-- Listing 4: Revised Query Using Conventional Techniques and Derived Table
SELECT C.companyname, OOD.orderid, P.productname, OOD.qty
FROM Customers AS C
  LEFT OUTER JOIN
    (SELECT O.orderid, O.custid, OD.productid, OD.qty
     FROM Orders AS O
       JOIN OrderDetails AS OD
         ON OD.orderid = O.orderid) AS OOD
    ON OOD.custid = C.custid
  FULL OUTER JOIN Products AS P
    ON P.productid = OOD.productid