Make sure that no objects are selected in Database Diagram designer by clicking anywhere within the designer except on an object.

确保没有在数据库关系图设计器中选择任何对象，方法是在该设计器中对象以外的任意位置单击。

youdao

This designer provides a rich user interface for creating an object model from an existing database.

此设计器提供了用于从现有数据库创建对象模型的丰富用户界面。

youdao

This designer provides a rich user interface for creating an object model from an existing database.

此设计器提供了用于从现有数据库创建对象模型的丰富用户界面。

youdao