select distinct Merchants_xingzhi,Merchants_id from Merchants order by Merchants_xingzhi
=======================
这说明你Merchants_id对应Merchants_xingzhi不唯一啊!!
表设计或数据有问题!!
select Merchants_xingzhi ,Merchants_id
from
(select *,row_number()over(partition by Merchants_xingzhi order by Merchants_xingzhi) as cnt
from table) A
where cnt =1