<?php
$link = mysqli_connect("localhost", "my_user", "my_password");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* print protocol version */
printf("Protocol version: %d\n", mysqli_get_proto_info($link));
/* close connection */
mysqli_close($link);
?>