Schema Translation - Information Systems Reengineering, Integration and Normalization - page 106

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Fig. 3.33 Map an entity to a class

Step 5—Map isa relationship to inheritance.
The concept of inheritance associated with a generalization (isa) relationship
in object-oriented schema permits classes to be organized in which specialized
class(es) inherit the properties and operations of a more generalized class. Class
carries common properties while deriving a specialized subclass. For example, the
isa relationship in Fig. 3.37 can be mapped into the following UML model where
subclass Graduate_Student inherits the properties of its superclass Student.