Q:

How to group by hour in HANA

I have the following table in HANA :
vehicle_id    time                          roaming_time        parking_time
    1          Sep 01,2016 3:09:03 AM            3                   9
    2          Sep 01,2016 3:12:03 AM            6                   8
    1          Sep 01,2016 9:10:03 AM            10                  6
    4          Sep 01,2016 10:09:03 AM           9                   3
    1          Sep 01,2016 10:10:03 AM           10                  10
    4          Sep 01,2016 12:09:03 AM           3                   9

from these information I wanted to know that what is the sum of roaming time and sum of parking time for each hour from all the vehicles and want the output in the format:
time                         roaming_time     parking_time
____                         _____________    ____________
2016-09-01 00:00:00                3                9
2016-09-01 01:00:00                6                8
2016-09-01 02:00:00                9                6
2016-09-01 03:00:00                3                6
2016-09-01 04:00:00                12               3
2016-09-01 05:00:00                15               8
2016-09-01 06:00:00                18               4
2016-09-01 07:00:00                8                3
2016-09-01 08:00:00                9                4
2016-09-01 09:00:00                6                6
2016-09-01 10:00:00                6                9
........
2016-09-01 23:00:00                3                12

I need  to group the following query  which gives all the sum  by hour wise and get the expected result:
select sum(roaming_time) as roaming_time,sum(parking_time) as parking_time from time>='2016-09-01 00:00:00'    time>='2016-09-01 23:59:59'

I do not know how to do the grouping by hour in HANA. Any help is appreciated

A:

Here is one method . . . it converts the time to a date and hour format:
select to_varchar(time, 'YYYY-MM-DD'), hour(time),
       sum(roaming_time) as roaming_time, sum(parking_time) as parking_time from t
group by date(time), hour(time)
order by to_varchar(time, 'YYYY-MM-DD'), hour(time);

