📅 最后修改于: 2021-01-02 15:58:20 🧑 作者: Mango
JPA(Java持久性API)是Java的规范，用于访问，管理和持久化Java对象与关系数据库之间的数据。它被视为对象关系映射的标准方法。
JPA可以看作是面向对象的域模型和关系数据库系统之间的桥梁。作为规范，JPA本身不会执行任何操作。因此，它需要实施。因此，Hibernate，TopLink和iBatis等ORM工具实现了JPA规范以实现数据持久性。
Hibernate是一个Java框架，用于将Java对象存储在关系数据库系统中。它是一个开源的，轻量级的ORM(对象关系映射)工具。
Hibernate是JPA的实现。因此，它遵循JPA提供的通用标准。
到目前为止我们已经看到，JPA是一个规范。它为ORM工具提供了通用的原型和功能。通过实现相同的规范，所有ORM工具(如Hibernate，TopLink，iBatis)都遵循通用标准。将来，如果要将我们的应用程序从一种ORM工具切换到另一种，则可以轻松完成。
| JPA | Hibernate |
|---|---|
| Java Persistence API (JPA) defines the management of relational data in the Java applications. | Hibernate is an Object-Relational Mapping (ORM) tool which is used to save the state of Java object into the database. |
| It is just a specification. Various ORM tools implement it for data persistence. | It is one of the most frequently used JPA implementation. |
| It is defined in javax.persistence package. | It is defined in org.hibernate package. |
| The EntityManagerFactory interface is used to interact with the entity manager factory for the persistence unit. Thus, it provides an entity manager. | It uses SessionFactory interface to create Session instances. |
| It uses EntityManager interface to create, read, and delete operations for instances of mapped entity classes. This interface interacts with the persistence context. | It uses Session interface to create, read, and delete operations for instances of mapped entity classes. It behaves as a runtime interface between a Java application and Hibernate. |
| It uses Java Persistence Query Language (JPQL) as an object-oriented query language to perform database operations. | It uses Hibernate Query Language (HQL) as an object-oriented query language to perform database operations. |