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Question 3.3
How can one compare the abstract level of the EER model and UML, and the fea-
tures of a relational database and object-oriented database?
Question 3.4
a. Show the steps needed in designing an entity-relationship model. What are the
steps of mapping an EER model into a relational model?
b. Consider a case study with the following business requirements and relational
database:
− Acompanyhastworegions,AandB.
− Eachregionformsitsowndepartments.
− Eachdepartmentapprovesmanytripsinayear.
− Eachstaffmakesmanytripsinayear.
− Ineachtrip,astaffneedstohirecarsfortransportation.
− Eachhiredcarcancarrymanystaffforeachtrip.
− Astaffcanbeeitheramanageroranengineer.
The data requirements are:
Data field
Description
Department_id
The identity number of department
Salary
The salary of department staff
Classification
The classification of regional office
Trip_id
The identity of each business trip by department staff
Car_model
The model of the car rented by staff during the business trip
Staff_id
The identity number of department staff
Name
The name of the staff who rents the car during business trip
DOB
Date of birth of department staff
Size
The size of the car rented by department staff for business
trip
Description
Description of the car rented by department staff on business
trip
Title
The job title of department staff on business trip
Based on the user and data requirement, design an EER model to meet these re-
quirements.
Question 3.5
(a) What are the steps of mapping Unified Modeling Language into an object-ori-
ented schema?
(b) Map the following Unified Modeling Language into an object-oriented schema:
(c)
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