error in databse connection

Question

<?php

$servername = "localhost";

$username = "madhuri_abc";

$password = "happy123";

$dbname = "madhuri_789";

// Create connection

$conn = new mysqli($servername, $username, $password, $dbname);

// Check connection

if ($conn->connect_error) {

die("Connection failed: " . $conn->connect_error);

}

?>

this is my code it was workin in local host but not working in real time . Guys pls hepl me im begineer in php