The #1 Easy, Commonsense Guide to Database Design—Now Updated Foreword by Michelle Poolet, Mount Vernon Data Systems LLC Database Design for Mere Mortals has earned worldwide respect as the simplest way to learn relational database design. Now, this hands-on, software independent tutorial is even clearer and easier to use. Step by step, this new 25th Anniversary Edition shows you how to design modern databases that are soundly structured, reliable, and flexible, even in the latest online applications. Michael Hernandez guides you through everything from planning to defining tables, fields, keys, table relationships, business rules, and views. You will learn practical ways to improve data integrity, how to avoid common mistakes, and when to break the rules. Updated review questions and figures help you learn these techniques more easily and effectively. Understand database types, models, and design terminology Perform interviews to efficiently capture requirements—even if everyone works remotely Set clear design objectives and transform them into effective designs Analyze a current database so you can identify ways to improve it Establish table structures and relationships, assign primary keys, set field specifications, and set up views Ensure the correct level of data integrity for each database Identify and establish business rules Preview and prepare for the future of relational databases Whatever relational database systems you use, Hernandez will help you design databases that are robust and trustworthy. Never designed a database before? Settling for inadequate generic designs? Running existing databases that need improvement? Start here.

Table of Contents:
Foreword     xix Preface     xxi Introduction xxix What's New in the Fourth Edition     xxxi Who Should Read This Book     xxxii The Purpose of This Book     xxxiii How to Read This Book     xxxvi How This Book Is Organized     xxxvii A Word about the Examples and Techniques in This Book     xl PART I:  RELATIONAL DATA BASE DESIGN     1 Chapter 1:  The Relational Database     3 Topics Covered in This Chapter     3 What Is a Database?     3 The Relational Database     5     Retrieving Data     7     Advantages of a Relational Database     9     Relational Database Management Systems     10 What's Next?     11 Summary     13 Review Questions     14 Chapter 2:  Design Objectives     17 Topics Covered in This Chapter     17 Why Should You Be Concerned with Database Design?     17 The Importance of Theory     19 The Advantage of Learning a Good Design Methodology     21 Objectives of Good Design     22 Benefits of Good Design     23 Database-Design Methods     24     Traditional Design Methods     24     The Design Method Presented in This Book     26 Normalization     27 Summary     30 Review Questions     31 Chapter 3:  Terminology     33 Topics Covered in This Chapter     33 Why This Terminology Is Important     33 Value-Related Terms     35     Data     35     Information     35     Null     37     The Value of Null     38     The Problem with Null     39 Structure-Related Terms     41     Table     41     Field     44     Record     45     View     46     Keys     48     Index     50 Relationship-Related Terms     50     Relationships     50     Types of Relationships     52     Types of Participation     57     Degree of Participation     57 Integrity-Related Terms     59     Field Specification     59     Data Integrity     59 Summary     61 Review Questions     62 PART II:  THE DESIGN PROCESS     65 Chapter 4:  Conceptual Overview     67 Topics Covered in This Chapter     67 The Importance of Completing the Design Process     68 Defining a Mission Statement and Mission Objectives     69 Analyzing the Current Database     70 Creating the Data Structures     72 Determining and Establishing Table Relationships     73 Determining and Defining Business Rules     74 Determining and Defining Views     75 Reviewing Data Integrity     75 Summary     77 Review Questions     78 Chapter 5:  Starting the Process     81 Topics Covered in This Chapter     81 Conducting Interviews     82     Participant Guidelines     84     Interviewer Guidelines (These Are for You)     86 Defining the Mission Statement     91     The Well-Written Mission Statement     91     Composing a Mission Statement     93 Defining the Mission Objectives     96     Well-Written Mission Objectives     97     Composing Mission Objectives     99 Summary     103 Review Questions     104 Chapter 6:  Analyzing the Current Database     107 Topics Covered in This Chapter     107 Getting to Know the Current Database     107     Paper-Based Databases     111     Legacy Databases     111 Conducting the Analysis     113 Looking at How Data Is Collected     113 Looking at How Information Is Presented     116 Conducting Interviews     120     Basic Interview Techniques     121     Before You Begin the Interview Process     128 Interviewing Users     128     Reviewing Data Type and Usage     129     Reviewing the Samples     131     Reviewing Information Requirements     135 Interviewing Management     143     Reviewing Current Information Requirements     144     Reviewing Additional Information Requirements     145     Reviewing Future Information Requirements     146     Reviewing Overall Information Requirements     147 Compiling a Complete List of Fields     148     The Preliminary Field List     148     The Calculated Field List     156     Reviewing Both Lists