Sql server SQL计算特定状态下的总时间

我把这些数据放在一张表格里

_____DateTime____|Variable__|Value
2017/03/29 23:00:00 | Variable1   | 1     
2017/03/31 01:00:00 | Variable1   | 0     
2017/03/31 02:00:00 | Variable1   | 1     
2017/03/31 03:00:00 | Variable1   | 0     
2017/03/31 04:00:00 | Variable2   | 1     
2017/03/31 23:00:00 | Variable1   | 1     
2017/04/01 01:00:00 | Variable1   | 0     

我想计算两个日期之间每个变量处于状态1的总持续时间

例如，Var1 2017/03/31 00:00:00和2017/04/01 00:00:00之间 结果是：

1 hour between 2017/03/31 00:00:00 and 2017/03/31 01:00:00
1 hour between 2017/03/31 02:00:00 and 2017/03/31 03:00:00
1 hour between 2017/03/31 23:00:00 and 2017/04/01 00:00:00

所以我希望Var1的结果应该是3小时

例如，Var2 2017/03/31 00:00:00和2017/04/01 00:00:00之间 结果是： 2017/03/31 04:00:00和2017/04/01 00:00:00之间的1小时之前没有值，但因为它更改为1，我认为它之前为0

所以我想要的Var2的结果应该是20小时

变量| u时间（以秒为单位）

变量1 | 180

变量2 | 1200

如果有人能帮我

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由于lead和concat，提前感谢SQL Server 2012+

使用堆叠cte生成小时表，以内部联接子查询，该子查询使用window函数获取按变量分区的状态更改的下一个日期

为了适应以前的版本，使用外部应用程序获取每个变量的下一个dt，而不是前导；以及使用正确转换而不是concat的常规字符串连接

如果您需要经常这样做，您可以考虑创建一个实际的表数小时。否则，使用堆叠cte与大多数其他选项一样快，并且随着生成的值数量的增加，比递归cte快得多

编号和日历表参考：

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这总是按小时吗？非常感谢你的回答，它工作得很好。事实上，我只想要每个变量在特定状态下的持续时间，以小时为单位不是一个好主意！！！更正@SqlZim。它不起作用，因为它给了我2017-03-29 23:00:00和2017-03-31 01:00:00之间的时间。因为我的查询是从2017-03-31 00:00:00开始的，所以我只想要2017-03-31 00:00:00和2017-03-31 01:00之间的时间：00@StéphanF更新为使用minh.datehour

declare @fromdate datetime = '20170331 00:00:00';
declare @thrudate datetime = '20170401 00:00:00';
;with n as (select n from (values(0),(1),(2),(3),(4),(5),(6),(7),(8),(9)) t(n))
, hours as (
  select top ((datediff(hour, @fromdate, @thrudate)+1))
      [DateHour]=dateadd(hour,(row_number() over (order by (select 1)) -1),@fromdate)
  from n as deka cross join n as hecto cross join n as kilo 
                cross join n as tenK cross join n as hundredK
   order by 1
)
select variable, value
  , hours = count(h.datehour)
  , start_dt = convert(varchar(20),min(h.datehour),120)
  , end_dt   = convert(varchar(20),end_dt,120)
  , txt = concat(
            count(h.datehour),' '
          , case when count(h.datehour) < 2 then 'hour' else 'hours' end
          , ' between '
          , convert(varchar(20),min(h.datehour),120)
          , ' and '
          , convert(varchar(20),end_dt,120)
    )
from hours h
  inner join (
  select 
      variable
    , value
    , start_dt = dt
    , end_dt   = case when coalesce(lead(dt) over (partition by variable order by dt),@thrudate) > @thrudate 
                        then @thrudate 
                      else coalesce(lead(dt) over (partition by variable order by dt),@thrudate) 
                      end
  from t
    ) s
    on h.datehour >= s.start_dt
   and h.datehour <  s.end_dt
  where h.datehour >= @fromdate
    and h.datehour <  @thrudate
    and s.value = 1
group by variable, value, start_dt, end_dt

+-----------+-------+-------+---------------------+---------------------+--------------------------------------------------------------+
| variable  | value | hours |      start_dt       |       end_dt        |                             txt                              |
+-----------+-------+-------+---------------------+---------------------+--------------------------------------------------------------+
| Variable1 |     1 |     1 | 2017-03-31 00:00:00 | 2017-03-31 01:00:00 | 1 hour between 2017-03-31 00:00:00 and 2017-03-31 01:00:00   |
| Variable1 |     1 |     1 | 2017-03-31 02:00:00 | 2017-03-31 03:00:00 | 1 hour between 2017-03-31 02:00:00 and 2017-03-31 03:00:00   |
| Variable1 |     1 |     1 | 2017-03-31 23:00:00 | 2017-04-01 01:00:00 | 1 hour between 2017-03-31 23:00:00 and 2017-04-01 01:00:00   |
| Variable2 |     1 |    20 | 2017-03-31 04:00:00 | 2017-04-01 00:00:00 | 20 hours between 2017-03-31 04:00:00 and 2017-04-01 00:00:00 |
+-----------+-------+-------+---------------------+---------------------+--------------------------------------------------------------+