element user from other db

[hungmei]

Hi?
My joomla site's DB is Adb, and I create another connection Bdb.
Bdb is just for fabrik table, not a joomla site
When I create a form in joomla , and the table is at Bdb.

However, I use element user , can't get user's data, because of different db.
And my dropdown use eval populate to show options
How can I change to get user's data?
Thanks!!

$user = JFactory::getUser();
$groups = $user->get('groups');
$isAdmin = in_array(8, $groups);??//super users
$isus = in_array(11, $groups);

if ($isus || $isAdmin){
$opts[] = JHTML::_('select.option', 'us', 'us');
}