This is my first book review for the O'reilly Blogger Review Program, I read this book on my Amazon Kindle 3 - a great experience in itself.
A great resource for starting and experienced SQL programmers alike, this book is indeed what it claims to be - a pocket guide for SQL. It is highly informative and covers a lot of ground in a concise and readable manner.
When programming in any language a handy reference is always helpful, today it is easy to find almost anything on the web (vendor website or elsewhere), but sometimes especially if you work in multiple environments it is better to have an organized form of the reference in a book (hard copy or ebook). If you find yourself in such a need for SQL this book is what you are looking for, and for the price I would recommend you buy it.
It organizes the information you need by section (SELECT, UPDATE, PIVOT, Window Functions) and inside the section gives all the information relevant for the different SQL platforms (SQL Server, MySql, Oracle, etc...) - including basic explanation on the functionality and the required syntax and differences between them.
The reference itself is very useful, but the book also provides explanations on the different functionalities and concepts which I think could greatly assist beginners in understanding more fully what they can do and why.