Basics of Creating Persistent Objects for Existing Data Tables（为现有数据表创建持久对象的基础知识 ）
To access an existing data table in a database and work with it using the functionality provided by eXpress Persistent Objects(XPO), you need to create a persistent object that describes this table. The persistent object should identify the target table’s name and required data fields. If you want to work with two or more tables linked by relationships, you need to create objects for each table, and then define relationships between objects using specific attributes.
要访问数据库中的存量数据表并使用eXpress持久性对象（XPO）提供的功能对其进行处理，您需要创建一个描述该表的持久性对象。持久性对象应标识目标表的名称和所需的数据字段。如果要使用两个或多个按关系链接的表，则需要为每个表创建对象，然后使用特定属性定义对象之间的关系。
It’s possible to automatically generate persistent classes for your existing databases. See Generating Persistent Objects for Existing
标签：Tables,Basics,persistent,Persistent,Existing,数据表,Objects,table From： https://blog.csdn.net/thomastang200912_126/article/details/141451083