Question

这可能是一个非常简单的问题，但是我想将两个独立的查询加入一个表中。其中一个查询显示按月注册我的网站，另一个查询显示已购买的注册。我想将两个查询合并到一个表中，所以有下表：

Month      Sign-ups  Sign-ups with Purchase
Jan 2019   250       40
Feb 2019   500       120

我该怎么做？这是我的两个查询：

注册：

select
  count(u.id) as Sign_Ups
  , month(From_iso8601_timestamp(u.created)) as Month
from
   prodjoinreel.users u
where
  year(From_iso8601_timestamp(u.created)) = 2019
group by
  2
order by
  2 asc

注册购买：

select
  count(distinct g.owner) as Sign_Ups_with_Reel
  , month(From_iso8601_timestamp(u.created)) as Month
from
  prodjoinreel.goals g
  right join prodjoinreel.users u on
    g.owner = u.id
where
  year(From_iso8601_timestamp(u.created)) = 2019
group by
  2
order by
  2 asc

谢谢！

Answer 1

我认为您可以在第二个查询中添加一个count(distinct u.id)：

select
  month(From_iso8601_timestamp(u.created)) as Month,
  count(distinct u.id) as Sign_Ups,
  count(distinct g.owner) as Sign_Ups_with_Reel
from
  prodjoinreel.users u
  left join prodjoinreel.goals g on g.owner = u.id
where year(From_iso8601_timestamp(u.created)) = 2019
group by 1
order by 1

注意：我将您的right join更改为left join；大多数人倾向于认为right join是违反直觉的，而倾向于left join。

将具有不同where子句的两个查询联接到1个表中

1 个答案: