About JPA

tutorial

Eclipse/JPA Web Application Tutorial

Step by step tutorial that demonstrates how to build a simple database web application (with Servlet and JSP) in Eclipse using JPA. This is the Eclipse version of the JPA Web App tutorial. It demonstrates how to create and run a ... web application in Eclipse - 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 Guest ...

 
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JPA Query Criteria API (JPA 2.0)

The JPA Criteria API supports dynamic definition of JPQL queries using CriteriaBuilder as a factory. ObjectDB supports dynamic definition of JPQL queries as strings and expected to support also the new JPA 2 Criteria API in future versions.   JPA Feature Version: Priority: Normal Status: Fixed ... Type:  JPA Feature ... 2010-05-14 11:17 The JPA Criteria API supports dynamic definition of JPQL queries using ...

 
faq

Is ObjectDB better than competitive object databases?

... with built in support of the Java Persistence API (JPA). It also supports a more recent and advanced version of the Java Data ... object databases. By using a standard API such as JPA you can keep your application portable. If necessary, you will always be ...

 
manual

Comparison in JPQL and Criteria API

Explains how comparison operators can be used in JPQL queries, including in comparing null values.... (which are described above) are available also as JPA criteria query expressions. The CriteriaBuilder javax.persistence.criteria.CriteriaBuilder JPA interface Used to construct criteria queries, compound selections, ... javax.persistence.criteria.Expression JPA interface Type for query expressions. See JavaDoc Reference Page... ...

 
manual

Deleting JPA Entity Objects

Explains how to use JPA to delete (remove) entity objects from the database.... javax.persistence.TransactionRequiredException JPA exception Thrown by the persistence provider when a transaction is ... CascadeType javax.persistence.CascadeType JPA enum Defines the set of cascadable operations that are propagated to ...

 
manual

Auto Generated Values

Explains the different strategies for generating auto values (mainly for primary key fields) in JPA.... javax.persistence.GeneratedValue JPA annotation Provides for the specification of generation strategies for ... javax.persistence.GeneratedValue JPA annotation Provides for the specification of generation strategies for ... @Entity javax.persistence.Entity JPA annotation Specifies that the class is an entity. See JavaDoc ...

 
manual

Query Parameters in JPA

Explains how to use parameters (named parameters and ordinal parameters) in JPA queries.... EntityManager javax.persistence.EntityManager JPA interface Interface used to interact with the persistence context. ... TypedQuery javax.persistence.TypedQuery JPA interface Interface used to control the execution of typed queries. ...

 
api-jpa

JPA Annotations for Mapping (ORM)

Reference (JavaDoc) of JPA 2 ORM annotations. The following JPA annotations and enums are designated for mapping a JPA object model to a relational database, and are not required by ObjectDB: ...

 
forum_thread

JPA vs JDO - which is more efficient for OneToMany queries?

I'm curious about the trade offs between JDO and JPA. Seems to me that JDO will perform better and be statically typed. For example: Assume there are Customers and Orders.... I'm curious about the trade offs between JDO and JPA. Seems to me that JDO will perform better and be statically typed. For ... Order { } Whereas with JPA I tend to do this: @ Entity class Customer { ...

 
faq

Where can I learn how to use ObjectDB?

... with prior experience in database development, SQL or JPA, but such experience is definitely not a prerequisite. ...