Some of this software might be useful to you.
Hibernate is a powerful, ultra-high performance object/relational persistence and query service for Java. Hibernate lets you develop persistent objects following common Java idiom - including association, inheritance, polymorphism, composition and the Java collections framework. Extremely fine-grained, richly typed object models are possible. The Hibernate Query Language, designed as a "minimal" object-oriented extension to SQL, provides an elegant bridge between the object and relational worlds. Hibernate is now the most popular ORM solution for Java.
All database engines provide some kind of client interface, even if it is as primitive as a text based DOS window. Here are some other client programs that either interface via a general ODBC connection, or can use the native protocol to a particular server.