php - Last login of user not updated in database -

i inserted last_login field inside user table , put $update query in dologin.php not update timestamp in database when user logs in. there missing?

        $update = "update `user` set last_login = now()  id='user_id'";         $row = mysqli_fetch_array($result);         $_session['user_id'] = $row['id'];         $_session['username'] = $row['user_name'];         $_session['email'] = $row['email_address'];         $_session['gender'] = $row['gender_id'];         $_session['role_id'] = $row['role_id'];         $msg1 = $_session['username'];         $msg2 = "gender: " . $_session['gender'] . "<br/>";         $msg3 = "email: " . $_session['email'] . "<br/>";         $msg .= "you logged in " . $_session['role_type'] . "<br/>"; 

see added mysqli_query($update); next query

         $update = "update `user` set last_login = now()  id='user_id'";         mysqli_query($update);         $row = mysqli_fetch_array($result);         $_session['user_id'] = $row['id'];         $_session['username'] = $row['user_name'];         $_session['email'] = $row['email_address'];         $_session['gender'] = $row['gender_id'];         $_session['role_id'] = $row['role_id'];         $msg1 = $_session['username'];         $msg2 = "gender: " . $_session['gender'] . "<br/>";         $msg3 = "email: " . $_session['email'] . "<br/>";         $msg .= "you logged in " . $_session['role_type'] . "<br/>";