Structured Query Language, or SQL, can be daunting to learn. There are many books available that purport to ramp the user up from mere mortal to godlike status. This book is not one of them. Having written and taught SQL lessons to many groups ranging from support to developers, it eventually dawned on me that all too often I was presuming a ""base"" knowledge of SQL and databases and I was losing the room from the first slide. I needed to back up and explain more about why users would want to combine tables and why data was not just put in one single table. From there we could move on to how to combine tables to get answers. It was good to see lights come on in people's eyes. This book is a distillation of those lessons.