Fatal error: Call to a member function prepare() on null in

[degadea]

Prova a connetterti a database on questo codice

$servername = "127.0.0.1";
$username = "root";
$password = "root";
$db_name = "nome_databse";

// mi connetto al server database
$conn = mysqli_connect($servername, $username, $password, $db_name);

// controllo connessione
if (!$conn) {
    die("Connessione al Database PhpMyAdmin fallita.<br>Codice errore: " . mysqli_connect_error());
}