Relational Database Principles

The first time a person tries to use Microsoft Access, they are likely to miss the whole point of what a database is and how to use it. When they start having trouble making it work for them, they think in terms of what they may be doing wrong in their use of the obvious tools of Access. But often their problem is that they are unfamiliar with the principles that make databases so useful and they have started with a flawed database schema.

This tutorial is intended to explain the underlying principles of relational databases. It is, admittedly, rather theoretical and perhaps even boring. But without an understanding of these principles, a beginner cannot hope to use Access for any really useful purpose. If you are a beginner, I urge you to read through the entire tutorial.

There are several issues that arise time and time again, such as:

. Storing multiple values in a field.
. Storing calculated values in a table.
. Determining primary keys.
. Using Autonumbers.
. How many tables does this database need?
. Why don't my queries work?

Sometimes answers in the forum make it sound like these things are a matter of preference, or "which is the best?" But in most cases, they are not--there are well established rules that determine the one correct answer. It is only with an understanding of the principles of relational database theory that you can determine the answers.

So I hope you will find it worth your time to study this 7-page tutorial. If you think you've found something in it that's incorrect, incomplete or impossible to understand, please feel free to contact me. I have been known to make mistakes!