Question

这背后的逻辑是如果同一位置的Ser_request数相同，那么考虑具有Max“停电前功率”的行。需要更新的行是列名称ID ，其最小值为

我需要创建三个新列Adj Start date，Adj end date，Adj DC power并插入来自各列的数据

downtime_start =调整开始日期

-downtime_end =调整结束日期

-power_before_downtime =调整直流电源

我试过这样做但是通过分组相同的值我无法找到第一行。

我正在使用sql server 2012

这是我到目前为止所尝试的：

select location,downtime_start  , count(*)
from dbo.TB1
group by location,downtime_start  , count(*)
having count(*)>1

在此查询之后我得到了TB1的结果，我不知道如何对它们进行分组并将值插入到各自的列中。

感谢任何帮助

谢谢

ID | location | downtime_start      | downtime_end         | power_before_downtime | power_after_downtime | creation_time       | end_time            | ser_request
1  | xyz.a    | 3/8/2017 2:00:00 PM | 3/10/2017 8:00:00 AM | 14.16                 | 13.67                | 3/8/2017 3:25:37 PM | 3/8/2017 6:41:59 PM | 0003 
2  | xyz.a    | 3/8/2017 2:00:00 PM | 3/10/2017 8:00:00 AM | 14.16                 | 13.67                | 3/8/2017 3:25:37 PM | 3/8/2017 6:41:59 PM | 0003
3  | xyz.a    | 3/8/2017 2:00:00 PM | 3/10/2017 8:00:00 AM | 14.16                 | 13.67                | 3/8/2017 3:25:37 PM | 3/8/2017 6:41:59 PM | 0003

输出表应该是：

ID | location | downtime_start        | downtime_end           | power_before_downtime|   power_after_downtime| creation_time        | end_time 
      |ser_request |  Adj Start date        |   Adj end date           |  Adj DC power

1  | xyz.a    | 3/8/2017 2:00:00 PM   | 3/10/2017 8:00:00 AM   | 14.16                |   13.67              |3/8/2017 3:25:37 PM    |  3/8/2017 6:41:59 PM| 0003       | 3/8/2017 2:00:00 PM    |  3/10/2017 8:00:00 AM    |     14.16

2  |  xyz.a   |  3/8/2017 2:00:00 PM  |   3/10/2017 8:00:00 AM |    14.16

| 13.67 | 3/8/2017 3:25:37 PM | 3/8/2017 6:41:59 PM | 0003
| 0 | 0 | 0

3  |  xyz.a   |    3/8/2017 2:00:00 PM|   3/10/2017 8:00:00 AM |   14.16

| 13.67 3/8/2017 3:25:37 PM | 2017年3月8日下午6:41:59 | 0003 | 0 | 0 | 0

Answer 1

UPDATE T
SET 
[Adj Start date] = downtime_start,
[Adj end date]   = downtime_end,
[Adj DC power]   = power_before_downtime
FROM (
    SELECT [Adj Start date], [Adj end date], [Adj DC power], downtime_start, downtime_end, power_before_downtime, 
        rn = ROW_NUMBER() OVER (PARTITION BY downtime_start, downtime_end ORDER BY id) 
    FROM dbo.TB1
) T
WHERE rn = 1

如果您需要选择数据，请使用CASE WHEN rn = 1 THEN downtime_start ELSE 0 END

如何更新其他列中相同的值？

1 个答案: