这里比例怎么算?
amker 2010-11-25 02:43:28 表A:日期,车号,里程
2010-01-01,AA,10000
2010-01-02,BB,20000
2010-02-03,BB,10000
2010-03-04,AA,20000
2010-04-05,CC,30000
....很多数据
表B,年月,车号,保险费
2010-01,AA,300
2010-01,BB,320
2010-02, CC, 310
2010-02, AA, 300
2010-02, BB, 320
2010-03, AA, 300
2010-03, BB, 320
2010-03, CC, 310
怎么把的第一季度的保险保险按照里程分摊到每公里:
这样写如何:
select 日期,车号,(select sum(b.保险费) from 表B b where b.车号=车号)*10000*(select sum(a.里程) from 表A a where a.车号=车号)
from A