코드 : 

$mysqli = new mysqli("db_host", "db_user", "db_pass","db_name", 3306);

    $queries = "SELECT * FROM mytable; SELECT * FROM anothertable";

    if(mysqli_multi_query($mysqli, $queries)) {
        do {
            if($result = mysqli_store_result($mysqli)) {
                while($row = mysqli_fetch_row($result)) {
                    foreach($row as $key => $value) {
                        echo "$key => $value";        
                    }
                }
                mysqli_free_result($result);        
            }
            if(mysqli_more_results($mysqli)) {                
                echo "Next result set";
            }
        } while(mysqli_next_result($mysqli));
    }
    mysqli_close($mysqli);