private function updateBoundColumns(array $row)
    {
        foreach ($this->columnBinding as $column => &$metadata) {
            $index = $this->collection->getColumnIndex($column);
            if ($index === null) {
                // todo: I would like to throw an exception and tell someone they screwed up
                // but i think that would violate the PDO api
                continue;
            }

            // Update by reference
            $value           = $this->typedValue($row[$index], $metadata['type']);
            $metadata['ref'] = $value;
        }
    }