Concepts of Database Design and Management

First Normal Form

Now that we have clarified these concepts, lets move into the Normalization Process. The First Normal Form is defined as a table that does not contain repeating groups.

For example:

Now, from that example, you should easily see the problem. First off, in this setup, Order Number is considered the Primary Key, but this is not entirely true. The true Primary Key is Order Number and Part Number. In every order, a part will only ever be ordered once (though the amount ordered can be greater than 1). However, multiple parts can be ordered in on Order Number. So, when we retool this table, we end up getting this:

This is much easier to understand, and is a much better design then the previous table. And this time, the Primary Key is both the Order Number and Part Number, and everything else in the table depends on that key.

This was the First Norm Form, or 1NF. Most people can do this right, however, I have seen some tables designed without this in mind, and for a while, it looks like things are all right, but when you start filling the table up with lots of information, it can become quite cumbersome. Definitely, not a shining point in someone's career, but a most valuable lesson indeed.