zend framework select where not working

[thepreacher]

I have the following that is to fetch only records that have the field "loan_cycle_number" = 0; yet it still fetches all the records. I have googled all I can and still no solution found:

        
        $groups = new Application_Model_GroupsMapper();
        $db = $groups->getDbTable()->select();
        $select->where('loan_cycle_number = ?', 0);

        $rows = $groups->fetchAll($select);

the getDbTable method is like so

    public function getDbTable()
    {
        if (null === $this->_dbTable) {
            $this->setDbTable('Application_Model_DbTable_Groups');
        }
        return $this->_dbTable;
    }

Thanks