Database Management Systems/3e
Review Questions and Exercises
Chapter 2
Review Questions
1. How are business rules represented in class diagrams?
2. What is the purpose of a class diagram (or entity-relationship diagram)?
3. What is a reflexive association and how is it shown on a class diagram?
4. What is a primary key?
5. What is multiplicity and how is it shown on a class diagram?
6. What are the primary data types used in business applications?
7. How is inheritance shown in an entity-relationship diagram?
8. How do events and triggers relate to objects or entities?
9. What problems are complicated with large projects?
10. How can computer-aided software engineering tools help on large projects?
Post, Database Management Systems, 3/e – Review Questions and Exercises
©2005 McGraw-Hill/Irwin
Exercises
1. A small company that rents canoes needs a database to track basic information about
the rental and the canoes. Eventually, the firm wants to identify customers who cause
problems by damaging the canoes, but for now, the managers just want to track the
costs. The managers have outlined the data as a form. Create the class diagram for this
case.
Rental ID
Canoe Rental
Rent Date
Customer
Credit Card Number
Last Name, First Name
Expiration Date
Email
Phone
Name on Card
Address
Deposit Amount
City, State PostalCode
Country
Number Description:
Length,
Material
Returned
Date
Fee
Damage
Charge
Total
Total
2. A small company that specializes in pet grooming needs a database to record the work
done by its employees. Currently, the company uses a paper sheet similar to the form
shown here. For each time slot, the employee records information about the customer,
the pet, and the tasks performed. All tasks have a base fee, but the employee can alter
the amount depending on the difficulty and the animal. The employees are also
encouraged to record comments regarding the pet and the specific task. Create the class
diagram for this case.
Employee
Last Name
First Name
DateHired
Specialty
Daily Grooming Record
Date
Start Time
Owner Name, Phone, Address
Pet Name, Category, Gender
Task Time Fee
Comments
Post, Database Management Systems, 3/e – Review Questions and Exercises
©2005 McGraw-Hill/Irwin
3. A dentist who runs a small office employing himself, three hygienists, and a receptionist
wants a database to schedule appointments. He has a commercial billing system to
handle payments and insurance, but appointments are currently written on a paper
form similar to the sample shown here. The form currently only tracks the patient name
and the primary procedure to be performed (cleaning, x-ray, filling, and so on). He
wants to add a little more detail and list al of the procedures planned, the estimated fee
for each procedure, and the estimated insurance coverage. The base fees should be
stored with the procedures, but the insurance amounts are highly variable and will be
entered by the receptionist who can get estimates from the billing system. The system
also has to track the patient’s phone number and e-mail address and record how they
want to be notified. Eventually, it could send e-mail messages to patients as reminders.
Create the class diagram for this case.
Date
Time Dentist
10:00
Patient Name
Procedure
Fee
10:30
Hygienist
Mary
Patient Name
Procedure
Hygienist
Susan
Hygienist
David
Patient Name
Procedure
11:00
Post, Database Management Systems, 3/e – Review Questions and Exercises
©2005 McGraw-Hill/Irwin
4. An aging shoe manufacturing company has decided to abandon the highly competitive
market for low-cost mass-market shoes. Instead, it wants to have customers order
custom shoes that will be made on demand. Customers will trace or scan their feet and
molds will be built specifically for each customer. The foot information will be digitized
and stored in the database so it can be retrieved and used whenever the customer
orders shoes. The firm will produce a variety of standard styles of shoes. Customers will
select a style, choose a color and size, and in many cases choose a material. The orders
are sent to company factories that customize the shoe to each person. Customers can
also specify minor adjustments to most shoes—such as asking for slightly wider shoes
for certain tasks. The basic information is entered on the sample form, but the company
needs everything in a database. Create the normalized tables for this case.
OrderID
Estimated Ship Date
Order Date
Actual Ship Date
Shipping Cost
Customer
Last Name, First Name, Phone, Email
Address, City, State, PostalCode
Country
LeftFootID, RightFoodID, Comments
Shipping Address
City, State, PostalCode
Country
StyleID
Description
Color Material
Size
Adjustments Price
5. Experience exercise: Talk to a manager (or a local store) and create a class diagram for
the system.
