About entity

forum_thread

Source control of database

Hi, I'm new with ObjectDB. I want to know how I can evolve my model, adding new fields, new classes, perform refactors between versions, etc... There is something like http://www.liquibase.org that can I use over ObjectDB? ... Found! http://www.objectdb.com/java/jpa/entity/schema   Sorry, and thanks! ...

 
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 ...

 
issue

Issue with full cross joins

hi, There seems to be an issue with full cross joins & maps. This query: ... they do have valid "MitgliedDebitorenKontoFragment" entity reference in their "qubletFRAGMENTMAP" map!? ...

 
tutorial

Step 4: Create an ObjectDB Data Set

Explains how to create an ObjectDB data set for BIRT reports.... The database in this tutorial contains Point entity objects. We will use a simple JPQL query that retrieves points with x ...

 
forum_thread

Maven Enhancement with OSGi Plugins

Hello, I've an OSGi environment and try to enhance Classes with Maven as it is described in your tutorials. Now I get ClassNotFoundException's with some entity classes, which contains enums from other plugins. Is there a way to include classes in enhancement process? Thanks for your help. ... Now I get ClassNotFoundException's with some entity classes, which contains enums from other plugins. Is there a way to ...

 
tutorial

Step 3: Define a Spring DAO Component

Explains how to define a JPA DAO component (bean) in a NetBeans Spring MVC JPA web application project.... persist - for storing a new  Guest entity object in the database. getAllGuests - for ...

 
api-jpa

OneToOne.fetch

(Optional) Whether the association should be lazily loaded or must be eagerly fetched.(Annotation Element of javax.persistence.OneToOne)

 
api-jpa

javax.persistence.PreRemove

Is used to specify callback methods for the corresponding lifecycle event.(Annotation of JPA)

 
api-jpa

getCriteriaBuilder()

Return an instance of CriteriaBuilder for the creation of CriteriaQuery objects.(Method of javax.persistence.EntityManagerFactory)

 
forum_thread

Query to search for common elements in two separate collections.

I'm trying to work out the most efficient way to build a query that can compare two collections for identical members. Something like: "SELECT o FROM Object o WHERE o.someCollection CONTAINS MEMBER OF :someCollection" Is something like this possible in the JPA spec? ... should be stored in an indexed field, possibly in a new entity or embeddable class that would wrap the collection with its hash code. ...