(b) A newspaper company manages subscriptions to a number of magazines. Customers can subscribe to receive one or more of the magazines. Each magazine has a category, such as Motoring or Current Affairs and a yearly subscription rate, which is the cost of subscribing to receive a magazine for 12 months.

The details of customers’ subscriptions to magazines are stored in a database using the three entities: Magazine, Subscription and Customer.

i) Define the details of the three entities, making sure that they are normalised up till the Third-Normal Form: appropriately name the entities and explain the inclusion of the attributes and your choice of primary and foreign keys.
ii) Define the data types for the attributes within the Magazine entity.
iii) Define clearly, using a short notation (as in the example of ENTITY shown below), the three entities Magazine, Subscription and Customer. ENTITY (attrb1, attrb2,….attrbN).
iv) Construct an Entity-Relationship diagram for the database.