Practical SQL Handbook, The: Using SQL Variants, Fourth Edition

The Focus of This Book

This book focuses on the real world of commercial SQLs—“industry SQLs”—rather than on the more abstract SQL represented by the ANSI standard. We chose to focus here because industry SQLs provide a better teaching tool in the areas of notation, target audience, and overall functionality:

• The syntax notation used to document most industry SQLs is reasonably clear and intuitively understandable. The ISO-ANSI publications, on the other hand, use BNF (Backus Naur Form) notation, which is very precise but difficult to read and understand.

• All the industry SQLs support an interactive interface for the beginning or casual user; the ISO-ANSI standard is largely concerned with the embedded SQL interface for programmers and applications ...