Usage-Driven Database Design: From Logical Data Modeling through Physical Schema Definition

© George Tillmann 2017

George Tillmann, Usage-Driven Database Design, 10.1007/978-1-4842-2722-0_3

3. More About the E-R Approach

George Tillmann¹ 

(1)Ship Bottom, New Jersey, USA

The relationship between the data is more important than the data.

—James Burke

Data matures like wine, applications like fish.

—James Governor

Chapter 2 introduced logical data modeling using the entity-relationship approach. This chapter expands the logical data model building blocks: relationships, entities, and attributes.

More About Relationships

Relationships, so far, seem rather pale and lifeless. However, relationships have three characteristics that give them the texture needed to express the richness of the real world, namely, membership class, degree, and relationship ...