Zend_Auth: Join Query Issue

Question

I'm a new guy for zendframework. i am facing zend auth join query issue..

Here I attach my zend_auth login sample code. My login information's are stored in two tables. I mean email address in separate table and password separate. Here I was try to join my table, but I am getting Following error...

Message: The supplied parameters to Zend_Auth_Adapter_DbTable failed to produce a valid sql statement, please check table and column names for validity.

Please advise me.

My code is here...

$authAdapter = new Zend_Auth_Adapter_DbTable(Zend_Db_Table::getDefaultAdapter());
$authAdapter->setTableName(array('users','details'))
         ->setIdentityColumn('name')
         ->setCredentialColumn('pwd');

$name = 'test';
$pwd = '123';

$authAdapter->setIdentity($name)
    ->setCredential($pwd);


$select = $authAdapter->getDbSelect();

$select->where('pwd = 123')
    ->joinLeft( array('d' => 'details'),'d.id = users.id');


$auth = Zend_Auth::getInstance();
$result = $auth->authenticate($authAdapter);