1, MySQL decimal(x,y) 存入根据y的下一位四舍五入,查了半天以为是laravel模型做了预处理,结果发现不是,是mysql decimal类型数据自动处理的,有好,也不好,合并订单数据计算会有误差 2,在字符集为UTF-8的情况下: MySQL | ver < 4.1: VARCHAR以字节为单位存储,所以假设全部为常用汉字(UTF-8 3字节编码长度),则VARCHAR(255)共可存放约85个汉字: MySQL | ver >= 4.1: VARCHAR以字符为单位存…
Today, I had spent 3 hours to fix one problem, The old program has a bug, originally, when a user profile don't now allow Multi Logon, It will update the other login records of [LoginAudit] table of this user, But the code has a problem, it may no…