mysql group中能否使用两个count呢

Answer 1

其實最好寫明你的表格結構，以下答案是根據你提供的有限資訊：

select district as 行政区
，count(1) as 小区数 -- 我默认你每个小区时一条记录，且无重复
, sum(if(idNB = 1 ,1 ,0)) as 高档小区数 -- 假设高档小区的idNB标记为1
from table_name 
group by district

其实 sum(if(idNB = 1 ,1 ,0)) 也可以替换成count(idNB = 1 or null)

Answer 2

mysql不支援分析函數:

select t1.district, 
    (select count(t2.xiaoqu) from table t2 where t2.district=t1.district) count_xiaoqu,
    (select count(t2.idNB) from table t2 where t2.district=t1.district) count_idNB
from table t1

分析函數的寫法:

select district, 
count(xiaoqu) over (district) count_xiaoqu, 
count(idNB) over (district) count_idNB
from table

Answer 3

我這邊說下我的思路吧，使用MySQL將區內的高階小區和非高階小區統計出來

select district,idNB,count(*) from xx GROUP BY district,idNB

然後區內小區的總數再由服務端這邊自己處理計算。