我有关于在不同国家旅行的人的数据，如下所示：
country | begintimestamp | distance
Germany | 2015-01-01 00:00:00 | 100
Germany | 2015-01-01 01:12:13 | 30
France | 2015-01-01 02:13:14 | 40
France | 2015-01-01 03:14:15 | 20
Spain | 2015-01-01 04:15:16 | 10
France | 2015-01-01 05:16:17 | 30
France | 2015-01-01 05:17:18 | 5
Germany | 2015-01-01 06:18:19 | 3
我需要的是能够收到这样的结果 -distance与最早的连续行相加begintimestamp：
country | begintimestamp | distance
Germany | 2015-01-01 00:00:00 | 130 // 100+30, the distance of two first rows summed. …