You can add additional columns from the parent table to a primary key or an alternate key.
        
            - 
                Open the key's property sheet and click the Columns tab.
            
 
            - 
                Click the Add Columns tool to open a selection box listing all the columns in the table (except those already attached to the primary key).
            
 
            - 
                Select one or more columns and click OK in each of the dialog boxes.