Assignment 2

1
Assignment 2

• Quiz 1
• Assignment 1
• Assignment 2

2
Assignment 3

• E-R Model Forthe University Accommodation Office
• Document

3
Wednesday

• Short Lecture
• Quiz 1
• Lab 206

4
E-R Model Forthe University Accommodation Office

• Make assumptions
• Identify entity types
• Identify relationship types
• Describe entity types and relationship types in
  detail
• Attributes Composite, Multi-valued,
  Derived
• Primary key and alternate keys for
  entity types
• Describe relationship types in detail
• Attributes
• Multiplicity
• Using UML to draw the E-R diagram

5
Assumptions

• A student can rent only one room for any specific
  period of time.
• A student may have multiple leases at the same
  time for different periods of time.
• A student may be waiting for multiple rooms at
  the same time.
• One person could be NextOfKin for multiple
  students.
• At most one NextOfKin is recorded for any
  student.
• Each hall could have more than one phone number.
• Different halls cannot share one phone number.
• Different halls have different names and
  addresses.
• Only one course is listed for each student.
• Address is considered as a simple attribute.
• Only one phone number is recorded for a student
  or NextOfKin.

6
Entity Types

• Hall
• Room
• Student
• Course
• NextOfKin

7
Relationship Types

• Hall Has Room
• Student Rents Room
• Student WaitsFor Room
• Student EnrolledIn Course
• Student IsRelatedTo NextOfKin

8
Entity Type in Detail

• Hall
• HallNo
• Address
• Phone Multi-Value
• Name
• Primary Key HallNo
• Alternate Keys Address
• Name
• Room
• PlaceNo
• RoomNo
• Rent
• Primary Key PlaceNo
• Alternate Keys None
• Course
• CourseID

Student MatricNo Name Composite
(firstName, lastName) Birthday Composite
Phone Multi-Value Address Composite
(street, city, state, zipcode) Primary Key
MatricNo Alternate Keys None NextOfKin
FirstName LastName Phone
Address Primary Key NONE Weak
Entity
9
Relationship Types in Detail

• Hall (1..1) Has
  (1..) Room
• Student (0..) Leases
  (0..) Room
• startDate, endDate
• Student (0..) WaitFor
  (0..) Room
• dateOnWaitingList
• Student (1..) IsEnrolledIn
  (1..1) Course
• NextOfKin (0..1) IsRelatedTo (1..)
  Student
• relationship