How do I use Paypal on my website with PHP and MySQL?

I'm develo开发者_如何学Cping a website with PHP and MySQL. How can I make it so that if you click the Paypal button and pay successfully it will change a string in the database from "Personal" to "Professional"?

Assuming you're talking about PayPal Website Payments Standard (if you're not paying a monthly fee, you are), then you need to use Instant Payment Notification. You can either enable it account-wide from the profile tab of your account, or per payment button/link by setting the notify_url parameter.

PayPal will send an HTTP POST to your notify URL when a payment is completed. Your script at that URL should verify that the POST is authentic, then update the appropriate row in the database now that you know it's paid for.