如何插入具有多对多关系的实体？

-- 插入学生
INSERT INTO Student (student_id, name) VALUES (1, 'Alice');
INSERT INTO Student (student_id, name) VALUES (2, 'Bob');

-- 插入课程
INSERT INTO Course (course_id, title) VALUES (1, 'Math');
INSERT INTO Course (course_id, title) VALUES (2, 'Science');

-- Alice 选修 Math 和 Science
INSERT INTO Student_Course (student_id, course_id) VALUES (1, 1); -- Alice - Math
INSERT INTO Student_Course (student_id, course_id) VALUES (1, 2); -- Alice - Science

-- Bob 选修 Science
INSERT INTO Student_Course (student_id, course_id) VALUES (2, 2); -- Bob - Science

from sqlalchemy import create_engine, Column, Integer, String, ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship, sessionmaker

Base = declarative_base()

class Student(Base):
    __tablename__ = 'Student'
    student_id = Column(Integer, primary_key=True)
    name = Column(String)
    courses = relationship("Course", secondary="Student_Course")

class Course(Base):
    __tablename__ = 'Course'
    course_id = Column(Integer, primary_key=True)
    title = Column(String)
    students = relationship("Student", secondary="Student_Course")

class Student_Course(Base):
    __tablename__ = 'Student_Course'
    student_id = Column(Integer, ForeignKey('Student.student_id'), primary_key=True)
    course_id = Column(Integer, ForeignKey('Course.course_id'), primary_key=True)

engine = create_engine('sqlite:///example.db')
Base.metadata.create_all(engine)
Session = sessionmaker(bind=engine)
session = Session()

# 插入数据
alice = Student(name='Alice')
bob = Student(name='Bob')
math = Course(title='Math')
science = Course(title='Science')

session.add_all([alice, bob, math, science])
session.commit()

# 建立多对多关系
alice.courses.append(math)
alice.courses.append(science)
bob.courses.append(science)

session.commit()