Introduction Of Vfp

Introduction Welcome to Using Visual FoxPro 6, Special Edition! This book is your guide to the exciting world of working with the latest release of Microsoft's award-winning database product, Visual FoxPro. Visual FoxPro has a long and illustrious history as the most flexible and powerful database application on the market. Starting from its origination as Fox Software's FoxBASE product, "Fox" (as it's known among its international community of developers) has always been known for its reliability, speed, and effectiveness as a programmer's database product. This book is designed to take you into the world of Visual FoxPro. Whether you're a beginner, intermediate, or advanced user, this book has what you need to strengthen and improve your development efforts.

What is Visual FoxPro? Don't laugh, it's not that silly a question. FoxPro has changed radically over the years. It's not a bad idea to take a little time and review how it has gotten where it is. This will give you additional perspective on the product you're now reading about. The History Back in the "old days" (the late 1980s), FoxBASE was intended to be a dBASE clone. If dBASE did it, FoxBASE would do it better and faster (or at least that was the idea). Although FoxBASE had some revolutionary features in it, it was not really intended to be revolutionary; it was designed to be better and faster and, above all, compatible with dBASE III.

FoxPro 1.0 was the first departure from the compatibility dance with dBASE. It began to introduce some new concepts in GUI design and ways of developing software that put it ahead of the by-then floundering dBASE. FoxPro really came into its own with version 2.0. When FoxPro 2.0 was introduced, several key technologies were included that revolutionized the PC database development market: •

•

•

The addition of Rushmore did the unthinkable. All of a sudden, tables with millions of records were not only possible but feasible in a PC database system without moving to other, more expensive, technologies. I distinctly recall Dr. David Fulton, the founder of Fox Software, demonstrating searches on a table with over a million records that completed in a fraction of a second. The crowd went wild, and a new era was born. SQL statements were another revolution introduced in version 2.0. For the first time, Fox developers were using single statements that replaced entire procedures. SQL was, and still is, the language of data. FoxPro 2.0 also introduced a somewhat WYSIWYG means of developing reports and screens with the addition of the Screen and Report Designers. The Screen Designer generated code, but definitely enabled a new and exciting way of developing GUIs in a text-based environment.

I could go on and on, but you get the idea. FoxPro 2.0 was the real advent of the exciting capabilities you have today in Visual FoxPro. GUI design services, SQL, and lightning-fast data access were its hallmarks.

Windows support was added in FoxPro 2.5. Support for Dynamic Data Exchange came along for the ride, but as anyone who was around in those days will testify, the Windows version of 2.5 had the look and feel of a DOS app made to look "windowsy." The next major revolution had to wait until the release of Visual FoxPro 3.0. Once again, FoxPro, now in the hands of Microsoft (which bought out Fox Software during the development of FoxPro for Windows), revolutionized the database development world. Version 3.0 added a host of long-awaited features and took the PC database development world by storm. Here are just a few of the features added in 3.0: •

•

•

The Database Container, also known as the DBC, added support for stored procedures, data rules bound to tables, and a host of additional data functions that Fox developers had been anticipating for years. Views, which are updatable SQL cursors, added a whole new method of accessing data for processing, GUI representation, and reporting. Two types of views were supported, local and remote views. A local view is a view based on Visual FoxPro tables. A remote view is a view based on any ODBC data source, including SQL Server, Oracle, Access-you name it. This revolutionary addition made Visual FoxPro the premier tool for accessing remote and local data. For all intents and purposes, creating enterprisewide applications and using data stored in remote data sources became almost as easy as using Visual FoxPro tables themselves. A full, robust implementation of object orientation turned the development paradigm on its ear. A robust object model and the

capability to create your own classes and subclasses created an entirely new way of developing software. Version 5.0 was an upgrade of 3.0 and contained a lot of bug fixes and some interesting new features. The capability to use and create COM servers (a topic covered in-depth in Part V of this book) was introduced. Some additional commands and functions were added and you saw the beginning of support for publishing Visual FoxPro on the Internet. But 5.0 was not a radical departure from 3.0.