查找标志处于活动状态时的间隔

Question

我需要从下面的 table 中找出标志 inserted 何时处于活动状态 (inserted = 1)。当 inserted 处于活动状态时，我需要显示间隔 date_from 到 date_to。

这里是 table:

no              dcr                     action deleted     inserted
--------------- ----------------------- ------ ----------- -----------
191005040000806 2014-04-17 10:39:59.790 U      1           0
191005040000806 2014-04-17 14:23:41.650 U      0           1
191005040000806 2015-03-25 09:46:03.270 U      1           0
191005040000806 2015-03-25 12:01:49.533 U      0           1

结果应该是这样的：

no              date_from               date_to
--------------- ----------------------- -----------------------
191005040000806 NULL                    2014-04-17 10:39:59.790
191005040000806 2014-04-17 14:23:41.650 2015-03-25 09:46:03.270
191005040000806 2015-03-25 12:01:49.533 NULL

第一行 date_from 是 NULL 因为我们不知道 inserted 标志何时开始激活，但我们知道它在 2014-04-17 10:39:59.790 结束。最后一行 date_to 是 NULL 因为 inserted 标志仍然有效。

每一行的两个标志不能相同；如果删除 = 0，则插入 = 1，反之亦然。我正在使用 SQL Server 2008R2。

Answer 1

这是一种解决方案：

DECLARE @t TABLE
    (
      no VARCHAR(20) ,
      dcr DATETIME ,
      inserted BIT
    )

INSERT  INTO @t
VALUES  ( '191005040000806', '2014-04-17 10:39:59.790', 0 ),
        ( '191005040000806', '2014-04-17 14:23:41.650', 1 ),
        ( '191005040000806', '2015-03-25 09:46:03.270', 0 ),
        ( '191005040000806', '2015-03-25 12:01:49.533', 1 )


;WITH cte AS(
            SELECT  no ,
                    ( SELECT    TOP 1 dcr
                      FROM      @t t2
                      WHERE     t2.no = t1.no AND t2.dcr < t1.dcr
                                AND t2.inserted = 1
                      ORDER BY dcr desc                  
                    ) AS date_from,
                   CASE WHEN dcr = '99991231' THEN NULL ELSE dcr end AS date_to    
            FROM  ( SELECT * FROM @t UNION ALL SELECT no, '99991231', 0 FROM @t GROUP BY no) t1
            WHERE t1.inserted = 0
)
SELECT no, date_from, MIN(date_to) AS date_to FROM cte
GROUP BY no, date_from

输出：

no              date_from                date_to
191005040000806 NULL                     2014-04-17 10:39:59.790
191005040000806 2014-04-17 14:23:41.650  2015-03-25 09:46:03.270
191005040000806 2015-03-25 12:01:49.533  NULL

查找标志处于活动状态时的间隔

Find intervals when flag was active

sql

tsql

sql-server

sql-server-2008-r2