Hi,

How to map a normat containment using hibernate?

e.g.

I have a Teacher class that contains an array of Subjects he teaches.

public class Teacher {

private long TeacherID;
private String Name;
private Subject[] subjectsTaught;
}

And a Subject class

public class Subject implements Serializable {
private int SubjectId;
private String Name;
private int HrsperWeek;
private long TaughtBy;
}

I have 2 tables, with Subject Table having a foreign key to Teacher.

How to map this such that when I say session.save(teacherObject), I should get the subjects saved and their foreign keys set correctly?

If I just mark the 'subjectsTaught' member of Teacher as Property with type=Subject, and a many-to-one mapping for Subject's foreign key member 'TaughtBy', it throws an error,

multiple imports : Teacher.

One mroe, How can I get help on error messages displayed by hibernate, like meaning of 'multiple imports'

Hi again,

I could successfully do the mapping after using set instead of array for the 'many' side.

But, now I'm facing another problem.

When I call session.save(aNewTeacher) on the parent object, Hibernate correctly fires INSERT query. But it does not out the primary key of this inserted row in foreign key field of the child set of Subjects.

So I get Oracle error of cannot insert NULL into taughtby (foreign key field).

How should I overcome this?

Is there a forum for beginners also?

Thanks.

The forum for beginners is called Hibernate Reference Documentation.

In your case look at chapter 16.

HTH
Ernst