Find and list the full name of customers who bought products above-average quantity.
full name of the customer = FirstName, MiddleInitial, LastName; above-average quantity = Quantity > AVG(Quantity);
SELECT T2.FirstName, T2.MiddleInitial, T2.LastName FROM Sales AS T1 INNER JOIN Customers AS T2 ON T1.CustomerID = T2.CustomerID GROUP BY T1.Quantity HAVING T1.Quantity > ( SELECT AVG(Quantity) FROM Sales )
database name:db_id sales
Customers table Customers Cols: Customer ID dtype integer, First Name dtype text, Middle Initial dtype text, Last Name dtype text, 
Employees table Employees Cols: Employee ID dtype integer, First Name dtype text, Middle Initial dtype text, Last Name dtype text, 
Products table Products Cols: Product ID dtype integer, Name dtype text, Price dtype real, 
Sales table Sales Cols: Sales ID dtype integer, SalesPerson ID dtype integer, Customer ID dtype integer, Product ID dtype integer, Quantity dtype integer, 
