private function createMapping()
    {
        $columns = $this->pdoStatement->columnCount();
        if ($columns > 0) {
            $this->mapping = [];
            for ($i = 0; $i < $columns; $i++) {
                $meta = $this->pdoStatement->getColumnMeta($i);
                $this->mapping[$i] = [$meta['table'], $meta['name']];
            }
        }
    }