Hi,

I am using Hibernate 3.0 with Oracle 9i. I have four entities with the following configuration,

Entities
******

1. SchemeMember
2. SchemeMemberConfigurationGroup
3. ConfigurationGroup
4. ValidResponse

Relationships
***********

1. SchemeMember -> SchemeMemberConfigurationGroup : one-to-many bidirectional.
2. SchemeMemberConfigurationGroup -> ConfigurationGroup : many-to-one bidirectional
3. ConfigurationGroup -> ValidResponse : one-to-many bidirectional

Code
*****

List findBySchemeMember(SchemeMember schemeMember) {

Criteria criteria = getSession().createCriteria(SchemeMemberConfigurationGroup.class);
criteria.add(Restrictions.eq("schemeMember", schemeMember));
criteria.setFetchMode("configurationGroup", FetchMode.JOIN);
criteria.setFetchMode("configurationGroup.validResponses", FetchMode.JOIN);
return criteria.list();

}

Problem
*******

The code above returns duplicate SchemeMemberConfigurationGroup objects with the same primary key. For example if a given SchemeMember has two SchemeMemberConfigurationGroup objects and the ConfigurationGroup object associated with each SchemeMemberConfigurationGroup objects has two ValidResponse objects, the query returns four SchemeMemberConfigurationGroup objects instead of two. However, if I comment out the line that sets the fetch mode for the association path configurationGroup.validResponses, the query returns the correct number of SchemeMemberConfigurationGroup objects which is two. This is not a desirable option as this will result in n + 1 reads.

Any help on this will be highly appreciated.

Ta
Abu Mariam

Try this:

This question has been posted more than once before and I think the answer is usually to add the results to a Set which will remove the duplicates.

I don't remember the rationale for this being what is returned.

http://forum.hibernate.org/viewtopic.ph ... esults+set

jdl Wins!!

Thanks buddy! You just saved me from using manually concatenated HQL out of frustration from the duplicates.

Great Tip!

Thanks, setting the results transformer fixed the problem.

Is the a similar approach when doing a fetch join with EJB3 EQL that preserves the order?