This book describes what SQL is, why it is important, and how to use it. SQL is Structured Query Language developed at IBM as a standard Query and Programming language for all their networked computers. This book is not specific to one brand or dialect of SQL. Rather, it describes the core of the SQL language and the differences among the most popular SQL variations such as OS/2, Oracle, Sybase, Ingres, and dBASE IV. The authors use step-by-step explanations of the language, and how and where it is implemented, and also addresses programming SQL.