在SQL中比較兩個不相關的計數

Question

我有兩個布爾值，我想劃分它們的計數。

假設一個表在列X中有1個yes值，在列Y中有2個yes值。 我希望SELECT Count（X）/ Count（Y）返回.5。

我在網上找到的解決方案使用WITH，其中MS-Access s不允許我使用。

這是我不得不使用WITH更多的澄清：

WITH T2 AS 
(SELECT GRANTS.[Grant Program Number] AS GPN, Count(GRANTS.[Grant Awarded]) AS AwardCount 
FROM GRANTS 
WHERE GRANTS.[Grant Awarded]=Yes) 
SELECT (T2.AwardCount)/(T1.SubCount) AS [Award Rate] 
FROM (SELECT GRANTS.[Grant Program Number] AS GPN, Count(GRANTS.[Grant Submitted]) AS SubCount 
FROM GRANTS 
WHERE GRANTS.[Grant Submitted]=Yes) AS T1 INNER JOIN GRANTS ON T1.GPN = T2.GPN 
GROUP BY [Award Rate]; 

Answer 1

如果您正在尋找獎率對於整個表格，則查詢將是

SELECT 
    SUM(IIF([Grant Awarded],1,0))/ NZ(SUM(IIF([Grant Submitted],1,0)),1) as [Award Rate] 
FROM 
    GRANTS 

Answer 2

聲明，我用不上所以這可能無法正常工作。也許它會給你一些想法，無論如何：

select (1.0 * count(case when X = 'yes' then 1 end)) 
      /count(case when Y = 'yes' then 1 end) 
from T; 

如果X和Y是布爾：

select (1.0 * count(case when X then 1 end)) 
      /count(case when Y then 1 end) 
from T; 

你可以試試這個：

select (1.0 * sum(IIf(X, 1, 0))) 
      /sum(IIf(Y, 1, 0)) 
from T;