1、 导入hellodb.sql生成数据库
[root@centos01 ~]# mysql -uroot -p < hellodb_innodb.sql
Enter password:
[root@centos01 ~]# mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 15
Server version: 8.0.28 MySQL Community Server - GPL
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 |
+--------------------+
| hellodb |
| information_schema |
| mysql |
| performance_schema |
| sys |
+--------------------+
5 rows in set (0.01 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
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 Age > 25 and Gender ="M";
+--------------+-----+
| 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) |
+---------+----------+
| 2 | 36.0000 |
| 1 | 20.5000 |
| 4 | 24.7500 |
| 3 | 20.2500 |
| 5 | 46.0000 |
| 7 | 19.6667 |
| 6 | 20.7500 |
| NULL | 63.5000 |
+---------+----------+
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) |
+---------+----------+
| 2 | 36.0000 |
| 5 | 46.0000 |
| NULL | 63.5000 |
+---------+----------+
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192.168.184.0/24网段可以连接mysql
mysql> create user magedu@'192.168.184.%' identified by 'Zhrmghg@123';
Query OK, 0 rows affected (0.01 sec)
mysql> grant all on hellodb.* to magedu@'192.168.184.%';
Query OK, 0 rows affected (0.01 sec)
验证登录：
[root@centos01 ~]# mysql -h 192.168.184.147 -u magedu -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 19
Server version: 8.0.28 MySQL Community Server - GPL
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 |
+--------------------+
| hellodb |
| information_schema |
+--------------------+
2 rows in set (0.00 sec)
