SQL in a Nutshell

Preface

The explosive growth of the information technology industry and the constantly growing need to compile, store, access, and manipulate increasingly larger masses of data have required the development of ever more sophisticated database management tools.

Since its first incarnation in the 1970s, Structured Query Language (SQL) has been developed hand in hand with the information boom, and as a result, is the most widely used database manipulation language in business and industry. A number of different software companies and program developers, including those in the open source movement, have concurrently developed their own SQL dialects in response to specific needs. All the while, standards bodies have developed a growing list of common features.

SQL in a Nutshell identifies the differences between the various vendor implementations of SQL. Readers will find a concise explanation of the Relational Database Management System (RDBMS) model, a clear-cut explanation of foundational RDBMS concepts, and thorough coverage of basic SQL syntax and commands. Most importantly, programmers and developers who use SQL in a Nutshell will find a concise guide both to the most popular commercial database packages on the market (Microsoft SQL Server and Oracle8i ), and to two of the best known open source ( http://www.opensource.org) database products (MySQL and PostgreSQL). SQL in a Nutshell ’s attention to open source SQL products is an affirmation of the growing importance of the open source movement within the computing community.

As a result, SQL in a Nutshell benefits several distinct groups of users: the knowledgeable programmer who requires a concise and handy reference tool, the developer who needs to migrate from one SQL dialect to another, and the user who comes to SQL from another programming language and wants to learn the basics of SQL programming.

How This Book Is Organized

This book is divided into five chapters and one appendix:

Chapter 1

This chapter discusses the Relational Database Model, describes the current and previous SQL standards, and introduces the SQL vendor implementations covered in this book.

Chapter 2

This chapter describes the fundamental concepts necessary for understanding relational databases and SQL commands.

Chapter 3

This chapter is an alphabetical command reference. It details each SQL99 command, as well as the implementations of each command by Oracle, Microsoft SQL Server, MySQL, and PostgreSQL.

Chapter 4

This chapter is an alphabetical reference of the SQL99 functions, describing vendor implementations of these functions and vendor extensions.

Chapter 5

This chapter lists commands that are included in the SQL standards, but have not yet been implemented by any of the vendors.

Appendix A

The appendix provides a table that displays keywords declared in SQL99 and by the various database vendors.