我有一个记录表，其中包含如下所示的数据：
ID MSG DATE --------------------------------------------- 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
它包含（除其他外）应用程序编写的消息标记。我有兴趣为所有这样的“工作开始”和“工作结束”对生成一份报告，说明在“工作开始”记录和“工作结束”记录之间写入的所有内容。理想情况下，报告看起来像这样：
BATCH_NUM ID MSG DATE --------------------------------------------------------- 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
（添加批次之间的换行符以便于阅读）
输出报告省略了“作业开始和”作业结束“消息，以及”TEst“消息（存在于”作业开始“和”作业结束“对之外。
我甚至不确定从哪里开始编写这种查询，或者最好还是选择PL / SQL。哎呀，我甚至不确定是否有适当的技术术语来表达我的想法。 ;）
（oracle版本为10g）
答案 0 :(得分：1)
我确信有更多的分析方法可以做到这一点，但是我在用标量子查询作弊来构建窗口。
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
答案 1 :(得分：0)
以下示例使用与Adam Musch的答案大致相同的想法，但是将记录集的开始和结束记录在一个选择中，该选择连接到日志记录语句，而不是使用标量子查询。
我认为DENSE_RANK（）不能直接使用，因为没有可用于分区的列。
此外，这些解决方案中的任何一个都假定永远不会重叠日志集。如果第二组在第一组结束之前开始，那就是一个全新的问题......
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;
答案 2 :(得分：0)
这是一种在不使用窗口函数的情况下执行相同技巧的方法，以防万一。
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