Data Security And Data Integrity Assignment

Student Name and Number:
Lecturer Name:
Course Number and Name:
Submission Date:

Introduction
Academic institutions often have huge amounts of data about their staff, students,
finance details, academic details etc. For organized storage of these data,
databases often provide a better solution. A database refers to an organized
collection of data that enable efficient storage and retrieval of the data. Databases
often enable the data to be well organized in a manner that enables quick storage
and retrieval, helps to reduce redundancy, enhance data consistency, enforce data
security, enhance data integrity just to mention a few. A database usually contains
entities which are the objects which we model information about and the attributes
which describe these entities (Coronel & Morris, 2014).
However, for a detailed illustration of the database structure, database modelling is
used. Database modelling helps the database designers to have a detailed
understanding of the internal structure of the database through use of various
methods. Entity relationship diagrams are popularly used to provide a visual
understanding of the internal database structure. They usually capture the entities
being modelled, their attributes, relationships and the cardinalities between the
entities (Tillmann, 2017).
In this assignment, we shall be implementing both the Conceptual and Logical
models for Blue Mountains College Database. The database is expected to store
details for courses offered by the college, Students details, Staff members
(Lecturers) details, class details, unit details, building, rooms, student course
enrollment details, students’ units’ enrollment and students’ scores per unit. Both
the conceptual and Logical Entity Relationship diagrams will be provided to
illustrate the database structure. The business rules governing the relationship
between different entities will also be provided to justify the design of the Entity
Relationship Diagram (ERD).

Part 1: Conceptual Model
- In this part, we shall be designing the conceptual model for the database. We
shall be identifying the database entities, entity supertypes, subtypes,
inheritance and discriminator(s), Describing the relationships between
entities and their cardinalities, identifying Primary Keys and design of
Conceptual Model Entity Relationship Diagram (Bagui & Earp, 2011).
a. Identification of entities
The following are the entities which have been identified for Blue Mountains
College Database:
 Course
 Education Form
 Face to Face Course
 Online Course
 Student
 Lecturer
 Unit
 Class
 Face to Face Class
 Online Class
 Room
 Building
 Student Course Enrollment
 Student Unit Enrollment
b. Identification of entity supertypes, subtypes, inheritance and
discriminator(s)

Supertype Entities:
- Course is a supertype entity since it has two different child entities i.e.
Face to Face Course and Online Course.
- Class is also a Supertype entity since it has two different types of classes:
Face to Face class and Online Class.
(Date, 2016)
Subtype Entities:
- Face to Face Course and Online course are the subtype entities which are
the two types of the supertype entity Course.
- Face to Face class and online class are subtypes of the supertype Class.
- In terms of entity inheritance, the subtype entities Face to Face
Education and Online course inherit attributes of the supertype entity
Course.
- In addition, the subtypes Face to face Class and Online class inherit the
attributes of the supertype entity Class.
 Discriminator entities are the Student Course Enrollment and Student
Unit Enrollment. These are weak entities which are formed as a result of
combing attributes of other entities. For instance, the Student Course
Enrollment entity has been formed as a result of combining Student’s
attribute Student ID and Course’s attribute course ID. For Student Unit
Enrollment entity, Student’s attribute Student ID and Unit’s attribute Unit
ID can be combined to form this entity. Since these two weak entities do
not have a Primary Key, a discriminator key can be created to uniquely
identify each record.
c. Description of relationships between entities and their cardinalities
i. One course can be pursed by many students but each student can only
pursue one and only one course at a time. Therefore, this forms a one to
many relationships between the entity Course and entity Student and a
one to many cardinalities.
ii. A student can enroll for many units and each unit can have many students
taking that particular unit. Therefore, the cardinality that exists between
the entity Student and unit is a many to many cardinalities.