sql - 在一个 SQL SELECT 查询中为多个计数添加百分比

我有一个类似于下面的 SELECT 语句，它在一个查询中返回多个计数。

SELECT  invalidCount = (SELECT COUNT(*) FROM <...a...> WHERE <...b...>),
        unknownCount = (SELECT COUNT(*) FROM <...c...> WHERE <...d...>),
        totalCount   = (SELECT COUNT(*) FROM <...e...> WHERE <...f...>)

这工作正常，但我想向 SELECT 添加两个百分比列:

invalidCount * 100 / totalCount AS PercentageInvalid,
unknownCount * 100 / totalCount AS UnknownPercentage

如何修改我的 SELECT 语句来处理这个问题？

最佳答案

您可以在 from 子句中使用子查询:

select
    s.invalidCount,
    s.unknownCount,
    s.totalCount,
    invalidCount * 100 / s.totalCount as PercentageInvalid,
    unknownCount * 100 / s.totalCount as PercentageUnknown
from
    (select  invalidCount = (SELECT COUNT(*) FROM <...a...> WHERE <...b...>),
        unknownCount = (SELECT COUNT(*) FROM <...c...> WHERE <...d...>),
        totalCount       = (SELECT COUNT(*) FROM <...e...> WHERE <...f...>)) s

关于sql - 在一个 SQL SELECT 查询中为多个计数添加百分比，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/1306112/