part 1
Includes all modeling concepts of basic ER
Additional concepts: subclasses/superclasses,
specialization/generalization, categories, attribute
inheritance
The resulting model is called the enhanced-ER or
Extended ER (E2R or EER) model
It is used to model applications more completely
and accurately if needed
It includes some object-oriented concepts, such as
inheritance
www.cse.ohio-state.edu
part 2
Fundamental Principle of Modeling:
• Data Abstraction
Basic Process of Modeling
• Define building blocks for
• holding groups of data
• Use rules of a data model to establish
• relationships among blocks
Add constraints - structural/ semantic
www.cse.ohio-state.edu
