SQL 服务器分组按每小时的日期时间计数和更新最大值计数为 table？

Question

我有这段代码可以每小时计算一组事件的发生次数。现在我需要 MAX COUNT 并将其输入另一个 table。我是 SQL 的新手，我在使用 UPDATE 语句以及 MAX 和下面的所有内容时遇到问题。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 到 return 具有 Max HourCount 的行。您只需将此作为子查询加入 table 即可更新或将其作为新行插入。如果您包括要将此数据移动到的 table，我可以更新此答案以反映您的 table。

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;

SQL 服务器分组按每小时的日期时间计数和更新最大值计数为 table？

SQL Server Group by Count of DateTime Per Hour and Update Max count into table?

sql-server

count

max

hour