SQL Server組按月

Question

我有一個具有此架構

ItemID UserID Year IsPaid PaymentDate Amount 
1   1   2009 0   2009-11-01 300 
2   1   2009 0   2009-12-01 342 
3   1   2010 0   2010-01-01 243 
4   1   2010 0   2010-02-01 2543 
5   1   2010 0   2010-03-01 475 

我試圖讓查詢工作，顯示每月總計的表。到目前爲止，我已經嘗試了DateDiff和嵌套選擇，但都沒有給我我想要的。這是我最接近的我的想法：

DECLARE @start [datetime] = 2010/4/1; 
SELECT ItemID, IsPaid, 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 And DateDiff(m, PaymentDate, @start) = 0 AND UserID = 100) AS "Apr", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =1 AND UserID = 100) AS "May", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =2 AND UserID = 100) AS "Jun", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =3 AND UserID = 100) AS "Jul", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =4 AND UserID = 100) AS "Aug", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =5 AND UserID = 100) AS "Sep", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =6 AND UserID = 100) AS "Oct", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =7 AND UserID = 100) AS "Nov", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =8 AND UserID = 100) AS "Dec", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =9 AND UserID = 100) AS "Jan", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =10 AND UserID = 100) AS "Feb", 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 AND DateDiff(m, PaymentDate, @start) =11 AND UserID = 100) AS "Mar" 
FROM LIVE L INNER JOIN Payments I ON I.LiveID = L.RECORD_KEY 
WHERE UserID = 16178 

但我只是得到空值，當我應該得到的價值。我錯過了什麼嗎？

Answer 1

SELECT CONVERT(NVARCHAR(10), PaymentDate, 120) [Month], SUM(Amount) [TotalAmount] 
FROM Payments 
GROUP BY CONVERT(NVARCHAR(10), PaymentDate, 120) 
ORDER BY [Month] 

您也可以嘗試：

SELECT DATEPART(Year, PaymentDate) Year, DATEPART(Month, PaymentDate) Month, SUM(Amount) [TotalAmount] 
FROM Payments 
GROUP BY DATEPART(Year, PaymentDate), DATEPART(Month, PaymentDate) 
ORDER BY Year, Month 

Answer 2

DECLARE @start [datetime] = 2010/4/1; 

應該是...

DECLARE @start [datetime] = '2010-04-01'; 

你擁有的是一個2010除以4，然後按1，然後轉換到一個約會。這是1900-01-01第57.5天。

嘗試SELECT @start初始化後檢查這是否正確。

Answer 3

如果你需要頻繁地做到這一點，我可能會一個計算列PaymentMonth添加到表：

ALTER TABLE dbo.Payments ADD PaymentMonth AS MONTH(PaymentDate) PERSISTED 

它堅持並存儲在表 - 所以真的沒有性能開銷查詢它。這是一個4字節的INT值 - 所以空間開銷也很小。

一旦你的，你可以簡化您的查詢是沿着線的東西：

SELECT ItemID, IsPaid, 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 And PaymentMonth = 1 AND UserID = 100) AS 'Jan', 
(SELECT SUM(Amount) FROM Payments WHERE Year = 2010 And PaymentMonth = 2 AND UserID = 100) AS 'Feb', 
.... and so on ..... 
FROM LIVE L 
INNER JOIN Payments I ON I.LiveID = L.RECORD_KEY 
WHERE UserID = 16178 

Answer 4

現在查詢被明確地望着只支付了一年= 2010，但是，我想你的意思是你的1月/ 2月/ 3月實際上代表了2009年。如果是這樣，你需要對此稍微調整一下。不要重新查詢每列的總和值，只需要以月份爲單位的日期差異條件。將剩下的部分放在WHERE子句中。

SELECT 
     SUM(case when DateDiff(m, PaymentDate, @start) = 0 
      then Amount else 0 end) AS "Apr", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 1 
      then Amount else 0 end) AS "May", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 2 
      then Amount else 0 end) AS "June", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 3 
      then Amount else 0 end) AS "July", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 4 
      then Amount else 0 end) AS "Aug", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 5 
      then Amount else 0 end) AS "Sep", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 6 
      then Amount else 0 end) AS "Oct", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 7 
      then Amount else 0 end) AS "Nov", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 8 
      then Amount else 0 end) AS "Dec", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 9 
      then Amount else 0 end) AS "Jan", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 10 
      then Amount else 0 end) AS "Feb", 
     SUM(case when DateDiff(m, PaymentDate, @start) = 11 
      then Amount else 0 end) AS "Mar" 
    FROM 
     Payments I 
     JOIN Live L 
      on I.LiveID = L.Record_Key 
    WHERE 
      Year = 2010 
     AND UserID = 100 

Answer 5

限制NVARCHAR的尺寸至7，供給到轉換成只顯示「YYYY-MM」

SELECT CONVERT(NVARCHAR(7),PaymentDate,120) [Month], SUM(Amount) [TotalAmount] 
FROM Payments 
GROUP BY CONVERT(NVARCHAR(7),PaymentDate,120) 
ORDER BY [Month] 

Answer 6

的另一種方法，不涉及添加列到的結果，是隻需簡單地將日期的day組成部分清零，那麼2016-07-13和2016-07-16都將是2016-07-01 - 因此會使它們按月相等。

如果你有date（不是datetime）值，那麼你就可以直接零它：

SELECT 
    DATEADD(day, 1 - DATEPART(day, [Date]), [Date]), 
    COUNT(*) 
FROM 
    [Table] 
GROUP BY 
    DATEADD(day, 1 - DATEPART(day, [Date]), [Date]) 

如果你有datetime價值，就需要使用CONVERT刪除時間OF-天部分：

SELECT 
    DATEADD(day, 1 - DATEPART(day, [Date]), CONVERT(date, [Date])), 
    COUNT(*) 
FROM 
    [Table] 
GROUP BY 
    DATEADD(day, 1 - DATEPART(day, [Date]), CONVERT(date, [Date])) 

Answer 7

我喜歡結合DATEADD和DATEDIFF功能是這樣的：

GROUP BY DATEADD(MONTH, DATEDIFF(MONTH, 0, Created),0) 

總之，這兩個函數爲零時的日期分量比指定的日期部分較小（即MONTH在這個例子中）。

您可以將datepart位更改爲YEAR，WEEK,DAY等......這是非常方便的。你原來的SQL查詢會看起來像這樣（我不能測試它，因爲我沒有你的數據集，但它應該把你放在正確的軌道上）。

DECLARE @start [datetime] = '2010-04-01'; 

SELECT 
    ItemID, 
    UserID, 
    DATEADD(MONTH, DATEDIFF(MONTH, 0, Created),0) [Month], 
    IsPaid, 
    SUM(Amount) 
FROM LIVE L 
INNER JOIN Payments I ON I.LiveID = L.RECORD_KEY 
WHERE UserID = 16178 
AND PaymentDate > @start 

一兩件事：在Month列的類型是DateTime這也是一個很好的優勢，如果你需要進一步處理的數據或將其映射.NET對象爲例。