mysql允许任意计算机登录

设置用户root密码：SET PASSWORD FOR 'root'@'localhost' = PASSWORD ('root');
允许任意计算机登录mysql服务器：GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'root' WITH GRANT OPTION;


异常：com.mysql.jdbc.PacketTooBigException：
查看：show VARIABLES like '%max_allowed_packet%'
设置：set global max_allowed_packet = 2*1024*1024*10;