[root@localhost ~]# yum install mariadb mariadb-server -y

[root@localhost ~]# systemctl start mariadb

[root@localhost ~]# 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):
OK, successfully used password, moving on...

Setting the root password ensures that nobody can log into the MariaDB
root user without the proper authorisation.

Set root password? [Y/n] y         #重设root密码
New password:
Re-enter new password:
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     #删除匿名用户
 ... 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] y      #禁止root远程登录
 ... Success!

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
 - 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         #刷新表，重读刚刚的配置
 ... 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!

[root@localhost ~]# mysql -uroot -p
Enter password:    #这里输入密码
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 3
Server version: 5.5.56-MariaDB MariaDB Server

Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.

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

MariaDB [(none)]>

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.01 sec)

MariaDB [(none)]> set password = password('2');
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> create user lee@localhost identified by '3';
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> use mysql
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MariaDB [mysql]> select host,user,password from user where user="lee";
+-----------+------+-------------------------------------------+
| host      | user | password                                  |
+-----------+------+-------------------------------------------+
| localhost | lee  | *C4E74DDDC9CC9E2FDCDB7F63B127FB638831262E |
+-----------+------+-------------------------------------------+
1 row in set (0.00 sec)

MariaDB [(none)]> grant select,update,delete,insert on mysql.user to lee@localhost;
Query OK, 0 rows affected (0.00 sec)

MariaDB [mysql]> revoke select,update,delete,insert on mysql.user from lee@localhost;
Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> show grants for lee@localhost;
+------------------------------------------------------------------------------------------------------------+
| Grants for lee@localhost                                                                                   |
+------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'lee'@'localhost' IDENTIFIED BY PASSWORD '*C4E74DDDC9CC9E2FDCDB7F63B127FB638831262E' |
| GRANT SELECT, INSERT, UPDATE, DELETE ON `mysql`.`user` TO 'lee'@'localhost'                                |
+------------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

[root@localhost ~]# mysql -ulee -p3

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
+--------------------+
2 rows in set (0.00 sec)

MariaDB [(none)]> show tables from mysql;
+-----------------+
| Tables_in_mysql |
+-----------------+
| user            |
+-----------------+
1 row in set (0.00 sec)

MariaDB [(none)]> create database LEE；
Query OK, 1 row affected (0.00 sec)

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| LEE                |
| mysql              |
| performance_schema |
+--------------------+
4 rows in set (0.00 sec)

MariaDB [(none)]> use LEE
Database changed
MariaDB [LEE]> create table worker (name char(15),age  int,sex char(5));
Query OK, 0 rows affected (0.00 sec)

MariaDB [LEE]> describe worker;
+-------+----------+------+-----+---------+-------+
| Field | Type     | Null | Key | Default | Extra |
+-------+----------+------+-----+---------+-------+
| name  | char(15) | YES  |     | NULL    |       |
| age   | int(11)  | YES  |     | NULL    |       |
| sex   | char(5)  | YES  |     | NULL    |       |
+-------+----------+------+-----+---------+-------+
3 rows in set (0.00 sec)

MariaDB [lee]> show tables;
+---------------+
| Tables_in_lee |
+---------------+
| worker        |
+---------------+
1 row in set (0.00 sec)

MariaDB [LEE]> insert into worker(name,age,sex) values ('lee','18','man');
Query OK, 1 row affected, 1 warning (0.00 sec)

MariaDB [LEE]> select * from worker;
+------+------+------+
| name | age  | sex  |
+------+------+------+
| lee  |   18 | man  |
+------+------+------+
1 row in set (0.00 sec)

MariaDB [LEE]> select * from worker;   #首先加一些数据
+--------+------+-------+
| name   | age  | sex   |
+--------+------+-------+
| lee    |   18 | man   |
| join   |   19 | man   |
| kylin  |   17 | woman |
| aobama |   40 | man   |
+--------+------+-------+
4 rows in set (0.00 sec)

MariaDB [LEE]> select * from worker where sex='man';  #查找man的数据
+--------+------+------+
| name   | age  | sex  |
+--------+------+------+
| lee    |   18 | man  |
| join   |   19 | man  |
| aobama |   40 | man  |
+--------+------+------+
3 rows in set (0.00 sec)

MariaDB [LEE]> select * from worker where sex!='man';  #查找不是man的数据
+-------+------+-------+
| name  | age  | sex   |
+-------+------+-------+
| kylin |   17 | woman |
+-------+------+-------+
1 row in set (0.00 sec)

[root@localhost ~]# mysqldump -uroot -p2 lee > /root/lee.dump
[root@localhost ~]# ls -l /root/lee.dump
-rw-r--r--. 1 root root 1941 7月   1 21:34 /root/lee.dump
[root@localhost ~]# mysql -uroot -p2
MariaDB [(none)]> drop database lee;
Query OK, 1 row affected (0.00 sec)

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.00 sec)

MariaDB [(none)]> create database lee;
Query OK, 1 row affected (0.00 sec)

MariaDB [(none)]> exit
Bye
[root@localhost ~]# mysql -uroot -p2 lee < /root/lee.dump
[root@localhost ~]# mysql -uroot -p2
MariaDB [(none)]> use lee
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
MariaDB [lee]> select * from worker;
+--------+------+-------+
| name   | age  | sex   |
+--------+------+-------+
| lee    |   18 | man   |
| join   |   19 | man   |
| kylin  |   17 | woman |
| aobama |   40 | man   |
+--------+------+-------+
4 rows in set (0.00 sec)