即使没有价值也显示 LastDateOfMonth [重复]答案

【问题标题】：Show LastDateOfMonth even where there is no value [duplicate]即使没有价值也显示 LastDateOfMonth [重复]
【发布时间】：2015-02-02 13:42:14
【问题描述】：

这是我正在做的事情：

  WITH cte AS (
  SELECT * FROM TimeDim 
  )
SELECT t.TimeDimPK, c.ID 
FROM CTE AS t
LEFT OUTER JOIN TABLE c ON c.TimeDimFK = t.TimeDimPK
ORDER BY t.TimeDimPK
WHERE c.ID = 1

结果，缺少日期如下图：

TimeDimPK   ID
20120930    1
20121231    1
20130131    1

我想得到什么

TimeDimPK   ID
20120930    1
20121031    NULL
20121130    NULL
20121231    1
20130131    1

【问题讨论】：

标签： sql-server left-join common-table-expression

【解决方案1】：

看起来您的WHERE 子句正在删除其他日期。试试这个：

WITH    cte
          AS ( SELECT   TimedimPK
               FROM     TimeDim
             )
    SELECT  t.TimeDimPK ,
            c.ID
    FROM    cte t
            LEFT OUTER JOIN TABLEname c ON c.TimeDimFK = t.TimeDimPK
    WHERE   c.ID = 1
            OR c.ID IS NULL
    ORDER BY t.TimeDimPK

【讨论】：

这对我不起作用:(我需要查询来生成缺少的日期，同时在 ID 上使用 where。
您需要提供更多描述性反馈，然后“这对我不起作用”。运行查询时，缺少什么？
我需要查询来生成缺少的日期，同时对特定 ID 使用 where 条件。

【解决方案2】：

您可以尝试使用“数字/日期生成器”，此查询将填写所有缺失的日期，然后选择该月的最后一天。我不确定你所有的数据细节，所以我目前给你两个建议：

1 - 简洁建议：

DECLARE @minDate DATETIME, @maxDate DATETIME;

SELECT @minDate = MIN(TimeDimPK), @maxDate = MAX(TimeDimPK) FROM TimeDim;

WITH DateGenerator AS
(
    --Create a list with a lot of dates from @minDate
    SELECT TimeDimPK = CONVERT(DATE, DATEADD(dd, ROW_NUMBER() OVER (ORDER BY OBJECT_ID), @minDate)) FROM sys.objects
)
--List all days, including missing days
SELECT TimeDimPK
, c.ID
FROM DateGenerator n
LEFT JOIN AnotherTable c ON c.TimeDimFK = n.TimeDimPK
WHERE 
--Stop the number generator at the last day of the last month from the cte table
n.TimeDimPK <=  CONVERT(DATE, DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0, @maxDate )+1,0)))
--This will get the last day of every month
AND TimeDimPK = CONVERT(DATE, DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,TimeDimPK)+1,0)))

2 - 如果您想将其用于一些调整，请对您的 cte 子句提出建议：

WITH NumberGenerator AS
(
    --Create a number list 1,2,3,4,5,6,7,8,++
    SELECT Number = ROW_NUMBER() OVER (ORDER BY OBJECT_ID) FROM sys.objects
), cte AS (
    --Your cte query with a date number based on the days between the firts and current days
    SELECT 
    TimeDimPK = CONVERT(DATETIME, TimeDimPK)
    --Get the number of days to add from the first day in your table
    , DateNumber = DATEDIFF(dd,  MIN(TimeDimPK) OVER (), TimeDimPK)
    FROM #TimeDim 
), TableWithMissingDates AS
(
    --Fill missing days
    SELECT TimeDimPK = CONVERT(DATE, DATEADD(dd, n.Number - 1, MIN(t.TimeDimPK) OVER ()))
    , c.ID
    FROM NumberGenerator n
    LEFT JOIN cte t ON t.DateNumber = n.Number 
    LEFT JOIN #Test2 c ON c.TimeDimFK = t.TimeDimPK
    --Stop the number generator at the last day of the last month from the cte table
    WHERE CONVERT(DATE, DATEADD(dd, n.Number - 1, (SELECT MIN(TimeDimPK) FROM cte))) <  CONVERT(DATE, DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0, (SELECT MAX(TimeDimPK) FROM cte) )+1,0)))
)
SELECT * FROM TableWithMissingDates
WHERE 
--This will get the last day of every month
TimeDimPK = CONVERT(DATE, DATEADD(s,-1,DATEADD(mm, DATEDIFF(m,0,TimeDimPK)+1,0)))

两个查询都将返回同一个表：

【讨论】：