如何使用保留订单的运行计数形成查询

Question

我有一个跟踪表,看起来像这样

我想获得一个看起来像以下输出的运行总计 - 保留订单非常重要 - 因为这是存储的部分的执行顺序 - 它将帮助我分析系统中的瓶颈

我试过了

select max(RowNumber),objectname, count(1) from rob
where eventclass = 42
group by objectname

但这破坏了秩序

这在SQL中是否可行？

更新:我试过这个

select RowNumber,objectname, count(1) from rob
where eventclass = 42
group by objectname,RowNumber
order by RowNumber

但是这个(因为查询非常正确地说rownumber的组(必须有它按顺序排列))

Answer 1

select objectname, 
       count(*)
from (
     select RowNumber,
            objectname,
            row_number() over(order by RowNumber) - row_number() over(order by objectname, RowNumber) as grp
     from rob
     where eventclass = 42
     ) as T
group by grp, objectname
order by min(RowNumber)

使用表变量工作样本.

declare @T table
(
  RowNumber int,
  objectname varchar(50)
)

insert into @T values
(8, 'f_system_log_init'),
(10, 'f_purge_system_log'),
(25, 'f_system_log_msg'),
(65, 'f_system_log_msg'),
(104, 'f_system_log_msg'),
(143, 'f_system_log_msg'),
(182, 'f_system_log_msg'),
(221, 'f_system_log_msg'),
(5015, 'f_get_system_logs_parent_log_id_for_dataloader'),
(5055, 'f_system_log_msg'),
(5096, 'f_system_log_msg')

select objectname, 
       count(*)
from (
     select RowNumber,
            objectname,
            row_number() over(order by RowNumber) - row_number() over(order by objectname, RowNumber) as grp
     from @T
     ) as T
group by grp, objectname
order by min(RowNumber)

结果:

objectname                                         
-------------------------------------------------- -----------
f_system_log_init                                  1
f_purge_system_log                                 1
f_system_log_msg                                   6
f_get_system_logs_parent_log_id_for_dataloader     1
f_system_log_msg                                   2