安装
sudo apt-get update
sudo apt-get install mysql-server mysql-client初始化数据库
sudo mysql_secure_installationSecuring the MySQL server deployment.
Connecting to MySQL using a blank password.
VALIDATE PASSWORD COMPONENT can be used to test passwords
and improve security. It checks the strength of password
and allows the users to set only those passwords which are
secure enough. Would you like to setup VALIDATE PASSWORD component?
Press y|Y for Yes, any other key for No: Y
There are three levels of password validation policy:
LOW Length >= 8
MEDIUM Length >= 8, numeric, mixed case, and special characters
STRONG Length >= 8, numeric, mixed case, special characters and dictionary file
Please enter 0 = LOW, 1 = MEDIUM and 2 = STRONG: 0
Skipping password set for root as authentication with auth_socket is used by default.
If you would like to use password authentication instead, this can be done with the "ALTER_USER" command.
See https://dev.mysql.com/doc/refman/8.0/en/alter-user.html#alter-user-password-management for more information.
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. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.
Remove anonymous users? (Press y|Y for Yes, any other key for No) : Y
Success.
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) : No
... skipping.
By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.
Remove test database and access to it? (Press y|Y for Yes, any other key for No) : No
... skipping.
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
Success.
All done!
密码设置
-- 使用默认的认证方式
ALTER USER 'root'@'localhost' IDENTIFIED BY '123456';
FLUSH PRIVILEGES;卸载mysql
如果安装配置出问题，使用此命令卸载后重新安装。否则生成的文件可能不全。
sudo apt-get autoremove mysql* --purge
修改/查看密码强度
修改
mysql> set global validate_password.policy=0; #设置密码强度为最低
mysql> set global validate_password.length=6; # 设置密码长度为0
查看密码强度
mysql> SHOW VARIABLES LIKE 'validate_password%';
忘记密码
在[mysqld]的段中加上一句：skip-grant-tables保存并退出
vim /etc/my.cnf
[mysqld]
......
skip-grant-tables
systemctl restart mysqld.service mysql -u root
use mysql;
update user set authentication_string='' where user='root';
exit;屏蔽 skip-grant-tables：vim /etc/my.cnf，在skip-grant-tables前面添加#
systemctl restart mysqld.service
mysql -u root
use mysql;
update user set host='%' where user='root';
FLUSH PRIVILEGES;
ALTER USER 'root'@'%' IDENTIFIED WITH mysql_native_password BY 'root';
FLUSH PRIVILEGES;