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时返回NULL。

Answer 2

select accepted_count, rejected_count, accepted_count/rejected_count ratio
from (
    select sum(CASE WHEN status="accepted" THEN 1 ELSE 0 END) accepted_count,
           sum(CASE WHEN status="rejected" THEN 1 ELSE 0 END) rejected_count
    from my_table 
    ) A

Answer 3

我认为这会奏效：

SELECT (Select count(*) from my_table where status="accepted") / (select count(*) from my_table where status="rejected") AS ratio

Answer 4

select status, count(*) from my_table 
where status in ("rejected", "accepted")
group by status;

Answer 5

select sum(case when status='accepted' then 1 else 0 end) as AcceptedCount,
       sum(case when status='rejected' then 1 else 0 end) as RejectedCount
    from my_table

如何将两个计数查询组合到它们的比例？

5 个答案: