USE AdventureWorks2008R2
GO

-- Number of Orders Per Sales Person Name
SELECT		P.FirstName, 
			P.LastName, 
			COUNT(*) AS [Number Of Orders]
FROM		Person.Person AS P
			INNER JOIN
			Sales.SalesOrderHeader AS SOH
			ON P.BusinessEntityID = SOH.SalesPersonID
GROUP BY	P.FirstName, 
			P.LastName
ORDER BY	[Number Of Orders] DESC
GO

-- Verify Number of Sales Person Who Had Orders
SELECT	COUNT(DISTINCT SalesPersonID)
FROM	Sales.SalesOrderHeader
GO