前言

Working with both Object-Oriented software and Relational Databases can be cumbersome and time consuming. Development costs are significantly higher due to a paradigm mismatch between how data is represented in objects versus relational databases. Hibernate is an Object/Relational Mapping solution for Java environments. The term Object/Relational Mapping refers to the technique of mapping data from an object model representation to a relational data model representation (and visa versa).

在今日的企业环境中，把面向对象的软件和关系数据库一起使用可能是相当麻烦、浪费时间的。由于数据在对象和关系数据库之间的表示方式不匹配，开发成本显着增高。Hibernate是一个面向Java环境的对象/关系数据库映射工具。对象/关系数据库映射(object/relational mapping (ORM))这个术语表示一种技术，用来将数据从对象模型表示映射到关系数据模型表示（反之亦然）的技术。

Hibernate not only takes care of the mapping from Java classes to database tables (and from Java data types to SQL data types), but also provides data query and retrieval facilities. It can significantly reduce development time otherwise spent with manual data handling in SQL and JDBC. Hibernate’s design goal is to relieve the developer from 95% of common data persistence-related programming tasks by eliminating the need for manual, hand-crafted data processing using SQL and JDBC. However, 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.

Hibernate不仅仅管理Java类到数据库表的映射（包括Java数据类型到SQL数据类型的映射），还提供数据查询和获取数据的方法，可以大幅度减少开发时人工使用SQL和JDBC处理数据的时间。Hibernate的设计目标是通过消除对使用SQL和JDBC的手动，手工数据处理的需求，使开发人员从95％的常见数据持久性相关的编程任务中脱离出来。但是，与许多其他持久性解决方案不同，Hibernate不会隐藏SQL的强大功能，并保证您对关系技术和知识的投资与始终一样有效。

Hibernate may not be the best solution for data-centric applications that only use stored-procedures to implement the business logic in the database, it is most useful with object-oriented domain models and business logic in the Java-based middle-tier. However, Hibernate can certainly help you to remove or encapsulate vendor-specific SQL code and will help with the common task of result set translation from a tabular representation to a graph of objects.

对于以数据为中心的程序来说,它们往往只在数据库中使用存储过程来实现商业逻辑,Hibernate可能不是最好的解决方案;对于那些在基于Java的中间层应用中，它们实现面向对象的业务模型和商业逻辑的应用，Hibernate是最有用的。不管怎样，Hibernate一定可以帮助你消除或者包装那些针对特定厂商的SQL代码，并且帮你把结果集从表格式的表示形式转换到一系列的对象去。