Class InfoContact has the following mapping.




I would want the InfoContact-object to have a List of
FieldValue-object where the 'field' part isn't necessarily unique,
for example:

InfoContact:data
[field1; value1]
[field1; value2]
[field2; value7]
etc.

Problem in short is this:

When I execute the following code (JUnit-test)

[code]public void testCreateNew() throws HibernateException
{
InfoContactDAO infomgr = new InfoContactDAO();
ContactMetaDAO metamgr = new ContactMetaDAO();
ContactFieldDAO fieldmgr = new ContactFieldDAO();
InfoContact contact = new InfoContact();
ContactField gender = fieldmgr.retrieve("K

Well its a rather lengthy post, so shortening it would help.

It seems that rather than having a component inside a class you have a List of components. The former will map to the class's table and be identified by its owning class. The latter will map to a foreign table (unless your DB supports objects in the the DB) and will need to have a unique key.

I suggest changing the mapping. do not use a nested component, use a separate class and a separate mapping for it. You can unique the object off of its index (though this will pose a problem if you ever need to change the list of items in the owning/main class). Instead of a List you probably want to use a Map for this case (so the keys can be arbitrary).

In short if you have multiple instances of a class (i.e., not a simple nested component) you must define a key property for that class. That key must not change for the lifetime of the instance. A single nested component is more like a custom user type -- it is a value object vis-a-vis its containing class. This nicety is lost as soon as you have a one-to-many relationship with your components.

Hi, thanks for answering!


I've tried that approach, even implemented equals and hashCode for the ternary association object (which were contained as List in the InfoContact object) but ran into numerous NPE:s when trying to manipulate the collection.

Somehow I fixed the above problem by turning cascade="save-update" into cascade="none". I still don't know why it works exactly.
A theory is that the ContactMeta object, which is loaded before the InfoContact containing FieldValue-collection, chokes when InfoContactDAO.create() tries to saveOrUpdate the ContactMeta object involved.

Sincerely,

/F

I also then went and re-read some of the relevant parts of the reference docs (chapters 7, I believe). And discovered to my embarassment, that much of what I said is wrong. Hibernate is very flexible... Anyway, glad you got it working.