数据库的导入和授权用户

Posted 2022-02-21 一夜入秋

1、 导入hellodb.sql生成数据库

1.1、mysql环境准备

root@ubuntu:~# mysql --version
mysql  Ver 14.14 Distrib 5.7.37, for Linux (x86_64) using  EditLine wrapper
root@ubuntu:~# mysql -uroot -p
Enter password: #这里敲上自己设置好的密码
Welcome to the MySQL monitor.  Commands end with ; or \\g.
Your MySQL connection id is 10
Server version: 5.7.37-0ubuntu0.18.04.1 (Ubuntu)

Copyright (c) 2000, 2022, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

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

mysql> select version();
+-------------------------+
| version()               |
+-------------------------+
| 5.7.37-0ubuntu0.18.04.1 |
+-------------------------+
1 row in set (0.00 sec)

#查看已有的数据库
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
4 rows in set (0.00 sec)
#退出mysql
mysql> exit
Bye

#导入数据库并验证
root@ubuntu:~# mysql -uroot -p < hellodb_innodb.sql 
Enter password: 
root@ubuntu:~# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or \\g.
Your MySQL connection id is 12
Server version: 5.7.37-0ubuntu0.18.04.1 (Ubuntu)

Copyright (c) 2000, 2022, Oracle and/or its affiliates.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

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

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| hellodb            |
| mysql              |
| performance_schema |
| sys                |
+--------------------+
5 rows in set (0.00 sec)

(1) 在students表中，查询年龄大于25岁，且为男性的同学的名字和年龄

#进入hellodb数据库
mysql> use hellodb
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
mysql> select name,age from students where gender=M and age>25;
+--------------+-----+
| name         | age |
+--------------+-----+
| Xie Yanke    |  53 |
| Ding Dian    |  32 |
| Yu Yutong    |  26 |
| Shi Qing     |  46 |
| Tian Boguang |  33 |
| Xu Xian      |  27 |
| Sun Dasheng  | 100 |
+--------------+-----+
7 rows in set (0.00 sec)

(2) 以ClassID为分组依据，显示每组的平均年龄

mysql> select classid,avg(age) from students group by classid;
+---------+----------+
| classid | avg(age) |
+---------+----------+
|    NULL |  63.5000 |
|       1 |  20.5000 |
|       2 |  36.0000 |
|       3 |  20.2500 |
|       4 |  24.7500 |
|       5 |  46.0000 |
|       6 |  20.7500 |
|       7 |  19.6667 |
+---------+----------+
8 rows in set (0.00 sec)

(3) 显示第2题中平均年龄大于30的分组及平均年龄

mysql> select classid,avg(age) from students group by classid having avg(age)>30;
+---------+----------+
| classid | avg(age) |
+---------+----------+
|    NULL |  63.5000 |
|       2 |  36.0000 |
|       5 |  46.0000 |
+---------+----------+
3 rows in set (0.00 sec)

(4) 显示以L开头的名字的同学的信息

mysql> select * from students where name like L%;
+-------+-------------+-----+--------+---------+-----------+
| StuID | Name        | Age | Gender | ClassID | TeacherID |
+-------+-------------+-----+--------+---------+-----------+
|     8 | Lin Daiyu   |  17 | F      |       7 |      NULL |
|    14 | Lu Wushuang |  17 | F      |       3 |      NULL |
|    17 | Lin Chong   |  25 | M      |       4 |      NULL |
+-------+-------------+-----+--------+---------+-----------+
3 rows in set (0.00 sec)

2、数据库授权magedu用户，允许192.168.1.0/24网段可以连接mysql

#创建用户
mysql> create user magedu@192.168.1.% identified by Mysql@2022;
Query OK, 0 rows affected (0.00 sec)

mysql> show grants for magedu@192.168.1.%;
+----------------------------------------------+
| Grants for magedu@192.168.1.%                |
+----------------------------------------------+
| GRANT USAGE ON *.* TO magedu@192.168.1.% |
+----------------------------------------------+
1 row in set (0.00 sec)

#授权
mysql> grant all on *.* to magedu@192.168.1.% identified by Mysql@2022;
Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> show grants for magedu@192.168.1.%;
+-------------------------------------------------------+
| Grants for magedu@192.168.1.%                         |
+-------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO magedu@192.168.1.% |
+-------------------------------------------------------+
1 row in set (0.00 sec)

mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

mysql> select host,user from mysql.user;
+-------------+------------------+
| host        | user             |
+-------------+------------------+
| 192.168.1.% | magedu           |
| localhost   | debian-sys-maint |
| localhost   | mysql.session    |
| localhost   | mysql.sys        |
| localhost   | root             |
+-------------+------------------+
5 rows in set (0.00 sec)