sql - SQL查询根据移动日期窗口有条件地求和

Question

我试图找出我的用户的一些滑动窗口统计信息。我有一个包含用户的表，以及 created_at 和 verify_at 等列。对于每个月，我想知道有多少用户注册（按 created_at 的 date_trunc 进行简单分组），然后在这些人中，有多少人在我的滑动窗口内进行了验证（称之为 60 天）。

我想做一个 SQL 查询，它给了我类似的东西：

Month    | Registered | Verified in 60 days
Jan 2009 | 1543       | 107
Feb 2009 | 2000       | 250

我正在使用postgresql。我开始查看 sum(case...)，但我不知道我是否可以让我的案例以某种方式依赖于 date_trunc。

当然，这是行不通的，但想法是这样的：

SELECT DATE_TRUNC('month', created_at) as month, 
COUNT(*) as registered,
SUM(CASE WHEN verified_at < month+60 THEN 1 ELSE 0 END) as verified
FROM users
GROUP BY DATE_TRUNC('month', created_at)

Answer 1

SELECT  COUNT(created_at) AS registered,
        SUM(CASE WHEN verified_at <= created_at + '60 day'::INTERVAL THEN 1 ELSE 0 END) AS verified
FROM    generate_series(1, 20) s
LEFT JOIN
        users
ON      created_at >= '2009-01-01'::datetime + (s || ' month')::interval
        AND created_at < '2009-01-01'::datetime + (s + 1 || ' month')::interval
GROUP BY
        s

Answer 2

SELECT
    MONTH,
    COUNT(*) AS Registered,
    SUM (CASE WHEN datediff(day,reg_date,ver_date) < 60 THEN 1 ELSE 0) as 'Verified in 60 //days datediff is an MSSQL function amend for postgresql'
FROM
    TABLE
GROUP BY
    MONTH

Answer 3

也许你可以在不同的月份联合起来。

select sum(whatever), 'january' from user where month = 'january'
union all
select sum(whatever), 'february' from user where month = 'february'
...