SQL Pocket Guide is exactly that, a small guide to most things SQL. You won’t find a lot of background or extraneous content. Instead you’ll get good examples of SQL syntax for nearly every SQL command supported by PostgreSQL, MySQL, Oracle, DB2 and Microsoft SQL Server.
I’ve been using this book daily at work, and while it doesn’t officially support the SQL database engine we use, I’ve found it to be most helpful. This isn’t the type of book you’d sit down and read. It is meant to be a reference, but I find the content to be interesting enough that I often read about an extra command or two after the command I was looking for.
Don’t buy this book (at least not first) if you are new to SQL. You need a working knowledge of SQL and relational databases to make the most of this. But if you do work with SQL on even a semi-regular basis I really recommend it.
The only thing I’d like to see changed is adding support for SQLite. It is, after all, by numbers of installations, the most popular SQL engine in the world. Plus it is the one I prefer to use for most of my projects. Still much of the content is applicable, but it may take some trial-and-error to find the precise syntax.
Full disclosure: If it wasn’t obvious I received a free PDF version of this book for free in exchange for writing this review. I’ve followed the review guidelines set by O’Reilly. Especially (and always) “First and foremost, we want nothing but complete honesty in your reviews”.