演示数据库

在本教程中，我们将使用 LintCode 样本数据库。

下面是选自 "teachers" 教师表的数据：

+----+------------------+---------------------------+-----+---------+
| id | name             | email                     | age | country |
+----+------------------+---------------------------+-----+---------+
|  1 | Eastern Heretic  | [e-mail] |  20 | UK      |
|  2 | Northern Beggar  | [e-mail]    |  21 | CN      |
|  3 | Western Venom    | [e-mail]     |  28 | USA     |
|  4 | Southern Emperor | [e-mail]   |  21 | JP      |
|  5 | Linghu Chong     | NULL                      |  18 | CN      |
+----+------------------+---------------------------+-----+---------+

下面是 "courses" 课程表的数据：

+----+-------------------------+---------------+------------+------------+
| id | name                    | student_count | created_at | teacher_id |
+----+-------------------------+---------------+------------+------------+
|  1 | Advanced Algorithms     |           880 | 2020-06-01 |          4 |
|  2 | System Design           |          1350 | 2020-07-18 |          3 |
|  3 | Django                  |           780 | 2020-02-29 |          3 |
|  4 | Web                     |           340 | 2020-04-22 |          4 |
|  5 | Big Data                |           700 | 2020-09-11 |          1 |
|  6 | Artificial Intelligence |          1660 | 2018-05-13 |          3 |
|  7 | Java P6+                |           780 | 2019-01-19 |          3 |
|  8 | Data Analysis           |           500 | 2019-07-12 |          1 |
| 10 | Object Oriented Design  |           300 | 2020-08-08 |          4 |
| 12 | Dynamic Programming     |          2000 | 2018-08-18 |          1 |
+----+-------------------------+---------------+------------+------------+