Database Design Problem...

From: Jimmy <c6635500_at_comp.polyu.edu.hk>
Date: 1998/03/09
Message-ID: <3504A096.8CB@comp.polyu.edu.hk>#1/1

Hello all,

	I have a databases design problem.
	Recently, I want to implement a table which stores information about
books.
	So I decide to create the table BOOK with the following attributes:

	book_id number,
	book_name char(10),
	author	char(30)...

	book_id is a primary key and is automatically generated by the system.


(max + 1)

	Then another table, ORDER, which is used to store the inforamtion about

the order. One of the attributes of this table is book_id, which is a foreign key and related with the book_id of the table BOOK. I think the design is OK.

        However, one day, a person ask me, "Why you put book_id in the table BOOK? book_name is unique all the time, why you create additional column
(book_id) in table BOOK? Moreover, I don't know which book is from the
table ORDER since it contains book_id only. book_id is meaningless. Why don't you delete the book_id column in table BOOK and replace book_id with book_name in table ORDER?"

        I think create the ID column for the book (or other table) is common in the relational database. Although the book name is unique, create an ID column is much easier to manipulate. Am I right? Or should I delete the ID column? Any comment will be appreicated.

Thanks,
Jimmy Received on Mon Mar 09 1998 - 00:00:00 CST