This book describes MYSQL's SQL dialect. It teaches how and why to use certain features of the language. Not only the classic features of SQL are described, but also the more advanced features. Every aspect of the language is discussed thoroughly and critically. The following aspects of SQL, among other things, are covered: Querying and updating data (joins, functions, and subqueries), creating tables, specifying primary and foreign keys and other constraints, using indexes, data security, developing stored procedures and triggers. Application development with PHP and Python, transactions, optimization of statements, is also discussed. Many users of MySQL have only very limited knowledge of SQL and would be significantly more productive if they had a better understanding of SQL. Others know SQL, but are unfamiliar with the idiosyncracies of MySQL's SQL implementation. In either case, this is the book for them. The exercises are a key benefit for readers familiar with other SQL variants. The structure, style and approach of this book is based on van der Lans best-selling Introduction to SQL (published by Addison-Wesley since 1987). This book is still being used at many universities, and is now in a fourth edition. And that structure and approach have therefore been tested over and over again.