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Chapters 12 13 (Enhanced) Entity Relationship Modeling
12.1 Represent each of the following requirements with an ER diagram:
(a) A company called Perfect Pets runs a number of clinics. A clinic has many staff and a
member of staff manages at most one clinic (not all staff manage clinics). Each clinic
has a unique clinic number (clinicNo) and each member of staff has a unique staff
number (staffNo).
(b) When a pet owner contacts a
owner can own one or more pets, but a pet can only register with one clinic. Each owner
has a unique owner number (ownerNo) and each pet has a unique pet number (petNo).
(c) When the pet comes along to the clinic, it undergoes an examination by a member of the
consulting staff. The examination may result in the pet being prescribed with one or
more treatments. Each examination has a unique examination number (examNo) and
each type of treatment has a unique treatment number (treatNo).
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(d) Represent the complete set of requirements in one ER diagram.
12.2 Represent each of the following requirements with an ER diagram:
A regional council requires the design of a database system that can provide information on
all schools in the region. The requirements collection and analysis phase of the database
design process has provided the following data requirements for the schools database system.
(a) Every school has many pupils and many teachers. Each pupil is assigned to one school
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Reliable Rentals Case Study
The requirements collection and analysis phase of the database design process has provided
the following data requirements for a company called Reliable Rentals, which rents out
vehicles (cars and vans). The Company has various outlets (garage/offices) throughout
Glasgow. Each outlet has a number, address, phone number, fax number, and a manager who
Clients may hire vehicles for various periods of time (minimum 1 day to maximum 1 year).
Each individual hire agreement between a client and the Company is uniquely identified using
address and phone number, date the client started the hire period, date the client wishes to
terminate the hire period, the vehicle registration number, model and make, the mileage before
12.3 Create a conceptual schema for Reliable Rentals using the concepts of the Enhanced Entity
Relationship (EER) model. To simplify the diagram, only show entities, relationships and the
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