Question

问一个mysql查询语句，查询a大于0和小于0的数量，能用一个语句实现吗

Answer 1

select count(*) from abc表 where a>0 and a<0

Answer 2

select case when a>0 then 1 else 0 end,count(*)
from table_name
where a <> 0
group by case when a>0 then 1 else 0 end

Answer 3

SELECT
count(CASE WHEN id > 88 THEN 1 END) AS a,
count(CASE WHEN id <= 88 THEN 1 END) AS b
FROM
test

亲测可用

Answer 4

应该不能的