mysql 5.7 設置root密碼方法

• 操做系統：
  

  [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)

• 安裝mysql的yum repo 源：
  

  rpm -ivh http://repo.mysql.com//mysql57-community-release-el7-7.noarch.rpm

• 安裝mysql
  

  yum install mysql-community-server
  yum install mysql-community-client

• 修改mysql 配置文件跳過密碼驗證
  

  [mysqld]
  skip-grant-tables
  skip-networking

• 啓動mysql：
  

  systemctl start mysqld

• 匿名登陸mysql 設置root密碼：
  

  [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

• 取消跳過密碼認證：
  

  [mysqld]
  #skip-grant-tables
  #skip-networking

• 重啓mysql：
  

  systemctl restart mysqld

• 必須使用alter user 重置密碼：
  

  mysql> show databases;
  ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

• 從新設置密碼：
  

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

• 密碼須要複雜度要求：
  

  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)

  
  

  ERROR 1820 (HY000): You must SET PASSWORD before executing this statement
  mysql> set password=password('xxxx');
  Query OK, 0 rows affected (0.00 sec)