a) Map the ERD, from the sample solution, into a set of relations in at least Third
Normal Form (3NF). You must ensure that your relations meet 3NF. There is no
need to show your working.
b) Select any two of your relations from the previous step, 1a), and perform the following for
each of those two relations:
• List all the functional dependencies exist in the relation.
• Demonstrate that the relation meets Third Normal Form (3NF).
For your help, an example for a Student relation’s 3NF justification has been provided below:
STUDENT (StudentID, Name, Address, DateOfBirth)
i. The primary key is StudentID which identifies a student. There will be one student name
per Student ID because only one name is recorded for each student. Even though a
student may have multiple addresses (e.g. a home address and a work address), the
case study states that there is a need to record the home address only and hence there
will be only one address for each student. There will be only one date of birth for each
student. Thus, there are no repeating groups. Hence, this relation is in 1NF.
ii. The primary key is StudentID. This is the only candidate key since Name is not
guaranteed to be unique (two different students may have the same name). Address is
also not guaranteed to be unique. This means that Student ID functionally determines
every other attribute in the table. There is a single valued simple candidate key
(StudentId) and therefore no partial dependencies are possible. Hence, the relation is in
2NF.
iii. Name cannot be used to functionally determine any other attribute in the table since two
different students may have the same name; likewise for address and date of birth.
Therefore there are no transitive dependencies in the table. Therefore it meets the
requirements of first, second and third normal form