Hibernate version: 1.2

Is there a limit on the level of left join fetching that can be issued to hydrate an object graph with a single query?

I have a scenario that looks like the following:

select s from Survey s left join fetch s.SurveySections ss left join fetch ss.SurveySectionXRQuestions q left join fetch q.Answers where s.Id = ?

The SurveySectionXRQuestions mapping off of a SurveySection looks like this:


<map name="SurveySectionXRQuestions" inverse="false" lazy="true" cascade="none">
<cache region ="default" usage ="read-write" />
<key column="SurveySectionId"/>
<index column="QuestionId" type="Guid"/>
<one-to-many class="DosRios.SurveyManagement.SurveySectionXRQuestion, DosRios.SurveyManagement"/>
<filter name="IncludeActiveRecords" condition="'True' = Active"/>
</map>


The query will execute a single SQL statement, however it doesn't populate the Questions collection within the object graph until I iterate over it, as if it's lazy loading the collection. I was under the impression that the HQL query would override the lazy attribute within the hbm mapping. Any suggestions would be appreciated. Thanks.

I don't think that HQL will override the lazy attribute. Have you tried it with lazy="false".

You can specifiy the maximun depth for joining in the configuration with "hibernate.max_fetch_depth", but I don't think, that's the problem here.

http://www.hibernate.org/hib_docs/nhibernate/1.2/reference/en/html/session-configuration.html#configuration-optional

Thanks for the suggestion, neither one of those provided any adjustments to the queries being generated, however I ended up changing the way we were doing left join fetches through object association to another alias and that helped dramatically. So, as an example, the query might have looked like this:

Select s from Survey s left join fetch s.Sections ss left join fetch ss.Content.Resources

and I changed it to:

Select s from Survey s left join fetch s.Sections ss left join fetch ss.Content ssc left join fetch ssc.Resources