Which database? MySQL or SQLServer? I don't know if MySQL provides a way for VB applications to write to the database. I know that SQLServer does.PHP is not involved in the data acquisition process at all, if I understand you correctly.PHP is involved in the data display process, but that is a completely separate issue. Making PHP get data from a SQLServer instance might be an interesting challenge.
ODBC - Open DataBase Connectivity - http://en.wikipedia.org/wiki/ODBC
Can you teach me about to connect VB6 to database with use ODBC??
Google will give you a hundred sites explaining how to use ODBC and VB6.