I have 2 tables:
tblcurriculum
- curriculum_id (suregat key)
- student_id
- opleidingsonderdeel_id

tblopleidingsonderdeel
-opleidingsonderdeel_id
-...

In my class curriculum I want to map the corresponding opleidingsonderdeel objects to an arraylist. But it doesn't work out very good...

Here is the mapping file I have tried to use:



Any one any idea what's wrong with it? I always get an error "Repeated column in mapping for collection: curriculum.opleidingsonderdelen column: opleidingsonderdeel_id

First of all curriculum_id column should be present in your tblopleidingsonderdeel table.

Only then you can have a list of opleidingsonderdeel in one instance of curriculum i.e. you want multiple rows of table tblopleidingsonderdeel to have the same curriculum_id

Then, the appropriate mapping would be:

<list name="opleidingsonderdelen" table="tblopleidingsonderdeel">
<key column="curriculum_id" />

But what about the index tag? I've read it contains index of the list but how do you need to do this in the table? Can't it be done automatically?

Index would be the name of your index ON the curriculum_id column of tblopleidingsonderdeel table.

I'doesn't work out I've tried several things but it just won't work.

Now I've tried to use a set:

But now I always get the following error: identifier of instance was altered from 1 to 0

glennvc i can understand the frustration.
But dont give up on it and consider the step by step approach. Your mapping is fine now - just check whether your primary keys are fine.

Just a checklist to help you go through the problem:

1)
Your mapping for Curriculum should be:
<set name="opleidingsonderdelen" inverse="true">
<key>
<column name="curriculum_id"/>
</key>
<one-to-many class="fully.qualified.classname.opleidingsonderdeel" />
</set>


2)
Your mapping for Opleidingsonderdeel should contain:

<many-to-one name="curriculum" class="fully.qualified.classname.Curriculum">
<column name="CURRICULUM_ID" />
</many-to-one>

3) Class Curriculum should have a getter / setter for Set opleidingsonderdelen

4) Class Opleidingsonderdeel should have a gettter / setter for Curriculum

5) Just open a session and execute
session.createQuery(" from Curriculum c ").list()

Has to work!

Hope you get it to work :)

Do I really need a link to curriculum in opleidingsonderdeel? Cause the main thought is that one curriculums have multiple opleidingsonderdeel instances but an opleidingsonderdeel can be placed in several curriculums instances, but in opleidingsonderdeel isn't normaly a link to a curriculum.

It really doesn't seame to work out...

For the record.

The 2 tables look like this:

tlbcurriculum
curriculum_id | student_id | opleidingsonderdeel_id
1 1 1
2 1 2
tblopleidingsonderdeel
opleidingsonderdeel_id | benaming
1 test
2 test

in my class curriculum I have a set<opleidingsonderdeel> that I want to fill with instances of the class opleidingsonderdeel according to the tables.

But It just won't work using hibernate. Anyone that can help me out?