数据表test如图：要求统计截止到某月的总额。。。
sql：
方法1：
select t2.month,Sum(t1.amount) from test t1 inner join test t2 on t1.month<=t2.month group by t2.month |
方法2：
select t1.month,(select sum(t2.amount) from test t2 where t2.month<=t1.month) from test t1 |