SQL Queries for Mere Mortals: A Hands-On Guide to Data Manipulation in SQL(For Mere Mortals)

This is the eBook version of the printed book. If the print book includes a CD-ROM, this content is not included within the eBook version. Unless you are working at a very advanced level, this is the only SQL book you will ever need. The authors have taken the mystery out of complex queries and explained principles and techniques with such clarity that a "Mere Mortal" will indeed be empowered to perform the superhuman. Do not walk past this book! --Graham Mandeno, Database Consultant SQL Queries for Mere Mortals provides a step-by-step, easy-to-read introduction to writing SQL queries. It includes hundreds of examples with detailed explanations. This book provides the tools you need to understand, modify, and create SQL queries --Keith W. Hare, Convenor, ISO/IEC JTC1 SC32 WG3--the International SQL Standards Committee I learned SQL primarily from the first edition of this book, and I am pleased to see a second edition of this book so that others can continue to benefit from its organized presentation of the language. Starting from how to design your tables so that SQL can be effective (a common problem for database beginners), and then continuing through the various aspects of SQL construction and capabilities, the reader can become a moderate expert upon completing the book and its samples. Learning how to convert a question in English into a meaningful SQL statement will greatly facilitate your mastery of the language. Numerous examples from real life will help you visualize how to use SQL to answer the questions about the data in your database. Just one of the "watch out for this trap" items will save you more than the cost of the book when you avoid that problem when writing your queries. I highly recommend this book if you want to tap the full potential of your database. --Kenneth D. Snell, Ph.D., Database Designer/Programmer I don't think they do this in public schools any more, and it is a shame, but do you remember in the seventh and eighth grades when you learned to diagram a sentence? Those of you who do may no longer remember how you did it, but all of you do write better sentences because of it. John Viescas and Mike Hernandez must have remembered because they take everyday English queries and literally translate them into SQL. This is an important book for all database designers. It takes the complexity of mathematical Set Theory and of First Order Predicate Logic, as outlined in E. F. Codd's original treatise on relational database design, and makes it easy for anyone to understand. If you want an elementary- through intermediate-level course on SQL, this is the one book that is a requirement, no matter how many others you buy. --Arvin Meyer, MCP, MVP Even in this day of wizards and code generators, successful database developers still require a sound knowledge of Structured Query Language (SQL, the standard language for communicating with most database systems). In this book, John and Mike do a marvelous job of making what's usually a dry and difficult subject come alive, presenting the material with humor in a logical manner, with plenty of relevant examples. I would say that this book should feature prominently in the collection on the bookshelf of all serious developers, except that I'm sure it'll get so much use that it won't spend much time on the shelf! -- Doug Steele, Microsoft Access Developer and author Over the last several decades, SQL has evolved from a language known only to computer specialists to a widely used international standard of the computer industry. The number of new applications deployed each year using SQL now totals in the millions. If you are accessing corporate information from the Internet or from an internal network, you are probably using SQL. This new edition of SQL Queries for Mere Mortals helps new users learn the foundations of SQL queries, and is an essential reference guide for intermediate and advanced users. The accompanying CD contains five sample databases used for the example queries throughout the book in four different formats: Microsoft SQL Server 2000 and later, Microsoft Access 2000 and later, MySQL version 5.0 and later, and SQL scripts that can be used with most other implementations of the language.

