mysql - 我希望MySQL查询结果在同一行

Question

SELECT sum(case when (gender)=1 THEN 1 ELSE 0 END),
       GROUP_CONCAT(sum(case when (gender)=2 THEN 1 ELSE 0 END) SEPARATOR ' ') as combine         
from family_member_tbl
GROUP BY gender 

Answer 1

不，你不能像这样嵌套分组函数。而是先获取总和，然后再获取 group_concat() 就像

select sum_1, sum_2, group_concat(sum_2) as combine
from (
SELECT gender,
       sum(case when gender = 1 THEN 1 ELSE 0 END) as sum_1,
       sum(case when gender = 2 THEN 1 ELSE 0 END) as sum_2         
from family_member_tbl
GROUP BY gender ) xxx
group by gender;