linux 系统中mysql密码问题

一、如果忘记密码：

在 /etc/my.cnf 文件的[mysqld]文段下添加 skip-grant-tables 来跳过密码，直接登录mysql;
只需要在命令行输入：mysql ,即可登录

二、修改密码

alter user 'root'@'localhost' identified by 'Wangbi@1';

如果提示：

mysql> alter user 'root'@'localhost' identified by 'Wangbi@1';
ERROR 1290 (HY000): The MySQL server is running with the --skip-grant-tables option so it cannot execute this statement
mysql> 

则执行：

flush privileges 

alter user 'root'@'localhost' identified by 'Wangbi@1';

mysql> flush privileges 
    -> ;
Query OK, 0 rows affected (0.00 sec)

mysql> alter user 'root'@'localhost' identified by 'Wangbi@1';
Query OK, 0 rows affected (0.01 sec)

mysql> exit
Bye

然后退出，去掉“skip-grant-tables ”， 重启mysqld ，通过用户名+ 密码登录：

[root@iZwz98th8v1tdszuxpw570Z etc]# systemctl restart mysqld
[root@iZwz98th8v1tdszuxpw570Z etc]# systemctl status mysqld
● mysqld.service - MySQL Server
   Loaded: loaded (/usr/lib/systemd/system/mysqld.service; enabled; vendor preset: disabled)
   Active: active (running) since Thu 2020-12-17 14:06:38 CST; 9s ago
     Docs: man:mysqld(8)
           http://dev.mysql.com/doc/refman/en/using-systemd.html
  Process: 2549 ExecStartPre=/usr/bin/mysqld_pre_systemd (code=exited, status=0/SUCCESS)
 Main PID: 2573 (mysqld)
   Status: "Server is operational"
   CGroup: /system.slice/mysqld.service
           └─2573 /usr/sbin/mysqld

Dec 17 14:06:37 iZwz98th8v1tdszuxpw570Z systemd[1]: Starting MySQL Server...
Dec 17 14:06:38 iZwz98th8v1tdszuxpw570Z systemd[1]: Started MySQL Server.
[root@iZwz98th8v1tdszuxpw570Z etc]# 
[root@iZwz98th8v1tdszuxpw570Z etc]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.20 MySQL Community Server - GPL

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