Super Entity & Sub Entity Yong Choi School of Business CSU, Bakersfield

Structure of Super & Sub Entity 1

Example of Super & Sub Entity 1

Structure of Super & Sub Entity 2

Example of Super & Sub Entity 1

Simple Example of E-ERD

Generalization (bottom-up strategy) Start with candidate sub entities

Generalization (top-down Strategy) Start with candidate Super entity

Specialization and Rule Total Specialization Partial Specilization Rule Disjoint Rule Overlap Rule

Total Specialization Only two choices with changes: Outpatient to Resident patient or vice versa.

Partial Specialization That is, it cannot be something else (like a motor cycle).

Disjoint Rule

Overlap Rule