Hibernate没有在onetomany关系中插入列

@Entity
public class Student {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;

    @OneToMany(mappedBy = "student", cascade = CascadeType.ALL)
    private List<Course> courses = new ArrayList<>();

    // 其他getter和setter方法
}

@Entity
public class Course {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;

    @ManyToOne
    @JoinColumn(name = "student_id")
    private Student student;

    // 其他getter和setter方法
}

   <session-factory>
       <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
       <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/mydb</property>
       <property name="hibernate.connection.username">root</property>
       <property name="hibernate.connection.password">password</property>
       <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
       <property name="hibernate.show_sql">true</property>
       <property name="hibernate.hbm2ddl.auto">update</property>

       <mapping class="com.example.Student"/>
       <mapping class="com.example.Course"/>
    </session-factory>
</hibernate-configuration>

Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();

Student student = new Student();
student.setName("John Doe");

Course course1 = new Course();
course1.setName("Math");
course1.setStudent(student);

Course course2 = new Course();
course2.setName("English");
course2.setStudent(student);

student.getCourses().add(course1);
student.getCourses().add(course2);

session.save(student);
transaction.commit();
session.close();