select city,district,count(*) from tb group by city,district
select city,count(distinct code) from tb group by city
select distinct code from tb

------解决方案--------------------

不顯示總計
SQL code
use Tempdb
go
--> --> 
 
if not object_id(N'Tempdb..#T') is null
    drop table #T
Go
Create table #T([Code] int,[city] int,[district] int)
Insert #T
select 305,23,10 union all
select 305,23,14 union all
select 305,23,14 union all
select 305,23,14 union all
select 305,24,9 union all
select 802,2,3 union all
select 802,2,4 union all
select 802,2,3 union all
select 803,5,6
Go
Select 
[Code],
[city]=CASE WHEN GROUPING([Code])=0 AND GROUPING(district)=1 OR GROUPING([Code])=1  THEN '*' ELSE RTRIM([city]) end,
[district]=CASE  WHEN GROUPING([Code])=0 AND GROUPING(district)=1 OR GROUPING([Code])=1  THEN 'sum' ELSE RTRIM(district) end,
COUNT(1) AS TotalCount 
from #T 
GROUP BY [Code],[city],district WITH rollup
HAVING GROUPING([Code])=0

/*
Code    city    district    TotalCount
305    23    10    1
305    23    14    3
305    *    sum    4
305    24    9    1
305    *    sum    1
305    *    sum    5
802    2    3    2
802    2    4    1
802    *    sum    3
802    *    sum    3
803    5    6    1
803    *    sum    1
803    *    sum    1
*/