how to implement If statement in the select statement

We can implement the if statement in the select statement by using the Decode statement. Example      SELECT DECODE (EMP_CAT,'1','First','2','Second'Null); Here the Null is the else statement where null is done . Here DECODE implement below IF – ELSE logic                      IF EMP_CAT = ‘1’ THEN                                   ‘FIRST’                       ELSIF EMP_CAT = ‘2’ THEN                                   ‘SECOND’                      ELSE                                    NULL                      END IF;