1.向下取整 var num1 = 12.10345; var num2 =12.9801; var newnum1=Math.floor(num1) //结果 12 var newnum2=Math.floor(num2) //结果 12 注:Math.floor()不进行四舍五入,直接舍去小数部分 2.向上取整 var num1 = 12.10345; var num2 =12.9801; var num3=12: var num4=12.0: var newnum1=Mat
安装bugfree后,访问报错:CDbConnection 无法开启数据库连线: SQLSTATE[HY000] [2003] Can't connect to MySQL server on '192.168.0.99' (4) 现象:虚机的ip是192.168.1.188,但是192.168.1.188/bugfree去访问的时候,提示连接不到192.168.0.99. 尝试解决: ip的配置是在程序的配置文件里配置的 1.可能是mysql没启动,查看mysql的运行情况:service m
MySQL :: MySQL 8.0 Reference Manual :: B.6.4.3 Problems with NULL Values https://dev.mysql.com/doc/refman/8.0/en/problems-with-null.html MySQL 8.0 Reference Manual / ... / Problems with NULL Values B.6.4.3 Problems with NULL Values The concept of