Пример новового оператора PIVOT
SELECT VendorID, [244] AS POCount1, [231] AS POCount2, [266] AS POCount3
FROM 
(SELECT PurchaseOrderID, EmployeeID, VendorID
FROM Purchasing.PurchaseOrderHeader) p
PIVOT
(
COUNT (PurchaseOrderID)
FOR EmployeeID IN
( [244], [231], [266] )
) AS pvt
ORDER BY VendorID