Table of Contents
What is persistence unit in JPA?
A JPA Persistence Unit is a logical grouping of user defined persistable classes (entity classes, embeddable classes and mapped superclasses) with related settings. Defining a persistence unit is optional when using ObjectDB, but required by JPA.
Is EclipseLink and ORM?
3.1 Understanding EclipseLink Native ORM EclipseLink Native Object Relational Mapping (ORM) provides an extensible object-relational mapping framework. It provides high-performance object persistence with extended capabilities configured declaratively through XML.
Is EclipseLink a framework?
Eclipse Persistence Services Project (EclipseLink) is a comprehensive persistence framework delivering a set of persistence services based around leading standards with advanced extensions. Consumers can use EclipseLink within Java EE, SE, and OSGi/Equinox environments.
What is the difference between EclipseLink and Hibernate?
EclipseLink is more standards compliant, since it is the reference implementation for JPA 2, Hibernate has some compliancy issues, but is more mature. One of the main benefits of EclipseLink is that you can call native SQL functions directly in your JPQL queries. In Hibernate this is not directly possible.
Where can I find persistence xml?
If you package the persistence unit as a set of classes in a WAR file, persistence. xml should be located in the WAR file’s WEB-INF/classes/META-INF directory.
How do I use EclipseLink JPA?
Setup and Configuration
- Install JDK 5.0.
- Install Ant.
- Install and setup your relational database: Apache Derby.
- Install and setup your Web container: Installing and Setting Up Tomcat.
- Install EclipseLink: Add eclipselink.
- Create and populate the database.
- Deploy the web application.
- Run the application.
How do you configure EntityManager Factory and transaction manager?
We can configure the entity manager factory bean by following these steps:
- Create a new LocalContainerEntityManagerFactoryBean object.
- Configure the used datasource.
- Configure the Hibernate specific implementation of the JpaVendorAdapter interface.
- Configure the packages that are scanned for entity classes.
What is the difference between EclipseLink and hibernate?
What is persistence XML in JPA?
The persistence.xml file is the deployment descriptor file for persistence using JPA. It specifies the persistence units and declares the managed persistence classes, the object/relation mapping, and the database connection details.
What is persistence XML file in Salesforce?
The persistence.xml file defines one or more persistence units, and you can configure things like: which managed persistence classes are part of a persistence unit, how these classes shall be mapped to database tables, the persistence provider that shall be used at runtime, the data source you want to use to connect to your database,
What is EclipseLink persistence unit?
This configuration for EclipseLink adds all managed persistence classes from the root to the persistence unit and uses a set of properties to connect to a PostgreSQL database on localhost. It also logs all executed SQL statements with the bind parameter values.
What is EclipseLink PostgreSQL persistence?
This configuration for EclipseLink adds all managed persistence classes from the root to the persistence unit and uses a set of properties to connect to a PostgreSQL database on localhost. It also logs all executed SQL statements with the bind parameter values.