public function findMany($conditions = '', $params = array(), $orderBy = null, $limit = null, $offset = null){
        $cmd = $this->db->builder()->select()->from($this->table)->where($conditions, $params);
        if($orderBy){
            $cmd->orderBy($orderBy);
        }
        $rows = $cmd->limit($limit, $offset)->queryAll();
        if(false === $rows){
            return false;
        }
        else{
            return $this->mapModels($rows);
        }
    }