In the near future, I’m going to be making a small website for a tea shop, and they’ll be offering 50-100 items available for purchase online. I’ll have to take care of the transactions, but also update inventory and whatnot in a database (MySQL). After I thought about this for a while, I was a little confused as to how to go about doing this. If I use PayPal or something similar (I don’t have experience with any of them), doesn’t it typically take the user out of the site? And if it does, how would I go about making adjustments to the database, since it would need to go through PayPal before knowing if the adjustment should be made?