Question

稍微难以解释，我的SQL Server不是最好的，但任何事情都会在这里做。

首先，创建一些表格：

CREATE TABLE [dbo].[Quarterly](
[QuarterDate] [datetime] NOT NULL,
[SomeText] [nvarchar](50) NULL,
CONSTRAINT [PK_Quarterly] PRIMARY KEY CLUSTERED 
(
[QuarterDate] ASC
)
GO

CREATE TABLE [dbo].[TmpDegreeDays](
[Date] [datetime] NOT NULL,
[Value] [nvarchar](50) NOT NULL,
CONSTRAINT [PK_TmpDegreeDays] PRIMARY KEY CLUSTERED 
(
[Date] ASC
)
GO

然后插入一些数据：

INSERT [dbo].[Quarterly] ([QuarterDate], [SomeText]) VALUES (CAST(0x00009CF100000000 AS DateTime), N'Blah')
INSERT [dbo].[Quarterly] ([QuarterDate], [SomeText]) VALUES (CAST(0x00009D4B00000000 AS DateTime), N'Fools')
INSERT [dbo].[Quarterly] ([QuarterDate], [SomeText]) VALUES (CAST(0x00009DA600000000 AS DateTime), N'Later')
INSERT [dbo].[Quarterly] ([QuarterDate], [SomeText]) VALUES (CAST(0x00009E0400000000 AS DateTime), N'Something')
INSERT [dbo].[Quarterly] ([QuarterDate], [SomeText]) VALUES (CAST(0x00009E5E00000000 AS DateTime), N'New year')
INSERT [dbo].[Quarterly] ([QuarterDate], [SomeText]) VALUES (CAST(0x00009EC300000000 AS DateTime), N'In april')

然后将2010-01-01到（包括）2012-03-10的日期范围插入表TmpDegreeDays

最后：

我想计算当前TmpDegreeDays与Quarterly结果集中下一条记录之间QuarterDate表中每条记录Quarterly中[值]的总和

类似的东西：

DECLARE @startDate datetime, @endDate datetime
SET @startDate = '2010-01-01'
SET @endDate = '2010-12-31'

SELECT q.QuarterDate, q.SomeText, CustomSum = 
(SELECT SUM(CAST([Value] AS float))
FROM TmpDegreeDays 
WHERE [date] >= q.QuarterDate AND *Current QuarterDate* < *Some query here to get next row QuarterDate*)

FROM Quarterly q

WHERE q.QuarterDate BETWEEN @startDate AND @endDate

我正在寻找的最终输出示例：

2010-01-01   Sum of [Value] between 2010-01-01 and 2010-03-31
2010-04-01   Sum of [Value] between 2010-04-01 and 2010-06-30
2010-07-01   Sum of [Value] between 2010-07-01 and 2010-09-31
2010-10-03   Sum of [Value] between 2010-10-03 and 2010-10-03

这有意义吗？

Answer 1

您可以尝试这样的方法 - 使用CTE（在SQL Server 2005 和更新版本中提供）查找每个季度的日期，然后总结度数值：

;WITH QuarterlyDates AS
(        
   SELECT 
       QuarterDate, 
       QuarterEndDate = DATEADD(MILLISECOND, -3, DATEADD(MONTH, 3, QuarterDate))
   FROM [dbo].[Quarterly]
)
SELECT
    qd.QuarterDate, qd.QuarterEndDate,
    DegreeSum = (SELECT SUM(DegreeValue) 
                 FROM [dbo].[TmpDegreeDays] 
                 WHERE [Date] BETWEEN qd.QuarterDate AND qd.QuarterEndDate)
FROM
    QuarterlyDates qd

确定QuarterEndDate的奇怪函数的根源在于DATETIME在SQL Server中的精度为3.33ms。因此，给定月份的最后日期是该月的最后一天，时间是23:59:59.997（不是.999）。因此，我需要在该季度的开始日期增加三个月，然后从下一季度的开始日期减去3毫秒，以获得本季度的最后一毫秒。

更新：好的，为了从表中获取四分之一的开始和结束日期，您需要两个嵌套的CTE才能确定“下一个季度的结束日期减去3毫秒” “在本季度末 - 这样的事情：

;WITH QuarterStarts AS
(
    SELECT  
        QuarterDate,
        QNumber = ROW_NUMBER() OVER(ORDER BY QuarterDate)   -- ordering number
    FROM [dbo].[Quarterly]
),
Quarters AS
(
    SELECT
        QuarterStartDate = q1.QuarterDate,
        QuarterEndDate = DATEADD(MILLISECOND, -3, q2.QuarterDate) 
    FROM
        QuarterStarts q1
    INNER JOIN 
        QuarterStarts q2 ON q2.QNumber = q1.QNumber + 1 
)
SELECT
    q.QuarterDate, q.QuarterEndDate,
    DegreeSum = (SELECT SUM(DegreeValue) 
                 FROM [dbo].[TmpDegreeDays] 
                 WHERE [Date] BETWEEN q.QuarterDate AND q.QuarterEndDate)
FROM
    Quarters q

当前记录与下一条记录之间的列的总和

1 个答案: