Hi, I have two entities:

Course
{
...
Set<Student> student;
}

Studen

{
....
Set<Course> course ;
}

It's is a many to many relation, behind is the table CourseStudent contain StuID and CourseID

When I add a course to a student:

transaction = session.beginTrans...
stu.getCourses.add(c);
session.commit();

It run success but it's doesn't insert any record to CourseStudent table???
It mean no "course" was "added" for the student

How to I get "CourseStudent" records to be added like it must be?