>But as you know, there are too many rows in Orderlines(Chooseit) and really
>hard to control. The second thing is: Currently, our company clients only
>completely repeat the previous order, use spprice will save much time on
>entering new orders.
>
>)_(' sorry for write too long!

Justok,

I am having trouble understanding what you are saying, it may be the language barrier. Are you saying that Spprice is NOT a look up to find out the price for a particular item for a particular customer? Is Spprice actually where the price for a specific order line item is stored?

If the second is true then Spprice is NOT related to customers or items but is related to order lines and through order lines it is related to items and orders and through orders it is related to customer. Storing customer ID and order ID in Spprice, in this situation, may speed up finding those entities but it also introduces a possible data consistency problem, that is when the spprice points to a different customer than the related order points to.

Also in this scenario you would ahve to manage the extra foreign keys inspprice yourself as they are violations of normalization, you would not diagram these into the E-R diagram because they are things you have chosen to add for performance and are violations of normalization.