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School of Computer Science
COMP9120 Database Management Systems
Tutorial Week 2: Conceptual Design with Entity-
Relationship Diagrams
Exercise 1. Meet your tutors
Every week there will be tutorials that provide an opportunity to gain practical
experience in the areas introduced in the preceding lecture. Tutorials take place in
the labs of the School of Information Technologies Building J12, as well as in the
Link Building J13, as shown below:
Exercise 2. ER Diagrams Analysis
Consider a real-estate company, which manages rental properties. Each property
has an address, a number of bedrooms, bathrooms, and car spaces. A rental
property may have a number of rental agreements. A rental agreement details the
weekly rent that is agreed upon with one or more tenants for a property for a given
period of time. For each of these tenants, the details that need to be recorded
include first name, last name, and date of birth. At any point in time, each staff
member must be responsible for managing at least one property, where a property
can be managed by multiple staff members and must be managed by at least one
staff member at any point in time. Staff members also have a first name, last name,
and date of birth. At any point in time a property is owned by one or more land-lords.
The ownership of each property may also change over time.
The E-R diagram shown on the next page is one attempt at modelling this domain.
Consider what errors you can identify in this model.
