You are designing a database that will contain customer orders. Customers will be able to order multiple products each time they place an order. You review the database design, which is show below:

Customers <----- Orders <------> Products

CustomerID OrderID ProductID
CompanyName ProductID Description
Address OrderDate UnitPrice
City Quantity
State CustomerID


You want to promote quick response times for queries and minimize redundant data. What should you do? (Each correct answer presents part of the solution. Choose two)

A. Create a new order table named OrdersDetail. Add OrderID, ProductID, and Quantity columns to this table.
B. Create a composite PRIMARY KEY constraint on the OrderID and ProductID columns of the Orders table
C. Remove the ProductID and Quantity columns from the Orders table
D. Create a UNIQUE constraint on the OrderID column of the Orders table.
E. Move the UnitPrice column from the Products table to the Orders table.

Ответ дан A,C. Только я не пойму зачем создавать дополнительнйю таблицу OrdersDetail? Получается две таблицы OrdersDetail и Orders с информацией, которая как мне кажеться должна быть в одной таблице.

Если это правильный ответ, поясните мне почему?

Спасибо.