About the Author... xiii Introduction... xiv Acknowledgments and Thanks... xv Terminology... xvii Sample Code... xvii

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1 About the Author... xiii Introduction... xiv Acknowledgments and Thanks... xv Terminology... xvii Sample Code... xvii Part I: Getting Started... 1 Chapter 1: Setup and Parts of the Environment... 3 Starting dbase Plus... 4 dquery the Startup Program... 5 Some Basic Setup... 5 The dbase Desktop The Title Bar The Menu Bar The Tool Bar The Navigator Window The Command Window The Status Bar Important Tools in dbase PLUS Speed Menus Getting Help Using the Knowledgebase Other Tools Summary Chapter 2: Items to Consider When Developing an Application Administrator Rights for an Administrator Account? The Environment The Development Environment The Deployment/Application s Environment Windows Folder Structures The Program and Other Files (CSIDL_PROGRAM_FILES) Shared Configuration and Non-Updateable Data Files (CSIDL_COMMON_APPDATA) Master Copies of Files Used by Each User (CSIDL_COMMON_APPDATA) Shared/Updatable Data Files (CSIDL_COMMON_APPDATA) Getting the Folders Set Up Referencing These Folders in Your Application INI File User BDE Aliases Windows Vista, Windows 7 and the UAC What Happens When a dbase Application Starts? What About Windows XP? Speaking of the BDE Code Signing Windows Registry Settings Installing Your Application Don t Wish To Use the UAC? Other Considerations Partitioning of Hard Drives iii

2 Data Execution Prevention (DEP)...30 Application Compatibility Toolkit (ACT)...31 Summary Part II: Data Chapter 3: Table Types Should I Change the Table Level? Terminology The dbf Field Types Field Properties...37 Null Values...38 Field Names...39 Table Language Drivers...40 Indexes...41 Using BLOB Fields...42 DBF Table Limits...43 Table Design Guidelines Identify the Type of Information You Need to Store...43 Break the Information Down...43 Determine the Relationships Among the Tables...44 Making it Possible to Upsize to Other Platforms Designing Your Tables and Application Appropriately...46 Summary Chapter 4: SQL - A Different Language What Is SQL and Why Is It Important? The SQL SELECT Statement Calculated Fields SQL Joins The WHERE Clause Read Only Queries Other Useful Local SQL Commands Creating a Table...56 Add/Remove Fields...57 Deleting a Table...57 Renaming a Table...57 Creating an Index Tag...57 Deleting an Index Tag...57 Adding Data to a Table...57 Update a Set of Data...57 Cleanup Summary Chapter 5: Working with Databases SQL and Local What Is SQL Data, versus dbase or Local Tables? Database Aliases...59 User BDE Aliases...60 Making the Connection Start the Data Engine...64 Create the Database Alias...64 Start dbase...66 Other Data Engines iv

3 v Table of Contents ODBC Drivers In General Creating a Database Alias for Local Tables Cleanup Summary Part III: Object Oriented Code and dbase Chapter 6: Introduction to Objects and dbase PLUS OOP Concepts and Terminology Working with Simple Objects Creating a Form Object Creating Objects On A Form Dot Notation Containership Understanding the Object Inspector Understanding Events Windows is Event-Driven What is Event-Driven Programming? dbase Events Using the dbase Form to See How This Works Event Handlers Assigning Event Handlers Working With Methods Codeblocks Expression Codeblocks Statement Codeblocks Using Codeblocks as Event Handlers Using Custom Properties and Methods The Object is Built From the Class Parts of a Class The Class Declaration Statement The Class Constructor Code Class Declaration of Methods The ENDCLASS Statement The classname and baseclassname Properties Working with Object Reference Variables The dbase Object Class Types of Classes Stock Classes User-created Custom Classes Building Custom Classes from Scratch General Syntax for Custom Classes Declaring Class Parameters Using Class Hierarchies Using the Scope Resolution Operator Overriding Methods and Events Object Containership The Keyword This The Keyword Form The Keyword CLASS Using Objects as Parameters

4 Making Objects Go Away Multiple References to the Same Object Multiple Instances of the Same Class Protecting Members of a Class Encapsulation Knowing What the Members of a Class Are Summary Chapter 7: Working with the Data Object Model (OODML) An Overview Creating and Coding Query Objects How Do I Use a Query? Query Objects and SQL Server Databases Rowset and Field Objects The Heart of the Data Object Structure Some Basic Information about Rowsets Rowset Events and Event Handlers Navigation in a Rowset Programmatically Stepping Through a Rowset Editing Data in a Rowset Deleting Rows Fields Array and Field Objects Field Class Looping Through All Fields in a Table Other Field Object Events, Methods, etc OLE, Binary and Memo Fields Creating and Coding Database Objects The Default Database Creating a Database Object Reference Table Maintenance Transaction Processing Using the Index Object(s) More on Expressions Creating and Coding Session Objects The Default Session Creating and Coding Stored Procedure Objects The TableDef Object List Field Information List Index Information The UpdateSet Object Summary Part IV: Data Objects and the Language Chapter 8: OODML, SQL, and XDML How to Do Things You May Have Done Before Finding Data Performing Lookups in Other Tables Shortening References Relating Tables Setting a Relationship between Parent and Child Tables Set Skip Referential Integrity Adding a Parent to Parent/Child Referential Integrity Cascading Deletes vi

