按时间间隔分组

这是一个主意，但您需要一个数字表

select (m.startts + n.n - 1) as starttime,
       (m.startts + n.n) as enddtime,
       sum(case when vehicle_type = 'bus' then 1 else 0 end) as bus,
       sum(case when vehicle_type = 'car' then 1 else 0 end) as car
from (select min(Timestamp) as startts from table t) m cross join
     (select 1 as n union all select 2 union all select 3) n left join
     table t
     on t.timestamp >= m.startts + n.n - 1 and 
        t.timestamp < m.startts + n.n
group by m.startts + n.n;

由于采用了浮点算法，因此有点危险，但它可能会满足您的目的。