冗长乏味的JDBC开发导致对象关系映射(ORM)框架的诞生，该框架提供一个数据访问抽象层。
The tedium of JDBC development led to the creation of the object relational mapping (ORM) framework, which provides a data access abstraction layer.
在这样的设计中，更新被应用到了对象上，映射层的职责就是将这种变化反映到关系数据库中。
In such a design, updates are applied to objects and it is the responsibility of the mapping layer to migrate those changes to a relational database.
Session对象为程序员提供了一个临时的存储层，它非常像传统的对象关系映射工具中可以看到的层，而且还可以将它看作到特定工作区的连接。
The Session object provides the programmer with a transient storage layer, much like those found in traditional object-relational mapping tools, and also serves as a link to a particular workspace.
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