ERD Tutorial 1
Question 1
Coca Cola Co. in Atlanta, Georgia produces a wide range of products that are delivered to the
customers once a week. The Coca Cola Co. keeps the information about the employees,
products, and customers in a database. The database considers the following set of tables:
The company keeps the following information about each customer: customer identification
number, name, address, X (longitude) and Y (latitude) coordinates of their location, amount
of time (fraction of an hour) required to make a stop at a customer, type of product that is
used by a customer, mean rate at which customer uses product per day in a week, standard
deviation of this usage rate, the limit on how much inventory of a product can be held at a
customer, initial inventory of product at a customer.
Each employee has an employee identification number, name, address (the address consists
of: city, state and zip code), sex, birthday, position in the company, wage earned per hour of
regular timework, wage earned per hour of overtime work, number of dependents, and
number of years working for Coca Cola Co.
Each product has a product identification number, price and number of units produced per
day.
Draw an E-R diagram for the Coca Cola Co and add the minimum and maximum relationship
cardinalities. Identify the: (a) key attributes for each entity (b) composite attributes.
Question 2
Newtown Records has decided to store information about musicians who perform on its albums
(as well as other company data) in a database. The company has wisely chosen to hire you as a
database designer.
Each musician that records at Newtown has an SSN, a name, an address, and a phone
number.
Each instrument that is used in songs recorded at Newtown has a name (e.g., guitar,
synthesizer, flute) and a musical key (e.g., C, B-flat, E-flat).
Each album that is recorded on the Newtown label has a title, a copyright date, a format
(e.g., CD or MC), and an album identifier.
Each song recorded at Newtown has a title and an author.
Each musician may play several instruments, and a given instrument may be played by
several musicians.
Each album has a number of songs on it, but no song may appear on more than one
album.
Each song is performed by one or more musicians, and a musician may perform a number
of songs.
Each album has exactly one musician who acts as its producer. A musician may produce
several albums.
Draw an ER diagram for the above schema. Indicate all key and cardinality constraints and
any assumptions that you make. State any assumptions that you make.
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Question 3
Major airlines companies that provide passenger services in Taiwan are: UniAir,
TransAsia Airways, Far Eastern Transport, Great China Airlines etc. Taiwan’s Federal
Aviation Administration (TFAA) keeps a database with lots of information on all airlines.
This information is made accessible to all airlines in Taiwan with the intention of helping
the companies assess their competitive position in the domestic market. The information
kept consists of:
Each airline has an identification number, name and address, name of the contact person
and telephone number.
For each aircraft an aircraft identification number, capacity, and model is recorded.
Each employee has an employee identification number, name, address, birthday, sex,
position with the company, and qualification.
Each route has a route identification number, origin, destination, classification (into
domestic or international route), distance of the route, and price charged per passenger.
Each airline keeps information about their buy/sell transactions (for example selling an
airplane ticket is a sell transaction, paying for maintenance is a buy transaction). Each
transaction has a transaction identification number, date, description, and amount of
money paid/received.
Hint: The relationship between airline, route and aircraft is ternary.
Draw an E-R diagram for the database presented above. Make sure to identify the associative
entity (entities) and provide corresponding key attribute (attributes).
