查询余额

查询余额

select * from cash

查正余额
select userid,balance
from
(
 select userid ,balance = (sum(income)-sum(payout))
 from cash
 group by userid
) a where balance > 0

查总余额
select userid,
balance = (sum(income)-sum(payout) )
from cash
group by userid with rollup

说明：不能直接用sum(balance),最后那个balance 数据才是余额。
      with rollup       加多一行统计总和

cash 表
Id  userid   date       income    payout  balance currency
6     6    2007-04-29   1000.00   0.00    1000.00     1
56    7    2007-05-08   100.00    0.00    -75.15      1