Question

我的数据结构如下 -

1.每个ID月表示报告月份，Sub created是原始订阅购买日期，状态=客户是否活跃，任期为生命周期月份（客户返回时重置为1）

ID  Month       Sub_created status  tenure
100 2017-02-01  2017-02-01  active  1
100 2017-03-01              active  2
100 2017-04-01              active  3
100 2017-05-01              churned 3
100 2021-02-01  2021-02-01  active  1
100 2021-03-01            active    2
100 2021-04-01            active    3
100 2021-05-01            active    4
100 2021-06-01            active    5
100 2021-07-01            active    6

我希望能够为所有行创建 sub，直到它有一个新的订阅日期。我试图获得的输出低于 -

ID  Month       Sub_created status  tenure
100 2017-02-01  2017-02-01  active  1
100 2017-03-01  2017-02-01  active  2
100 2017-04-01  2017-02-01  active  3
100 2017-05-01  2017-02-01  churned 3
100 2021-02-01  2021-02-01  active  1
100 2021-03-01  2021-02-01  active  2
100 2021-04-01  2021-02-01  active  3
100 2021-05-01  2021-02-01  active  4
100 2021-06-01  2021-02-01  active  5
100 2021-07-01  2021-02-01  active  6

谁能建议雪花代码？谢谢

Answer 1

您可以像这样使用 last_value() 窗口函数：

with CTE as (
select 100 as ID, '2017-02-01' as Month, '2017-02-01' as Sub_created, 'active' as status, 1 as tenure union all 
select 100 as ID, '2017-03-01' as Month, null         as Sub_created, 'active' as status, 2 as tenure union all 
select 100 as ID, '2017-04-01' as Month, null         as Sub_created, 'active' as status, 3 as tenure union all 
select 100 as ID, '2017-05-01' as Month, null         as Sub_created, 'churned' as status, 3 as tenure union all 
select 100 as ID, '2021-02-01' as Month, '2021-02-01' as Sub_created, 'active' as status, 1 as tenure union all 
select 100 as ID, '2021-03-01' as Month, null         as Sub_created, 'active' as status, 2 as tenure union all 
select 100 as ID, '2021-04-01' as Month, null         as Sub_created, 'active' as status, 3 as tenure union all 
select 100 as ID, '2021-05-01' as Month, null         as Sub_created, 'active' as status, 4 as tenure union all 
select 100 as ID, '2021-06-01' as Month, null         as Sub_created, 'active' as status, 5 as tenure union all 
select 100 as ID, '2021-07-01' as Month, null         as Sub_created, 'active' as status, 6 as tenure
)
select ID, Month, Sub_created as Sub_created_orig, 
last_value(sub_created ignore nulls) over (partition by id order by month rows between unbounded preceding and current row) as Sub_created_new,
status, tenure
from CTE
order by ID, month;

雪花中的窗函数

1 个答案: