The author clearly states in the preface what this book is, and is not. The book is primarily a command reference. It is intended as a reference tool, not a tutorial. Nor is it expository.
This is useful ONLY as a reference. Its organization is utterly useless unless you already know SQL top to bottom and just need a refresh on the fiddly bits. That said, if the above is what you're looking for, it is good at that job.