Table of Contents:
Foreword xvii Preface xix About the Authors xxi Introduction xxiii Are You a Mere Mortal? xxiii About This Book xxiv What This Book Is Not xxv How to Use This Book xxvi Reading the Diagrams Used in This Book xxvii Sample Databases Used in This Book xxx "Follow the Yellow Brick Road" xxxii Part I: Relational Databases and SQL 1 Chapter 1: What Is Relational? 3 Topics Covered in This Chapter 3 Types of Databases 3 A Brief History of the Relational Model 4 Anatomy of a Relational Database 6 What's in It for You? 15 Where Do You Go from Here? 16 Summary 17 Chapter 2: Ensuring Your Database Structure Is Sound 19 Topics Covered in This Chapter 19 Why Is This Chapter Here? 19 Why Worry about Sound Structures? 20 Fine-Tuning Fields 21 Fine-Tuning Tables 30 Establishing Solid Relationships 42 Is That All? 50 Summary 51 Chapter 3: A Concise History of SQL 53 Topics Covered in This Chapter 53 The Origins of SQL 54 Early Vendor Implementations 55 ". . . And Then There Was a Standard" 56 Evolution of the ANSI/ISO Standard 58 Commercial Implementations 64 What the Future Holds 65 Why Should You Learn SQL? 65 Summary 66 Part II: SQL Basics 69 Chapter 4: Creating a Simple Query 71 Topics Covered in This Chapter 71 Introducing SELECT 72 The SELECT Statement 73 A Quick Aside: Data versus Information 75 Translating Your Request into SQL 77 Eliminating Duplicate Rows 84 Sorting Information 87 Saving Your Work 92 Sample Statements 93 Summary 102 Problems for You to Solve 103 Chapter 5: Getting More Than Simple Columns 105 Topics Covered in This Chapter 105 What Is an Expression? 106 What Type of Data Are You Trying to Express? 107 Changing Data Types: The CAST Function 110 Specifying Explicit Values 112 Types of Expressions 117 Using Expressions in a SELECT Clause 128 That "Nothing" Value: Null 135 Sample Statements 139 Summary 147 Problems for You to Solve 149 Chapter 6: Filtering Your Data 151 Topics Covered in This Chapter 151 Refining What You See Using WHERE 151 Defining Search Conditions 156 Using Multiple Conditions 178 Nulls Revisited: A Cautionary Note 193 Expressing Conditions in Different Ways 197 Sample Statements 198 Summary 206 Problems for You to Solve 207 Part III: Working with Multiple Tables 211 Chapter 7: Thinking in Sets 213 Topics Covered in This Chapter 213 What Is a Set, Anyway? 214 Operations on Sets 215 Intersection 216 Difference 222 Union 228 SQL Set Operations 233 Summary 242 Chapter 8: INNER JOINs 243 Topics Covered in This Chapter 243 What Is a JOIN? 243 The INNER JOIN 244 Uses for INNER JOINs 262 Sample Statements 263 Summary 288 Problems for You to Solve 289 Chapter 9: OUTER JOINs 293 Topics Covered in This Chapter 293 What Is an OUTER JOIN? 293 The LEFT/RIGHT OUTER JOIN 295 The FULL OUTER JOIN 314 Uses for OUTER JOINs 318 Sample Statements 319 Summary 335 Problems for You to Solve 335 Chapter 10: UNIONs 339 Topics Covered in This Chapter 339 What Is a UNION? 339 Writing Requests with UNION 342 Uses for UNION 352 Sample Statements 353 Summary 365 Problems for You to Solve 366 Chapter 11: Subqueries 369 Topics Covered in This Chapter 369 What Is a Subquery? 370 Subqueries as Column Expressions 372 Subqueries as Filters 377 Uses for Subqueries 392 Sample Statements 394 Summary 409 Problems for You to Solve 410 Part IV: Summarizing and Grouping Data 413 Chapter 12: Simple Totals 415 Topics Covered in This Chapter 415 Aggregate Functions 416 Using Aggregate Functions in Filters 428 Sample Statements 431 Summary 438 Problems for You to Solve 439 Chapter 13: Grouping Data 441 Topics Covered in This Chapter 441 Why Group Data? 442 The GROUP BY Clause 444 "Some Restrictions Apply" 454 Uses for GROUP BY 458 Sample Statements 459 Summary 470 Problems for You to Solve 471 Chapter 14: Filtering Grouped Data 473 Topics Covered in This Chapter 473 A New Meaning of "Focus Groups" 474 When You Filter Makes a Difference 478 Uses for HAVING 486 Sample Statements 487 Summary 496 Problems for You to Solve 496 Part V: Modifying Sets of Data 499 Chapter 15: Updating Sets of Data 501 Topics Covered in This Chapter 501 What Is an UPDATE? 501 The UPDATE Statement 502 Uses for UPDATE 516 Sample Statements 517 Summary 533 Problems for You to Solve 534 Chapter 16: Inserting Sets of Data 537 Topics Covered in This Chapter 537 What Is an INSERT? 537 The INSERT Statement 539 Uses for INSERT 550 Sample Statements 552 Summary 562 Problems for You to Solve 563 Chapter 17: Deleting Sets of Data 567 Topics Covered in This Chapter 567 What Is a DELETE? 567 The DELETE Statement 568 Uses for DELETE 575 Sample Statements 576 Summary 583 Problems for You to Solve 584 In Closing 587 APPENDICES 589 Appendix A: SQL Standard Diagrams 591 Appendix B: Schema for the Sample Databases 60 Appendix C: Date and Time Functions 607 Appendix D: Suggested Reading 615 Index 617

