The open source ecommerce programs osCommerce and Zen Cart use such a database and (like most ecommerce solutions) you add, edit, delete, manage your products through an admin login of the ecommerce programs ( you do not use phpmyadmin).
Can I ask one silly question??
Why are you trying to re-invent the wheel
If I may make an un-solicited suggestion .... follow this link ... here`s a data base / shopping cart that has everything you are looking for.
Scroll to the bottom of the page and you`ll find exactly what you are looking for ... and its fully tested. It really does work .. and its ALL off-line ... just what you are looking for.