Hello,

I've got two tables Community and Zipcode with a one to many relationsship (one community may have multiple zipcodes).

I'd like to pre-fetch the zipcodes in order to access them after the session is closed. If I modify the mapping file by setting lazy="false" then it works!

But if I specifiy a Join Fetch explicitely in the Criteria or HQL, then the query will return the same Community entity multiple times. The entities are the same. All of them contain the same associated Zipcodes.

Any ideas what I'm doing wrong?

Thanks.




Hibernate version: 3.1.3

Mapping documents:
<hibernate-mapping>
<class name="Community" table="COMMUNITY" schema="XXX">
<id name="communityId" type="java.lang.Long">
<column name="COMMUNITY_ID" precision="22" scale="0" />
<generator class="assigned" />
</id>
<property name="name" type="java.lang.String">
<column name="NAME" length="200" not-null="true" />
</property>
<set name="zipcodes" inverse="true">
<key>
<column name="COMMUNITY_ID" precision="22" scale="0" not-null="true" />
</key>
<one-to-many class="Zipcode" />
</set>
</class>
</hibernate-mapping>

<hibernate-mapping>
<class name="Zipcode" table="ZIPCODE" schema="XXX">
<id name="zipcodeId" type="java.lang.Long">
<column name="ZIPCODE_ID" precision="22" scale="0" />
<generator class="assigned" />
</id>
<many-to-one name="basPlace" class="Place" fetch="select">
<column name="PLACE_ID" precision="22" scale="0" not-null="true" />
</many-to-one>
<many-to-one name="community" class="Community" fetch="select">
<column name="COMMUNITY_ID" precision="22" scale="0" not-null="true" />
</many-to-one>
<many-to-one name="supplier" class="Supplier" fetch="select">
<column name="SUPPLIER_ID" precision="22" scale="0" not-null="true" />
</many-to-one>
<property name="zipcode" type="java.lang.String">
<column name="ZIPCODE" length="6" not-null="true" />
</property>
</class>
</hibernate-mapping>

Code between sessionFactory.openSession() and session.close():
DetachedCriteria criteria = DetachedCriteria.forClass(Community.class);
criteria.setFetchMode("zipcodes", FetchMode.JOIN);
criteria.addOrder(Property.forName("name").asc());
List<Community> communities = getHibernateTemplate().findByCriteria(criteria);


Name and version of the database you are using: Oracle 10g

Hi I am having the same problem. if you found the solution can you please share with me!

thank you in advance

There is not much Hibernate can do. It is one-to-many relation, and you tell use join-fetch when retrieving Community. So it makes a join to Zipcode in one SQL (look on the sql). This works properly, but the use of join-fetch in this case is not correct here.

Just also call setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY) on your criteria instance. This should let each instance only once.