Fill in the blanks (remember, for a blank, drop blank as the answer)

SELECT	Item.UPC, Item.Item_Description, Item.ItemType_Id,
	Item.ItemSize_Id, COUNT(Invoice.Invoice_Number) AS Invoice_Count,
	SUM(InvoiceDetail.Detail_Quantity) AS Total_Sales
	FROM item
	InvoiceDetail ON item.=.UPC
	Invoice ON. Invoice_Number = InvoiceDetail.
	GROUP BY Item.UPC
	ORDER BY Item.ItemType_id, Item.Item_Description, Item.ItemSize_Id;