About begin

tutorial

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 ...

 
forum_thread

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 ( ) ...

 
issue

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 ...

 
api-jdo

javax.jdo.spi.StateManager

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

 
forum_thread

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 ...

 
forum_thread

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 ...

 
forum_thread

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 ( ...

 
forum_thread

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 ) ; ...

 
forum_thread

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 ...

 
forum_thread

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 ...