Database Modeling and Design, 4th Edition

2 The Entity-Relationship Model

This chapter defines all the major entity-relationship (ER) concepts that can be applied to the conceptual data modeling phase of the database life cycle. In Section 2.1, we will look at the simple level of ER modeling described in the original work by Chen and extended by others. The simple form of the ER model is used as the basis for effective communication with the end user about the conceptual database. Section 2.2 presents the more advanced concepts; although they are less generally accepted, they are useful to describe certain semantics that cannot be constructed with the simple model.

2.1 Fundamental ER Constructs

2.1.1 Basic Objects: Entities, Relationships, Attributes

The basic ER model consists of three ...