sto cercando di fare un sistema di login con PDO.
ho aggiunto questo metodo alla classe:
Codice PHP:
    public function login($user, $pass) {
        $pass = sha1($pass);
        $strQuery = "SELECT * FROM user WHERE username='" . $user . "' AND user_pass='" . $pass . "'";
        try {
            $query = $this->pdo->query($strQuery);
            if ($query->fetchColumn() == 1) {
                $_SESSION['login_eseguito'] = TRUE;
                $_SESSION['user_id'] = $result->user_id;
                return TRUE;
            } else {
                return FALSE;
            }
        } catch (PDOException $e) {
            print "Error!: " . $e->getMessage() . "
";
            die();
        }
    } 
questa la pagina di login:
Codice PHP:
<?php
session_start();
include_once 'config.php';
$obj = new Config();
if ($obj->verifica_sessione()) {
    header("location:index.php");
}
if ($_SERVER["REQUEST_METHOD"] == "POST") {
    $login = $obj->login(htmlentities($_POST['username'], ENT_QUOTES), htmlentities($_POST['password'], ENT_QUOTES));
    if ($login) {
        header("location:area_riservata.php");
    } else {
        echo 'I dati indicati non sono corretti.';
    }
}
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Login</title>
    </head>
    <body>
        <?php
        include_once 'menu.html';
        ?>
        <table>
            <form action="<?php echo $_SERVER['PHP_SELF']; ?>" method="POST">
                <tbody>
                    <tr>
                        <td>User:</td>
                        <td><input type="text" name="username" value="ogadmin" /></td>
                    </tr>
                    <tr>
                        <td>Password:</td>
                        <td><input type="password" name="password" value="ogferzap" /></td>
                    </tr>
                    <tr>
                        <td><input type="submit" value="Send" /></td>
                    </tr>
            </form>
        </table>
    </body>
</html>
quando do invio ottengo sempre questo errore:
Fatal error: Call to a member function fetchColumn() on a non-object in /web/htdocs/www.orangeneration.it/home/og/email/config.php on line 33
la riga 33 è quella dove inizia l'if:
if ($query->fetchColumn() == 1) {

qualche idea??