查询以获取每个组的最大时间

Question

I have data in the following format and would like to output it in second format. I've tried a self join on the data and group by on id, time and event but nothing I've tried seems to work correctly.

The time at EV-2 is the starting time and the time at EV-5 is the ending time. EV-5 time can be written as the end time for each EV-2 - EV-5 event.

Thanks for any guidance with this matter.

ID  TIME                        EVENT
1   2016-03-21 12:30:00.000     EV-1    
1   2016-03-21 12:30:30.000     EV-2
1   2016-03-21 12:33:00.000     EV-3
1   2016-03-21 12:33:00.000     EV-4
1   2016-03-21 12:33:45.000     EV-5
1   2016-03-21 12:33:50.000     EV-1    
1   2016-03-21 12:33:55.000     EV-2
1   2016-03-21 12:35:15.000     EV-3
1   2016-03-21 12:35:15.000     EV-4
1   2016-03-21 12:40:20.000     EV-5
2   2016-03-21 12:40:50.000     EV-1    
2   2016-03-21 12:41:25.000     EV-2
2   2016-03-21 12:41:25.000     EV-3
2   2016-03-21 12:42:13.000     EV-4
2   2016-03-21 12:47:35.000     EV-5

Output
ID  TIME(startTime)             EVENT   endTime
1   2016-03-21 12:30:00.000     EV-1    
1   2016-03-21 12:30:30.000     EV-2    2016-03-21 12:33:45.000
1   2016-03-21 12:33:00.000     EV-3    2016-03-21 12:33:45.000
1   2016-03-21 12:33:00.000     EV-4    2016-03-21 12:33:45.000
1   2016-03-21 12:33:45.000     EV-5    2016-03-21 12:33:45.000
1   2016-03-21 12:33:50.000     EV-1    
1   2016-03-21 12:33:55.000     EV-2    2016-03-21 12:40:20.000
1   2016-03-21 12:35:15.000     EV-3    2016-03-21 12:40:20.000
1   2016-03-21 12:35:15.000     EV-4    2016-03-21 12:40:20.000
1   2016-03-21 12:40:20.000     EV-5    2016-03-21 12:40:20.000
2   2016-03-21 12:40:50.000     EV-1    
2   2016-03-21 12:41:25.000     EV-2    2016-03-21 12:47:35.000
2   2016-03-21 12:41:25.000     EV-3    2016-03-21 12:47:35.000
2   2016-03-21 12:42:13.000     EV-4    2016-03-21 12:47:35.000
2   2016-03-21 12:47:35.000     EV-5    2016-03-21 12:47:35.000

What I've tried:

select d.ID, d.TIME, d.EVENT, max(dd.TIME) endTime
from dataTable d
  inner join dataTable dd on d.ID = dd.ID and d.EVENT = dd.EVENT and d.TIME < dd.TIME
group by d.ID, d.TIME, d.EVENT

Answer 1

Simple solution, use a correlated sub-select to return the smallest EV-5 time larger or equal to the current row's time. (Have a case expression to do this for all events but EV-1.)

select t1.*, case when t1.event <> 'EV-1' then (select min(t2.TIME) from dataTable t2
                                                where t2.event = 'EV-5'
                                                  and t2.TIME >= t1.time)
             end as endTime
from dataTable t1

Alternatively, if id can be used, do a self (left) join:

select t1.*, case when t1.event <> 'EV-1' then t2.TIME
             end as endTime
from dataTable t1
  left join dataTable t2 on t1.id = t2.id and t2.event = 'EV-5'

( left join to also return id's without any EV-5, if needed.)

Answer 2

@jarhl's logic for DBMSes supporting Windowed Aggregate Functions like SQL Server 2014:

SELECT t.*,
   CASE
     WHEN EVENT <> 'EV-1' 
     THEN MIN(CASE WHEN EVENT = 'EV-5' THEN TIME end) 
          OVER (PARTITION BY ID -- maybe not needed 
                ORDER BY TIME
                ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING)
   END AA endTime
FROM tablename AS t1

Answer 3

Correcting your ID column to an actual ID, try

IF (SELECT OBJECT_ID('tempdb..#Events')) IS NOT NULL
BEGIN
    DROP TABLE #Events
END

CREATE TABLE #Events (ID INT,EventTime datetime, eventName varchar(4))
INSERT INTO #Events
VALUES        
(1, '2016-03-21 12:30:00.000','EV-1'),
(1, '2016-03-21 12:30:30.000','EV-2'),
(1, '2016-03-21 12:33:00.000','EV-3'),
(1, '2016-03-21 12:33:00.000','EV-4'),
(1, '2016-03-21 12:33:45.000','EV-5'),
(2, '2016-03-21 12:33:50.000','EV-1'),
(2, '2016-03-21 12:33:55.000','EV-2'),
(2, '2016-03-21 12:35:15.000','EV-3'),
(2, '2016-03-21 12:35:15.000','EV-4'),
(2, '2016-03-21 12:40:20.000','EV-5'),
(3, '2016-03-21 12:40:50.000','EV-1'),
(3, '2016-03-21 12:41:25.000','EV-2'),
(3, '2016-03-21 12:41:25.000','EV-3'),
(3, '2016-03-21 12:42:13.000','EV-4'),
(3, '2016-03-21 12:47:35.000','EV-5')
;
WITH cteEvent AS
(
    SELECT ID, EventTime AS startTime,en.endTime
    FROM #Events e
    CROSS APPLY (
                    SELECT EventName,EventTime AS endTime 
                    FROM #Events e2 
                    WHERE e2.ID = e.id AND CAST(RIGHT(e2.eventname,1) AS INT) = 5) as en
    WHERE e.EventName = 'EV-1'
)
SELECT c.id,eventName,startTime,
    CASE 
        WHEN eventName = 'EV-1' 
        THEN NULL
        ELSE endTime
    END  AS endTime
FROM cteEvent c
LEFT JOIN #Events e ON c.id = e.id