Fatal error: Uncaught TypeError: mysqli_select_db(): Argument #1 ($mysql) must be of type mysqli, string given in D:\web\school\interactive\Connections\DB.php:54 Stack trace: #0 D:\web\school\interactive\Connections\DB.php(54): mysqli_select_db('school', Object(mysqli)) #1 D:\web\school\interactive\Connections\DB.php(24): DB->connect('localhost', 'root', '%j4f0k0*', 'school', 1) #2 D:\web\school\interactive\gallery.php(11): DB->__construct() #3 {main} thrown in D:\web\school\interactive\Connections\DB.php on line 54