I appreciate that this is an example for an exam, and learning how to PIVOT (and UNPIVOT) is important.

I haven't redone the performance testing recently, but from memory there was a performance issue with pivot which meant that you were actually better off doing a CASE statement to get the same values. Is that still valid, or have they fixed PIVOT?

So your query becomes something like this:

DECLARE

@StartDate DATE

, @EndDate DATE

SET @StartDate = '2005-01-01'

SET @EndDate = '2006-12-31'

SELECT

YEAR(OrderDate) AS OrderYear

, TerritoryID

, SUM(CASE WHEN MONTH(OrderDate) BETWEEN 1 AND 3 THEN 1 ELSE 0 END) AS [1]

, SUM(CASE WHEN MONTH(OrderDate) BETWEEN 4 AND 6 THEN 1 ELSE 0 END) AS [2]

, SUM(CASE WHEN MONTH(OrderDate) BETWEEN 7 AND 9 THEN 1 ELSE 0 END) AS [3]

, SUM(CASE WHEN MONTH(OrderDate) BETWEEN 10 AND 12 THEN 1 ELSE 0 END) AS [4]

FROM Sales.SalesOrderHeader

WHERE OrderDate >= @StartDate

AND OrderDate <= @EndDate

GROUP BY YEAR(OrderDate), TerritoryId

ORDER BY YEAR(OrderDate), TerritoryId