一.安装mysql

这里我们基础系统是centos7.5
[ ~]# yum install -y mariadb-server
[ ~]# systemctl start mariadb && systemctl enable mariadb
[ ~]# mysql_secure_installation

NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB
SERVERS IN PRODUCTION USE! PLEASE READ EACH STEP CAREFULLY!

In order to log into MariaDB to secure it, we‘ll need the current
password for the root user. If you‘ve just installed MariaDB, and
you haven‘t set the root password yet, the password will be blank,
so you should just press enter here.
Enter current password for root (enter for none): 【输入数据库超级管理员root密码，注意不是系统root的密码，第一次进入还没有设置直接回车】
Setting the root password ensures that nobody can log into the MariaDB
root user without the proper authorisation.

Set root password? [Y/n] Y 【设置密码】
New password:
Re-enter new password: 【再次输入密码】
Password updated successfully!
Reloading privilege tables..
... Success!

By default, a MariaDB installation has an anonymous user, allowing anyone
to log into MariaDB 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? [Y/n] y 【移除匿名用户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? [Y/n] n 【拒绝root远程登录n】
... skipping.

By default, MariaDB 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? [Y/n] y 【删除test数据库，y：删除】

• 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? [Y/n] y 【重新加载权限表y】
... Success!

Cleaning up...

All done! If you‘ve completed all of the above steps, your MariaDB
installation should now be secure.

Thanks for using MariaDB!

这里测试能否登录

[ ~]# mysql -uroot -ptest_123
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 10
Server version: 5.5.65-MariaDB MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.

MariaDB [(none)]>