SQL in a Nutshell, 3rd Edition

Why This Book?

The primary source of information for relational databases is the documentation and help files provided by the vendors themselves. While each vendor’s documentation is an indispensable resource that most database programmers and database administrators turn to first, this documentation has a number of limitations:

• It describes the vendor’s implementation of SQL without giving you any context as to how well that implementation meets the ANSI standard for SQL.

• It covers only a single, specific vendor’s product. There is no coverage of translation, migration, or integration issues.

• It typically describes programming methods in a multitude of small, disconnected documents or help files.

• It covers individual commands, often in confusing detail, obscuring the simple and direct uses of commands that programmers and administrators use every day.

In other words, the documentation included with a vendor’s database provides an exhaustive explanation of every aspect of that particular vendor’s platform. This is only natural; after all, help texts are geared toward delivering the main facts about a product. They’ll tell you a command’s specific syntax (and all its obscure variants) and, in general terms, how to implement it. However, if you move between RDBMSs and you need to be productive very quickly, you will rarely use those obscure command variations; instead, you’ll utilize the capabilities most common in real-life situations.

This book begins where the vendor documentation ends ...