About JPA

tutorial

JPA Web Application Tutorial

This tutorial demonstrates how to create run a database driven Java web application in Eclipse - using Tomcat 6, ObjectDB and JPA.... driven Java web application using Tomcat 6, ObjectDB and JPA. The demo web application manages a basic guestbook page. Every ... the form: Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a  ...

 
manual

JPA Primary Key

Explains how to define and use primary keys in JPA, including composite and embedded primary keys.... not required. But ObjectDB also supports explicit standard JPA primary keys, including composite primary keys and automatic ... @Entity javax.persistence.Entity JPA annotation Specifies that the class is an entity. See JavaDoc ...

 
api-jpa

JPA Metamodel API

Reference (JavaDoc) of the JPA Metamodel API, including all the type and attribute interfaces. The JPA Metamodel API, which is introduced in JPA 2.0, enables examining the classes, fields and properties of the persistent ... the Java reflection API. The main interface of the JPA Metamodel API is: javax.persistence.metamodel.Metamodel ...

 
manual

JPA Persistable Types

Explains how JPA manages types, including entity classes, embeddable classes, primitive types, wrappers, string, date, enum, collections and maps.... in storing data in the database. ObjectDB supports all the JPA persistable types, which are: User defined classes - Entity ... it with the Entity javax.persistence.Entity JPA annotation Specifies that the class is an entity. See JavaDoc ...

 
api-jpa

JPA Exceptions

Reference (JavaDoc) of the JPA exception classes, including PersistenceException, EntityExistsException, EntityNotFoundException, LockTimeoutException, NonUniqueResultException, NoResultException, OptimisticLockException, PessimisticLockException, QueryTimeoutException, RollbackException, TransactionRequiredException. JPA exceptions are represented by a hierarchy of unchecked exceptions: ... Exception Class Overview The root of the JPA exception class subtree is: ...

 
faq

Can I use ObjectDB to access a relational database?

... relational databases using the Java Persistence API (JPA) you will need an Object Relational Mapping (ORM) tool, such as Hibernate, TopLink, EclipseLink, Open JPA or DataNucleus. The DataNucleus ORM implementation supports also the Java ...

 
api-jpa

javax.persistence.criteria.Expression

Type for query expressions.(Interface of JPA)

 
manual

Locking in JPA

Explains how to use optimistic locking and pessimistic locking in JPA. JPA 2 supports both optimistic locking and pessimistic locking . Locking ... data by two concurrent users. Locking in ObjectDB (and in JPA) is always at the database object level, i.e. each database object is ... javax.persistence.OptimisticLockException JPA exception Thrown by the persistence provider when an optimistic ...

 
tutorial

Step 1: Create a Java Project

Explains how to create an Eclipse project with ObjectDB/JPA support.... you can see in the [New] menu a command for creating a [JPA Project]. We are not using that type of project in this tutorial but ... Now you should have a new Eclipse project with ObjectDB/JPA support. ObjectDB/JPA can also be added to existing projects, by adding ...

 
tutorial

Step 1: Create a Java Project

Explains how to create a NetBeans project with ObjectDB/JPA support.... the project. To add ObjectDB/JPA support for the project: Right click the Libraries folder in ... Now you should have a new NetBeans project with ObjectDB/JPA support. The next step is creating a JPA Entity class . ...