About the Author :
John L. Viescas is an independent consultant with more than 40 years of experience. He began his career as a systems analyst, designing large database applications for IBM mainframe systems. He spent six years at Applied Data Research in Dallas, Texas, where he directed a staff of more than 30 people and was responsible for research, product development, and customer support of database products for IBM mainframe computers. While working at Applied Data Research, John completed a degree in business finance at the University of Texas at Dallas, graduating cum laude. John joined Tandem Computers, Inc., in 1988, where he was responsible for the development and implementation of database marketing programs in Tandem's U.S. Western Sales region. He developed and delivered technical seminars on Tandem's relational database management system, NonStop SQL, in a geographic area spanning Hawaii to Colorado and Alaska to Arizona. John wrote his first book, A Quick Reference Guide to SQL (Microsoft Press, 1989), as a research project to document the similarities in the syntax among the ANSI-86 SQL standard, IBM's DB2, Microsoft's SQL Server, Oracle Corporation's Oracle, and Tandem's NonStop SQL. He wrote the first edition of Running Microsoft Access (Microsoft Press, 1992) while on sabbatical from Tandem. He has since written four editions of Running, two editions of Microsoft Office Access Inside Out (Microsoft Press, 2004 and 2007--the successor to the Running series), and Building Microsoft Access Applications (Microsoft Press, 2005). John formed his own company in 1993. He provides information systems management consulting for a variety of small to large businesses around the world, with a specialty in the Microsoft Access and SQL Server database management products. He maintains offices in Nashua, New Hampshire, and Paris, France. He has been recognized as a "Most Valuable Professional" every year since 1993 by Microsoft Product Support Services for his assistance with technical questions on public support forums. You can visit John's Web site at www.viescas.com. Michael J. Hernandez is a veteran database developer with more than 20 years of experience developing applications for a wide variety of clients in diverse industries. Mike specializes in relational database design and is the author of the best-selling database design book Database Design for Mere Mortals, Second Edition (Addison-Wesley, 2004). He has worked with SQL throughout his career, developing applications using SQL-based databases such as Microsoft Access and Microsoft SQL Server. He has also been a contributing author and technical editor to various database-related books and periodicals. Mike became a full-time employee at Microsoft in 2002. He initially was the Community Program Manager for the Visual Studio Tools for Office (VSTO) Team, leading and managing the team's developer community engagement efforts. In 2006, Mike became the Product Manager for VSTO, becoming responsible for helping to guide the strategic future of the product and promoting VSTO to customers and developers via a variety of venues. As he has done so often throughout his career, Mike often speaks at developer events, conferences, and user group meetings across the nation and around the world. In a previous life, Mike had a career as a musician and performed for audiences far and wide. He attributes both his easygoing presentation style and his ability to connect with an audience to his days as a performer. Ever the musician, Mike formed a band from members of the VSTO team and gets to play his beloved guitar before new crowds and audiences. He still tinkers on his guitar quite a bit, stealing a few minutes here and there between meetings at work. Mike enjoys the little things in life, such as spending long hours at Barnes & Noble, sipping a tall Americano at Starbucks, puffing on a fine cigar, and riding his mountain bike along with his wife, Kendra.