Listing 2: GROUP BY with Additional Aggregates
SELECT OD.ProductID AS 'Product ID'
	, count(OD.Quantity) AS 'Orders Placed'
	, avg(OD.Quantity) AS 'Average Qty Per Order'
	, sum(OD.Quantity) AS 'Total Sold'
FROM northwind.dbo.[Order Details] AS OD
GROUP BY OD.ProductID
ORDER BY OD.ProductID