When developing an application, you need to know how to use the following application components:
- Persistence context
To further simplify the persistence programming model:
- The EntityManager is used to perform Create Read Update Delete (CRUD) operations that involve entities.
- The EntityManager API and object-relational mapping meta-data handle most of the database operations without requiring you to write JDBC or SQL code to maintain persistence
- JPA provides a query language, extending the independent EJB querying language (also known as JPQL), that you can use to retrieve objects without writing SQL queries specific to the database you are working with.
JPA is based on the Java programming model that applies to Java EE environments, but JPA can function within a Java SE environment. See JPA - Entity Manager