• 系統版本

[[email protected] sbin]# cat /etc/redhat-release 
CentOS Linux release 7.5.1804 (Core) 

• Mysql版本

[[email protected] sbin]# mysql -V
mysql  Ver 14.14 Distrib 5.7.23, for Linux (x86_64) using  EditLine wrapper

• 修改/etc/my.cnf檔案

[[email protected] sbin]# vi /etc/my.cnf
 

datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
skip-grant-tables  #新增此行

• 重啟mysql

[[email protected] sbin]# systemctl restart mysqld

• 重設Mysql密碼

[[email protected] sbin]# mysql
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 5.7.23 MySQL Community Server (
 
GPL)

Copyright (c) 2000, 2018, 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>
 
 USE mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> UPDATE user SET Password = password ( 'Qwert123!' ) WHERE User = 'root';  
ERROR 1054 (42S22): Unknown column 'Password' in 'field list'
#報錯了，阿西吧。錯誤的原因是 5.7版本下的mysql資料庫下已經沒有password這個欄位了，password欄位改成了authentication_string

mysql> update mysql.user set authentication_string=password('Qwert123!') where user='root';       
Query OK, 1 row affected, 1 warning (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 1
#修改成功

mysql> flush privileges;  #使其立即生效
Query OK, 0 rows affected (0.01 sec)

mysql> exit
Bye
[[email protected] sbin]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 5.7.23 MySQL Community Server (GPL)

Copyright (c) 2000, 2018, 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> exit
Bye

[[email protected] sbin]# vi /etc/my.cnf 
skip-grant-tables  #將剛才新增的此行再刪除