Question

我正在尝试找到每月执行操作A或操作B的＃个用户。

表：用户 - ID - “creationDate”

表：action_A - user_id（= user.id） - “creationDate”

表：action_B - user_id（= user.id） - “creationDate”

我尝试做的一般想法是，我会找到在第X个月执行操作A的用户列表以及在第X个月执行操作B的用户列表，然后计算有多少个ID每月根据generate_series的月度日期。

我尝试了以下操作，然而，查询在运行时超时，我不确定是否有任何方法可以优化它（或者它是否正确）。

SELECT monthseries."Month", count(*)
FROM
  (SELECT to_char(DAY::date, 'YYYY-MM') AS "Month"
   FROM generate_series('2014-01-01'::date, CURRENT_DATE, '1 month') DAY) monthseries
LEFT JOIN
  (SELECT to_char("creationDate", 'YYYY-MM') AS "Month",
          id
   FROM action_A) did_action_A ON monthseries."Month" = did_action_A."Month"
LEFT JOIN
  (SELECT to_char("creationDate", 'YYYY-MM') AS "Month",
          id
   FROM action_B) did_action_B ON monthseries."Month" = did_action_B."Month"
GROUP BY monthseries."Month"

任何评论/帮助都会非常有帮助！

Answer 1

如果您想计算不同的用户：

select to_char(month, 'YYYY-MM') as "Month", count(*)
from
    generate_series(
        '2014-01-01'::date, current_date, '1 month'
    ) monthseries (month)
    left join (
        (
            select distinct date_trunc('month', "creationDate") as month, id
            from action_a
        ) a
        full outer join (
            select distinct date_trunc('month', "creationDate") as month, id
            from action_b
        ) b using (month, id)
    ) s using (month)
group by 1
order by 1

加入generate_series并计算

1 个答案: