O'Reilly logo

Database Modeling and Design, 4th Edition by Sam S. Lightstone, Tom Nadeau, H.V. Jagadish, Toby J. Teorey

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

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 ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required