Defining a Primary Key
Every table in a relational database should have a primary key. If you use the procedure outlined in Chapter 3, you should know what fields must make up the primary key for each of your tables.
Telling Microsoft Access how to define the primary key is quite simple. Open the table in Design view, and then select the first field for the primary key by clicking the row selector to the left of that field’s name. If you need to select multiple fields for your primary key, hold down the Ctrl key and click the row selector of each additional field you need.
After you select all the fields you want for the primary key, click the Primary Key button on the toolbar or choose the Primary Key command from the Edit menu. Access displays ...