一.更改root密码

1.mysqladmin直接修改

mysqladmin -uroot -p"SH123.com" password "ty123.com"

2.登陆MySQL修改相应表

mysql> desc mysql.user;
mysql> select host,user,authentication_string from mysql.user;
mysql> update mysql.user set authentication_string=password("SH123.com") where user="root" and host=‘localhost‘;

//刷新授权表

mysql> flush privileges;

二.忘记密码：

vi  /etc/my.cnf
 [mysqld]
basedir=/soft/mysql
datadir=/soft/mysql/data
skip-grant-tables   # 新增授权表

//重启MySQL数据库

systemctl restart mysqld.service

//登陆MySQL修改相应表

mysql> update mysql.user set authentication_string=password("ty123.com") where user=‘root‘ and host=‘localhost‘;
mysql> desc mysql.user;
mysql> select host,user,authentication_string from mysql.user;
mysql> update mysql.user set authentication_string=password("SH123.com") where user="root" and host=‘localhost‘;

//刷新授权表

mysql> flush privileges;

注：登陆成功后
注释skip-grant-tables 使用新的密码登陆

修改Mysq数据库密码