I'm having trouble understanding what to do for the modifying register review part of chapter 9 using mysql and PHP. It says you should you mysqli_query() to check if the user is entering a repeat email/account reg info but then it says this checks if it is safe to insert the reg info via the form. How are you supposed to enter 2 queries using the mysqli_query() function when that is not possible; I have read. Apparently you have to use multi queries which I cannot wrap my head around.
Any help on this subject would be much appreciated, thanks .