Centos7忘记mysql的root用户密码

1、先停止mysql服务

​[root@CentOS ~]# ps -ef | grep mysql
root                : pts/    :: /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/usr/local/mysql/data --pid-file=/usr/local/mysql/data/CentOS.pid
mysql            : pts/    :: /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=CentOS.err --pid-file=/usr/local/mysql/data/CentOS.pid
root             : pts/    :: grep --color=auto mysql
[root@CentOS ~]# service mysql stop    # 停止 mysql 服务
Shutting down MySQL.. SUCCESS!
[root@CentOS ~]# 

2、使用 mysqld_safe 来启动mysql服务

​[root@CentOS ~]# cd /usr/local/mysql/bin/
[root@CentOS bin]# ./mysqld_safe --skip-grant-tables
--02T07::.491532Z mysqld_safe Logging to '/usr/local/mysql/data/CentOS.err'.
--02T07::.528458Z mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data

在执行 ./mysqld_safe --skip-grant-tables 后终端窗口会暂停输出。其中 --skip-grant-tables 选项表示MySql服务器不加载权限判断，任何用户都能访问数据库。

3、然后另外打开一个终端窗口，免密码登录mysql

​[root@CentOS bin]# ./mysql -u root -p
Enter password:                     # 此处为空密码，直接回车即可
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is
Server version: 5.7. MySQL Community Server (GPL)

Copyright (c) , , Oracle and/or its affiliates. All rights reserved.

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> 

4、重置 root 密码

​mysql> flush privileges;
Query OK,  rows affected (0.01 sec)

mysql> SET PASSWORD FOR 'root'@'localhost' = PASSWORD('root');    # 将 root 密码修改为 'root'
Query OK,  rows affected,  warning (0.00 sec)

mysql> 

修改密码完成后，将使用 mysqld_safe --skip-grant-tables 命令启动的终端窗口关闭，接下来就可以使用新设置的密码登录Mysql了。