SQL查询：获取每行的调整值

Question

我在SQL表中有几列，我想计算表中每一行的结果。我的数据看起来是这样的：

data 
name  value adjustor1 adjustor2 
Comp1 20  0.05  0.08 
Comp2 80  -0.07  0.065 

的每一行的调整值的计算公式为：

adjusted_value = value*(1 + adjustor1)*(1 + adjustor2)*(100/sum(value)) 

所以调整后的输出应该是：

data 
name  adjusted_value 
Comp1 22.25 
Comp2 77.75 

原始值总和到100，调整后的值也应该总和为100.我试过的东西如：

SELECT adjusted*(100/sum(adjusted)) 
FROM (
     SELECT value*(1+adjustor1)*(1+adjustor2) as adjusted 
     FROM data 
) as result 

它给我的错误：ERROR: column "result.adjusted" must appear in the GROUP BY clause or be used in an aggregate function

但如果我只是做：

SELECT sum(adjusted) 
FROM (
     SELECT value*(1+adjustor1)*(1+adjustor2) as adjusted 
     FROM data 
) as result 

OR

SELECT adjusted 
FROM (
     SELECT value*(1+adjustor1)*(1+adjustor2) as adjusted 
     FROM data 
) as result 

我能得到任何总和或调整值，但不能同时。

Answer 1

列名value是不是一个好的选择，这是一个保留字。我将其改为val。

这是你需要查询：

WITH data(name,val,adjustor1,adjustor2) AS (
    VALUES 
    ('Comp1'::text,20,0.05,0.08), 
    ('Comp2',80,-0.07,0.065) 
) 
SELECT name,val,adjustor1,adjustor2, 
     CAST(val*(1+adjustor1)*(1+adjustor2)*(100/sum(
     val*(1+adjustor1)*(1+adjustor2) 
     ) OVER()) AS numeric(10,3)) adjusted_value 
    FROM data; 

我必须承认，这是一个有点笨拙，子查询可以更容易地理解（SQL Fiddle）：

WITH data(name,val,adjustor1,adjustor2) AS (
    VALUES 
    ('Comp1'::text,20,0.05,0.08), 
    ('Comp2',80,-0.07,0.065) 
) 
SELECT name, CAST(adj*(100/sum(adj) OVER()) AS numeric(8,3)) adjusted_value 
    FROM (
    SELECT name,val,adjustor1,adjustor2, 
      val*(1+adjustor1)*(1+adjustor2) adj 
     FROM data) s; 

一些注意事项：

• 原始sum(adj)被替换为sum(adj) OVER()，这是0123的语法。
• 我也加了[CAST()][3]为了收集数值。

Answer 2

你可以得到一个子查询的SUM，然后你可以做CROSS JOIN达到你想要什么

SELECT name, 
     value*(1+adjustor1)*(1+adjustor2)*(100/T.adjSum) as adjusted_value 
FROM data 
CROSS JOIN 
(SELECT SUM(value*(1+adjustor1)*(1+adjustor2)) as adjSum 
FROM data) T