以下是代码部分：
from flask import Flask from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) # 配置数据库信息 app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql://root:mysql@127.0.0.1/student_course' app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False db = SQLAlchemy(app) # 多对多模型需要添加一张单独的表去记录两张表之间的对应关系 tb_student_course = db.Table('tb_student_course', db.Column('student_id', db.Integer, db.ForeignKey('students.id')), db.Column('course_id', db.Integer, db.ForeignKey('courses.id')) ) # 创建学生表 class Students(db.Model): __tablename__ = 'students' id = db.Column(db.Integer,primary_key=True) name = db.Column(db.String(64),unique=True) # 创建课程表 class Course(db.Model): __tablename__ = 'courses' id = db.Column(db.Integer, primary_key=True) name = db.Column(db.String(64), unique=True) # 在任意一个模型中添加关系引用 students = db.relationship('Students', secondary=tb_student_course, #### 引用实例对象，不加引号 backref='courses', lazy='dynamic') @app.route('/') def helloworld(): return 'hello world' if __name__ == '__main__': db.drop_all() db.create_all() # 添加测试数据 stu1 = Students(name='张三') stu2 = Students(name='李四') stu3 = Students(name='王五') cou1 = Course(name='物理') cou2 = Course(name='化学') cou3 = Course(name='生物') stu1.courses = [cou2, cou3] stu2.courses = [cou2] stu3.courses = [cou1, cou2, cou3] db.session.add_all([stu1, stu2, stu2]) db.session.add_all([cou1, cou2, cou3]) db.session.commit() app.run(debug=True)