一、一键安装MySQL脚本
二、修改策略和密码
执行完以上脚本可以看到MySQL的密码，如下方法登录修改策略，因为默认密码要求比较高，可以根据自己需求来决定是否更改策略：
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Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_length=4;
Query OK, 0 rows affected (0.00 sec)
mysql> alter user 'root'@'localhost' identified by 'Yanglt123.';
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> quit
三、数据库密码策略：
1、查看数据库策略：
因为上文已经将 validate_password_length 值改为4，所以下文显示为4，默认情况下为8
mysql>
2、各项值说明
validate_password_policy：密码安全策略，默认MEDIUM策略
策略 检查规则
0 or LOW Length
1 or MEDIUM Length; numeric, lowercase/uppercase, and special characters
2 or STRONG Length; numeric, lowercase/uppercase, and special characters; dictionary file
validate_password_dictionary_file：密码策略文件，策略为STRONG才需要
validate_password_length：密码最少长度 ，测试发现最小值得为4。
validate_password_mixed_case_count：大小写字符长度，至少1个
validate_password_number_count ：数字至少1个
validate_password_special_char_count：特殊字符至少1个
3、修改策略，跟上文第二操作一样
mysql> set global validate_password_policy=0;
Query OK, 0 rows affected (0.00 sec)
mysql> set global validate_password_length=4;
Query OK, 0 rows affected (0.00 sec),
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
4、修改简单密码测试
mysql> alter user 'root'@'localhost' identified by '1234'; #测试发现密码长度最少为4位
Query OK, 0 rows affected (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)
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>