Question

我的表格包含以下值id和amt

id         amt      amt%
1           500     16.7
2           600     20
3           900     30
4          1000     33.3
-----------------------------
           3000     100%

我必须通过将amt%除以id=1来找到amt的{{1}}。如何在sql中编写查询？

Answer 1

select id, amt, 100.0 * amt / (select sum(amt) from tab) as amt_percent
from tab

注意100.0，.0非常重要，它会“强制”将int转换为float s。

评论后

添加：

select t.id, t.amt, 100.0 * t.amt / p.s as amt_percent
from tab t
join (
    select id, sum(amt) as s
    from tab
    group by id
) p on p.id = t.id

和替代方式：

select id, amt, 
    100.0 * amt / (
        select sum(amt) 
        from tab t1 
        where t1.id = t.id
    ) as amt_percent
from tab t

我更喜欢加入子查询 - 第一个。

Answer 2

select id, amt, 100*amt/(select NULLIF(sum(amt),0) from tbl) as "amt%"
from tbl

或者可能是

select t.id, t.amt, 100*amt/sm.s as "amt%"
from tbl t, (select NULLIF(sum(amt),0) as s from tbl) sm

修改检查除以零

Answer 3

您可以尝试这样的事情：

SELECT 
   id, amt, 
   amt / (SELECT SUM(amt) FROM tabl) * 100 as amtperc
FROM tabl

Answer 4

假设您使用的是Oracle（如上一个问题所述），请尝试：

select id, amt, 100 * amt / sum(amt) over () amtperc
from your_table

Answer 5

select id, amt, 100 * amt/(case when (select sum(amt)as ss from tablename)>0 then 
(select sum(amt)as ss from tablename) else 1 end) as [amt%] from tablename

SQL-如何找到百分比

5 个答案: