It is obvious, from the very first paragraphs you read, that the author is deeply familiar with SQL. The in-depth knowledge that Ben-Gan displays is impressive and is very off the path of the traditional beginning SQL book. I look forward to grabbing other titles from him, but I will be sure to target them with the following general idea in mind.
This book is not a good one to use as a base to learn SQL. It should be looked at as a supplement for someone that has a basic understanding and wants a beginning look "under the hood". It covers sections very quickly, is very text bookish while reading and is short in length. Looking through the summary prior to purchase, I was excited to see so many different topics to be covered. Once I arrived, it was disappointing to find these topics condensed to a couple of pages, with much of that filled with SQL code examples. It's brilliant, but left me wanting more on each topic consistently.
I yearn for the author that can write a guide on SQL in the same manner that Wheelan wrote on economics in Naked Economics, clear, easy to understand and engaging.