Alex Feldstein

Alex Feldstein

Alex has been programming database systems since 1985. He has used all versions of dBase and FoxPro in DOS, UNIX and Windows systems. Alex has been awarded Most Valuable Professional (MVP) status by Microsoft for Visual FoxPro for 2001/2002 for his constant help to the developer community in online forums and specifically Spanish language newsgroups. Alex is fluent in English, Spanish and Portuguese.
You can reach Alex at:
alex@feldstein.net

You can download the source code for this article from
http://www.feldstein.net/supermarketcode.zip

Articles Authored

  • Embedded Visual Basic and your Pocket PC

    Last updated: Friday, December 5, 2025

    Published in: CODE Magazine: 2002 - July/August

    In this article, Alex Feldstein explores the development of custom database applications for Pocket PC devices using Microsoft’s eMbedded Visual Basic (eVB) and the eMbedded Visual Tools Development Kit. He guides readers through setting up the development environment, connecting to the device, and building a sample supermarket inventory application with Pocket Access and ADOCE. Feldstein highlights key differences between ADOCE and standard ADO, discusses data type conversions, and covers practical coding examples for creating, adding, viewing, and deleting records. The article emphasizes the potential of Pocket PC programming for mobile, data-driven solutions.

  • Understanding the Crypto API

    Last updated: Sunday, December 7, 2025

    Published in: CODE Magazine: 2002 - March/April

    In this article, Alex Feldstein explains the fundamentals of cryptography and demonstrates how developers can leverage the Windows CryptoAPI to add robust security to their applications without deep cryptographic expertise. Feldstein outlines key concepts such as symmetric and public-key cryptography, hash functions, and digital signatures, and emphasizes practical implementation using a COM wrapper class to simplify CryptoAPI usage. By providing sample code in Visual FoxPro and VBA, he shows how to encrypt and decrypt data efficiently, making industrial-strength encryption accessible for securing sensitive information in software projects.