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Er Model Uao

This document outlines the entity-relationship (E-R) model for a university accommodation office database. It identifies 5 main entity types - Hall, Room, Student, Course, and EmergencyContact - and describes their attributes and relationships. Halls have many rooms, students can lease or wait for rooms, and each student is enrolled in one course and can have one emergency contact. A diagram depicts the 1-to-many and many-to-many relationships between the entities.

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Jerome Rivera
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50 views3 pages

Er Model Uao

This document outlines the entity-relationship (E-R) model for a university accommodation office database. It identifies 5 main entity types - Hall, Room, Student, Course, and EmergencyContact - and describes their attributes and relationships. Halls have many rooms, students can lease or wait for rooms, and each student is enrolled in one course and can have one emergency contact. A diagram depicts the 1-to-many and many-to-many relationships between the entities.

Uploaded by

Jerome Rivera
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as DOC, PDF, TXT or read online on Scribd
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The E-R Model for the University Accommodation Office

1. Identify entity types with brief description


Hall : All dorm buildings
Room : All rooms in all halls
Student : All students renting or waiting
Course : One course is recorded for each student
EmergencyContact: Each student should have one emergency contact

2. Relationship Types with attributes and multiplicity

Hall (1..1) Has (1..*) Room

A hall has many rooms.


A room can only be in one hall.

Student (0..*) Leases (0..*) Room


Attributes: Start, End

A student can rent only one room for any specific period of time
One room is leased to one student at any given time
Old leases are still stored in the database
Students can sign new leases before their current leases expired

Student (0..*) WaitFor (0..*) Room


Attribute: dateOnWaitingList

One student can request multiple rooms for different time spans
One room could be requested by multiple students, even for the same time span

Student (1..*) IsEnrolledIn (1) Course

Only one course is recorded for one student, and not all courses are stored
Each student must be enrolled in one course

Student (1..*) IsRelatedTo (0..1) EmergencyContact


Attributes: relationship

One student should have one contact


One person could be contact for multiple students

3. Entity Type Details

Hall
HallNo
Address
Phone: Multi-Value
Name

Primary Key: HallNo


Alternate Keys: Address
Name

Each hall could have more than one phone number


Different halls cannot share one phone number
Different halls have different names and addresses

Room
PlaceNo
RoomNo
Rent

Primary Key: PlaceNo


Alternate Keys: None

Student
MatricNo
Name: Composite (first, middle, last)
Birthday: Composite (year, month, day)
Phone
Address: Composite (Street, City, State, ZipCode)

Primary Key: MatricNo


Alternate Keys: None

Course
CourseID
Title
Department
CourseLeader

Primary Key: CourseID


Alternate Keys: Title

EmergencyContact:
FirstName
LastName
Phone
Address: Optional

4. E-R Diagram

Hall
HallNo

1
Has
1..*

Room
PlaceNo

0..* 0..*

WaitFor Leases

0..* 0..*

Student
MatricNo

1..* 1..*
IsEnrolledIn IsRelatedTo

0..1
1

Course Contact
CourseID ID

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