问题描述
这是一个孤岛问题。有不同的方法,但是一种简单的方法使用不同的行号:
with paaf as (<your first query here>
)
select paaf.assignment_id,
paaf.position_id,
min(paaf.effective_start_date) as effective_start_date,
max(paaf.effective_end_date) as effective_end_date
from (select paaf.*,
row_number() over (order by effective_start_date) as seqnum,
row_number() over (partition by position_id order by effective_start_date) as seqnum_p
from paaf
) paaf
group by (seqnum - seqnum_p), position_id, assignment_id;
解决方法
我有以下查询
select paaf.assignment_id,paaf.position_id,paaf.effective_start_date effective_start_date,paaf.effective_end_date effective_end_date
from per_all_assignments_f paaf
where paaf.position_id is not null
and paaf.assignment_type in ('E','C')
and paaf.primary_flag = 'Y'
and paaf.assignment_number like '209384%'
order by 3
哪个返回
"assignment_id" "position_id" "effective_start_date" "effective_end_date"
6518 5323 01/01/2013 28/02/2014
6518 8133 01/03/2014 30/06/2014
6518 8133 01/07/2014 31/10/2015
6518 239570 01/11/2015 15/11/2015
6518 239570 16/11/2015 31/12/2015
6518 8133 01/01/2016 27/07/2016
6518 8133 28/07/2016 31/12/4712
我将其分组为:
select paaf.assignment_id,min(paaf.effective_start_date) effective_start_date,max(paaf.effective_end_date) effective_end_date
from per_all_assignments_f paaf
where paaf.position_id is not null
and paaf.assignment_type in ('E','C')
and paaf.primary_flag = 'Y'
and paaf.assignment_number like '209384%'
group by paaf.assignment_id,paaf.position_id
哪个返回:
"assignment_id" "position_id" "effective_start_date" "effective_end_date"
6518 5323 01/01/2013 28/02/2014
6518 8133 01/03/2014 31/12/4712
6518 239570 01/11/2015 31/12/2015
但是我需要一个返回的查询
"assignment_id" "position_id" "effective_start_date" "effective_end_date"
6518 5323 01/01/2013 28/02/2014
6518 8133 01/03/2014 31/10/2015
6518 239570 01/11/2015 31/12/2015
6518 8133 01/01/2016 31/12/4712
也就是说8133的position_id必须具有两行,因为按时间顺序有两个部分必须分组为2行而不是1(对于8133)。
是否有某种使用日期顺序完成此操作的方法?
答案是:
with paaf as
(
select paaf.assignment_id,paaf.effective_end_date effective_end_date
from per_all_assignments_f paaf
where paaf.position_id is not null
and paaf.assignment_type in ('E','C')
and paaf.primary_flag = 'Y'
-- and paaf.assignment_number like '209384%'
order by 1,3
)
select paaf2.assignment_id,paaf2.position_id,min(paaf2.effective_start_date) as effective_start_date,max(paaf2.effective_end_date) as effective_end_date
from (
select paaf.*,row_number() over (order by paaf.assignment_id,paaf.effective_start_date) as seqnum,row_number() over (partition by paaf.assignment_id,paaf.position_id order by paaf.assignment_id,paaf.effective_start_date) as seqnum_p
from paaf
) paaf2
group by (paaf2.seqnum - paaf2.seqnum_p),paaf2.assignment_id,paaf2.position_id