5 vii Table of Contents Referential Integrity Cascading Updates Child Table Sorted Differently? Other Parent/Child Concerns Calculated Fields Morphing Data Record Numbers? More on Data Object Events Query Object - canopen() Rowset Object onappend() Rowset Object cansave() UpdateSet Copying a Table or Rowset Using copy() with Calculated Fields Appending Rows From Another Table Updating Rows From Another Rowset Updating Rows and Adding NEW Rows Deleting Rows Summary Chapter 9: Creating and Working With Datamodules What Is a Datamodule, and Why Should You Care? Starting dquery Using dquery to Create and Modify Datamodules Opening an Existing Datamodule Examining the Source Code Filtering Data with Conditional Statements Adding Calculated Fields A More Complex Calculated Field? Using Multiple-Table Queries Understanding Relationships among Different Tables Using Multiple Database Queries Cleanup Summary Chapter 10: Working in a Shared Environment Programming for a Shared Environment Opening a Table for Exclusive Use Opening a Table for Read-Only (RO) Access Locking Data Implicit Locks Explicit Locks Control of Locked Rows Using the Session Object to Modify Lock Behavior Locking the Rowset The _DBASELOCK Field Maximum Locks Using Session Objects Session Objects and User BDE Aliases Adding a Session Object in the Form Designer Adding a Session Object to a DataModule The Session Object and Encrypted Tables Temporary Database?

6 Locking Related Tables Processing Transactions Drawbacks to Using Transactions CacheUpdates Using UNC Paths on a Network Working with Non-dBASE Tables Transaction Processing Issues When Deploying an Application Summary Chapter 11: Security The PROTECT Command SET ENCRYPTION LOGOUT Security and Paradox Tables Security and SQL Server Tables The Session Object The Database Object Application Security Summary Part V: Designing the User Interface Chapter 12: Working With the Designers A Warning The Form Designer Form Designer Properties The Menu Designer The Report/Label Designer The Table Designer The SQL Designer The Data Module Designer Designer Common Tools The Inspector The Component Palette The Field Palette The Format Toolbar Summary Chapter 13: Creating Forms What is a Form? Design Concepts Types of Forms Creating a Form Form Metrics Add a Text Control Saving the Form Modifying Properties of the Text Control Add a Pushbutton Run the Form Add an Event Handler Modifying.WFM files viii

7 Two-Way Tools OODML and Forms Put Some Fields on the Form Interacting With the Data Putting Buttons on the Form Form Cosmetics Multi-Page Forms Changing Pages Using a TabBox Control Changing Pages Using PushButtons Potential Problems Running Forms Communicating Between Forms Passing Data to and Returning Data from a Dialog Form It Is Important That You Understand What Can This Be Used For? Naming Your Controls Tab Order of Controls Some Notes on Tab Order Adding Help to Your Forms Windows Form Control Appearance Forms and User BDE Aliases Before Moving On To A New Chapter Summary Chapter 14: Stock Form Controls Windows Themes and Other Changes Exercises Common Properties, Events and Methods A Brief Overview of the Stock User-Interface Controls Text TextLabel Entryfield Spinbox Checkbox Radiobutton Container Notebook Editor Combobox Listbox Grid Getting Started With a Grid Tabbox Pushbutton Windows XP and Later Versions, Themes, and Pushbuttons Line Rectangle Image Shape TreeView and TreeItem ix

8 Progress Slider ActiveX ReportViewer SubForm Other Controls Paintbox Scrollbars OLE Browse Summary Chapter 15: Working With the Grid Getting Started The Columns Array The Column s editortype Property Use of the Mouse with the Grid Editable or Not? Editable Grids Non-Editable Grids Display Issues Fonts Colors Other Grid Appearance Properties Row Height Issues Changing the Appearance of Individual Columns Enhancing the Grid s Abilities Multiselect Grids Changing Rowset Sort Order Conditional Colors of Cells and Rows The Grid s rowselect and multiselect Properties and Colored Cells Coloring a Whole Row Saving and Restoring Column Positions Multi-User? Saving/Restoring More Properties Than Shown Here Using Multi Table Rowsets Building a Grid on the Fly Restating Datalinks Cleanup Summary Chapter 16: Common Properties and Event Handlers of Form Controls Common Properties Formatting Data Picture and Function The enabled Property and the when() Event Common Events Event Sequences The key() Event The onkey() Event The onchange() Event Using the onlostfocus() Event to Force Navigation and/or Validation The onmouseover() and onmouseout() Events x

9 Data Validation Table Designer/Field Level Validation Control Level Validation Form Level Validation Record Level Validation Drag and Drop What Else Can Be Done? Summary Chapter 17: Custom Forms and Custom Form Classes Source Code Aliases vs. Database Aliases, and Why They Are Important How to Create a Source Code Alias Using Custom Forms Why Work With Custom Form Classes? Changing Built-in Default Property Values Creating New (Custom) Properties for Custom Form Classes Assigning Default Actions to Event Handlers Creating Methods for a Custom Class Define Default Controls for a Form The Complete Custom Form Class Clearing Out the Custom Form Class Back to Using Custom Forms A Data Custom Form Placing Custom Forms in Source Alias Folder Using the Data Custom Form Creating Classes for Control Objects Why Create Your Own Custom Classes? Methods of Creating and Modifying Custom Classes Creating a Custom TextLabel Class Creating a Custom Entryfield Class Creating a Custom Spinbox Class Creating a Custom Editor Class Creating a Custom Image Class Cleaning up the Custom Class Code Putting These Custom Classes to Work Creating a Custom Pushbutton Class Putting the Custom Pushbutton Classes to Work Modifying the Base Pushbutton Class Using Your Custom Classes for New Forms Summary Chapter 18: Using the Custom Classes that Ship with dbase Custom Pushbuttons Custom Controls on the Form Controls Tab Seeker Splitter Animate Calendar Form Viewer Summary Index xi