统计PostgreSQL中的第一条记录

Question

我有一个 table 这样的（在我的用户过滤器之后）

ID    user_id      action_type    created_date
1       123            3           27/1/2022
2       123            3           30/1/2022
3       123            3           08/03/2022
4       123            3           08/03/2022

然后我有这个查询

select date_trunc('week', created_date::timestamptz) as "Week"
      ,count(distinct user_id) filter (where action_type = 3) as "linkbank"
From action_logs
Where action_type = 3 and user_id = '123'
Group by "Week"

查询结果是这样的

Week           linkbank
24/01/2022         1
07/03/2022         1

所以如果我必须第一次计算客户端链接库，我应该在查询中更改什么？

例如，如果我用 user_id =123 更改查询，我希望结果只取第一行

我会尝试你评论的一切。

感谢。

Answer 1

如果你只想要一个 user_id

select date_trunc('week', created_date::timestamptz) as "Week"
      ,count(distinct user_id) filter (where action_type = 3) as "linkbank"
From action_logs
Where action_type = 3 and user_id = 123
Group by "Week"
order by "Week"
limit 1;

如果您希望所有用户都能使用

with l as (
  select row_number() over (partition by user_id order by user_id, date_trunc('week', created_date::timestamptz)) as rn,user_id, date_trunc('week', created_date::timestamptz) as "Week"
        ,count(distinct user_id) filter (where action_type = 3) as "linkbank"
  From action_logs
  Where action_type = 3
  Group by user_id,"Week"
)
select * from l where rn = 1

Results here

统计PostgreSQL中的第一条记录

Count the first record in PostgreSQL

postgresql

count