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Manual
50

JPA Named Queries

can be defined in JPA XML mapping files instead of using the @NamedQuery annotation. ObjectDB supports JPA XML ... mainly for Object Relational Mapping (ORM) JPA providers and less so when using ObjectDB ... ("SELECT c FROM Country c"); List results = query.getResultList(); One of the reasons that JPA requires
Manual
50

Locking in JPA

JPA 2 supports both optimistic locking and pessimistic locking. Locking is essential to avoid ... in ObjectDB (and in JPA) is always at the database object level, i.e. each database object is locked ... some ORM JPA providers) is defined in the entity class or not. Pessimistic Locking The main
Manual
49

Chapter 4 - JPA Queries (JPQL / Criteria)

The JPA Query Language (JPQL) can be considered as an object oriented version of SQL. Users ... well as how to use the JPA Criteria API, which provides an alternative way for building queries in JPA, based on JPQL. The first section describes the API that JPA provides for using dynamic and static
JPA Doc
49

JPA Queries

Queries are represented in JPA by the Query and TypedQuery interfaces: The JPA Query API section (in chapter 4 of the ObjectDB manual) provides detailed explanation of how exactly to use ... JPQL strings into a valid complete JPQL query. JPA 2 introduced the JPA Criteria Query API, as
Manual
49

Retrieving JPA Entity Objects

The Java Persistence API (JPA) provides various ways to retrieve objects from the database ... that has already been fetched from the database is available in objects that are detached. JPA 2 introduces methods ... queries. The official query language of JPA is JPQL (Java Persistence Query Language). It enables
Manual
49

Updating JPA Entity Objects

classes are in use. It is usually recommended to use collections rather than arrays when using JPA. Collections are more portable to ORM JPA implementations and provide better automatic change tracking ... have to be modified in one operation. The UPDATE Queries in JPA/JPQL in chapter 4 explains how to use JPA UPDATE queries.
Manual
48

Deleting JPA Entity Objects

object references, if any). Orphan Removal JPA 2 supports an additional and more aggressive remove ... when many entity objects have to be deleted in one operation. The DELETE Queries in JPA/JPQL in chapter 4 explains how to use JPA DELETE queries.
Tutorial
48

Eclipse/JPA Java EE 6 Tutorial

This is the Eclipse version of the Java EE JPA tutorial. It demonstrates how to create and run ... and JPA. The demo web application manages a basic guestbook page. Every visitor can sign the guestbook ... : Persistence is managed by JPA. Every visitor that has signed the guestbook is represented by a Guest entity
Tutorial
48

Eclipse/JPA Web Application Tutorial

This is the Eclipse version of the JPA Web App tutorial. It demonstrates how to create and run a database driven Java web application in Eclipse - using Tomcat 6, ObjectDB and JPA. The demo web ... . The visitors that have already signed are listed below the form: Persistence is managed by JPA
Manual
48

JPA Primary Key

required. But ObjectDB also supports explicit standard JPA primary keys, including composite primary ... ; : } When an entity has multiple primary key fields, JPA requires defining a special ID class ... values. Obtaining the Primary Key JPA 2 provides a generic method for getting the object ID (primary key