Let’s now create the relation between the tables Customer and Account through this foreign key. Click the Foreign Keys tab at the bottom of the screen to add foreign key constraints. First, you have to enter a foreign key constraint name of you choosing. In this example, we will enter Account_user_fk . Note that the constraint name is NOT the name of the Foreign Key attribute. Next, click the drop-down box under Referenced Table and pick an available reference table. A reference table is where the foreign key column will look to find the primary key column. In this example, we pick the Customer table. After you pick the reference table, you need to check which column(s) hold the foreign key and primary key value in each table. For this example, we use CustomerID as the primary and foreign key columns. Create ER diagram and Relationships We can now use the defined tables to create an EER diagram and define the relationships between each table. You define relationships by creating an association between primary and foreign key columns. 10. At the top of the Model Overview window, click Add Diagram to create an ERD. It launches an EER Diagram palette and canvas. You can click the tables you want in the Catalog Tree window and drag them to the Diagram canvas. It’s the easiest way to create an EER diagram. Under Bank_db , click on Tables and Drag the Customer and Account tables to the Diagram canvas.