环境： CentOS7

 mysql源选择本地源：

[root@master ~]# ll win-share/mysql/57/
总用量 207346
-rwxrwxrwx. 1 root root  26468960 2月  28 22:17 mysql-community-client-5.7.33-1.el7.x86_64.rpm
-rwxrwxrwx. 1 root root    315280 12月 11 13:20 mysql-community-common-5.7.33-1.el7.x86_64.rpm
-rwxrwxrwx. 1 root root   2458780 12月 11 13:21 mysql-community-libs-5.7.33-1.el7.x86_64.rpm
-rwxrwxrwx. 1 root root   1260364 12月 11 13:21 mysql-community-libs-compat-5.7.33-1.el7.x86_64.rpm
-rwxrwxrwx. 1 root root 181817592 2月  26 16:45 mysql-community-server-5.7.33-1.el7.x86_64.rpm
drwxrwxrwx. 1 root root         0 3月   2 10:36 repodata

　　

安装：

[root@master ~]# yum install mysql-community-server

　　

查看mysql的登录密码： ?O:Askd)s9tu就是系统生成的密码

[root@master ~]# grep "temporary password is generated" /var/log/mysqld.log
2021-03-09T23:36:31.157066Z 1 [Note] A temporary password is generated for root@localhost: ?O:Askd)s9tu

　　

登录：因密码中有特殊字符所以要在-p后加“”（双引号）

[root@master ~]# mysql -uroot -p"?O:Askd)s9tu"
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 4
Server version: 5.7.33

Copyright (c) 2000, 2021, Oracle and/or its affiliates.

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> 

　　

修改密码强度限制：（默认8位、大小写字母、特殊符号、数字）

注意：因为是实验环境密码强度可以降低，如果是生产环境要注意安全。

先修改默认密码：否则什么都不会让你操作

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '?O:Askd)s9tu1';
Query OK, 0 rows affected (0.00 sec)

查看密码规则：

mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+--------+
| Variable_name                        | Value  |
+--------------------------------------+--------+
| validate_password_check_user_name    | OFF    |
| 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      |
+--------------------------------------+--------+
7 rows in set (0.01 sec)

在mysql降低密码强度等级，

mysql>  set global validate_password_policy=LOW; 
Query OK, 0 rows affected (0.00 sec)　

密码长度设为6 默认8

mysql> set global validate_password_length=6;
Query OK, 0 rows affected (0.01 sec)

 设置密码为123456

mysql> ALTER USER 'root'@'localhost' IDENTIFIED BY '123456'; 
Query OK, 0 rows affected (0.00 sec)

　　

 

 

 

 

 

参考：

http://blog.csdn.net/wohiusdashi/article/details/89358071

http://zhuanlan.zhihu.com/p/200909519