Allen G. Taylor - SQL All-In-One For Dummies

SQL All-In-One For Dummies, 3rd Edition

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Copyright 2019 by John Wiley & Sons, Inc., Hoboken, New Jersey

Published simultaneously in Canada

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Library of Congress Control Number: 2019934589

ISBN 978-1-119-56961-9 (pbk); ISBN 978-1-119-56960-2 (ebk); ISBN 978-1-119-56959-6 (ebk)

1. Book 1 Chapter 4
2. Book 1 Chapter 5
3. Book 1 Chapter 6
4. Book 2 Chapter 2
5. Book 2 Chapter 3
6. Book 2 Chapter 4
7. Book 3 Chapter 1
8. Book 3 Chapter 2
9. Book 3 Chapter 3
10. Book 3 Chapter 4
11. Book 4 Chapter 1
12. Book 4 Chapter 2
13. Book 4 Chapter 4
14. Book 6 Chapter 3

1. Book 1 Chapter 1
2. Book 1 Chapter 2
3. Book 1 Chapter 3
4. Book 1 Chapter 5
5. Book 2 Chapter 1
6. Book 2 Chapter 2
7. Book 2 Chapter 3
8. Book 3 Chapter 2
9. Book 3 Chapter 3
10. Book 4 Chapter 1
11. Book 5 Chapter 2
12. Book 5 Chapter 4
13. Book 5 Chapter 5
14. Book 5 Chapter 7
15. Book 7 Chapter 1
16. Book 7 Chapter 3

SQL is the internationally recognized standard language for dealing with data in relational databases. Developed by IBM, SQL became an international standard in 1986. The standard was updated in 1989, 1992, 1999, 2003, 2008, 2011, and 2016. It continues to evolve and gain capability. Database vendors continually update their products to incorporate the new features of the ISO/IEC standard. (For the curious out there, ISO is the International Organization for Standardization, and IEC is the International Electrotechnical Commission.)

SQL isnt a general-purpose language, such as C++ or Java. Instead, its strictly designed to deal with data in relational databases. With SQL, you can carry out all the following tasks:

• Create a database, including all tables and relationships.
• Fill database tables with data.
• Change the data in database tables.
• Delete data from database tables.
• Retrieve specific information from database tables.
• Grant and revoke access to database tables.
• Protect database tables from corruption due to access conflicts or user mistakes.

This book isnt just about SQL; its also about how SQL fits into the process of creating and maintaining databases and database applications. In this book, I cover how SQL fits into the larger world of application development and how it handles data coming in from other computers, which may be on the other side of the world or even in interplanetary space.

Here are some of the things you can do with this book:

• Create a model of a proposed system and then translate that model into a database.
• Find out about the capabilities and limitations of SQL.
• Discover how to develop reliable and maintainable database systems.
• Create databases.
• Speed database queries.
• Protect databases from hardware failures, software bugs, and Internet attacks.
• Control access to sensitive information.
• Write effective database applications.
• Deal with data from a variety of nontraditional data sources by using XML.

I know that this is a For Dummies book, but I dont really expect that youre a dummy. In fact, I assume that youre a very smart person. After all, you decided to read this book, which is a sign of high intelligence indeed. Therefore, I assume that you may want to do a few things, such as re-create some of the examples in the book. You may even want to enter some SQL code and execute it. To do that, you need at the very least an SQL editor and more likely also a database management system (DBMS) of some sort. Many choices are available, both proprietary and open source. I mention several of these products at various places throughout the book but dont recommend any one in particular. Any product that complies with the ISO/IEC international SQL standard should be fine.

Take claims of ISO/IEC compliance with a grain of salt, however. No DBMS available today is 100 percent compliant with the ISO/IEC SQL standard. For that reason, some of the code examples I give in this book may not work in the particular SQL implementation that youre using. The code samples I use in this book are consistent with the international standard rather than with the syntax of any particular implementation unless I specifically state that the code is for a particular implementation.