Apache Empire-db 是一个开源的关系型数据持久化组件，能够实现数据库无关的动态查询定义，简便的数据读取和更新。与其它持久化组件相比 如：Hibernate、TopLink、iBATIS或JPA实现，Empire-db更注重编译期类型安全，减少冗余，开发效率的改进。 Empire-db所有的数据库实体都通过动态bean进行管理，因此允许在运行期改变数据模型。

特性列表：

• No XML schemas or annotations to learn – everything's in Java (Plain Old Java Code).
• Zero configuration footprint - not even one single configuration file!
• DBMS independent data model definition, record handling and command definition, which keeps code portable to all SQL databases.
• Metadata accessible and extensible through standard Java code.
• Type-safe API for dynamic SQL command generation lets you build virtually any SQL statement exactly as you want it; intuitive and completely string-free.
• No need to always work with full database entities. Build queries to provide you with the data exactly as you need it, and obtain the result for example as a list of any type of POJO with matching property setters or constructor.
• Query results or record data may alternatively be obtained as XML even with added metadata.
• Works with dynamic beans and type-safe field access. Special support for data exchange to and from traditional JavaBeans / POJOs is provided.
• Automatic tracking of record state and field modification (aka "dirty checking") to only insert/ update modified fields.
• Support for optimistic locking through timestamp column.
• DDL generation for target DBMS from object definition, either for the entire database or for individual objects such as tables, views, columns and relations.
• Support for data model changes (DDL) at runtime with full dynamic bean support.

项目主页：http://www.open-open.com/lib/view/home/1358231273981