S'il vous plait j'arrive pas a se connecter a MySQL Databases

<?php
$mysqli = new mysqli();
$mysqli->connect('Hostname', 'DBusername', 'DBpassword', 'DBname');

//Hostname - normaly localhost 
//DBusername - your mysql username 
//DBpassword - your mysql password 
//DBname - your mysql database name 


if ($mysqli->connect_errno) { echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error; } 

?>

$mysqli= new mysqli('Hostname', 'DBusername', 'DBpassword', 'DBname');
 
if($mysqli->connect_errno > 0){
    die('Failed to connect to MySQL: [' . $mysqli->connect_error . ']');
}