PDO获取user_id

Question

Okey, i have some trouble with my Login code..All work's great ,but when i try to get the row from my secound user ,it show me the row from the first user (i mean the information about the username,password,email,...).

public function login($username, $password){
    global $pdo;

    $query = $pdo->prepare("SELECT * FROM users WHERE username = ? AND password = ?");
    $query->bindValue(1, $username);
    $query->bindValue(2, $password);

    $query->execute();

    $result = $query->rowCount();

    if($result === 1){
    return true;

    } else {
    return false;
     }     
  }

I can't use mysql_result,but how i can get it like this ?

 function user_id_from_username($username){
  return mysql_result(mysql_query("SELECT user_id FROM users WHERE username = $username"), 0, 'user_id');   
}

function login($username, $password){
  $user_id = user_id_from_username($username);

  return (mysql_result(mysql_query("SELECT COUNT(user_id) FROM users WHERE username = $username AND password = $password "),0) == 1)? $user_id : false;
}

Sorry for my englsih ^^

Answer 1

public function login($username, $password){
    global $pdo;

    $query = $pdo->prepare("SELECT id FROM users WHERE username = ? AND password = ?");
    $query->execute(array($username, $password));
    return $query->fetchColumn();
}