如何将两个计数查询组合到它们的比例？

Question

我有两个问题:

select count(*) from my_table where status="accepted"

和

select count(*) from my_table where status="rejected"

我要找到接受/拒绝的比例,所以我想知道是否可以组合这两个查询,所以我不必执行两个查询

Answer 1

因为到目前为止没有提供这个答案是正确的

select count(case when status = "accepted" then 1 end) /
       count(case when status = "rejected" then 1 end) as Ratio
from my_table
where status in ("accepted","rejected")

如果您还需要个人计数

select count(case when status = "accepted" then 1 end) Accepted,
       count(case when status = "rejected" then 1 end) Rejected,
       count(case when status = "accepted" then 1 end) /
       count(case when status = "rejected" then 1 end) as Ratio
from my_table
where status in ("accepted","rejected")

注意:MySQL没有除零问题.当Rejected为0时,它返回NULL.