The Problem Assume you are creating a database for Blockbust

The Problem: Assume you are creating a database for Blockbuster Video Rental. The database needs to support the following business functions: Allow customer to search the inventory by making a transaction. The inventory includes video tapes and DVDs for movies and TV series. Customer wants to search by different properties of the movies and TV series, e.g.: by title, by director, by time, by genre. Customer also wants to know pricing information (new item is usually charged a higher price). The employee of Blockbuster record the information of each transaction. Each transaction has a rent date and a total payment (including prices of each item rented in that transaction and sales tax). It does not matter which employee records the information. A customer can rent more than one items in a rental transaction. Thus, each transaction should have more details such as: it is necessary to record the due date and return date for each item in a transaction. In case an item is overdue, employee needs to send a notice to the customer and charge a fine for late items. Questions:

(a) Please identify the entities. Do not create too many entities (There are 4 basic entities).

(b) For each entity, please identify the attributes each entity has. The grade will depend on whether you have selected those attributes that are necessary for the above business functions. For example, think of how you try to find a DVD to rent.

(c) For each attribute, please identify whether this attribute is optional or required, single valued or multi- valued, simple or composite, stored or derived.

Solution

a) The entities are

1. DVD

2. Video tapes

3. Customer

4. Transaction

b & c)