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avihaimar
 Post subject: How to use in idbag
PostPosted: Wed Dec 13, 2006 5:34 pm 
Beginner
Beginner

Joined: Thu Nov 02, 2006 2:23 pm
Posts: 33
Hey,

i use in hyperjaxb2 , it generate a jaxb and hiebenate mapping from xsd.

it supports for collection only in :
Bag,Idbag,List

i have many to many relation (no need for biderctional)

lets say :
Book:
bookId- assign by application (pk)
name

Company:
companyId -assign by application (pk)
name.

I have a table Book_To_Comany with column:
bookId
companyId

i want that book will have many to many relation with company.

how can i write the idbag section in Book hbm?

I dont need list , because the order is not important and i dont need or want index, and bag is not good due to performence ( and Book can not have multiple company)

Thank you
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dsiefert
 Post subject: bag
PostPosted: Wed Dec 13, 2006 6:19 pm 
Newbie

Joined: Wed Dec 06, 2006 6:30 pm
Posts: 8
The idbag mapping should be something like:
Code:
<idbag name="companies" table="company" lazy="true">
  <collection-id type="long" column="id">
    <generator class="native"/>
  </collection-id>
  <key column="book_id"/>
  <many-to-many class="Company" column="company_id"/>
</idbag>


Consult the following manual page for more information: http://www.hibernate.org/hib_docs/v3/reference/en/html/collections.html#collections-idbag

-David
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avihaimar
 Post subject: Thank you , can you please explain what is the collection-id
PostPosted: Wed Dec 13, 2006 6:34 pm 
Beginner
Beginner

Joined: Thu Nov 02, 2006 2:23 pm
Posts: 33
for wich column it need to be mapped?
why you need generator?

i did something like this but i got ClassCastException with the long


Code:
Caused by: java.lang.ClassCastException
   at org.hibernate.type.LongType.set(LongType.java:42)
   at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:83)
   at org.hibernate.type.NullableType.nullSafeSet(NullableType.java:65)
   at org.hibernate.persister.collection.AbstractCollectionPersister.writeIdentifier(AbstractCollectionPersister.java:784)
   at org.hibernate.persister.collection.AbstractCollectionPersister.recreate(AbstractCollectionPersister.java:1074)
   at org.hibernate.action.CollectionRecreateAction.execute(CollectionRecreateAction.java:26)
   at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:248)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:232)
   at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:143)
   at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:297)
   at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:27)
   at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:993)
   at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:340)
   at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:106)
   at com.mercado.s2002.analysis.util.TransactionManager.commit(TransactionManager.java:230)
   at com.mercado.s2002.analysis.util.TransactionManager.close(TransactionManager.java:370)
   at com.mercado.s2002.analysis.dao.hibernate.QueryEventDAO.save(QueryEventDAO.java:54)
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dsiefert
 Post subject:
PostPosted: Wed Dec 13, 2006 6:40 pm 
Newbie

Joined: Wed Dec 06, 2006 6:30 pm
Posts: 8
You would need a generator for the primary key for each item--unless you would be assigning them by hand.

Sorry, the table in <idbag ...> should be whatever the association table is and NOT company table. Also, make sure that table has the id column.
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