mysql 间接引用

-- 创建学生表
CREATE TABLE students (
    student_id INT PRIMARY KEY,
    student_name VARCHAR(100)
);

-- 创建课程表
CREATE TABLE courses (
    course_id INT PRIMARY KEY,
    course_name VARCHAR(100)
);

-- 创建中间表
CREATE TABLE student_course (
    student_id INT,
    course_id INT,
    PRIMARY KEY (student_id, course_id),
    FOREIGN KEY (student_id) REFERENCES students(student_id),
    FOREIGN KEY (course_id) REFERENCES courses(course_id)
);

-- 插入示例数据
INSERT INTO students (student_id, student_name) VALUES (1, 'Alice');
INSERT INTO students (student_id, student_name) VALUES (2, 'Bob');
INSERT INTO courses (course_id, course_name) VALUES (101, 'Math');
INSERT INTO courses (course_id, course_name) VALUES (102, 'Science');
INSERT INTO student_course (student_id, course_id) VALUES (1, 101);
INSERT INTO student_course (student_id, course_id) VALUES (1, 102);
INSERT INTO student_course (student_id, course_id) VALUES (2, 101);

-- 查询学生选课信息
SELECT s.student_name, c.course_name
FROM students s
JOIN student_course sc ON s.student_id = sc.student_id
JOIN courses c ON sc.course_id = c.course_id;