如何将两个计数查询结合到它们的比率？ [英] How to combine two count queries to their ratio?

问题描述

我有两个查询：

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

和

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

拒绝，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

I was to find the ratio of accepted/reject so I Was wondering if it's possible to combine the two queries so I don't have to execute two queries

推荐答案

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")

如果您还需要个别计数

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。

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