您的屏幕截图显示您的mysql服务器在端口3307上运行.默认情况下使用3306. 您需要替换此:

Your screenshot says your mysql server is running on port 3307. By default 3306 is used. You need to replace this :

$myConnection = mysqli_connect($hostname, $username, $password, $database) or die("Error " . mysqli_error($myConnection));

与此:

$myConnection = mysqli_connect($hostname, $username, $password, $database, 3307) or die("Error " . mysqli_error($myConnection));