PHP - MySQL

/// connect.php ///

<?php

// Credentials
$mysql_host = 'localhost';
$mysql_user = 'root';
$mysql_pass = '';

//Database to use
$mysql_db = 'a_database';

//Errors
$conn_error = 'Couldn\'t connect to mysql.';
$db_conn_error = "Couldn't connect to '$mysql_db'";


$connection = @mysqli_connect($mysql_host, $mysql_user, $mysql_pass) or die($conn_error);
// echo 'Connected to mysql<br>';

@mysqli_select_db($connection, $mysql_db) or die($db_conn_error);
// echo 'Connected to db';

?>

/// index.php ///

<?php
require 'connect.php';

$query = "SELECT food, calories FROM `food`; ";

if($result = $connection->query($query)) {
    echo 'Query success';

    foreach ($result as $result_row) {
        $food = $result_row['food'];
        $calories = $result_row['calories'];

        echo $food.' has '.$calories.' calories ';
    }

} else {
    echo 'Query failed';
}

?>