MySQL条件多对多

CREATE TABLE students (
    student_id INT PRIMARY KEY,
    student_name VARCHAR(100)
);

CREATE TABLE courses (
    course_id INT PRIMARY KEY,
    course_name VARCHAR(100)
);

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)
);

SELECT s.student_name
FROM students s
JOIN student_courses sc ON s.student_id = sc.student_id
JOIN courses c ON sc.course_id = c.course_id
WHERE c.course_name = 'Mathematics';

INSERT INTO students (student_id, student_name) VALUES (1, 'Alice');
INSERT INTO courses (course_id, course_name) VALUES (1, 'Mathematics');
INSERT INTO student_courses (student_id, course_id) VALUES (1, 1);

DELETE FROM student_courses WHERE student_id = 1 AND course_id = 1;