About field

forum_thread

Memory consumption of empty Strings

After doing some memory related research in my program, I found a possible place for an enhancement of objectdb: My program has several entities which contain many String. Often some of these String are empty (""). To avoid unnecessary memory consumption, the String within the entities are initialized like: String firstName = ""; ... a new String, the user should be able to specify that this field should be loaded via Stirng.internal() (with all its advantages and ...

 
manual

Running JPA Queries

Explains how to use JPA to run Java Persistence Query Language (JPQL) queries.... ; and the following query resets the area field in all the Country instances to zero: int count = em. ...

 
doc

java.lang.Exception

The class Exception and its subclasses are a form of Throwable that indicates conditions that a reasonable application might want to catch.(Exception of java.langException Exception)

 
api-jpa

javax.persistence.EntityExistsException

Thrown by the persistence provider when EntityManager.persist(Object) is called and the entity already exists.(Exception of JPA)

 
api-jpa

javax.persistence.PersistenceException

Thrown by the persistence provider when a problem occurs.(Exception of JPA)

 
api-jpa

javax.persistence.QueryTimeoutException

Thrown by the persistence provider when a query times out and only the statement is rolled back.(Exception of JPA)

 
forum_thread

Concerning coding style of the example in the posting instructions

(This forum item was spawned from discussions in a private helpdesk ticket.) I write with reference to the coding example in the posting instructions and many of your other examples posted in the forums. While I appreciate the recommended coding style as shown makes for convenient minimal examples and test cases,  I contest that it breaks the rules for JPA2 entities on at least 2 counts. Firstly, the posting instructions state:  #1 2012-03-14 00:28 (This forum item was spawned from discussions in a private helpdesk ticket.) I write with reference t ...

 
api-jpa

javax.persistence.NoResultException

Thrown by the persistence provider when Query.getSingleResult() or TypedQuery.getSingleResult()is executed on a query and there is no result to return.(Exception of JPA)

 
api-jpa

javax.persistence.NonUniqueResultException

Thrown by the persistence provider when Query.getSingleResult() or TypedQuery.getSingleResult() is executed on a query and there is more than one result from the query.(Exception of JPA)

 
api-jpa

javax.persistence.RollbackException

Thrown by the persistence provider when EntityTransaction.commit() fails.(Exception of JPA)