There was a time when Information Technology was only known as "Electronic Data Processing." Despite the fuss about innovative techniques, data process is still the heart of every system in the world-and even more so as the data sizes that are being managed today seems to grow at an exponential rate. Some of the architectural preferences are complete long shots on the future. You will definitely not only need an exceptionally firm grasp on the theoretical knowledge, but also rigor. However, those characteristics are essentials of any art. This book is definitely not a SQL cookbook wherein all possible problems and their solutions are listed. The aim is to impart not only a firm grasp of the fundamentals of database query language, but also a good working knowledge of the relational theory of SQL. It is also the aim of this book to help budding developers-and their administrators-to raise exceptionally good questions. There's a big chance that you'll still write bad code-inefficient queries after going through this book. A developer, from time to time, has to. Hopefully, however, it'll be knowingly and with perfectly good reason. Welcome readers to the world of SQL. Let's begin your journey.