Orderline.itemkey = Spprice.itemkey AND
Spprice.Cust_id = Orders.Cust_id AND
Orderline.itemkey = item.itemkey
The marked join is redundant because if the oderline is related to the order and the order is related to the customer and the order line is relateed to the spprice then there is no need to relate the spprice to teh cutsomer, so you can present this join as;
Customer.Cust_id = Orders.Order_id AND
Orders.Order_id = OrderLines.Order_id AND
OrderLine.Item_id = Items.Item_id AND
OrderLine.Spprice_id = spprice.Spprice_id
I still say that NOT storing the price in the Order_lines at the time the order is placed is going to cause big problems later on.
Spprice should only be involved for establishing the price at the time of the order, once the order has been made the price should be fixed in the orderlines table.
