Question

使用PostgreSQL 9.6。我想计算一列中两个其他值之间的值的次数。

在这个例子中，我正在搜索“mid”列，结果应该是5.如果我对值进行硬编码但是这是不可接受的。当使用字段值给出答案为20时，它会失败。它似乎完全忽略了低字段和高字段。

为什么在第二种情况声明中没有评估“低”和“高”字段？我该如何解决它？

SELECT low, mid, high,
        sum(case when mid between 35  and 57   then 1 end) over(partition by mid between 35  and 57) as "StaticNums",
        sum(case when mid between low and high then 1 end) over(partition by mid between low and high) as "non-StaticNums"
FROM
    (SELECT l-11 as low, l as mid, l+11 as high
        FROM generate_series(1,100,5) as l(n)
        group by l.n
     ) as t
group by mid, low, high
order by mid

我添加了一张我正在寻找使用excel的结果的图片。简而言之，我希望每行计算给定范围内的小部件数量（使用低和高值以及小部件中间）。但是我如何在sql中执行此操作？

Excel image showing example of what I'd like to accompish

在案例陈述

0 个答案: