Welcome to database development using SQL, the industry-standard database query language. Many database management system (DBMS) tools run on a variety of hardware platforms. The differences among the tools can be great, but all serious products have one thing in common: They support SQL data access and manipulation. If you know SQL, you can build relational databases and get useful information out of them.

About This Book

Relational database management systems are vital to many organizations. People often think that creating and maintaining these systems must be extremely complex activities — the domain of database gurus who possess enlightenment beyond that of mere mortals. This book sweeps away the database mystique. In this book, you

• Get to the roots of databases.
• Find out how a DBMS is structured.
• Discover the major functional components of SQL.
• Build a database.
• Protect a database from harm.
• Operate on database data.
• Determine how to get the information you want out of a database.

The purpose of this book is to help you build relational databases and get valuable information out of them by using SQL. SQL is the international standard language used to create and maintain relational databases. This edition covers the latest version of the standard, SQL:2016.

This book doesn’t tell you how to design a database (I do that in Database Development For Dummies, also published by Wiley). Here I assume that you or somebody else has already created a valid design. I then illustrate how you implement that design by using SQL. If you suspect that you don’t have a good database design, then by all means fix your design before you try to build the database. The earlier you detect and correct problems in a development project, the cheaper the corrections will be.

Foolish Assumptions

If you need to store or retrieve data from a DBMS, you can do a much better job with a working knowledge of SQL. You don’t need to be a programmer to use SQL, and you don’t need to know programming languages, such as Java, C, or BASIC. SQL’s syntax is like that of English. If you are a programmer, you can incorporate SQL into your programs. SQL adds powerful data manipulation and retrieval capabilities to conventional languages. This book tells you what you need to know to use SQL’s rich assortment of tools and features inside your programs.

Icons Used in This Book

When something in this book is particularly valuable, we go out of our way to make sure that it stands out. We use these cool icons to mark text that (for one reason or another) really needs your attention. Here’s a quick preview of the ones waiting for you in this book and what they mean.

Tips save you a lot of time and keep you out of trouble.

Pay attention to the information marked by this icon — you may need it later.

Heeding the advice that this icon points to can save you from major grief. Ignore it at your peril.

This icon alerts you to the presence of technical details that are interesting but not absolutely essential to understanding the topic being discussed.

Beyond the Book

In addition to the content in this book, you’ll find some extra content available at the www.dummies.com website:

• For the Cheat Sheet for this book, visit www.dummies.com/ and search for SQL For Dummies 9E cheat sheet.
• For updates to this book, if any, visit the www.dummies.com store and search for SQL For Dummies 9E.

Where to Go from Here

Now for the fun part! Databases are the best tools ever invented for keeping track of the things you care about. After you understand databases and can use SQL to make them do your bidding, you wield tremendous power. Co-workers come to you when they need critical information. Managers seek your advice. Youngsters ask for your autograph. But most importantly, you know, at a very deep level, how your organization really works.