O'Reilly logo

Beginning Database Design: From Novice to Professional, Second Edition by Clare Churcher

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

CHAPTER 6

image

Generalization and Specialization

As the data model begins to develop, situations will sometimes arise where we find that a class may not describe our possible objects as neatly as we might like. We might find that we have some objects for which some of the attributes do not really apply. For example, if we have a class to record information about all the people associated with a company, we might find that some have hourly pay rates while others have annual salaries. In many respects, much of the information about each of the employees is similar, but there are differences. We may also come across the case where we have started with ...

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