You can use three methods to create relationships between the tables in your database. The easiest method is to use a database diagram. A database diagram allows you to graphically establish the relationships between the tables in your database. The second method is via the Properties window for a table. Using the Relationships tab of the Properties window, you can easily add, modify, and remove relationships between the tables in your database. Finally, you can establish and maintain relationships using T-SQL code.
As mentioned previously, one way that you can establish and maintain relationships between SQL Server tables is to create a database diagram. It is important to understand how to create a database diagram, add tables to it, edit the diagram, and remove tables from the diagram. The sections that follow cover these topics.