这些对象可以保留来自许多不同表的信息，并由此减少必须在查询中使用的表数。

These objects can hold information from many different tables and can therefore reduce the number of tables you must use in a query.

youdao

这些对象可以保留来自许多不同表的信息，并由此减少必须在查询中使用的表数。

These objects can hold information from many different tables and can therefore reduce the number of tables you must use in a query.

youdao