mysql怎么建立关联表

CREATE TABLE students (
    student_id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(100) NOT NULL
);

CREATE TABLE courses (
    course_id INT PRIMARY KEY AUTO_INCREMENT,
    name VARCHAR(100) NOT NULL
);

CREATE TABLE student_courses (
    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)
);

-- 检查并修正数据类型
ALTER TABLE student_courses MODIFY COLUMN student_id INT;
ALTER TABLE student_courses MODIFY COLUMN course_id INT;

START TRANSACTION;
INSERT INTO students (name) VALUES ('Alice');
INSERT INTO courses (name) VALUES ('Math');
INSERT INTO student_courses (student_id, course_id) VALUES (LAST_INSERT_ID(), LAST_INSERT_ID());
COMMIT;