sql - 从同一列拆分时间并存储到 2 列并在 sql 中查找这 2 列之间的差异

Question

从同一列拆分时间并存储到 2 列，并在 sql server 中找出这两列之间的差异。

select SourceName,Active,EventTimeStamp,
case when Active=1
then EventTimeStamp END as ActiveTime,

case when Active=0
then EventTimeStamp END as InactiveTime

from dbo.AllEvent
where SourceName='R2_20'
order by SourceName 
;


sname   active  EventTimeStamp      Active      Inavtive
R2_20       1   14:51.9     14:51.9     NULL
R2_20       0   14:53.9     NULL        14:53.9
R2_20       1   15:05.9     15:05.9     NULL
R2_20       0   15:07.9     NULL        15:07.9
R2_20       1   15:15.9     15:15.9     NULL
R2_20       0   15:17.9     NULL        15:17.9
R2_20       1   15:26.0     15:26.0     NULL
R2_20       0   15:28.0     NULL        15:28.0
R2_20       1   15:36.0     15:36.0     NULL
R2_20       0   15:38.0     NULL        15:38.0

Answer 1

如果您使用的 SQL Server 版本支持 LEAD功能，使用它。但这只是我根据您提供的数据做出的猜测。

SELECT
  SourceName sname,
  Active active,
  EventTimeStamp start,
  [end],
  DATEDIFF(millisecond, EventTimeStamp, [end]) difference
FROM (
  SELECT
    *,
    LEAD(EventTimeStamp)
      OVER (PARTITION BY SourceName
            ORDER BY EventTimeStamp, Active DESC) [end]
  FROM AllEvents
) t
WHERE Active = 1;

但对于更复杂的数据集，以下查询可能更可取。

WITH
  AllEvents AS (
    SELECT
      sn SourceName,
      CAST(a as INT) Active,
      CAST(ts as TIME) EventTimeStamp
    FROM (VALUES
      ('R2_20', 1, '00:14:51.9'),
      ('R2_20', 1, '00:14:52.9'),
      ('R2_20', 0, '00:14:53.9'),
      ('R2_20', 1, '00:15:05.9'),
      ('R2_20', 0, '00:15:07.9'),
      ('R2_20', 1, '00:15:15.9'),
      ('R2_20', 1, '00:15:16.9'),
      ('R2_20', 0, '00:15:17.5'),
      ('R2_20', 0, '00:15:17.9'),
      ('R2_20', 1, '00:15:26.0'),
      ('R2_20', 0, '00:15:28.0'),
      ('R2_20', 1, '00:15:36.0'),
      ('R2_20', 0, '00:15:37.0'),
      ('R2_20', 0, '00:15:38.0')
    ) t(sn, a, ts)
  ),
  a AS (
    SELECT
      *,
      ROW_NUMBER() OVER (PARTITION BY SourceName ORDER BY EventTimeStamp) -
        ROW_NUMBER() OVER (PARTITION BY SourceName, Active ORDER BY EventTimeStamp) g
    FROM AllEvents
  ),
  b AS (
    SELECT
      SourceName,
      Active,
      IIF(Active = 0, MAX(EventTimeStamp), MIN(EventTimeStamp)) start
    FROM a
    GROUP BY SourceName, Active, g
  ),
  c AS (
    SELECT
      *,
      LEAD(start) OVER (PARTITION BY SourceName ORDER BY start, Active DESC) [end],
      DATEDIFF(millisecond,
               start,
               LEAD(start) OVER (PARTITION BY SourceName
                                 ORDER BY start, Active DESC)) difference
    FROM b
  )
SELECT * FROM c WHERE Active = 1 ORDER BY start;