SQL'de sorun var. Lütfen düzgün bağladığına emin ol!
Warning: Undefined variable $db in C:\xampp\htdocs\index.php on line 11

Fatal error: Uncaught Error: Call to a member function prepare() on null in C:\xampp\htdocs\index.php:11 Stack trace: #0 {main} thrown in C:\xampp\htdocs\index.php on line 11