How many employees sold over 20,000 quantities of "Touring-2000 Blue, 50"?
over 20,000 quantities refers to Quantity > 20000; 'Touring-2000 Blue, 50' is name of product;
SELECT COUNT(*) FROM ( SELECT SUM(Quantity) FROM Sales WHERE ProductID IN ( SELECT ProductID FROM Products WHERE Name = 'Touring-2000 Blue, 50' ) GROUP BY Quantity, SalesPersonID HAVING SUM(Quantity) > 20000 )