Designing and Constructing a Data Layer - Presented by Andy Kramek
It used to be the case that, when building an application, we simply used native VFP tables and rarely gave any thought to the possibility that we might have to access an external data source, let alone build an entire application that did not use Visual FoxPro as its primary data store. With the rapid growth in web-based applications, and the wider use of dedicated back end databases this is no longer the case. Even if the current plan for our application is to use only native VFP tables initially, there is no reason (or even tangible benefit) for ignoring the possibility that we might still have to migrate the application to use another data store (e.g. SQL Server) at some point in the future. It is an axiom that good application design is not dependent on the choice of any particular component and this includes the selected data store.
In this session Andy describes the design and implementation of a set of classes that can be used with any back end database that can handle an ODBC connection, and shows how a VFP application can be made truly "data store independent". These same classes can be compiled into a COM+ DLL that can either be accessed directly by a Web application, or be exposed as a web service. In either case the component returns the data as XML to the calling object.
Andy Kramek Bio
Andy is an independent consultant and long-standing FoxPro developer. After many years working in
He has spoken at User Groups and Conferences all over the world, recent conferences include Advisor DevCon (2001, 2002), GLGDW (Milwaukee 2000, 2001, 2002, 2003), Essential Fox (Kansas City, 2002, 2003, 2004), Southwest Fox (Tempe, 2004, 2005), European Devcon (Frankfurt 2001, 2002, 2003, 2005), CTTM( Amsterdam, 2000, 2002) and the Praha Devcon (Prague, 2002, 2005).
In addition to helping write white papers on Visual FoxPro 7.0 for Microsoft, he has been co-author of the monthly "Kitbox" column in FoxTalk Magazine, since April 1998 partnered, since December 2001 by his wife, Marcia Akins, and he now has more than 90 articles in that series to his credit. Book credits include "The Revolutionary Guide to Visual FoxPro OOP", Wrox Press, 1996 and, together with Marcia Akins and Rick Schummer, he co-wrote the very successful "1001 Things You Wanted to Know About VFP", Hentzenwerke Publishing, 2000 and “MegaFox: 1002 Things you Wanted to know about Extending VFP”, Hentzenwerke Publishing, 2002.