Tuples in Criteria result. Is it bug or feature?

Basilio · **Posted:** Thu Aug 04, 2005 6:35 pm

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Hibernate version:
3.0.5, 3.1b

I am getting tuples with Criteria API. I have two different classes mapped to the same table. They are not inherited from each other. Criteria was created to request one of them. I was very precise on what type of object I want.

Simplified mappings and code:

Map1:

Code:

 <class name="Account" table="account"> 
        <id name="accountId" column="ACCOUNT_ID" type="java.lang.Integer"> 
            <generator class="native"/> 
        </id> 
        <property name="balance" column="BALANCE" /> 
</class> 

Map2:

Code:

<class name="SearchAccount" table="account"> 

  <id name="accountId" column="ACCOUNT_ID" type="java.lang.Integer"> 
  <generator class="native"/> 
</id> 

  <property name="balance" column="BALANCE" /> 

  <one-to-one name="account" class="AjDataAccount" /> 

<set name="customers" lazy="true" order-by="ACCOUNT_ID"> 
  <key column="ACCOUNT_ID" /> 
  <one-to-many class="customer" /> 
</set> 

</class> 

I am trying to find account by ID and have built Criteria object for that:

Code:

search = session.createCriteria(SearchAccount.class).add(Expression.eq("accountId", accountId)); 

Collection accounts = search.list(); 

Collection accounts will contain one object and it will be Object[] with two elements Object[0] is Account object and Object[1] will be SearchAccount. Why I have array if I have requested specific type(class) of instance? Is it a bug?

This code was working in H2 and does not work in H3. I have tried that in H3.0.5 and H3.1b. Same result.

I much appreciate if somebody can point me on docs part related to that and how can I get homogeneous set of objects

Thank you

sergeya · **Joined:** Thu Dec 02, 2004 7:11 am **Posts:** 85

Try to set polymorphism="explicit" :

http://www.hibernate.org/hib_docs/v3/re ... tion-class

Basilio · **Posted:** Mon Aug 08, 2005 5:29 pm

sergeya wrote:

Try to set polymorphism="explicit" :

http://www.hibernate.org/hib_docs/v3/re ... tion-class

Sergey,
Thank you for your response. It does not help. Result the same. But I would like to share what I found. Before this simple crietria will be executed we call small function (pagination) that will determine what part of result set will be loaded (page). In this function we are using the same criteria with Projection set. Something like that:

Code:

            int count = 0;
            criteria.setProjection(Projections.rowCount()); 
            count =((Integer) criteria.uniqueResult()).intValue();
            criteria.setProjection(null);

Result is: if you have not set projection for criteria (just skip this piece of code) you will have in result only SearchAccount objects. Once you have it set to anything, like in code above, you will have tuples in your result that will contain Acount and SearchAccount objects stored in Object[2] array. I think it can be considered as a bug because it leads to inconsistent behaviour.

Anyway, thank you one more time,
Regards