public function count()
    {
        if ($this->_count !== null) {
            return $this->_count;
        }
        if ($this->_statement) {
            return $this->_count = $this->_statement->rowCount();
        }

        if ($this->_results instanceof SplFixedArray) {
            $this->_count = $this->_results->count();
        } else {
            $this->_count = count($this->_results);
        }

        return $this->_count;
    }