Fatal error: Uncaught PDOException: SQLSTATE[HY000] [1049] Unknown database 'chat' in C:\xampp\htdocs\CHAT\classes\DB.php:25 Stack trace: #0 C:\xampp\htdocs\CHAT\classes\DB.php(25): PDO->__construct('mysql:host=127....', 'root', '') #1 C:\xampp\htdocs\CHAT\classes\DB.php(38): classes\DB->__construct() #2 C:\xampp\htdocs\CHAT\models\User.php(31): classes\DB::getInstance() #3 C:\xampp\htdocs\CHAT\core\init.php(61): models\User->__construct() #4 C:\xampp\htdocs\CHAT\index.php(5): require_once('C:\\xampp\\htdocs...') #5 {main} thrown in C:\xampp\htdocs\CHAT\classes\DB.php on line 25