Question

我在Postgres有一个点模式，其中每个出租车旅行的接送时间和位置记录了几个月。我需要计算给定间隔（例如3月5日至3月27日之间）的时间窗口（例如，在00:00和03:00之间）的出租车行程的数量。因此，对于给定的示例，我需要计算在5点到6点，7点，3点和3月27日在00:00和03:00之间发生的总出租车行程。

我找到的唯一一个函数是'date_trunc'，但我并不认为它是合适的，因为窗口大小已经固定。

Answer 1

drop table if exists taxi_trips;

create table taxi_trips
( pickup timestamp
, dropoff timestamp null
, notes varchar(100)
);

insert into taxi_trips (pickup,  dropoff, notes) values ('2/28/2018 07:15', '2/28/2018 7:35', 'not found, date too early');
insert into taxi_trips (pickup,  dropoff, notes) values ('3/5/2018 01:15', '3/5/2018 1:35', 'found');
insert into taxi_trips (pickup,  dropoff, notes) values ('3/5/2018 06:15', '3/5/2018 6:35', 'not found, outside time window');
insert into taxi_trips (pickup,  dropoff, notes) values ('3/6/2018 01:15', '3/6/2018 1:35', 'found');
insert into taxi_trips (pickup,  dropoff, notes) values ('3/6/2018 06:15', '3/6/2018 6:35', 'not found, outside time window');
insert into taxi_trips (pickup,  dropoff, notes) values ('4/1/2018 07:15', '4/1/2018 7:35', 'not found, date too late');

select count(*)
from taxi_trips
where pickup between '3/5/2018' and '3/28/2018'
and extract (hour from pickup) between 0 and 3

Postgres - 查询时间序列模式

1 个答案: