1. 免密码登陆

[wyhcli]➜  ~ vim /etc/my.cnf skip-grant-tables  [wyhcli]➜  ~ systemctl restart mysqld

2. 将旧密码置空

[wyhcli]➜ ~ vim /etc/my.cnf skip-grant-tables 
[wyhcli]➜ ~ systemctl restart mysqld

3. 去除免密码登陆

  • 删掉步骤1的语句 skip-grant-tables
  • 重启服务 `service mysqld restart

4. 修改密码

[wyhcli]➜ ~ mysql -uroot -p # 提示输入密码时直接敲回车，刚刚已经将密码置空了
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.22

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Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> alter user 'root'@'localhost' identified by '新密码（码形式过于简单则会报错）';
Query OK, 0 rows affected (0.01 sec)


mysql>