About begin


Step 4: Add a Servlet Class

Explains how to add a servlet that manages persistence using JPA and ObjectDB to an Eclipse Web Application.... em. getTransaction ( ) . begin ( ) ; em. persist ( new ...


Problem with @UniqueConstraint

It seems there is a problem with @UniqueConstraint. Same annotations using hibernate works fine - an error will be thrown - duplicate name. ObjectDB - no exception will be thrown. with best regardsPeter... ; em. getTransaction ( ) . begin ( ) ; CI ci = new CI ( ) ...


Unexpected exception (Error 990)

Exception is thrown on commiting a transaction using this code: transaction.begin(); try { repository.setStatus(ImportStatusFlag.RUNNING_IMPORT); repository.setImportProgressMessage("Importing..."); //$NON-NLS-1$ repository.setImportProgressPercent(0); transaction.commit(); } finally { if (transaction.isActive()) { transaction.rollback(); } } "repository" is a Entity in database. Stracktrace as follows:   ... a transaction using this code: transaction. begin ( ) ; try { repository . setStatus ...



This interface is the point of contact between managed instances of PersistenceCapable classes and the JDO implementation.(Interface of JDO)


Possible issue for JPQL IS EMPTY expression

Possible issue for JPQL IS EMPTY comparison expression: SELECT e FROM MyEntity e WHERE e.collection-valued IS EMPTY throws javax.persistence.PersistenceException: Invalid operand type  for operator IS EMPTY (error 756) Thanks. ...   em. getTransaction ( ) . begin ( ) ; em. persist ( new MyEntity ...


Access entity version before commit transaction

Hi, I have a usecase where I need to write the updated entity id to the database before commiting the transaction: 1. Change entity field e.g. from a to b 2. Create a change entry in database containing the new version of the entity ... just creates a transaction (entityManager.getTransaction().begin();) and commits it automatically at the end ...


How to Remove records from many to many relationship tables in JPA

Hello All, I am getting the constraint violation exception whil deleting the entries I have Relation tables    TransportationEvent  and Conclusion  , relations like ... entityManager. getTransaction ( ) . begin ( ) ; entityManager. remove ( ...


Object explorer cannot open odb file. ObjectDB many-to-many relationship

I created a data model to test many-to-many relationship with a link table as following (full code in attachement) ... ;   em. getTransaction ( ) . begin ( ) ; em. persist ( p1 ) ; ...


ClassCastException: cannot be cast to com.objectdb.spi.TrackableUserType

Hello, I have a class TherapeauticDrugScreenRqst with two other nested subclasses - all using Groovy. My first attempt to persist TherapeauticDrugScreenRqst to Objectdb 2.2.8 is successfully. However, although my method to store the method is shown below: ... try { transaction. begin ( ) pm. makePersistent ( instance ...


Cascading merge() leading to "Attempt to persist a reference to a non managed instance" error

Dear Support Using Objectdb 2.3.4_02 I ran into an exception while performing some tests with a parent/child relationship and cascading merge() operations. The parent has an application defined id, while the child's id is generated, but I don't know if this is of concern. The following "test case" reproduces the error: ... = em. getTransaction ( ) ; tx. begin ( ) ;   em. merge ( new Child ...