计算SQL中日期差异的分布

Question

在我们的数据库中，每个用户都有created_at和cancelled_at日期。如何计算用户活动天数的分布（具有cancelled_at日期）。

Answer 1

通过分发，我希望你能看到直方图。为此，您需要聚合：

select date_part('day', cancelled_at - created_at) as activedays, count(*)
from databasetable
group by date_part('day', cancelled_at - created_at)
order by activedays;

Answer 2

SELECT *,DATE_PART('day', cancelled_at - created_at) as daysActive
FROM tableName
WHERE cancelled_at IS NOT NULL

Answer 3

with cte as
(
SELECT DATE_PART ('day', cancelled_at - created_at) as daysactive FROM yourTable WHERE
cancelled_at
IS NOT NULL 
)
select daysactive || ' day(s)'  as days_active from cte