About projection

forum_thread

Visibility of changes in Transaction is not visible to a JPA QL Query

I have two simple Entities ( see attachment ) and a simple SLSB with container managed transactions which is called by a trivial servlet. Inside a UserTransaction I add a number of items then check to see that they have been added #1 2011-08-24 19:11 I have two simple Entities ( see attachment ) and a simple SLSB with container managed transactions which is call ...

 
forum_thread

Future JDO versions?

We are about to release our first product using ObjectDB (as a small embedded store), and soon hope to release a much larger product using ObjectDB (will need an OEM license).  What really interests us is JDO.  We have been using JDO for over a decade and have found it consistently a far better API than JPA, as all kinds of features that are optional or require special extensions in JPA products, (such as large query optimisation, storage of collections of non-entities and automated management of identity) are built-in to JDO. #1 2014-06-15 21:01 We are about to release our first product using ObjectDB (as a small embedded store), and soon hope to release a ...

 
manual

Running JPA Queries

Explains how to use JPA to run Java Persistence Query Language (JPQL) queries.... for merely printing the country names, a query that uses projection and retrieves country names directly instead of fully built ...

 
forum_thread

Java 6/7 Performance Comparison

Hey, I've been using ObjectDB for a small scale home project to gain some familiarity before proposing it in a commercial project at work. What I've noticed though is that when using objectdb in embedded mode based on the console tutorial, there seems to be a bit of a performance gap running the same code between Java 6 & 7 Tracing it through I can see the bottle neck seems to be at the creation of the entity manager and I was wondering if there are any additional configuration options I may have missed while running under java 7. #1 2014-03-06 14:31 Hey, I've been using ObjectDB for a small scale home project to gain some familiarity before proposin ...

 
tutorial

Step 2: Define a JPA Entity Class

Explains how to define a JPA entity class in a NetBeans Web Application. To store objects in an ObjectDB database using JPA we need to define an entity class: Open the [New Java Class] dialog box, e.g. by right clicking the project node (in the [Projects] window) and selecting New > Java Class ... Enter G ...

 
forum_thread

Specify location of persistence.xml

Is it possible to tell objectdb explicitly where the persistence.xml is located? #1 2017-11-16 11:25 Is it possible to tell objectdb explicitly where the persistence.xml is located? The background is that I ...

 
api-jpa

javax.persistence.MapKeyEnumerated

Specifies the enum type for a map key whose basic type is an enumerated type.(Annotation of JPA)

 
forum_thread

Problem on JPA Merge Entity.

Hello, I have a problem with the EntityManager.merge() function. I set a property value of an entity (statement) with an other entity (newSingleConstraint). newSingleValue is already persisted. I do this myself (no use of cascade because sometimes the newSingleValue is already in database).   The statement update don't throw exception. And when i try to reload statement the value i have set before is a null value. I check with the Explorer, the statement has a null value on the property and the newSingleValue is present. #1 2011-02-03 16:57 Hello, I have a problem with the EntityManager.merge() function. I set a property value of an ent ...

 
forum_thread

Is it possible to remove parent/child entities without refresh?

We have a big object tree in our project. If I use the entityManage.remove method a entityManager.refresh is necessary in order to have an updated object tree in memory. But entityManager.refresh is too slow for our project. Do you know a possibilty to remove parent/child entities without entityManager.refresh after the entityManager.remove operation? I have searched for a solution with the following unit test (See testRemoveVariant2()). But my approach works correctly. Do you have an idea? #1 2015-01-13 07:41 We have a big entity object tree in our project. If I use the entityManager.remove(childEntity) method to remove ...

 
forum_thread

Embedding ObjectDB on server application

I'm trying to integrate ObjectDB as part of a server software I am developing. I'm a little lost at the connection file path for the persistent factory. So if I want to pass in the database file path, with relative path, where exactly is it relative to? So I did a test and just wrote: EntityManagerFactory emf = Persistence.createEntityManagerFactory("test.odb"); But I got: Exception: javax.persistence.PersistenceException Message: No Persistence provider for EntityManager named test.odb #1 2014-06-02 13:11 I'm trying to integrate ObjectDB as part of a server software I am developing. I'm a little lost at the c ...