Hive SQL 按状态变化查询

Question

vehicle	record_time	charging_state
TEST0000000000001	2022-12-28 14:55:54.0	3
TEST0000000000001	2022-12-28 15:00:00.0	3
TEST0000000000001	2022-12-28 15:16:10.0	3
12100000000000002	2022-12-28 15:37:11.0	0
12100000000000002	2022-12-28 15:40:34.0	0
12100000000000002	2022-12-28 15:41:50.0	3
TEST0000000000001	2022-12-28 15:45:30.0	3
TEST0000000000001	2022-12-28 15:51:46.0	3
TEST0000000000002	2022-12-28 15:57:16.0	2
TEST0000000000002	2022-12-28 15:57:39.0	0
TEST0000000000001	2022-12-28 15:57:47.0	0
TEST0000000000002	2022-12-28 16:02:41.0	3
TEST0000000000001	2022-12-28 16:02:48.0	3
TEST0000000000002	2022-12-28 16:08:03.0	3
12100000000000002	2022-12-28 16:17:34.0	0
TEST0000000000002	2022-12-28 16:24:18.0	2
TEST0000000000002	2022-12-28 16:27:43.0	2
12100000000000002	2022-12-28 16:29:22.0	0
12100000000000002	2022-12-28 16:32:44.0	0
TEST0000000000001	2022-12-28 16:34:17.0	3
TEST0000000000001	2022-12-28 16:34:36.0	3
TEST0000000000002	2022-12-28 16:35:02.0	0
TEST0000000000002	2022-12-28 16:35:08.0	2
TEST0000000000001	2022-12-28 16:41:28.0	3
TEST0000000000002	2022-12-28 16:42:34.0	2
TEST0000000000002	2022-12-28 16:46:00.0	2
TEST0000000000001	2022-12-28 16:46:23.0	3
TEST0000000000002	2022-12-28 16:46:31.0	2
TEST0000000000001	2022-12-28 16:46:48.0	0
TEST0000000000002	2022-12-28 17:14:27.0	0
TEST0000000000001	2022-12-28 17:14:41.0	0
TEST0000000000002	2022-12-28 17:18:58.0	2

charging_state == 0 means charging

I want to find out the count of all charge ends.

For each vehicle the previous data charging_state == 0 and the next data charging_state != 0 .

The result of the sample data should be

vehicle	count
TEST0000000000001	1
12100000000000002	1
TEST0000000000002	3

Answer 1

Assuming this is hive, you can use lead() to get next charging status and then compare them to calculate change of status.

select vehicle, 
sum( case when charging_state=0 and nvl(next_charging_state,0)<>0 then 1 else 0 end) as cnt
from (
select vehicle, charging_state, lead(charging_state) over (partition by vehicle order by vehicle,record_time ) as next_charging_state from mytable) rs
group by 1

Inner query will calculate a row and next row's status and Outer query will compare them and get a count of status change from 0 to anything else.