Oracle—记录对之间的分组

我确信有一种更具分析性的方法可以做到这一点,但是我用标量子查询来构建窗口。

SQL> select * from logging_table;

        ID MSG                            LOG_DT
---------- ------------------------------ -------------------
         1 TEst                           2010-01-01 09:00:00
         2 Job Start                      2010-01-01 09:03:00
         3 Do something                   2010-01-01 09:03:10
         4 Do something else              2010-01-01 09:03:12
         5 Do something                   2010-01-01 09:04:19
         6 Job End                        2010-01-01 09:06:30
         7 Job Start                      2010-01-01 09:18:03
         8 Do something                   2010-01-01 09:18:17
         9 Do other thing                 2010-01-01 09:19:48
        10 Job End                        2010-01-01 09:20:27

SQL> l
  1      select dense_rank() over (order by job_start_id) as batch, 
         -- ^-- this part gets the batch
  2             job_step_id, msg, log_dt
  3             -- nested select to filter out rows outside of the boundaries
  4        from (select *
  5                from (select id as job_step_id, msg, log_dt,
  6                             -- scalar subquery to get start of "window"
  7                             (select max(id)
  8                                from logging_table
  9                               where msg = 'Job Start'
 10                                 and id < log.id) as job_start_id,
 11                             -- scalar subquery to get end of "window"
 12                             (select min(id)
 13                                from logging_table
 14                               where msg = 'Job End'
 15                                 and id > log.id) as job_end_id
 16                       from logging_table log
 17                      -- filter out the "window" rows themselves
 18                      where msg not in ('Job Start', 'Job End')
 19                     )
 20               -- the filtering out of "unbounded" records
 21               where job_start_id is not null
 22                 and job_end_id is not null
 23             )
 24*      order by job_step_id
SQL> /

 BATCH JOB_STEP_ID MSG                            LOG_DT

     1           3 Do something                   2010-01-01 09:03:10
     1           4 Do something else              2010-01-01 09:03:12
     1           5 Do something                   2010-01-01 09:04:19
     2           8 Do something                   2010-01-01 09:18:17
     2           9 Do other thing                 2010-01-01 09:19:48

我不认为可以直接使用DENSE\u RANK(),因为没有可用于分区的列。

而且,这两种解决方案中的任何一种都假设日志集永远不会重叠。如果第二盘在第一盘结束之前开始,那是一个全新的问题。。。

WITH logging_sets AS
     (SELECT DENSE_RANK () OVER (ORDER BY start_date) AS set_rank, start_date, end_date
        FROM (SELECT CASE msg
                        WHEN 'Job End'
                           THEN NULL
                        ELSE LEAD (log_dt, 1, NULL) OVER (ORDER BY log_dt)
                     END AS end_date, log_dt AS start_date, msg
                FROM logging_table lt
               WHERE msg IN ('Job Start', 'Job End') )
       WHERE msg = 'Job Start')
SELECT ls.set_rank, lt.ID, lt.msg, lt.log_dt
  FROM logging_table lt, logging_sets ls
 WHERE lt.log_dt > ls.start_date AND lt.log_dt < ls.end_date 
   AND msg NOT IN ('Job Start', 'Job End')
ORDER BY ls.set_rank, lt.log_dt;

为了以防万一,这里有一种不使用窗口函数的方法。

with logging_table as (
    select 1 id, 'job start' msg from dual union
    select 2, 'do somenthing in batch 1' from dual union
    select 3, 'do somenthing else in batch 1' from dual union
    select 4, 'job end' from dual union
    select 5, 'job start' from dual union
    select 6, 'do somenthing in batch 2' from dual union
    select 7, 'do somenthing else in batch 2' from dual union    
    select 8, 'job end' from dual 
),
jobs as (
    select  lt_start.id id_start,
           (select min(id) 
            from logging_table lt_end 
            where lt_end.id > lt_start.id 
            and msg = 'job end') id_end,
            rownum as batch_no
    from    logging_table lt_start
    where   msg = 'job start'
)
select  *
from    logging_table join jobs 
        on id > id_start and id < id_end
order   by batch_no, id