You can create a computed column that compares two or more columns in a table and produces aggregate and/or scalar results.
               
            
            
            To create a computed column:
            
            
               
               
  
 Click the Create Computed Column command from the Column menu, or click the Computed Column button on the toolbar.
- In the Computed Column dialog box, type or pick from the function and column lists to create a calculated field. For example,
                  the following uses the string concatenation operator to combine last and first names into a single name.   lname||","||fname