Question

我有一个包含用户ID的数据集，这些用户ID随着时间的推移进行了购买。我想显示按年和年初至今已进行购买的用户数量，按州和国家/地区划分。输出将具有4列：国家，州，年，月，具有购买活动的不同用户的年初至今计数。

有没有办法做到这一点？当我从视图中排除月份并进行独立计数时，以下代码有效：

Select Year, Country, State,
   COUNT(DISTINCT (CASE WHEN ActiveUserFlag > 0 THEN MBR_ID END)) AS YTD_Active_Member_Count
From MemberActivity
Where Month <= 5
Group By 1,2,3;

当用户在多个月内进行购买时，就会发生此问题，因为我无法按月汇总，然后再求和，因为它重复了用户计数。

出于趋势目的，我需要查看一年中每个月的YTD计数。

Answer 1

计算出现的第一个月的用户：

select Country, State, year, month,
       sum(case when ActiveUserFlag > 0 and seqnum = 1 then 1 else 0 end) as YTD_Active_Member_Count
from (select ma.*,
             row_number() over (partition by year order by month) as seqnum
      from MemberActivity ma
     ) ma
where Month <= 5
group by Country, State, year, month;

Answer 2

每个会员在购买的第一个月仅退货一次，按月计数，然后应用累计金额：

select Year, Country, State, month,
   sum(cnt)
   over (partition by Year, Country, State
         order by month
         rows unbounded preceding) AS YTD_Active_Member_Count
from
  (
    Select Year, Country, State, month,
       COUNT(*) as cnt -- 1st purchses per month
    From 
     ( -- this assumes there's at least one new active member per year/month/country
       -- otherwise there would be mising rows 
       Select *
       from MemberActivity
       where ActiveUserFlag > 0 -- only active members
         and Month <= 5
         -- and year = 2019 -- seems to be for this year only
       qualify row_number() -- only first purchase per member/year
               over (partition by MBR_ID, year
                     order by month --? probably there's a purchase_date) = 1
     ) as dt
    group by 1,2,3,4
 ) as dt
;

使用Over Partition By运行计数不同

2 个答案: