The value of SQL is indisputable, as it is the primary language of most modern database management systems. Many professionals now are also adding SQL to their technical repertoire. This practical guide is a short and focused introduction to the main features of using SQL. The book is useful as both a tutorial and a reference, and includes chapter questions and exercises to ground students and professionals in various topics. It does not focus on a particular vendor's SQL implementation and uses syntax that complies with the 1999 standard. Specific DBMS peculiarities are included on a companion web site, along with the code for the book.