<?php
$mysqli = new mysqli("localhost", "my_user", "my_password");

/* Vérification de la connexion */
if (mysqli_connect_errno()) {
    printf("Echec de la connexion : %s\n", mysqli_connect_error());
    exit();
}

/* Affichage de la version du protocole */
printf("Version du protocole : %d\n", $mysqli->protocol_version);

/* Fermeture de la connexion */
$mysqli->close();
?>

<?php
$link = mysqli_connect("localhost", "my_user", "my_password");

/* Vérification de la connexion */
if (mysqli_connect_errno()) {
    printf("Echec de la connexion : %s\n", mysqli_connect_error());
    exit();
}

/* Affichage de la version du protocole */
printf("Version du protocole : %d\n", mysqli_get_proto_info($link));

/* Fermeture de la connexion */
mysqli_close($link);
?>