前言
网上找到的这些关于这类的博客要么就是mysql版本过时了要么就完全没有用，浪费了我好多时间，于是我就把自己成功的经历分享给大家，希望能减少大家走弯路的时间。
Mysql的安装
很简单，一句话
sudo apt install mysql-server
Msql密码的修改
修改密码我们得先进mysql，用管理员权限的话不论你输入什么样的密码都能成功。
sudo mysql -u root -p
进去结果如图所示，表示安装完成
接下来退出登录
quit;
之后对mysql密码的设置初始化
sudo mysql_secure_installation
之后的配置如图设置
#1
VALIDATE PASSWORD PLUGIN can be used to test passwords...
Press y|Y for Yes, any other key for No: N (选择N ,不会进行密码的强校验)#2
Please set the password for root here...
New password: (输入密码)
Re-enter new password: (重复输入)
(这里他会问你要不要修改密码，第一次选择y)
#3
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them...
Remove anonymous users? (Press y|Y for Yes, any other key for No) : N (选择N，不删除匿名用户)#4
Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network...
Disallow root login remotely? (Press y|Y for Yes, any other key for No) : N (选择N，允许root远程连接)#5
By default, MySQL comes with a database named 'test' that
anyone can access...
Remove test database and access to it? (Press y|Y for Yes, any other key for No) : N (选择N，不删除test数据库)#6
Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.
Reload privilege tables now? (Press y|Y for Yes, any other key for No) : Y (选择Y，修改权限立即生效)
做完后再登录
sudo mysql -uroot -p
选择mysql database
use mysql;
尝试第一次设置密码，这一次设置有可能会报错Your password does not satisfy the current policy requirements，这是因为你密码的长度不符合长度要求，没报错则无需以下步骤。
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '密码';
若报错则执行以下步骤
SHOW VARIABLES LIKE 'validate_password%';
mysql会输出以下参数
+--------------------------------------+--------+| Variable_name | Value |+--------------------------------------+--------+| validate_password.check_user_name | ON || validate_password.dictionary_file | || validate_password.length | 8 |//这个就是你要设置的密码长度| 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)
之后就是根据你电脑的参数和这里的参数一个个对照着看，一般来说除了密码长度不一样之外都是一样的，若存在不一直则按如下方法修改。
1 mysql> set global validate_password.policy=0;Query OK, 0 rows affected (0.00 sec)2 mysql> set global validate_password.special_char_count=0;Query OK, 0 rows affected (0.00 sec)3 mysql> set global validate_password.length=6;Query OK, 0 rows affected (0.00 sec)4 mysql> set global validate_password.mixed_case_count=0;Query OK, 0 rows affected (0.00 sec)
之后在来看一看参数修改成功没有
mysql> SHOW VARIABLES LIKE 'validate_password%';+--------------------------------------+-------+| Variable_name | Value |+--------------------------------------+-------+| validate_password.check_user_name | ON || validate_password.dictionary_file | || validate_password.length | 6 || validate_password.mixed_case_count | 0 || validate_password.number_count | 1 || validate_password.policy | LOW || validate_password.special_char_count | 0 |+--------------------------------------+-------+7 rows in set (0.01 sec)
最后重新输入之前的修改密码的命令。（注意这次密码要和你上面修改的长度一致）
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '密码';
保存设置并退出
flush privileges;quit;
最后我们来试验一下是否修改成功
mysql -u root -p //这里不要加sudo
输入密码，能进到mysql中不报错就是修改密码成功了。
