SQL Server 2012 Express 中的另一个 LEFT OUTER JOIN 失败

Question

我想知道是否有人可以解决我的查询问题。我有一个简单的 table，每月可以节省项目费用。总是有连续 12 个月的价值或储蓄，但第一个月可能会有所不同（例如：从 1 月开始有 12 个月，从 3 月开始有 12 个月，等等）。

我需要一份报告，了解给定年份的所有储蓄（按月）。这意味着对于某些项目的节省，如果开始月份不是 1 月，则该项目的部分节省将落入不同的报告年。

所以我需要一个查询，该查询将 return 当前报告年的所有月份，并且对于项目在该月没有储蓄值的地方有零。

我有一些项目从 7 月开始，我只能收回这 6 个月的价值。也就是说，回到 WITH 日期的左连接不是正确的外部连接。有人可以告诉我哪里出错了吗？

查看下面的代码：

DECLARE @MonthEndSnapshot SMALLDATETIME;
SELECT @MonthEndSnapshot =  getdate()

DECLARE @StartDate SMALLDATETIME, @EndDate SMALLDATETIME;
SELECT @StartDate = FORMAT(@MonthEndSnapshot, 'yyyy') + '0101', @EndDate = FORMAT(@MonthEndSnapshot, 'yyyy') + '1231';

;WITH d(d) AS 
(
    SELECT 
        DATEADD(MONTH, n, DATEADD(MONTH, DATEDIFF(MONTH, 0, @StartDate), 0))
    FROM 
        (SELECT TOP 
             (DATEDIFF(MONTH, @StartDate, @EndDate) + 1) 
             n = ROW_NUMBER() OVER (ORDER BY [object_id]) - 1
         FROM 
             sys.all_objects 
         ORDER BY [object_id]) AS n
)
select  
    left(datename(month, d.d), 3) as xAxisValueMon,
    datepart(mm, d.d) as xAxisValue,
    a.ProjectId as ProjectId, 
    ISNULL(SUM(a.Saving), 0) as yAxisValue
from 
    d 
LEFT OUTER JOIN 
    (SELECT 
         mes.ProjectId, mes.Saving, mes.SavingMonth
     FROM 
         dbo.sf_SnapshotMonthEndSaving() mes) AS a ON d.d = a.SavingMonth
group by 
    a.ProjectId,  datename(month, d.d), datepart(mm, d.d)
order by   
    a.ProjectId, datepart(mm, d.d)

WITH d(d) 部分有效，returns 12 个月的日期（从 1 月到 12 月的第 1 个月）。

我还尝试了以下结构作为查询：

;WITH d(d) AS 
(
  SELECT DATEADD(MONTH, n, DATEADD(MONTH, DATEDIFF(MONTH, 0, @StartDate), 0))
  FROM ( SELECT TOP (DATEDIFF(MONTH, @StartDate, @EndDate) + 1) 
    n = ROW_NUMBER() OVER (ORDER BY [object_id]) - 1
    FROM sys.all_objects ORDER BY [object_id] ) AS n
)
select  left(datename(month, d.d), 3) as xAxisValueMon,
    datepart(mm, d.d) as xAxisValue,
    mes.ProjectId as ProjectId, 
    ISNULL(SUM(mes.Saving), 0) as yAxisValue
from d LEFT OUTER JOIN 
    dbo.sf_SnapshotMonthEndSaving() mes 
    ON d.d = mes.SavingMonth
group by mes.ProjectId,  datename(month, d.d), datepart(mm, d.d)
order by   mes.ProjectId, datepart(mm, d.d)

但结果相同。 MonthEndSavingtable如下：

CREATE TABLE [dbo].[MonthEndSaving]
(
    [MonthEndSavingId] [int] IDENTITY(1,1) NOT NULL,
    [MonthEndSnapshot] [datetime] NOT NULL,   
    [ProjectId] [int] NOT NULL,
    [SavingMonth] [datetime] NOT NULL,
    [Saving] [money] NOT NULL,
    [DateCreated] [datetime] NOT NULL,

    PRIMARY KEY CLUSTERED (MonthEndSavingId)
)
GO

ALTER TABLE MonthEndSaving
    ADD CONSTRAINT [ProjectMonthEndSaving] 
    FOREIGN KEY (ProjectId) REFERENCES [dbo].[Project](ProjectId) 
GO

