public function getModifyColumnDDL(PropelColumnDiff $columnDiff)
    {
        $toColumn = $columnDiff->getToColumn();
        $pattern = "
ALTER TABLE %s MODIFY %s;
";

        return sprintf($pattern,
            $this->quoteIdentifier($toColumn->getTable()->getName()),
            $this->getColumnDDL($toColumn)
        );
    }