第一步：在/etc/my.cnf配置文件中加入skip-grant-tables

[mysqld]
basedir=/usr/local/mysql
datadir=/usr/local/mysql/data
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
default-storage-engine=InnoDB
innodb-file-per-table=1
character_set_server=utf8mb4

skip
 
-grant-tables
[mysqld_safe]

[client]
default-character-set=utf8mb4

第二步：重啟mysql

[[email protected]lave1 mysql]# service mysqld restart
Shutting down MySQL.. SUCCESS! 
Starting MySQL. SUCCESS! 

第三步：不使用密碼直接登錄mysql，然後修改mysql.user表中的authentication_string字段的值

在mysql 5.7之前，mysql數據庫用戶的密碼的字段是password，5.7之後變成了authentication_string

mysql> update mysql.user set authentication_string=password(‘123456‘) where user=‘root‘ and host=‘localhost‘;
Query OK, 1 row affected, 1 warning (0.02 sec)
Rows matched: 1  Changed: 1  Warnings: 1

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

mysql> \q

註意一定要執行flush privileges;不然不會生效，重置完密碼之後，要把my.cnf配置文件中的skip-grant-tables註釋到

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