Audience for This Book
This book was written for Oracle developers and database administrators (DBAs) who use SQL. The book is designed as a reference; the material is intentionally presented as concisely as possible. Since I assume that you are already somewhat familiar with relational concepts and the basics of the SQL language, I have attempted to provide you with the information you need in a location and format that allows you to access it quickly, as required. If you are looking for clear, concise information about Oracle's implementation of SQL, with plenty of summary tables and quick reference to syntax and usage, then you have come to the right place. However, if you are trying to learn SQL, and want a tutorial that will teach you about it from start to finish, you will probably want to start with an introductory text. Hang on to this book, however you'll find it very useful later on!
I certainly don't want to deter you from buying and using this book, but I want you to know that my approach is to cram as much concise and fast-moving material as possible into these pages.