SQL Server查询每月总计

Question

我有一个查询，总计了2010年1月1日所有活动的案例。

SELECT     COUNT(CaseID) AS Total
FROM         dbo.ClientCase
WHERE     (CaseStartDate <= CONVERT(DATETIME, '2010-01-01 00:00:00', 102)) AND (CaseClosedDate >= CONVERT(DATETIME, '2010-01-01 00:00:00', 102)) OR (CaseClosedDate IS NULL)
GROUP BY CaseStartDate

我还有一个Calendar表，我可以使用它创建一个查询，从1月1日，2月1日，3月1日到12月1日返回12个日期。

我无法弄清楚如何结合2个查询，所以我得到每个月1日的所有案例总数的计数。

我需要看到类似的东西

Month   Total
Jan     102
Feb     130
Mar     145
.....
Dec     162

Answer 1

SELECT cal.MonthName, COUNT(CaseID) AS Total 
FROM dbo.calendarTable cal
LEFT OUTER JOIN dbo.ClientCase cc
ON Month(cal.MonthStartDate) = Month(CaseStartDate)
WHERE 
(CaseStartDate <= CONVERT(DATETIME, cal.MonthStartDate, 102)) AND 
(CaseClosedDate >= CONVERT(DATETIME, cal.MonthStartDate, 102)) OR 
(CaseClosedDate IS NULL) 
GROUP BY cal.MonthName

• 左外连接以确保您获得所有月份，包括0个案例

Answer 2

假设Calendar有两个列，例如MonthName和FirstDate ，你想要s / like

SELECT Calendar.MonthName AS Month, COUNT(ClientCase.CaseId) AS Total,
  FROM ClientCase
  JOIN Calendar
    ON (MONTH(Calendar.FirstDate) = MONTH(ClientCase.CaseStartDate))
  GROUP BY Calendar.MonthName

Answer 3

您只需按查询的月份进行分组：

SELECT
    MONTH(CaseStartDate), COUNT(CaseID) AS Total
FROM         
    dbo.ClientCase
WHERE     
    (CaseStartDate <= CONVERT(DATETIME, '2010-01-01 00:00:00', 102)) 
    AND (CaseClosedDate >= CONVERT(DATETIME, '2010-01-01 00:00:00', 102)) OR 
        (CaseClosedDate IS NULL)
GROUP BY 
    MONTH(CaseStartDate)

这应该给你一个非常接近的输出（数月而不是1月，2月等 - 但足够接近）。

通过这个额外步骤，您将获得每个月名称的前三个字母：

SELECT
    SUBSTRING(DATENAME(MONTH, CaseStartDate), 1, 3) AS 'Month', 
    COUNT(CaseID) AS Total
FROM         
    dbo.ClientCase
WHERE     
    (CaseStartDate <= CONVERT(DATETIME, '2010-01-01 00:00:00', 102)) 
    AND (CaseClosedDate >= CONVERT(DATETIME, '2010-01-01 00:00:00', 102)) OR 
        (CaseClosedDate IS NULL)
GROUP BY 
    MONTH(CaseStartDate), SUBSTRING(DATENAME(MONTH, CaseStartDate), 1, 3)
ORDER BY
    MONTH(CaseStartDate)