Foreword

In the 20 years since the database language SQL was adopted as an international standard, and the 25 years since SQL database products appeared on the market, SQL has become the predominant language for storing, modifying, retrieving, and deleting data. Today, a significant portion of the world’s data—and the world’s economy—is tracked using SQL databases.

SQL is everywhere because it is a very powerful tool for manipulating data. It is in high-performance transaction processing systems. It is behind Web interfaces. I’ve even found SQL in network monitoring tools and spam firewalls.

Today, SQL can be executed directly, embedded in programming languages, and accessed through call interfaces. It is hidden inside GUI development tools, code generators, and report writers. However visible or hidden, the underlying queries are SQL. Therefore, to understand existing applications and to create new ones, you need to understand SQL.

SQL Queries for Mere Mortals, Second Edition, provides a step-by-step, easy-to-read introduction to writing SQL queries. It includes hundreds of examples with detailed explanations. This book provides the tools you need to understand, modify, and create SQL queries.

As a database consultant and a participant in both the U.S. and international SQL standards committees, I spend a lot of time working with SQL. So, it is with a certain amount of authority that I state, “The authors of this book not only understand SQL, they also understand how to explain it.” Both qualities make this book a valuable resource.

Keith W. Hare
Senior Consultant, JCC Consulting, Inc.
Vice Chair, INCITS H2—the USA SQL Standards Committee
Convenor, ISO/IEC JTC1 SC32 WG3—the International
SQL Standards Committee