如何使用 windows 功能检索第一个日期和最后一个日期？

Question

我有一些数据（表格有更多列，这是一个示例输出）：

我想检索 factory_id、first_read_date、last_read_date 和 total_count。 (first_read_date, last_read_date 是基于 factory_id) 我尝试使用 windows 功能，但最后一个 read_date 不正确。 这是我所做的：

with temptable as(
select
factory_id,
read_date,
rank() over(partition by factory_id order by read_date asc) as Ranked_first_read_date,
rank() over(partition by factory_id order by read_date desc) as Ranked_last_read_data,
concat(read_date,' _ ',rank() over(partition by factory_id order by read_date asc)) as first_read_date ,
concat(read_date,' _ ',rank() over(partition by factory_id order by read_date desc)) as last_read_date,
count(*) over() as total_count
from TestDatabase.sensor_data
order by factory_id,read_date)
select * from temptable a
where Ranked_first_read_date=1 and 
Ranked_last_read_data=(select max(b.Ranked_last_read_data) from temptable b where a.factory_id=b.factory_id group by factory_id)

我正在使用 BigQuery。 任何帮助将不胜感激。

Answer 1

您应该尝试执行以下查询：-

select factory_id , min(read_date) as first_read_date, max (read_date) as last_read_date  , count(*) as total_count_per_FacID,
(select count(*) from table) as total
FROM table
group by factory_id 

Answer 2

factory_id、first_read_date、last_read_date 和 total_count

对窗口函数使用聚合：

select sd.factory_id, min(sd.read_date) as first_read_date,
       max(sd.read_date) as last_read_date,
       count(*) as cnt_per_factory,
       sum(count(*)) over () as cnt_total
from TestDatabase.sensor_data sd
group by factory_id