[SOLVED] CS ER case study database FIT2094-FIT3171 2021 SSB

FIT2094-FIT3171 2021 SSB
FIT2094-FIT3171 Databases
FIT2094-FIT3171 Databases
Session 3 Tutorial Suggested Solution
CONCEPTUAL MODELLING
FIT Database Teaching Team
Author: FIT Database Teaching Team
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3.1. Conceptual Design Demo
Step 1: identify entities
Step 2: identify key attribute for each entity
Step 3: draw the relationships
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Step 4: add non-key attributes
project_noofemp derived attribute
emp_degrees multivalued attribute
Step 5: remove multivalued attribute and create a new entity
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3.2. Using Tools to draw an Entity Relationship Diagram 3.2.4 Drawing ER Diagram Using Lucidchart
(i) Basic ERD showing only key attributes
The cardinality of the places relationship at the ORDER end could also be (1,N) rather than (0,N) as illustrated this is a business rule (What constitutes a customer for the company)
(ii) Complete ERD showing all attributes
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3.2.6 Drawing UML Diagram Using Lucidchart
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3.3. Conceptual Modelling Exercise
Your solution to this task may be slightly different, this is a s tarting point. In this model we have some issues which need further attention, for example what happens if the same type of damage needs to be recorded on a given property for example a hole punched in a wall occured at 10am and then another hole punched in a wall at 3pm in the same property?
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The case study as provided is thus missing important data related to several issues, these are the types of items you need to seek clarification from your client.
How do you regard a large shopping center from a property point of view client response: we treat each sub property as a property in its own right and assign each a property number
What if a tenant wishes to negotiate a new lease agreement on the same property when their lease expires client response: we also record a lease start date
Do you record damage which is not caused by tenants client response: no, the only damage which is recorded is that caused by tenants so that the damage can be appropriately charged to the tenant who is responsible for it (the tenant is required to make one payment to cover the damage)
How is the same damage which occurs twice in one day recorded client response: we also record the time of the damage as well as the date
With this additional data we would arrive at a model of the form:
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Conceptual Model using UML Notation
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