session_start();
$userID = '9'; //user
$online = 'yes';
$time_check = $online-10; //We Have Set Time 1 Minutes


$sql="SELECT * FROM user WHERE userID='$userID'"; $result=mysql_query($sql);
$count=mysql_num_rows($result);

//If count is 0 , then enter the values
if($count=="no"){
    $sql="INSERT INTO user(userID, online)VALUES('$userID', '$online')";
    $result=mysql_query($sql);
}

// else update the values
else {
    $sql="UPDATE user SET online='$online' WHERE userID = '$userID'";
    $result=mysql_query($sql);
}

session_start();
$userID = '9'; //user
$online = 'yes';
$time_check = $online-10; //We Have Set Time 1 Minutes

$sql=""; $result=mysql_query($sql);
$count=mysql_num_rows($result);

$count = $pdo->query("SELECT * FROM user WHERE userID = $userID")->fetchColumn();

//If count is 0 , then enter the values
// !!!!! MIRA A VER SI EL COUNT TIENE QUE DECIR NO O TIENE QUE DECIR 0 PORQUE TU COMENTARIO DICE UNA COSA Y PONES OTRA
if($count=="no") {
    $stmt = $pdo->prepare("INSERT INTO user(userID, online) VALUES ($userID, $online)");
    $stmt->execute();
}

// else update the values
else {
    $stmt = $pdo->prepare("UPDATE user SET online = $online WHERE userID = $userID");
    $stmt->execute();
}

$host = '127.0.0.1';
$db   = 'test';
$user = 'root';
$pass = '';
$charset = 'utf8';

$dsn = "mysql:host=$host;dbname=$db;charset=$charset";
$opt = [
    PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
    PDO::ATTR_EMULATE_PREPARES   => false,
];
$pdo = new PDO($dsn, $user, $pass, $opt);