DBMS

Entities

Attributes

Relationships

Customer

· Customer_ID

· Customer_Code

· Customer_Name

· Customer_address

· Customer_Phone

· Customer_Email

· A customer can place zero or many orders.

· A Customer can have at least one contact detail

Author

· Author_ID

· Author_First Name

· Author_Initials

· Author_Last_Name

· An author can have one or many Books.

· An author can be booked by one or more Customers

· An author can be on one or more Book_Categories

Books

· Book_ID

· ISBN

· Book_Title

· Publication_Date

· Book_Comment

· A Book can be written by one or more authors.

· A Book can be ordered by one or more customers

· A Book can be on one or more Book_Categories

· A Book has an Item_Agreed_Price

Orders

· Order_Date

· Order_Value

· An order is always related to customers

· Order will have one or more Order_Items

· An order can be for one or more Authors’ Books

Order Items

· Item_Number

· Item_Agreed_Price

· Item_Comment

· Any book can be an Order_Item

· Any book can have an Item_Agreed_Price

· A Book may or may not have an Item_Comment

Contacts

· Contact_ID

· Contact_First _Name

· Contact_Last_Name

· Contact_WorkPhoneNumber

· Contact_OtherDetails

· Any Customer can have at least one contact detail.

·

Reference Contact Types

· Contact_Code

· Contact_Description

Any customer can have at least one Reference_Contact_Type.

Book Categories

· Book_Category_Code

· Book_Category_Description

· A Book Category can have zero or many Sub_Categories

· A Book_Sub_Category can belong to only one Book_Category