--按月求和
select month(created_date)  as month,sum(amount),sum(quan)
  from tb
    group by month(created_date)

------解决方案--------------------

SQL code

--应该把年份也考虑进来吧，如果不用那么2楼就是对的了
select year(created_date) as year,month(created_date)  as month,sum(amount),sum(quan)
from tb
group by year(created_date),month(created_date)