最近有一个需求:统计每日充值/消费之后的余额,对于这种需求,其实也很简单,只需要在每次充值/消费后,计算下余额,然后保存下来就可以了。但是对于这种需求,一条sql就能搞定,都不需要做冗余字段图表展示这个场景可能更直白需要的结果写法一:select t.,(select sum(price) from t_charge temp where temp.date <= t.date) as total_pricefrom t_charge tgroup by t.id;写法二:select t., sum(temp.price) as total_pricefrom t_charge t,t_charge tempwhere t.date <= temp.dategroup by t.id;欢迎订阅「K叔区块链」 - 专注于区块链技术学习 博客地址:http://www.jouypub.com简书主页:https://www.jianshu.com/u/756c9c8ae984segmentfault主页:https://segmentfault.com/blog/jouypub腾讯云主页:https://cloud.tencent.com/developer/column/72548