Recent studies under the paypal payment.
Paypal test site because of the recent update, once the tutorials are not very accurate.
Simply put on three steps:
1, officially registered paypal account. https://www.paypal.com/c2/webapps/mpp/merchant
2, with the official account login test environment. https://developer.paypal.com/
After login. In application-> sandbox accounts-> create account, you can add two test accounts, one is buyer, is a business.
3, log test account. The ability to view account information. https://www.sandbox.paypal.com/c2/webapps/mpp/home
Also, what are the interfaces need to be able to refer to the official documentation.
The main transaction process is, send the form (including parameters) to paypal. Jump to paypal payment, and then specify the success URL immediate payment.
paypal will ask the IPN's URL. Then the database can handle.