The Query API and JPQL

Abstract

The Java Persistence API (JPA) utilizes a query language for communicating with underlying data stores. Although Java EE uses entities rather than SQL for database access, it provides a query language so that developers can obtain the required information via the entities. The Java Persistence Query Language (JPQL) does just that because it provides a facility for querying and working with Java EE entity objects. Although it is very similar to SQL, it is an object-relational query language, so there are some minor differences of which developers should be aware. Using JPQL along with Java EE entities allows developers to create versatile applications because JPQL is not database-specific and applications can be written once and deployed to run on top of a myriad of databases.