既想聚合count(1) over(partition by a

select

  concat(act_dep_city,'_',act_arr_city) as key,

  concat(round(cast(city_line_num as float)/cast(city_all_num as float)*100,1),'%','-',rn) as value

from(

  select

      act_dep_city,

      act_arr_city,

      city_all_num,

      count(1) as city_line_num,

      row_number() over(partition by act_arr_city order by count(1) desc) as rn

  from(

      select

        act_dep_city,

        act_arr_city,

        count(1) over(partition by act_arr_city) as city_all_num

      from

        f_wide.wide_order where dt='20200530'

  )A group by act_dep_city,act_arr_city,city_all_num

)A