Wouldn’t use this book if I was trying to learn SQL because it’s soo basic. It’s pretty good as a refresher of basic queries. The book’s examples are way too simple. Coverage of the different types of joins aren’t great either. I wouldn’t recommend this book to a beginner.
One thing I hadn’t used in awhile was the CONCAT() operator. Well for MySQL it’s CONCAT(col1, “, “, col2, …) ; for Oracle it’s column1 || ‘, ‘ || col2 … ; for MS SQL Server it’s col1+’, ‘+col2+… .