Persistent object model
WebSphere Commerce deals with a large amount of persistent data. There are numerous tables defined in the current database schema. Even with this extensive schema, however, we might need to extend or customize the database schema for our particular business needs.
Beginning with WebSphere Commerce Version 9, the Java Persistence API (JPA) is the standard in the persistent object layer. EJB entity beans are replaced by JPA object, existing EJB-based access beans are replaced by JPA-based access Beans, and existing 2.x session beans have been replaced with 3.x session beans using JPA annotation, instead of XML, for configuration. The topics in this sections should be understood in the context of the WebSphere Commerce persistent object model implementation. Customization considerations
- WebSphere Commerce supports persistence object extension based on JPA and Access Bean framework. For an example, that demonstrates this support see Tutorial: Customizing the Transaction server using REST and JPA services
- Existing customization based on EJB should be migrated to JPA and 3.x session beans. A tool is provided to scan the source code, identify necessary changes and provide suggestions. See Migrating WebSphere Commerce Version 8 EJB entity beans to Java Persistence API.
- WebSphere Commerce enterprise beans
The persistence layer within the WebSphere Commerce architecture is implemented according to the JPA component architecture. However, a small number of stateless session beans are used to handle intensive database operations, such as performing a sum of all the rows in a particular column.
Related concepts
Extending the WebSphere Commerce object model
WebSphere Commerce enterprise beans
Related tasks
Working with enterprise beans
Related reference
Use of EJB 2.x entity beans