怎么加一行求和
select c_id,sum(c_amount) from tb_o_sg
where c_datetime>='2011-7-27' and c_datetime<='2011-8-2' and c_amount>0
group by c_id having sum(c_amount)>0 and sum(c_amount)<25
order by sum(c_amount) asc
6009413 5.00
6009037 5.00
6009206 5.00
6009211 8.00
6009372 10.00
6009183 11.00
8006885 16.00
6009344 16.00
2009938 16.00
8007342 18.00
8007474 18.00
6009314 19.00
8006745 20.00
8007060 20.00
8006880 20.00
8007307 20.00
8006889 20.00
2009976 20.00
8007498 20.00
8007226 20.00
请问怎么在查询后的数据再加一行求和呢?