When I fly across the country, I often pass the hours programming on my PowerBook. If that programming involves MySQL, I inevitably end up lugging around the book I cowrote, Managing and Using MySQL (O’Reilly). I don’t carry around the book to show it off; the problem is that no matter how experienced you are with MySQL, you never know when you will need to look up the exact syntax of an obscure function or SQL statement.
The MySQL Pocket Reference is a quick reference that you can take with you anywhere you go. Instead of racking your brain for the exact syntax of a variant of ALTER TABLE that you generally never use, you can reach into your laptop case and grab this reference. As an experienced MySQL architect, administrator, or programmer, you can look to this reference.
This book does not, however, teach MySQL. I expect that you have learned or are in the process of learning MySQL from a book such as Managing and Using MySQL. Though I start with a reference on MySQL setup, it is designed to help you remember the full process of MySQL configuration—not to teach you the process.