Question

这是我发布的earlier问题的后续内容。这段代码正是我所询问的内容，但我意识到最终让它工作，我试图做的事实上并不是我所需要的。

DECLARE @StartDateTime datetime = '2015-07-13 14:00:00',
        @EndDateTime datetime = '2015-07-13 16:00:00';

WITH JumpsOf15 AS
(
    SELECT ROW_NUMBER() OVER(ORDER BY object_id) * 15 AS Step
    FROM sys.objects
),
Dates as
(
SELECT currentDate = steppedDate.steppedDate
FROM JumpsOf15
CROSS APPLY(SELECT DATEADD(MINUTE,Step,@StartDateTime) AS steppedDate ) AS steppedDate
WHERE @EndDateTime>steppedDate.steppedDate 
)

SELECT  d.currentDate, t.Value, t.FK_ConfigId
FROM    Dates AS d
        OUTER APPLY
        (   SELECT  TOP 1 t.[Timestamp], t.Value, t.FK_ConfigId
            FROM    myTable AS t
            WHERE   t.[Timestamp] <= d.currentDate and t.FK_ConfigId in (208812, 208809, 208815)
            ORDER BY t.[Timestamp] DESC, t.Value, t.FK_ConfigId
        ) AS t

这给出了如下输出：

currentDate          value           FK_ConfigId
1/1/2015 12:15       2               208809
1/1/2015 12:30       5               208815
1/1/2015 12:45       1               208815

但实际上我需要在列表中指定的每个唯一FK_ConfigId的每个时间戳记录一条记录。现在我每个时间戳只获得一条记录，无论配置ID如何。我想要的输出：

currentDate          value           FK_ConfigId
1/1/2015 12:15       2               208809
1/1/2015 12:15       4               208815
1/1/2015 12:30       5               208809
1/1/2015 12:30       1               208815

我怎么能实现这个目标？

Answer 1

试试这个并告诉我你的想法：

DECLARE @StartDateTime datetime = '2015-07-13 14:00:00',
        @EndDateTime datetime = '2015-07-13 16:00:00';

WITH JumpsOf15 AS (
   SELECT Step = Row_Number() OVER (ORDER BY (SELECT 1)) * 15
   FROM sys.objects
),
Dates AS (
   SELECT currentDate = DateAdd(minute, Step, @StartDateTime)
   FROM JumpsOf15
   WHERE Step < DateDiff(minute, 0, @EndDateTime - @StartDateTime)
)
SELECT
   d.currentDate,
   t.ConfigId,
   t.Value
FROM
   Dates d
   CROSS JOIN (VALUES
      (208812), (208809), (208815)
   ) c (ConfigId)
   OUTER APPLY (
      SELECT TOP 1
          t.[Timestamp],
          t.Value,
          t.FK_ConfigId
      FROM myTable t
      WHERE
         d.currentDate >= t.[Timestamp]
         AND c.ConfigId = t.FK_ConfigId
      ORDER BY
         t.[Timestamp] DESC,
         t.Value
   ) t
;

如何按ID分组以及此查询的日期

1 个答案: