Open Database Diagram Designer (Visual Database Tools)
The Database Diagram Designer is a visual tool that allows you to design and visualize a database to which you are connected. When designing a database, you can use Database Designer to create, edit, or delete tables, columns, keys, indexes, relationships, and constraints. To visualize a database, you can create one or more diagrams illustrating some or all of the tables, columns, keys, and relationships in it.
You can open Database Diagram Designer by opening a new or existing diagram.
Open a new database diagram
Right-click the Database Diagrams node of your database in Object Explorer.
From the drop-down menu, click New Database Diagram.
In the Add Table dialog box, choose tables to work with in the diagram.
If you choose Close without adding tables, you can go back and add tables later.
The Database Diagram menu will be added to the main menu and the designer pane will open.
Open an existing database diagram
Right-click the diagram under the Database Diagrams node of your database in Object Explorer.
From the drop-down menu, click Design Database Diagram.
The Database Diagram menu will be added to the main menu and the diagram will open in the designer pane.