How to prevent duplicate Usernames in php/mysql

Question

(This is my first try with php)

I have a very basic register page. http://graves-incorporated.com/test_sites/member_test/register/register.php

* I j

Answer 1

Which DB driver are you using? Are you looking for DB errors? Some of them just happily sail past any DB errors and you have to call a function specifically to check for DB errors. your DB should throw an error on duplicate data, and you can pick that error up and alert the user.