Lecture 7 -Part 1

• cours magistral

1Lecture 7 Enhanced Entity-Relationship Modelling & Advanced Normalisation 2 Lecture 7 – Part 1 Enhanced Entity-Relationship Modelling 3 Introduction • Limitations of basic concepts of the ER model and requirements to represent more complex applications using additional data modelling concepts. • Most useful additional data modelling concepts of Enhanced ER (EER) model called: – specialization/generalization; – aggregation; – composition. • EER diagram using UML. 4 Specialization / Generalization • Superclass – An entity type that includes one or more distinct subgroupings of its occurrences.

• members of a superclass need
• consultant speciality specialism doc
• jul-05cr56 g102sg3712
• roomno
• -05cr56 g101sg510
• staffno
• superclass
• relation