步骤一：先停止数据库服务

[root@GGB ~]# systemctl  stop   mysql.service 
[root@GGB ~]# systemctl  status  mysql.service 
● mysql.service - MySQL ServerLoaded: loaded (/etc/systemd/system/mysql.service; enabled; vendor preset: disabled)Active: failed (Result: exit-code) since 五 2024-07-12 01:03:45 CST; 1s agoProcess: 3738 ExecStop=/usr/local/mysql/bin/mysqladmin shutdown (code=exited, status=1/FAILURE)Process: 2951 ExecStart=/usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf --basedir=/usr/local/mysql --datadir=/data/3306/data (code=exited, status=0/SUCCESS)Main PID: 2951 (code=exited, status=0/SUCCESS)

步骤二：采用安全模式启动数据库（空密码方式进入数据库） 
 

#mysqld_safe  一个命令
#--skip-grant-tables   Start without grant tables. This gives all users FULL  两个参数
#                      数据库服务启动时，不加载授权表（没有保安）
#--skip-networking     Don't allow connection with TCP/IP关闭远程连接端口
mysqld_safe --skip-grant-tables  --skip-networking   &[root@GGB ~] 
[root@GGB ~]  mysqld_safe --skip-grant-tables --skip-networking &
[1] 4642
[root@GGB ~]  2024-07-11T17:15:00.581337Z mysqld_safe Logging to '/data/3306/data/GGB.err'.
2024-07-11T17:15:00.600168Z mysqld_safe Starting mysqld daemon with databases from /data/3306/data[root@GGB ~]  
[root@GGB ~]  ps -ef | grep mysql
root       4642   2019  0 01:14 pts/0    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --skip-grant-tables --skip-networking
mysql      4798   4642  3 01:14 pts/0    00:00:00 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/data/3306/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --skip-grant-tables --skip-networking --log-error=GGB.err --pid-file=GGB.pid --socket=/tmp/mysql.sock
root       4840   2019  0 01:15 pts/0    00:00:00 grep --color=auto mysql
[root@GGB ~]# 

步骤三：登录数据库设置数据库密码信息

[root@GGB ~]  mysql -uroot
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 7
Server version: 8.0.26 MySQL Community Server - GPLCopyright (c) 2000, 2021, Oracle and/or its affiliates.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> flush privileges;
Query OK, 0 rows affected (0.01 sec)mysql> alter user root@'localhost' identified by '1';
Query OK, 0 rows affected (0.00 sec)mysql> 

步骤四：重启数据库服务

#先pkiil 掉之前后台启动的数据库
[root@GGB ~] pkill mysql
[root@GGB ~] 
[root@GGB ~] 2024-07-11T17:19:26.708758Z mysqld_safe mysqld from pid file /data/3306/data/GGB.pid ended[1]+  完成                  mysqld_safe --skip-grant-tables --skip-networking
[root@GGB ~] 
[root@GGB ~] 
[root@GGB ~] systemctl  start   mysql.service 
[root@GGB ~] systemctl  status  mysql.service 
● mysql.service - MySQL ServerLoaded: loaded (/etc/systemd/system/mysql.service; enabled; vendor preset: disabled)Active: active (running) since 五 2024-07-12 01:21:31 CST; 2s agoProcess: 3738 ExecStop=/usr/local/mysql/bin/mysqladmin shutdown (code=exited, status=1/FAILURE)Main PID: 5097 (mysqld)CGroup: /system.slice/mysql.service└─5097 /usr/local/mysql/bin/mysqld --defaults-file=/etc/my.cnf --basedir=/usr/local/mysql --datadir=/data/3306/data
[root@GGB ~] 

步骤五：验证数据库密码

[root@GGB ~] mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.26 MySQL Community Server - GPLCopyright (c) 2000, 2021, Oracle and/or its affiliates.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>