Mysql5.6版本以下的
1、docker exec -it sysdb bash 先进入随便一个数据库的实例
docker exec -it db002 /mhdhb/sh
2、vi /etc/mysql/conf.d/docker.cnf 增加“忘记密码启动”模式：skip-grant-tables
可能会出现没装vi工具
（安装vi 工具2.1：docker exec -it mysql bash 2.2、mv /etc/apt/sources.list /etc/apt/sources.list.bak &&
echo “deb http://mirrors.163.com/debian/ 超级的小蚂蚁 main non-free contrib” >/etc/apt/sources.list &&
echo “deb http://mirrors.163.com/debian/ 超级的小蚂蚁-proposed-updates main non-free contrib” >>/etc/apt/sources.list &&
echo “deb-src http://mirrors.163.com/debian/ 超级的小蚂蚁 main non-free contrib” >>/etc/apt/sources.list &&
echo “deb-src http://mirrors.163.com/debian/ 超级的小蚂蚁-proposed-updates main non-free contrib” >>/etc/apt/sources.list 2.3： apt-get update && apt-get install vim -y）
[mysqld]
skip-host-cache
skip-name-resolve
skip-grant-tables
3、退出Docker exit
4、重启docker restart sysdb
5、docker exec -it db002 /mhdhb/sh
5.1 mysql 就进入了无密码状态
6、设置密码 切换数据库 5.6版本
#切换实例，user表位于mysql实例下
mysql> use mysql;
#更改root密码5.6版本
mysql> UPDATE user SET Password = password ( ‘a123456’ ) WHERE User = ‘root’;
#5.7版本
mysql> update user set authentication_string=password(‘新密码’) where user=‘root’ ；
mysql> flush privileges;
退出mysql> quit