如何 select 最高值并从 Postgresql 嵌套查询中减去较低的值

Question

这就是我想要实现的目标 - 例如，假设我有一个包含人们年龄的整数列，我想 select 最高年龄并得到它与其他年龄的差异 select编辑年龄。所以如果我这样做：

SELECT ages FROM people
ORDER BY ages DESC

并得到 30 25 20 15 10 例如，我想做另一个 SELECT 来执行 30-30, 30-25, 30-20, 30-15, 30-10

SELECT --how do I perform that here? 
FROM (  
    SELECT ages FROM peoeple
    ORDER BY ages DESC
)foo

我怎样才能做到这一点？

Answer 1

使用 returns 最大年龄的子查询：

select (select max(age) from people) - age
from people
order by 1 -- ordering is optional, but it seems you want data in this order

顺便说一句，age 比 ages 更适合某人的年龄。

How to select the highest value and subtract the lower values from Postgresql nested query