While we don’t intend this book to serve as a tutorial on SQL or a handbook for the database architect, we do provide some coverage of introductory design topics. Chapters 1 and 2 provide a concise introduction to the language itself, covering essential structures, basic usage, and some history. If you’re new to SQL, these two chapters will help you get going.

Why This Book?

The primary and definitive source of information for any given relational database package is the official documentation, along with help files, tutorials, advisories, and other tidbits provided by the vendors themselves. But while each vendor’s documentation should be the resource that developers and database administrators turn to first, official documentation has a number of limitations:

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• It describes the vendor’s implementation of SQL without providing an indication of how well that implementation meets the SQL standard.
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• It covers only the vendor’s specific product, without discussing potential translation, migration, or integration issues across different vendors.
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• It covers individual commands in often unrelenting detail, thereby obscuring the most common use cases.
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• It typically describes programming methods in an overwhelming number of disconnected articles or help files.
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A vendor’s official documentation can be expected to provide an exhaustive explanation of every aspect of their offering. It will describe every command, including each obscure variant, along with some implementation guidance. Subjective commentaries are off-limits. However, if you move between data platforms and need to be productive quickly, you will rarely need this level of detail on all the obscure command variations. Instead, you’re looking for the most applicable usage found in real-life situations.

This book begins where the vendor documentation ends by distilling the experiences of professional database administrators and developers who have used these SQL products to support complex enterprise applications. It offers you the benefit of their decades of experience in a compact and easily usable format. Whether you’re new to SQL or you have been using SQL since its earliest days, there are always new tips and techniques to learn. And when you’re moving between different data platforms, it’s always important to uncover compatibility issues before they bite you.