如何使用Oracle SQL向rank()添加移动窗口

Question

我需要在移动时间窗口上对值进行排名.我从Tony Hasler的博客文章中得到了一些指示,请访问https://tonyhasler.wordpress.com/2012/10/24/model-clause-use-cases/#comment-5116,但是向非非 添加窗口条款的解决方案像中位数这样的窗口函数不适用于作为分析非窗口函数的rank()或percent_rank()函数.

使用median()函数的工作示例:

with a as (
    select 'a' sector, trunc(sysdate) dt, 64 v from dual union all
    select 'a' sector, trunc(sysdate)-1 dt, 2 from dual union all
    select 'a' sector, trunc(sysdate)-2 dt, 4 from dual union all
    select 'a' sector, trunc(sysdate)-3 dt, 128 from dual union all
    select 'a' sector, trunc(sysdate)-4 dt, 8 from dual union all
    select 'a' sector, trunc(sysdate)-5 dt, 16 from dual union all
    select 'a' sector, trunc(sysdate)-6 dt, 32 from dual union all
    select 'a' sector, trunc(sysdate)-7 dt, 256 from dual union all
    select 'a' sector, trunc(sysdate)-8 dt, 1 v from dual union all
    select 'a' sector, trunc(sysdate)-9 dt, 512 from dual union all
    select 'b' sector, trunc(sysdate) dt, 3 from dual union all
    select 'b' sector, trunc(sysdate)-1 dt, 27 from dual union all
    select 'b' sector, trunc(sysdate)-2 dt, 9 from dual union all
    select 'b' sector, trunc(sysdate)-3 dt, 81 from dual 
)
select * from a
model
partition by (sector)
dimension by (dt)
measures (v, 0 mov_rank)
rules 
(
    mov_rank[ANY] = median(v)[dt between CV()-3 and CV()]
)
order by sector, dt
;

如果我们用rank()替换中位数,则该示例不起作用,如下所示:

with a as (
    select 'a' sector, trunc(sysdate) dt, 64 v from dual union all
    select 'a' sector, trunc(sysdate)-1 dt, 2 from dual union all
    select 'a' sector, trunc(sysdate)-2 dt, 4 from dual union all
    select 'a' sector, trunc(sysdate)-3 dt, 128 from dual union all
    select 'a' sector, trunc(sysdate)-4 dt, 8 from dual union all
    select 'a' sector, trunc(sysdate)-5 dt, 16 from dual union all
    select 'a' sector, trunc(sysdate)-6 dt, 32 from dual union all
    select 'a' sector, trunc(sysdate)-7 dt, 256 from dual union all
    select 'a' sector, trunc(sysdate)-8 dt, 1 v from dual union all
    select 'a' sector, trunc(sysdate)-9 dt, 512 from dual union all
    select 'b' sector, trunc(sysdate) dt, 3 from dual union all
    select 'b' sector, trunc(sysdate)-1 dt, 27 from dual union all
    select 'b' sector, trunc(sysdate)-2 dt, 9 from dual union all
    select 'b' sector, trunc(sysdate)-3 dt, 81 from dual 
)
select * from a
model
partition by (sector)
dimension by (dt)
measures (v, 0 mov_rank)
rules 
(
    mov_rank[ANY] = rank() over (order by v)[dt between CV()-3 and CV()]
)
order by sector, dt
;

我将不胜感激任何帮助.

谢谢.

Answer 1

这可能有点“过时”，但您可能能够使用自连接而不是分析或来获得等效的结果model，如下所示：

with a as (
    select 'a' sector, trunc(sysdate) dt, 64 v from dual union all
    select 'a' sector, trunc(sysdate)-1 dt, 2 from dual union all
    select 'a' sector, trunc(sysdate)-2 dt, 4 from dual union all
    select 'a' sector, trunc(sysdate)-3 dt, 128 from dual union all
    select 'a' sector, trunc(sysdate)-4 dt, 8 from dual union all
    select 'a' sector, trunc(sysdate)-5 dt, 16 from dual union all
    select 'a' sector, trunc(sysdate)-6 dt, 32 from dual union all
    select 'a' sector, trunc(sysdate)-7 dt, 256 from dual union all
    select 'a' sector, trunc(sysdate)-8 dt, 1 v from dual union all
    select 'a' sector, trunc(sysdate)-9 dt, 512 from dual union all
    select 'b' sector, trunc(sysdate) dt, 3 from dual union all
    select 'b' sector, trunc(sysdate)-1 dt, 27 from dual union all
    select 'b' sector, trunc(sysdate)-2 dt, 9 from dual union all
    select 'b' sector, trunc(sysdate)-3 dt, 81 from dual 
)
select
    a.sector, 
    a.dt, 
    a.v, 
    count(case when self.v < a.v then self.v end) + 1 mov_rank
from
    a,
    a self
where
    self.sector = a.sector
    and
    self.dt between a.dt - 3 and a.dt + 3
group by 
    a.sector, 
    a.dt, 
    a.v
order by 
    a.sector, 
    a.dt, 
    a.v;