Post, Database Management Systems, 3/e – Review Questions and Exercises
©2005 McGraw-Hill/Irwin
6. Identify the typical relationships between the following entities. Write down any
assumptions or comments that affect your decision. Be sure to include minimum and
maximum values.
a) Bookstore, Book
b) Van, Driver
c) Computer, IP Address
d) Person, Prescription glasses
e) House, Kitchen
f) Cruise ship, Pool
g) Cruise ship, Docking berth
h) Bank, Federal Reserve district
i) Company, Director
j) Television show, Time slot
k) Company, NAICS 6-digit code
l) Checking account number, Customer
m) Automobile, VIN
n) Fishing license, Person
o) Drivers license, Person
p) Plane ticket, Passenger
q) Prescription, Patient
r) Latitude longitude point, Road
7. For each of the entities in the following list (left side), identify whether each of the items
on the right should be an attribute of that entity or a separate entity.
a) Shoes
Size, Sale date, Color, Price, Salesperson, Style, Manufacturer
b) Automobile
Model, Owner, Manufacturer, Salesperson, Engine, Driver
c) Factory
Machine, City, Employee, Manager, Owner, Size
d) Prison
Guard, Prisoner, Warden, Location, State/Federal, Capacity
e) Party
Location, Reason, Guest, Menu, Start time, Caterer, Band
Post, Database Management Systems, 3/e – Review Questions and Exercises
©2005 McGraw-Hill/Irwin
8. Your college radio station has a problem. To broadcast songs—particularly those
streamed over the Internet, the station has to keep a detailed log of what songs were
played. The studios also want to know how many listeners received the song. For
Internet streams, this number is shown by the streaming software. Although the
studios want detailed information on each song, the station’s DJs find it easier to pick
the songs by the artist and the CD. The station wants an easy-to-use database that lets
the DJ quickly pick the song each time it is played, enter the number of listeners, and
any comments—particularly if the song does not play all the way through for some
reason. Based on your knowledge of music and the sample log page, create the class
diagram for this case.
Date
Time
Employee
Song Artist CD
Studio
Post, Database Management Systems, 3/e – Review Questions and Exercises
Comments
#Listeners
©2005 McGraw-Hill/Irwin
9. A local company is creating a new in-car toll system. Customers will purchase an
emitter which is a small transmitter placed in the car. They will register a credit card
number with the company. Whenever the customer drives past the toll collection point,
the emitter sends an ID signal that is picked up at the booth. The time and fee are
recorded and the customer is sent a bill at the end of the month and the credit card is
automatically billed for the total monthly amount. The slightly complicated part is that
each location charges different fees based on the day of the week and the time of day.
For instance, rush hour charges are generally higher than at other times. The report
provides a partial picture of the fee structure and the data collected at a single location.
Of course, there are multiple locations, and the customer data has to be consolidated to
provide a total bill. To help reduce theft, emitters are identified with specific vehicles,
but customers can transfer them when they sell a car. Create the class diagram for this
case.
Fee Structure
Location Description
Traffic Log
Date
Time EmitterID
Fee
DayOfWeek
Start Time
End Time
Fee
MTWTF
6:00
8:00
$3
MTWT
F
SS
15:00
15:00
00:00
18:00
18:00
24:00
$3
$5
$2
Post, Database Management Systems, 3/e – Review Questions and Exercises
©2005 McGraw-Hill/Irwin
Sally’s Pet Store
10. Do some initial research on retail sales and pet stores. Identify the primary benefits you
expect to gain from a transaction processing system for Sally’s Pet Store. Estimate the
time and costs required to design and build the database application.
11. Extend the class diagram for Sally’s Pet Store by including the details needed to track
the genealogy of the all of the animals.
12. Extend the class diagram for Sally’s Pet Store by including the details needed to track
the health and veterinary records for the animals.
13. Extend the Pet Store class diagram to include scheduling of appointments for pet
grooming.
Rolling Thunder Bicycles
14. Redesign the Rolling Thunder class diagram using an object-oriented approach. Identify
all of the classes, properties, and methods.
15. Rolling Thunder Bicycles is thinking about opening a chain of bicycle stores. Explain
how the database would have to be altered to accommodate this change. Add the
proposed components to the class diagram.
16. If Rolling Thunder Bicycles wants to add a website to sell bicycles over the Internet,
what additional data needs to be collected? Extend the class diagram to handle this
additional data.
Post, Database Management Systems, 3/e – Review Questions and Exercises
©2005 McGraw-Hill/Irwin