tu planteamiento desde un inicio estaba mal, porque shippeddate? que no era mas facil un max(orderid)??
Código SQL:
Ver originalSELECT CompanyName,t1.customerid,t2.orderdate,orderid FROM Customers AS t1
LEFT JOIN
(
SELECT customerid,orderdate,orderid
FROM orders WHERE orderid IN (
SELECT MAX(orderid) FROM orders GROUP BY shipcountry)
) AS t2 ON (t1.customerid=t2.customerid)
WHERE t2.OrderID IS NOT NULL
saludos!