根据另一个表从一个表中拆分时间条目

Question

我有一个包含某些进程的开始和结束时间的表格，还有一个包含休息时间的开始和结束时间的表格。我想为每个进程生成一个包含单个条目的新视图，没有中断。我将尝试用一个例子来解释：

表一：

Process     |  START                |  STOP
Process xy  |  2020-08-18 08:00:00  |  2020-08-18 10:00:00

表二：

         |  pause_START          |  pause_STOP
Break 1  |  2020-08-18 08:20:00  |  2020-08-18 08:40:00
Break 2  |  2020-08-18 09:20:00  |  2020-08-18 09:40:00

期望的输出：

Process     |  START                |  STOP
Process xy  |  2020-08-18 08:00:00  |  2020-08-18 08:20:00
Process xy  |  2020-08-18 08:40:00  |  2020-08-18 09:20:00
Process xy  |  2020-08-18 09:40:00  |  2020-08-18 10:00:00

或视觉上：

---

如果每个条目使用选择和联合的组合最多有 一个 中断，我设法做到了，但如果每个进程有多个中断，这将不起作用。

首先我这样创建View1：

SELECT        TOP (100) PERCENT dbo.Table1.Process, dbo.Table1.START, dbo.Table1.STOP
FROM            dbo.Table1 LEFT OUTER JOIN
                        dbo.Table2 ON dbo.Table1.START <= dbo.Table2.pause_START AND (dbo.Table1.STOP >= dbo.Table2.pause_START OR
                        dbo.Table1.STOP IS NULL) AND ((dbo.Table1.STOP >= dbo.Table2.pause_STOP OR
                        dbo.Table1.STOP IS NULL) AND dbo.Table1.START <= dbo.Table2.pause_STOP OR
                        dbo.Table2.pause_STOP IS NULL)
WHERE        (dbo.Table1.START > CAST(DATEADD(DAY, - 1, GETDATE()) AS DATE)) OR
                        (dbo.Table1.STOP IS NOT NULL)

然后我得到这样的间隔：

SELECT        dbo.View1.Process, dbo.View1.START AS 'start', View1_1.pause_START AS 'stop', dbo.View1.TAB, dbo.View1.MA_ID
FROM            dbo.View1 INNER JOIN
                       dbo.View1 AS View1_1 ON dbo.View1.Process = View1_1.Process AND dbo.View1.TAB = View1_1.TAB
WHERE        (View1_1.pause_START IS NOT NULL)
UNION
SELECT        dbo.View1.Process, dbo.View1.pause_STOP, View1_1.STOP, dbo.View1.TAB, dbo.View1.MA_ID
FROM            dbo.View1 INNER JOIN
                       dbo.View1 AS View1_1 ON dbo.View1.Process = View1_1.Process AND dbo.View1.TAB = View1_1.TAB
WHERE        (View1_1.pause_START IS NOT NULL)
UNION
SELECT        dbo.View1.Process, dbo.View1.START, View1_1.STOP, dbo.View1.TAB, dbo.View1.MA_ID
FROM            dbo.View1 INNER JOIN
                       dbo.View1 AS View1_1 ON dbo.View1.Process = View1_1.Process AND dbo.View1.TAB = View1_1.TAB
WHERE        (View1_1.pause_START IS NULL)

但正如我所提到的，这对于每个间隔的休息时间不超过一次。

任何帮助将不胜感激！

Answer 1

假设休息不重叠并且总是在开始和停止之间（如您的示例），然后使用 union all 组合不同的时间段：

-- first record
select t1.process, t1.start, min(t2.start) as end
from table1 t1 cross join
     table2 t2
group by t1.process, t1.start
union all
-- all the breaks
select t1.process, t2.start, t2.end
from table1 t1 cross join
     table2 t2
union all
-- all the in-between times
select process, starttime, endtime
from (select t1.process, t2.end as starttime, lead(t2.start) over (partition by t1.process order by t1.start) as endtime
      from table1 t1 cross join
           table2 t2
     ) t
where endtime is not null
union all
-- last record
select t1.process, max(t2.end), t1.end
from table1 t1 cross join
     table2 t2
group by t1.process, t1.start;

这应该适用于您问题中的数据。您的实际情况可能更复杂（重叠中断、table2 中每个进程的多行或其他）。如果是这样，请提出一个新问题，并附上适当的样本数据、期望的结果和解释。