How many sales values have been created by sales representative and which sales representative have the highest sales?
sales representative refers to Title = 'Sales Representative'; sales values refers to MULTIPLY(Quantity, UnitPrice); the highest sales refers to max(MULTIPLY(Quantity, UnitPrice))
SELECT SUM(T3.UnitPrice * T3.Quantity) FROM Employees AS T1 INNER JOIN Orders AS T2 ON T1.EmployeeID = T2.EmployeeID INNER JOIN `Order Details` AS T3 ON T2.OrderID = T3.OrderID WHERE T1.Title = 'Sales Representative' ORDER BY SUM(T3.UnitPrice * T3.Quantity)