with Users and Management     156 Summary     162 Review Questions     164 Chapter 7:  Establishing Table Structures     165 Topics Covered in This Chapter     165 Defining the Preliminary Table List     166     Identifying Implied Subjects     166     Using the List of Subjects     168     Using the Mission Objectives     172 Defining the Final Table List     174     Refining the Table Names     176     Indicating the Table Types     182     Composing the Table Descriptions     182 Associating Fields with Each Table     189 Refining the Fields     191     Improving the Field Names     191     Using an Ideal Field to Resolve Anomalies     196     Resolving Multipart Fields     199     Resolving Multivalued Fields     201 Refining the Table Structures     208     A Word about Redundant Data and Duplicate Fields     208     Using an Ideal Table to Refine Table Structures     209     Establishing Subset Tables     216 Summary     229 Review Questions     231 Chapter 8:  Keys     233 Topics Covered in This Chapter     233 Why Keys Are Important     234 Establishing Keys for Each Table     234     Candidate Keys     235     Primary Keys     243     Alternate Keys     249     Non-keys     250 Table-Level Integrity     251 Reviewing the Initial Table Structures     251 Summary     259 Review Questions     260 Chapter 9:  Field Specifications     263 Topics Covered in This Chapter     263 Why Field Specifications Are Important     264 Field-Level Integrity     266 Anatomy of a Field Specification     267     General Elements     267     Physical Elements     275     Logical Elements     278 Using Unique, Generic, and Replica Field Specifications     283 Defining Field Specifications for Each Field in the Database     287 Summary     291 Review Questions     292 Chapter 10:  Table Relationships     293 Topics Covered in This Chapter     293 Why Relationships Are Important     294 Types of Relationships     295     One-to-One Relationships     296     One-to-Many Relationships     298     Many-to-Many Relationships     301     Self-Referencing Relationships     308 Identifying Existing Relationships     312 Establishing Each Relationship     323     One-to-One and One-to-Many Relationships     323     The Many-to-Many Relationship     331     Self-Referencing Relationships     337     Reviewing the Structure of Each Table     342 Refining All Foreign Keys     343     Elements of a Foreign Key     343 Establishing Relationship Characteristics     349     Defining a Deletion Rule for Each Relationship     349     Identifying the Type of Participation for Each Table     354     Identifying the Degree of Participation for Each Table     357     Verifying Table Relationships with Users and Management     360     A Final Note     360 Relationship-Level Integrity     361 Summary     366 Review Questions     368 Chapter 11:  Business Rules     369 Topics Covered in This Chapter     369 What Are Business Rules?     370     Types of Business Rules     373 Categories of Business Rules     375     Field-Specific Business Rules     375     Relationship-Specific Business Rules     376 Defining and Establishing Business Rules     378     Working with Users and Management     378     Defining and Establishing Field-Specific Business Rules     379     Defining and Establishing Relationship-Specific Business Rules     386 Validation Tables     394     What Are Validation Tables?     394     Using Validation Tables to Support Business Rules     395 Reviewing the Business Rule Specifications Sheets     400 Summary     408 Review Questions     409 Chapter 12:  Views     411 Topics Covered in This Chapter     411 What Are Views?     411 Anatomy of a View     413     Data View     413     Aggregate View     418     Validation View     422 Determining and Defining Views     424     Working with Users and Management     425     Defining Views     426     Reviewing the Documentation for Each View     434 Summary     441 Review Questions     442 Chapter 13:  Reviewing Data Integrity     445 Topics Covered in This Chapter     445 Why You Should Review Data Integrity     446 Reviewing and Refining Data Integrity     446     Table-Level Integrity     447     Field-Level Integrity     447     Relationship-Level Integrity     448     Business Rules     448     Views     448 Assembling the Database Documentation     449 Done at Last!     451 Summary     452 PART III:  OTHER DATA BASE DESIGN ISSUES     453 Chapter 14:  Bad Design—What Not to Do     455 Topics Covered in This Chapter     455 “Flat-File” Design     456 Spreadsheet Design     457     Dealing with the Spreadsheet View Mindset     459 Database Design Based on the Database Software     461 A Final Thought     463 Summary     463 Chapter 15:  Bending or Breaking the Rules     465 Topics Covered in This Chapter     465 When May You Bend or Break the Rules?     465     Designing an Analytical Database     465     Improving Processing Performance     466 Documenting Your Actions     469 Summary     471 Chapter 16:  In Closing     473 PART IV:  APPENDIXES     475 Appendix A:  Answers to Review Questions     477 Appendix B:  Diagram of the Database Design Process     501 Appendix C:  Design Guidelines     519 Appendix D:  Documentation Forms     529 Appendix E:  Database-Design Diagram Symbols     533 Appendix F:  Sample Designs     535 Appendix G:  On Normalization     541 Appendix H:  Recommended Reading     551 Glossary     553 References     567 Index     569