I have a class like this:



every node is an entity.

my mapping is like this:



Thanks for any help!

don't you mean one-to-many?
<one-to-many class="yourpackage.A" />
Justin

thanks for your help.

but I want to share every node ,if use <one-to-many> there would be many redundant data in the database.so I want to use many-to-one,so
some node could be re-referenced by A.

Hi,
I'm not quite sure if I understand your problem - what do you mean by redundant data?

If you are trying to share Nodes between A's where one Node can belong to many A's and an A can have any Node(s), aren't you after a many-to-many mapping?

i.e. Node *---------* A

Thanks,I have got the key.I think <many-to-many> is the solution for my problem.

Have a look at http://www.xylax.net/hibernate/ it will clarify some stuffs

Thanks Emmanuel!

I have been searching for similar examples. What i would like to see is how to implement these collection combinations using different collection interfaces. Every example uses a Set.

I am missing two things; can someone answer this: the session.find/query intertfaces return List objects, but the most common collection interface used is the Set, I would like to use the List from bottom to top of the MVC, but have some difficulties understanding many-to-many implementations and composite indexes.

cord

A result list (ie a query result) is a List. It has no relation with <set, <bag, etc...

Thank you, then maybe i am missing something (no maybe about it).

Here is my typical process:
want to display nested list of objects, monkeys and their bananas on one page and then provide add/edit/delete features from there. Here is my model:

monkeymanager class
getmonkeys()
monkey class
getbananas()
bananas class

first, my monkeymanager.getmonkeys() calls session.query("FROM monkey as monkey"). this returns a java.util.List. Now, i would like to be able to present this data using struts logic:iterate (or jstl equiv).

3 questions
- given that i want to not have to rebuild Set instances with List data, i want to use the List all the way from my data bean, to my business layer, to my formaction, to my presentation - is that not the most common practice, or do people build Sets from Lists given their query results.
- is there a 'better' hibernate way to get my list of monkeys?
- i know it has something to do with lazy initialization, but i am not sure why my list of bananas is not populated. In my struts presentation i have the following:
<l:iterate id="monkey" name="monkeys">
<b:write name="monkey" property="name"/>
<l:present name="monkey" property=
<l:iterate id="banana" property="monkey.bananas">
<b:write name="banana" property="producer"/>
</l:iterate>
</l:present>
</l:iterate>

i get the list of monkey names iterated, but no information on bananas. I populate my monkeys collection using the Find method, does this not populate the child collections too? when does that happen and when could i force this to happen?

Thank you

Cord