如何在雪花sql中用分区和order来计数不同的值？

Question

我的数据如下：

| user | eventorder| postal|
|:---- |:---------:| -----:|
| A    | 1         | 60616 |
| A    | 2         | 10000 |
| A    | 3         | 60616 |
| B    | 1         | 20000 |
| B    | 2         | 30000 |
| B    | 3         | 40000 |
| B    | 4         | 30000 |
| B    | 5         | 20000 |

--我需要解决的问题:在每个事件订购之前，用户需要停多少个不同的站点？

理想的结果如下：

| user | eventorder| postal| travelledStop|
|:---- |:---------:| -----:| ------------:|
| A    | 1         | 60616 |  1    |
| A    | 2         | 10000 |  2    |
| A    | 3         | 60616 |  2    |
| B    | 1         | 20000 |  1    |
| B    | 2         | 30000 |  2    |
| B    | 3         | 40000 |  3    |
| B    | 4         | 30000 |  3    |
| B    | 5         | 20000 |  3    |

以A为例，当事件顺序为1时，它只行驶了60616 - 1站.当事件顺序为2时，它已经行驶了60616站和10000 - 2站.当事件顺序为3时，此用户所走过的不同停止为60616和10000。-2站。

我不允许使用和order分区。我想做这样的事情，如计数(不同(邮政))在(按用户订单按事件顺序分区)，但这是不允许的。

有人知道怎么解决这个问题吗？非常感谢!

Answer 1

也许最简单的方法是使用子查询并计算“1”：

select t.*,
       sum(case when seqnum = 1 then 1 else 0 end) over (partition by usr order by eventorder) as num_postals
from (select t.*,
             row_number() over (partition by usr, postal order by eventorder) as seqnum
      from t
     ) t

Answer 2

我使用了您提供的样本数据(只是A的子集，但这应该是扩展的)。这里的目标实际上是为每一行生成一个数组，该数组累加前一个事件的所有that。

with _temp as (
select 'A' as usr, 1 as EventOrder, '60616' as Postal
UNION ALL
select 'A' as usr, 2 as EventOrder, '10000' as Postal
UNION ALL
select 'A' as usr, 3 as EventOrder, '60616' as Postal
),
_intermediate as (
select usr
    , eventorder
    , postal
    , array_slice(
          array_agg(postal)
            within group (order by eventorder)
            OVER (Partition by usr)
           , 0, eventorder) as full_array
from _temp
group by usr, eventorder, postal
)
select usr, eventorder, postal, count(distinct f.value)
from _intermediate i, lateral flatten(input => i.full_array) f
group by usr, eventorder, postal

Answer 3

我喜欢@Daniel Zagales的回答，但是这里有一个使用dense_rank和sum的方法。

with temp as (
select 'A' as usr, 1 as EventOrder, '60616' as Postal
UNION ALL
select 'A' as usr, 2 as EventOrder, '10000' as Postal
UNION ALL
select 'A' as usr, 3 as EventOrder, '60616' as Postal  
UNION ALL
select 'B' as usr, 1 as EventOrder, '20000' as Postal  
UNION ALL
select 'B' as usr, 2 as EventOrder, '30000' as Postal  
UNION ALL
select 'B' as usr, 3 as EventOrder, '40000' as Postal 
UNION ALL
select 'B' as usr, 4 as EventOrder, '30000' as Postal  
UNION ALL
select 'B' as usr, 5 as EventOrder, '20000' as Postal 
),
temp2 as(
select temp.* ,dense_rank()over(partition by usr,Postal order by EventOrder) rks
from temp 
)
select usr,eventorder,postal,sum(case when rks = 1 then 1 else 0 END)over(partition by usr order by EventOrder) travelledStop
from temp2 
order by usr,EventOrder 

主要是用dense_rank来得到第一次出现，停止而不是总结。

db<>fiddle