Understanding the most important database design principles

In general, when designing a database structure, you want it to be normalized. Very briefly, here are the basic rules regarding data normalization:

• Each row can be uniquely referenced by a single column or combination of columns (that is, always have a primary key).
• Each column should contain a single value, not a collection of values (that is, avoid columns such as artist_names that contain column-separated names of multiple artists).
• Each column should contain different data than contained in other columns (that is, avoid columns such as artist_name_1, artist_name_2, and so on).
• Each column in the table is only dependent on the primary key, and not dependent on another column (that is, avoid an artist_name and artist_country column in a tracks table).

There are a lot of books that cover database normalization. Please see the Further reading section at the end of the chapter for some examples. In...