Enterprise JavaBeansQuery Language
The Enterprise JavaBeans Query Language (EJBQL) defines the queries for the finder and select methods of an entity bean with container-managed persistence. A subset of SQL92, EJB QL has extensions that allow navigation over the relationships defined in an entity bean's abstract schema. The scope of an EJB QL query spans the abstract schemas of related entity beans that are packaged in the same EJB JAR file.
You define EJB QL queries in the deployment descriptor of the entity bean. Typically, a tool will translate these queries into the target language of the underlying data store. Because of this translation, entity beans with container-managed persistence are portable--their code is not tied to a specific type of data store.