SQL總和與非唯一日期

Question

我想寫一個SQL查詢，將總結從以下兩個例子表總產量：

Table: CaseLots 
DateProduced  kgProduced 
October 1, 2013  10000 
October 1, 2013  10000 
October 2, 2013  10000 

Table: Budget 
OperatingDate  BudgetHours 
October 1, 2013  24 
October 2, 2013  24 

我想輸出表如下：

TotalProduction TotalBudgetHours  
30000     48 

以下是我對到目前爲止的代碼：

SELECT 
Sum(kgProduced) AS TotalProduction, Sum(BudgetHours) AS TotalBudgetHours 
FROM 
dbo.CaseLots INNER JOIN dbo.Budget ON dbo.CaseLots.DateProduced = dbo.Budget.OperatingDate 
WHERE 
dbo.Budget.OperatingDate BETWEEN '2013-10-01' AND '2013-10-02' 

看來，查詢是雙總結在instan預算小時ces在一天內生產多個案例。我得到的表如下：

Total Production  BudgetHours 
30000    72 

我該如何解決這個問題？

Answer 1

想想內什麼JOIN在做。

對於CaseLot中的每一行，它都會查找具有匹配日期的預算中的任何行。

如果你要刪除SQL您彙總報表，並且只顯示內部聯接，你會看到下面的結果集：

DateProduced kgProduced OperatingDate BudgetHours

2013年10月1 10000 10月1日， 2013 24

2013年10月1日10000 2013年10月1日24

2013年10月2日10000 2013年10月2日24

（dammit StackOverflow，爲什麼你沒有Markdown的表:(）

運行你的聚合最重要的是，很容易看到你如何得到72小時的結果。

正確的查詢需要先聚合CaseLots表，然後加入到預算表中。

SELECT DateProduced, TotalKgProduced, SUM(BudgetHours) AS TotalBudgetHours 
FROM 
(
    SELECT DateProduced, SUM(kgProduced) AS TotalKgProduced 
    FROM CaseLots 
    GROUP BY DateProduced 
) AS TotalKgProducedByDay 
INNER JOIN 
Budget 
ON TotalKgProducedByDay.DateProduced = Budget.OperatingDate 
WHERE DateProduced BETWEEN '1 Oct 2013' AND '2 Oct 2013' 
GROUP BY DateProduced 

Answer 2

這可以通過本可以輕鬆實現：

SELECT 
    (SELECT SUM(kgProduced) FROM dbo.CaseLots WHERE DateProduced BETWEEN '2013-10-01' AND '2013-10-02') AS TotalProduction, 
    (SELECT SUM(BudgetHours) FROM dbo.Budget WHERE OperatingDate BETWEEN '2013-10-01' AND '2013-10-02') AS TotalBudgetHours 

有沒有必要加入兩個表。

Answer 3

試試這個：

select DateProduced,TotalProduction,TotalBudgetHours from 
    (select DateProduced,sum(kgProduced) as TotalProduction 
    from CaseLots group by DateProduced) p 
    join 
    (select OperatingDate,sum(BudgetHours) as TotalBudgetHours 
    from Budget group by OperatingDate) b 
    on (p.DateProduced=b.OperatingDate) 
where p.DateProduced between '2013-10-01' AND '2013-10-02' 

Answer 4

其他的答案是這種特殊情況下簡單。但是，如果您需要CaseLots表中的10個不同值，則需要10個不同的子查詢。以下是一般情況下，更擴展的解決方案：無需SUM的BudgetHours

SELECT 
    SUM(DayKgProduced) AS TotalProduction, 
    SUM(BudgetHours) AS TotalBudgetHours 
FROM (
    SELECT 
     DateProduced, 
     SUM(kgProduced) AS DayKgProduced, 
    FROM dbo.CaseLots 
    WHERE DateProduced BETWEEN '2013-10-01' AND '2013-10-02' 
    GROUP BY DateProduced 
) DailyTotals 
INNER JOIN dbo.Budget b ON DailyTotals.DateProduced = b.OperatingDate 

首先你SUM生產的每個CaseLot的。如果您在查詢中使用的SELECT * FROM上方你會看到：

Date  DayKgProduced BudgetHours 
2013-10-01 20000   24 
2013-10-02 10000   24 

但你想要的總總，所以我們SUM那些日常的價值觀，正確地產生：

TotalProduction TotalBudgetHours 
30000   48 

Answer 5

問題是在INNER JOIN產生3行表，因爲所有的鍵都匹配。所以有三個'24'，總數爲72.

要解決這個問題，可能會更容易將其拆分爲兩個查詢。

SELECT Sum(kgProduced) AS TotalProduction 
FROM dbo.CaseLots 
WHERE dbo.CaseLots.OperatingDate BETWEEN '2013-10-01' AND '2013-10-02' 

LEFT JOIN 

SELECT Sum(BudgetHours) AS TotalBudgetHours 
FROM dbo.Budget 
WHERE dbo.Budget.OperatingDate BETWEEN '2013-10-01' AND '2013-10-02'