简单的数据库结构以链接科目和考试委员会

以下是一个简单的数据库结构，用于链接科目和考试委员会的示例：

1. 创建科目表（subjects）：

CREATE TABLE subjects (
  subject_id INT PRIMARY KEY,
  subject_name VARCHAR(255) NOT NULL
);

2. 创建考试委员会表（exam_committees）：

CREATE TABLE exam_committees (
  committee_id INT PRIMARY KEY,
  committee_name VARCHAR(255) NOT NULL
);

3. 创建链接表（subject_committee_link）来链接科目和考试委员会：

CREATE TABLE subject_committee_link (
  link_id INT PRIMARY KEY,
  subject_id INT,
  committee_id INT,
  FOREIGN KEY (subject_id) REFERENCES subjects(subject_id),
  FOREIGN KEY (committee_id) REFERENCES exam_committees(committee_id)
);

4. 插入数据示例：

-- 插入科目数据
INSERT INTO subjects (subject_id, subject_name) VALUES (1, '数学');
INSERT INTO subjects (subject_id, subject_name) VALUES (2, '语文');
INSERT INTO subjects (subject_id, subject_name) VALUES (3, '英语');

-- 插入考试委员会数据
INSERT INTO exam_committees (committee_id, committee_name) VALUES (1, '数学考试委员会');
INSERT INTO exam_committees (committee_id, committee_name) VALUES (2, '语文考试委员会');
INSERT INTO exam_committees (committee_id, committee_name) VALUES (3, '英语考试委员会');

-- 插入链接数据
INSERT INTO subject_committee_link (link_id, subject_id, committee_id) VALUES (1, 1, 1);
INSERT INTO subject_committee_link (link_id, subject_id, committee_id) VALUES (2, 2, 2);
INSERT INTO subject_committee_link (link_id, subject_id, committee_id) VALUES (3, 3, 3);

这样，通过查询链接表（subject_committee_link），可以获得科目和对应的考试委员会的关联信息。

例如，查询数学科目对应的考试委员会：

SELECT subjects.subject_name, exam_committees.committee_name
FROM subject_committee_link
JOIN subjects ON subject_committee_link.subject_id = subjects.subject_id
JOIN exam_committees ON subject_committee_link.committee_id = exam_committees.committee_id
WHERE subjects.subject_name = '数学';

输出结果：

+--------------+----------------------+
| subject_name | committee_name       |
+--------------+----------------------+
| 数学         | 数学考试委员会        |
+--------------+----------------------+

这样，就可以通过数据库结构链接科目和考试委员会，并进行相关查询操作。