>Of cos, Orderline should not have price column, hard to manage in security
>reason and also duplicate on price column.
>But the special price really need lookup on it! Who(Customer)+Which(Itemkey)!!
Justok,

This is where I really think you are incorrect. Spprice is used to match a customer to an itme and get the price for an order. Spprice may change over time as itme prices changes or customer buying patterns change, but an order that is set should never have its price changed. There fore the domain definition for the spprice price is;

The current price for a specific item for a specific customer.

While the domain definition for the price column in the orderlines would be;

The price of this item for this customer at the time of this order.

You can see that the domains are different, if that is so then they are NOT redundant data and if the above is true then trying to use the prices in spprice for creating a join to produce and order is flat relationally wrong. You might run a join that gets an order date 6 months ago, but you would be pulling todays price into it.