确定谁在任何 30 天内花费超过一定金额？

Question

我有一个 table，其中列出了每个客户的交易以及交易发生的日期和花费的金额。我想要做的是获取在任何 30 天内花费 3000 英镑或更多的所有客户的列表。

我可以使用下面的代码获得在最后 30 天内花费 3000 英镑或更多的人的列表，但我不确定如何调整它以涵盖任意 30 天期限。如有任何帮助，我们将不胜感激！

select  *
from
        (
        select      customer_id, sum(spend) as total_spend
        from        transaction_table
        where       transaction_date between (current date - 30 days) and current date
        group by    customer_id
        )
where   total_spend >=3000
;

Answer 1

您可以将 SUM() 与 window 函数和 window 帧 30 一起使用。例如：

select *
from (
  select t.*,
    sum(t.spent) over(
      partition by customer_id 
      order by julian_day(transaction_date)
      range between 30 preceding and current row
    ) as total_spend
  from transaction_table t
) x
where total_spend >= 3000

对于数据集：

 CUSTOMER_ID  TRANSACTION_DATE  SPENT 
 ------------ ----------------- ----- 
 1            2021-10-01        2000  
 1            2021-10-15        1500  
 1            2021-12-01        1000  
 2            2021-11-01        2500

结果：

 CUSTOMER_ID  TRANSACTION_DATE  SPENT  TOTAL_SPEND 
 ------------ ----------------- ------ ----------- 
 1            2021-10-15        1500   3500

参见 db<>fiddle 中的运行示例。

Answer 2

试试下面的方法。
这个想法是计算每行过去 30 天的运行支出总和。

WITH TRANSACTION_TABLE (CUSTOMER_ID, TRANSACTION_DATE, SPEND) AS
(
VALUES
  (1, DATE ('2021-01-01'), 1000)
, (1, DATE ('2021-01-31'), 2000)
--, (1, DATE ('2021-02-01'), 2000)
)
SELECT DISTINCT CUSTOMER_ID
FROM
(
SELECT 
  CUSTOMER_ID
--, TRANSACTION_DATE, SPEND
, SUM (SPEND) OVER (PARTITION BY CUSTOMER_ID ORDER BY DAYS (TRANSACTION_DATE) RANGE BETWEEN 30 PRECEDING AND CURRENT ROW) AS SPEND_RTOTAL
FROM TRANSACTION_TABLE
)
WHERE SPEND_RTOTAL >= 3000

确定谁在任何 30 天内花费超过一定金额？

Identifying who spent more than a certain amount within any 30 day period?

sql

db2