账户余额表结构
现有三表:
1.account: accountID, ownerID, blance...;
2.income: incomeID, accountID, incomeAmount, time...
3.payout: payoutID, accountID, incomeAmount, time...
大家都知道账户余额 balance = Sum(incomeAmount) - Sum(incomeAmount),
但是到底要不要在account表中设一个balance字段呢?
如果设,每次交易都要更新account的balance;
若不设,每次查询余额都要来次 balance = Sum(incomeAmount) - Sum(incomeAmount);
有没有更好的办法?