Choosing a Version of MySQL
Distributions are available for several MySQL release series. Generally, you should use the highest-numbered version available in the series you want to use. Currently, stable releases are being produced in the 4.0 and 4.1 series and development releases come from the 5.0 series.
Normally, I recommend that you use a stable release and not a development release, which means using MySQL 4.0 or 4.1. However, MySQL 4.0 is missing many of the features available in MySQL 4.1 such as subqueries and multiple character set support, so 4.1 is a better choice.
Given these factors, this book uses MySQL 4.1 as its baseline and covers 4.1 and 5.0. For most readers, my recommendation is to use MySQL 4.1. If you want to experiment with the newest features such as stored procedures, views, or triggers, you can try MySQL 5.0. The following instructions assume that you'll install MySQL 4.1 or later.