Database Design for Mere Mortals™: A Hands-On Guide to Relational Database Design, Second Edition

Understanding Normal Forms

Before You Begin ...

So, you've identified your tables and populated them with the fields you believe are most appropriate at this time, and you've even gone so far as to identify relationships between some of the tables. Now you're ready to take them through the Normalization process. Or are you?

There are a couple of things you need to check before you start the Normalization process.

1. Each table must have a primary key.

2. A table cannot contain repeating groups of data.

Each of your tables must be in this state in order for the Normalization process to be effective. Otherwise, you could run into problems that might easily have been avoided.

Figure 9 shows a non-normalized Orders table. Although it's in ...