Question

在psql中，我编写了一个查询，每周返回唯一用户

COUNT(DISTINCT user_id)

但是，我也有兴趣计算每周唯一新用户的数量，换句话说，就是之前几周从未活跃过的用户。

如何在postgresql中编写此查询？

当前查询：

SELECT  TO_CHAR(date_trunc('week', start_time::date), 'YYYY-MM-DD') 
AS weekly, COUNT(*) AS total_transactions, COUNT(DISTINCT user_id) AS unique_users 
FROM transactions 
GROUP BY  weekly ORDER BY  weekly

Answer 1

使用min获取user_id的第一次出现。用它来计算每周的唯一身份用户。您可能还希望在年份中包含分组。

select 
TO_CHAR(date_trunc('week', first_appearance), 'YYYY-MM-DD') AS weekly, 
COUNT(*) AS total_transactions,
COUNT(DISTINCT user_id) AS unique_users
from (SELECT t.*,
      MIN(start_time::date) OVER(PARTITION BY user_id) AS first_appearance
      FROM transactions t
     ) t
GROUP BY weekly

每期独特的新用户

1 个答案: