How can I prevent database being written to again when the browser does a reload/back?

Question

I\'m putting together a small web app that writes to a database (Perl CGI & MySQL). The CGI script takes some info from a form and writes it to a database. I notice, h

Answer 1

If you aren't already using some sort of session-management (which would let you note and track form submissions), a simple solution would be to include some sort of unique identifier in the form (as a hidden element) that is either part of the main DB transaction itself, or tracked in a separate DB table. Then, when you are submitted a form you check the unique ID to see if it has already been processed. And each time the form itself is rendered, you just have to make sure you have a unique ID.