SQL Server组按每小时日期时间计数和更新最大计数到表中？

Question

我有这段代码可以按小时计算一组事件的发生次数。现在我需要 MAX COUNT 并在另一个表中输入。我是SQL的新手，我遇到UPDATE语句和MAX以及下面的所有问题。有人可以帮忙吗？谢谢！

    SELECT CAST(locate_received_date as date) AS 'ForDate', 
    DATEPART(hh, locate_received_date) AS 'OnHour', 
    COUNT (*) AS 'Count'
    FROM BELL_DPRA2_locates_fact
    WHERE locate_received_date BETWEEN '2016-12-01 00:00:00.000' AND '2016-12-01 23:59:59.999'
    GROUP BY CAST(locate_received_date as date), DATEPART(hh, locate_received_date); 

附上此脚本结果。

编辑：感谢@agfc，这个答案对我有用。我修改了一下为我工作。

UPDATE MyTable
SET MaxHourlyCount =
     (SELECT Max(A.HourCount)
      FROM (SELECT CAST(locate_received_date as date) AS 'ForDate', 
    DATEPART(hh, locate_received_date) AS 'OnHour', 
    COUNT (*) AS HourCount
    FROM BELL_DPRA2_locates_fact
   WHERE locate_received_date BETWEEN '2016-12-01 00:00:00.000' AND '2016-12-01 23:59:59.999'
    GROUP BY CAST(locate_received_date as date), DATEPART(hh, locate_received_date)) AS A)

Answer 1

-- I'd rename your 'Count' Field to something else not to use the SQL function name.     
UPDATE myOtherTable
    SET MaxField = SELECT Max(HourCount) FROM (SELECT CAST(locate_received_date as date) AS 'ForDate', 
        DATEPART(hh, locate_received_date) AS 'OnHour', 
        COUNT (*) AS HourCount
        FROM BELL_DPRA2_locates_fact
        WHERE locate_received_date BETWEEN '2016-12-01 00:00:00.000' AND '2016-12-01 23:59:59.999'
        GROUP BY CAST(locate_received_date as date), DATEPART(hh, locate_received_date)) As MyMaxResult; 

Answer 2

您可以使用TOP 1和ORDER BY返回包含Max HourCount的行。您只需将此作为子查询加入到表中即可更新或将其作为新行插入。如果您包含要移动此数据的表格，我可以更新此答案以反映您的表格。

SELECT TOP 1
    CAST(locate_received_date as date) AS 'ForDate', 
    DATEPART(hh, locate_received_date) AS 'OnHour', 
    COUNT (*) AS 'Count'
FROM BELL_DPRA2_locates_fact
WHERE
    locate_received_date BETWEEN '2016-12-01 00:00:00.000' AND '2016-12-01 23:59:59.999'
GROUP BY
    CAST(locate_received_date as date),
    DATEPART(hh, locate_received_date)
ORDER BY Count DESC;