select user_id,
    floor(sum(timestampdiff(minute,v.visit_time, v.leave_time)/10) ) as point
from visit_tb as v
group by user_id
order by point desc
#感觉也可以先合并时间区间，再计算
#可以计算每天的积分数目，比现在合理或者提前指定时间区间