Answer 1

这段代码应该可以满足您的需求：

DECLARE @MonthEndSnapshot SMALLDATETIME;
SELECT @MonthEndSnapshot =  getdate()



DECLARE @StartDate SMALLDATETIME, @EndDate SMALLDATETIME;
SELECT @StartDate = FORMAT(@MonthEndSnapshot, 'yyyy') + '0101', @EndDate = FORMAT(@MonthEndSnapshot, 'yyyy') + '1231';

;WITH d(d) AS 
(
  SELECT DATEADD(MONTH, n, DATEADD(MONTH, DATEDIFF(MONTH, 0, @StartDate), 0))
  FROM ( SELECT TOP (DATEDIFF(MONTH, @StartDate, @EndDate) + 1) 
    n = ROW_NUMBER() OVER (ORDER BY [object_id]) - 1
    FROM sys.all_objects ORDER BY [object_id] ) AS n
)
select  left(datename(month, d.d), 3) as xAxisValueMon,
    datepart(mm, d.d) as xAxisValue,
    prj.ProjectId as ProjectId, 
    ISNULL(SUM(a.Saving), 0) as yAxisValue
from d 
CROSS JOIN 
    (
        SELECT DISTINCT mes.ProjectId
        FROM dbo.sf_SnapshotMonthEndSaving() mes
    ) as prj
LEFT OUTER JOIN 
    (
        SELECT mes.ProjectId, mes.Saving, mes.SavingMonth
        FROM dbo.sf_SnapshotMonthEndSaving() mes 
    ) as a
    ON d.d = a.SavingMonth
    AND prj.ProjectID = a.ProjectID
group by prj.ProjectId,  datename(month, d.d), datepart(mm, d.d)
order by prj.ProjectId,  datepart(mm, d.d)

Answer 2

Dang，Laughing Vergil 似乎是一个更快的打字员 =) 无论如何，这个想法几乎是一样的。您的 'error' 是您每个月都加入 dbo.sf_SnapshotMonthEndSaving() 中的所有项目。如果一个适合，则仅返回那个，如果两个适合，它将显示这两个等等......但它不会对每个项目重复。这个应该。

DECLARE @StartDate datetime = '1 jan 2016',
        @EndDate datetime = '1 dec 2016'

;WITH d(FirstDayOfMonth) AS 
(
  SELECT DATEADD(MONTH, n, DATEADD(MONTH, DATEDIFF(MONTH, 0, @StartDate), 0))
  FROM ( SELECT TOP (DATEDIFF(MONTH, @StartDate, @EndDate) + 1) 
    n = ROW_NUMBER() OVER (ORDER BY [object_id]) - 1
    FROM sys.all_objects ORDER BY [object_id] ) AS n
),
RelevantProjects AS
(
   SELECT DISTINCT ProjectId
     FROM dbo.sf_SnapshotMonthEndSaving() mes
    WHERE mes.SavingMonth BETWEEN @StartDate AND @EndDate -- you could also join to d but I think this is faster
),
ProjectsAndDates AS
(
    SELECT ProjectID,
           FirstDayOfMonth
      FROM d
     CROSS JOIN RelevantProjects
)
select  left(datename(month, d.FirstDayOfMonth), 3) as xAxisValueMon,
        datepart(mm, d.FirstDayOfMonth) as xAxisValue,
        d.ProjectId as ProjectId, 
        ISNULL(SUM(mes.Saving), 0) as yAxisValue
   from ProjectsAndDates d 
    LEFT OUTER JOIN [MonthEndSaving] mes  -- dbo.sf_SnapshotMonthEndSaving() mes 
                 ON mes.SavingMonth = d.FirstDayOfMonth
                AND mes.Project_id  = d.ProjectID
   group by d.ProjectId, datename(month, d.FirstDayOfMonth), datepart(mm, d.FirstDayOfMonth)
   order by d.ProjectId, datepart(mm, d.FirstDayOfMonth)

SQL Server 2012 Express 中的另一个 LEFT OUTER JOIN 失败

Yet another LEFT OUTER JOIN fail in SQL Server 2012 Express

sql

sql-server

join

outer-join