Question

Question 29

Suppose I need to model a real-estate management company which manages multiple property types such as houses, apartments, and commerical buildings. Each type of property has certain attributes which are not held by the others (e.g., commercial buildings have number of elevators which is not applicable to houses or apartments).

What is the appropriate ER diagram construct to model these different types of properties?

		Supertype and Subtypes
		Composite Identifier
		Associative entity
		Multi-valued attributes
		Recursive Relationships

Answer 1

SOL:

The appropiate ER diagram construct to model these different types of properties are

supertype and subtypes

Explanation

Given that a real estate management company which manages multiple property types such as houses,apartments and commercial buildings

see here different entity sets like houses , apartments and commercial buildings are part of real estate management company so to show this hirearchy we use supertype and subtype relationship only

The houses , apartments and commercial buildings are the subclasses which inherits from the super class real estate management company

Each subclass are having different attributes here

The ISA relationship is used to model this hirearchy