The Blue Mountains College Database.

Running head: THE BLUE MOUNTAINS COLLEGE DATABASE
The Blue Mountains College Database
Name of the Student
Name of the University
Author’s note:

THE BLUE MOUNTAINS COLLEGE DATABASE1
Table of Contents
Conceptual Model:...........................................................................................................................2
Logical Model:.................................................................................................................................5
Bibliography:.................................................................................................................................11

THE BLUE MOUNTAINS COLLEGE DATABASE2
Conceptual Model:
Entities: The entities are as following
i. Courses
ii. FormOfEducation
iii. Students
iv. Units
v. Classes
vi. Rooms
vii. Buildings
viii. StaffMembers
Entity Super and Sub Types: The proposed database of Blue Mountains college has
classes as the super type and face to face and online classes as sub types. Super type is a special
entity that has relation with one or more subtype entities as well as it contain the attributes and
method that are common to its subtypes. The subtypes are referred to as the subgroups of
subtype entities and these subtypes has unique properties that make then differ from one another.
Each class will be either face to face or online. Both of these sub types entities will inherit the
attributes and methods of super type, classes class. The super-types and subtypes are parent and
child entities respectively. Inheritance is the technique in object oriented programming where
one or more classes acquire the property of another class. The class that contain the common
properties are called parent class. Additionally, the class that inherit the properties are called
child class. In the concept of database, there are no concept of classes but it has entities.
Inheritance can be of several types such as single, multiple, multilevel and hierarchical

THE BLUE MOUNTAINS COLLEGE DATABASE3
inheritance. In the proposed Blue Mountains College database the hierarchical inheritance can be
seen. In hierarchical inheritance, many child entities inherit the properties of parent entities. In
this database model face to face and online child entities inherits the properties of ‘classes’
entity.
Relationships and Cardinalities: Each staff member or lecturer will be assigned to each
class and classes must have lecturers. This way the optionality between staff member and class
entities become 1 and 1. As each staff member will assigned to one class and each class has only
one lecturer. This is why the cardinality between staff member and classes has one to one
cardinality. Each room is in a building. A building must have a room and a room must be in a
building. The optionality is 1 and 1. One building can have multiple rooms but a room is in one
building. Building and room entities has one to many cardinality. A room is assigned to a single
class and each class must have a single room. Therefore, the optionality and cardinality between
room and classes are 1-1 and one to one respectively. One student may not choose a unit while
registering to Blue Mountains College. The unit may not have any student at creation time. That
is why the student and unit entities has 0-0 optionality among them. One student can take
multiple units and a single unit has multiple students. Therefore, student and unit entities has
many to many cardinality among them. For each course, Blue Mountains College has several
units. It is not mandatory that a course must have a unit but a unit must be under a course. That is
course and unit entities has one to many cardinality and 0-1 optionality. A class is associated
with the currently taught unit.
Primary Keys:
i. Primary key of courses entity is course id
ii. Primary key of students entity is student id