SQL Queries for Mere Mortals: A Hands-on Guide to Data Manipulation in SQL [For Mere Mortals Series]

John L. Viescas, Michael J. Hernandez0321444434, 9780321444431

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 ConsultantSQL 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 CommitteeI 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. Ihighly recommend this book if you want to tap the full potential of your database. – Kenneth D. Snell, Ph.D., Database Designer/ProgrammerI 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, MVPEven 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 authorOver 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.

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Table of contents :
SQL Queries for Mere Mortals, 2nd Edition……Page 1
Contents……Page 8
Foreword……Page 18
Preface……Page 20
About the Authors……Page 22
Are You a Mere Mortal?……Page 24
About This Book……Page 25
What This Book Is Not……Page 26
How to Use This Book……Page 27
Reading the Diagrams Used in This Book……Page 28
Sample Databases Used in This Book……Page 31
“Follow the Yellow Brick Road”……Page 33
PART I: Relational Databases and SQL……Page 36
Types of Databases……Page 38
A Brief History of the Relational Model……Page 39
Anatomy of a Relational Database……Page 41
What’s in It for You?……Page 50
Where Do You Go from Here?……Page 51
Summary……Page 52
Why Is This Chapter Here?……Page 54
Why Worry about Sound Structures?……Page 55
Fine-Tuning Fields……Page 56
Fine-Tuning Tables……Page 65
Establishing Solid Relationships……Page 77
Is That All?……Page 85
Summary……Page 86
Topics Covered in This Chapter……Page 88
The Origins of SQL……Page 89
Early Vendor Implementations……Page 90
“. . . And Then There Was a Standard”……Page 91
Evolution of the ANSI/ISO Standard……Page 93
Commercial Implementations……Page 99
Why Should You Learn SQL?……Page 100
Summary……Page 101
PART II: SQL Basics……Page 104
Topics Covered in This Chapter……Page 106
Introducing SELECT……Page 107
The SELECT Statement……Page 108
A Quick Aside: Data versus Information……Page 110
Translating Your Request into SQL……Page 112
Eliminating Duplicate Rows……Page 119
Sorting Information……Page 122
Saving Your Work……Page 127
Sample Statements……Page 128
Summary……Page 137
Problems for You to Solve……Page 138
Topics Covered in This Chapter……Page 140
What Is an Expression?……Page 141
What Type of Data Are You Trying to Express?……Page 142
Changing Data Types: The CAST Function……Page 145
Specifying Explicit Values……Page 147
Types of Expressions……Page 152
Using Expressions in a SELECT Clause……Page 163
That “Nothing” Value: Null……Page 170
Sample Statements……Page 174
Summary……Page 182
Problems for You to Solve……Page 184
Refining What You See Using WHERE……Page 186
Defining Search Conditions……Page 191
Using Multiple Conditions……Page 213
Nulls Revisited: A Cautionary Note……Page 228
Expressing Conditions in Different Ways……Page 232
Sample Statements……Page 233
Summary……Page 241
Problems for You to Solve……Page 242
PART III: Working with Multiple Tables……Page 246
Topics Covered in This Chapter……Page 248
What Is a Set, Anyway?……Page 249
Operations on Sets……Page 250
Intersection……Page 251
Difference……Page 257
Union……Page 263
SQL Set Operations……Page 268
Summary……Page 277
What Is a JOIN?……Page 278
The INNER JOIN……Page 279
Uses for INNER JOINs……Page 297
Sample Statements……Page 298
Summary……Page 323
Problems for You to Solve……Page 324
What Is an OUTER JOIN?……Page 328
The LEFT/RIGHT OUTER JOIN……Page 330
The FULL OUTER JOIN……Page 349
Uses for OUTER JOINs……Page 353
Sample Statements……Page 354
Problems for You to Solve……Page 370
What Is a UNION?……Page 374
Writing Requests with UNION……Page 377
Uses for UNION……Page 387
Sample Statements……Page 388
Summary……Page 400
Problems for You to Solve……Page 401
Topics Covered in This Chapter……Page 404
What Is a Subquery?……Page 405
Subqueries as Column Expressions……Page 407
Subqueries as Filters……Page 412
Uses for Subqueries……Page 427
Sample Statements……Page 429
Summary……Page 444
Problems for You to Solve……Page 445
PART IV: Summarizing and Grouping Data……Page 448
Topics Covered in This Chapter……Page 450
Aggregate Functions……Page 451
Using Aggregate Functions in Filters……Page 463
Sample Statements……Page 466
Summary……Page 473
Problems for You to Solve……Page 474
Topics Covered in This Chapter……Page 476
Why Group Data?……Page 477
The GROUP BY Clause……Page 479
“Some Restrictions Apply”……Page 489
Uses for GROUP BY……Page 493
Sample Statements……Page 494
Summary……Page 505
Problems for You to Solve……Page 506
Topics Covered in This Chapter……Page 508
A New Meaning of “Focus Groups”……Page 509
When You Filter Makes a Difference……Page 513
Uses for HAVING……Page 521
Sample Statements……Page 522
Problems for You to Solve……Page 531
PART V: Modifying Sets of Data……Page 534
What Is an UPDATE?……Page 536
The UPDATE Statement……Page 537
Uses for UPDATE……Page 551
Sample Statements……Page 552
Summary……Page 568
Problems for You to Solve……Page 569
What Is an INSERT?……Page 572
The INSERT Statement……Page 574
Uses for INSERT……Page 585
Sample Statements……Page 587
Summary……Page 597
Problems for You to Solve……Page 598
What Is a DELETE?……Page 602
The DELETE Statement……Page 603
Uses for DELETE……Page 610
Sample Statements……Page 611
Summary……Page 618
Problems for You to Solve……Page 619
In Closing……Page 622
APPENDICES……Page 624
A: SQL Standard Diagrams……Page 626
B: Schema for the Sample Databases……Page 636
C: Date and Time Functions……Page 642
D: Suggested Reading……Page 650
B……Page 652
C……Page 653
D……Page 654
E……Page 655
G……Page 656
I……Page 657
M……Page 658
N……Page 659
P……Page 660
R……Page 661
S……Page 662
T……Page 664
U……Page 665
X……Page 666