread

More Efficient Primary Keys

Can you give us a recommendation as we can represent the Key (UUID) most efficient? Both in terms of memory usage of the database files, memory usage of the JVM and efficiency for queries. We already need the key before the entities are persisted so that we can build even references. #1 2015-08-21 08:26 Can you give us a recommendation as we can represent the Key (UUID) most efficient? Both in terms of memory u ...

 
manual

Numbers in JPQL and Criteria Queries

Shows how numbers, arithmetic expressions and numeric functions and operators (MOD, ABS) can be used in JPQL queries.... query expressions. The CriteriaBuilder javax.persistence.criteria.CriteriaBuilder JPA interface Used to ... and parameter expressions: Expression javax.persistence.criteria.Expression JPA interface Type for query ... "population" ) ; Expression javax.persistence.criteria.Expression JPA interface Type for query ...

 
api-jpa

javax.persistence.OrderBy

Specifies the ordering of the elements of a collection valued association or element collection at the point when the association or collection is retrieved.(Annotation of JPA)

 
manual

Date and Time in JPQL and Criteria Queries

Shows how date and time can be used in JPQL queries.... Queries The CriteriaBuilder javax.persistence.criteria.CriteriaBuilder JPA interface Used to ... current date expression: Expression javax.persistence.criteria.Expression JPA interface Type for query ... current time expression: Expression javax.persistence.criteria.Expression JPA interface Type for query ...

 
api-jdo

jdoPostDetach(detached)

This method is called during the execution of javax.jdo.PersistenceManager.detachCopy on the detached instance after the copy is made.(Method of javax.jdo.listener.DetachCallback)

 
api-jdo

getManagedObjects(classes)

Get the objects managed by this persistence manager being instances of the specified classes.(Method of javax.jdo.PersistenceManager)