Selecting on a Max Count of rows

Question

I would like some advice on the following SQL. I am trying to select the max(count(*)) of a selct count(*). (if you know what I mean??)
select district_id
from (
     -- retrieve a list of districts, plus the count of employee related records
     select d.district_id, count(*) CountX
     from station s, division d
     where s.resp_empl_num = :empID and
     s.stn_status_code = 'AC' and
     s.resp_div_num = d.division_code
     group by d.district_id
     -- match on the district with the max count #
where CountX = (
     select max(count(*))
     from station st, division dv
     where st.resp_empl_num = :empID and
     st.stn_status_code = 'AC' and
     st.resp_div_num = dv.division_code
     group by dv.district_id
)

Answer 1

Try this
select district_id
from ( select district_id,
              rank() over (order by count(*) desc) rn
       from   station s, division d
       where  s.resp_empl_num = :empID and
              s.stn_status_code = 'AC' and
              s.resp_div_num = d.division_code
       group by d.district_id
) where rn=1
;