操作系统：

[root@localhost ~]# cat /etc/redhat-release

CentOS Linux release 7.1.1503

mysql 版本5.7.9

mysql> select version()

-> ;

+-----------+

| version() |

+-----------+

| 5.7.9 |

+-----------+

1 row in set (0.00 sec)

安装mysql的yum repo 源：

rpm -ivh 外链网址已屏蔽

安装mysql

yum install mysql-community-server

yum install mysql-community-client

修改mysql 配置文件跳过密码验证

[mysqld]

skip-grant-tables

skip-networking

启动mysql：

systemctl start mysqld

匿名登录mysql 设置root密码：

[root@localhost ~]# mysql

Welcome to the MySQL monitor. Commands end with ; or \g.

Your MySQL connection id is 2

Server version: 5.7.9 MySQL Community Server (GPL)

Copyright (c) 2000, 2015, 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> update mysql.user set PASSWORD=PASSWORD('test') where user='root' and host='localhost';

ERROR 1054 (42S22): Unknown column 'PASSWORD' in 'field list'

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY 'test' ;

ERROR 1131 (42000): You are using MySQL as an anonymous user and anonymous users are not allowed to change passwords

mysql> update mysql.user set authentication_string=PASSWORD('test') where user='root' and host='localhost';

Query OK, 1 row affected, 1 warning (0.07 sec)

Rows matched: 1 Changed: 1 Warnings: 1

mysql> flush privileges;

Query OK, 0 rows affected (0.06 sec)

mysql> exit;

Bye

取消跳过密码认证：

[mysqld]

#skip-grant-tables

#skip-networking

重启mysql：

systemctl restart mysqld

必须使用alter user 重置密码：

mysql> show databases;

ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

重新设置密码：

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '********'

密码需要复杂度要求：

mysql> SHOW VARIABLES LIKE 'validate_password%';

+--------------------------------------+--------+

| Variable_name | Value |

+--------------------------------------+--------+

| validate_password_dictionary_file | |

| validate_password_length | 8 |

| validate_password_mixed_case_count | 1 |

| validate_password_number_count | 1 |

| validate_password_policy | MEDIUM |

| validate_password_special_char_count | 1 |

+--------------------------------------+--------+

6 rows in set (0.00 sec)