Farrukh Jabeen
Advanced Database Systems
Spring 2009
Assignment #1
Using Figure P2.8 as your guide, work problems 8-11. The Tiny College
relational diagram shows the initial entities and attributes for Tiny
College.
Question #8
Identify each relationship type and write all of the business rules.
Answer:
A business rule is a brief, precise and unambiguous description of a policy, procedure or principle within
a specific organization. In a sense, business rules are misnamed: they apply to any organization large or
small – a business, a government unit, a religious group or a research laboratory that stores and uses
data to generate information.
Using figure P2.8, we identify each relation type and write all business rules.
COURSE generates CLASS. One course can generate many classes. Each class is generated by one course.
CLASS is referenced in ENROLL. One class can be referenced in enrollment many times. Each individual
enrollment references one class. ENROLL entity is also related to STUDENT. Each entry in the ENROLL
entity references one student and the class for which that student has enrolled. A student cannot enroll
in the same class more than once. If a student enrolls in five classes, that student will appear in the
ENROLL entity five times, each time for a different class.
STUDENT is shown in ENROLL. One student can be shown in enrollment many times. Each individual
enrollment entry shows one student.
Question 9
Create the basic Crow’s Foot ERD for Tiny College.
Question 10
Create the network model that reflects the entities and relationships you
identified in the relational diagram.
In network database terminology, a relationship is called a set. Each set is composed of at least two
record types: an owner record that is equivalent to the hierarchical model’s parent and a member
record that is equivalent to hierarchical model’s child. A set represents a 1:* relationship between the
owner and member.
COURSE generates CLASS. One course can generate many classes(1.*) (one- to-many)
CLASS is referenced in ENROLL. One class can be referenced in enrollment many times(1.*)
STUDENT is shown in ENROLL. One student can be shown in enrollment many times(1.*)
Create the UML class diagram that reflects the entities and relationships
you identified in the relational diagram.
An entity is defined anything about which data are to be collected and stored. entity is represented in
the UML diagram by a rectangle.
Relationship describe associations among data.
In the following UML diagram
COURSE generates CLASS. One course can generate many classes. 1.* (one- to-many)
Each class is generated by one course.
CLASS is referenced in ENROLL. One class can be referenced in enrollment many times. So this
relationship is 1.* (one- to-many).
Each individual enrollment references one class.
STUDENT is shown in ENROLL. One student can be shown in enrollment many times. So this relationship
is 1.* (one- to-many).
Each individual enrollment entry shows one student.
References
Text Book( international edition)