Relational Persistence for Idiomatic Java

 Hibernate is a powerful, high performance object/relational persistence
 and query service. Hibernate lets you develop persistent classes
 following object-oriented idiom - including association, inheritance,
 polymorphism, composition, and collections. Hibernate allows you to
 express queries in its own portable SQL extension (HQL), as well as in
 native SQL, or with an object-oriented Criteria and Example API.
 .
 Unlike many other persistence solutions, Hibernate does not hide the
 power of SQL from you and guarantees that your investment in relational
 technology and knowledge is as valid as always.