1、安装
$ sudo apt update
$ sudo apt install mysql-server
2、配置mysql
$ sudo mysql_secure_installation
首先便是要求设置root用户的密码：
在成功设置root密码之后还会有一系列的一些安全设置：
Remove anonymous users? (Press y|Y for Yes, any other key for No) : n
... skipping.
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) : y
Success.
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) : y
- Dropping test database...
Success.
- Removing privileges on test database...
Success.
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!
3、验证mysql的安装：
$ systemctl status mysql.service
4、使用root命令和刚才设置的密码来登陆到 mysql中去
1，登进MySQL之后，
$ sudo mysql -uroot –p
2，输入以下语句，进入mysql库：
use mysql
3，更新域属性，'%'表示允许外部访问：
update user set host='%' where user ='root';
4，执行以上语句之后再执行：
FLUSH PRIVILEGES;
5，再执行授权语句：
GRANT ALL PRIVILEGES ON *.* TO 'root'@'%'WITH GRANT OPTION;
报错：
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'mysql_secure_installation
update user set host='localhost' where user ='root'' at line 1
执行sql：
select user,host,password from mysql.user;
执行sql：
ALTER USER 'root'@'localhost' IDENTIFIED BY '_huitao';
刷新
FLUSH PRIVILEGES;
修改参数：
注意到8.0 比5.7多了带“.”的变量导致只设置一半是不够的
set global validate_password.policy=0;
set global validate_password.length=4;
然后退出后再执行
mysql_secure_installation
update user set plugin="mysql_native_password",authentication_string=password('设置的密码') where user="root";
刷新权限
FLUSH PRIVILEGES;
navica连接不上数据库解决办法：
1，用如下语句查看MySQL当前加密方式
select host,user,plugin from user;
看第一行，root加密方式为caching_sha2_password。
2，使用命令将他修改成mysql_native_password加密模式：
update user set plugin='mysql_native_password' where user='root';
navica连接数据库：
