Hi hib gurus
I have a class called message.
Message has an id, a parent (an other message) and a smallcontent.
Given an id and i small content, I want to retrieve a (unique) grand child which has those properties.
This is my query:

query.append("select image from com.nmt.msp.resource.SimpleMessageResource as image");
query.append(" join image.parent as parent");
query.append(" join parent.parent as grandparent");
query.append(" where ");
query.append(" grandparent.id = :rootMessageId");
query.append(" and image.smallContent = :theImageName");

which I run in this way:
--------------------------------------------------------------------------
net.sf.hibernate.Query q=theMspSession.createQuery(query.toString());
q.setString("theImageName", theImageName);
q.setLong("rootMessageId", rootMessageId);
--------------------------------------------------------------------------

This is the produced sql:
--------------------------------------------------------------------------
19577 Query select simpleme0_.id as x0_0_ from message simpleme0_ inner join message simpleme1_ on simpleme0_.parentid=simpleme1_.id inner join message simpleme2_ on simpleme1_.parentid=simpleme2_.id where (simpleme2_.id=237 )and(simpleme0_.smallcontent='e.gif' )
--------------------------------------------------------------------------
(a table with the message id= 242, the right one) and then 2 messages are fetched:
--------------------------------------------------------------------------
19577 Query select simpleme1_.id as id0_, simpleme1_.parentid as parentid0_, simpleme1_.internal as internal0_, simpleme1_.smallcontent as smallcon4_0_, simpleme0_.id as id1_, simpleme0_.parentid as parentid1_, simpleme0_.internal as internal1_, simpleme0_.smallcontent as smallcon4_1_ from message simpleme0_ left outer join message simpleme1_ on simpleme0_.parentid=simpleme1_.id where simpleme0_.id=242
19577 Query select simpleme1_.id as id0_, simpleme1_.parentid as parentid0_, simpleme1_.internal as internal0_, simpleme1_.smallcontent as smallcon4_0_, simpleme0_.id as id1_, simpleme0_.parentid as parentid1_, simpleme0_.internal as internal1_, simpleme0_.smallcontent as smallcon4_1_ from message simpleme0_ left outer join message simpleme1_ on simpleme0_.parentid=simpleme1_.id where simpleme0_.id=237
--------------------------------------------------------------------------

though I want only the message with id 242 to be fetched....
Why the other is fetched?
This is my message.xml
--------------------------------------------------------------------------
<hibernate-mapping>
<class name="resource.SimpleMessageResource" table="message"
proxy ="service.Message">
<id name="id" column="id" type="long" unsaved-value="-1">
<generator class="native"/>
</id>

<many-to-one name="parent" column="parentid" class="resource.SimpleMessageResource" cascade="none" outer-join = "true"/>
<property name="internal" type="boolean">
<column name="internal" unique-key="name-system-internal" index="namesystem_idx" not-null="true"/>
</property>

<property name="smallContent" column="smallcontent" not-null="false" />
</class>
</hibernate-mapping>
--------------------------------------------------------------------------
and this is my hib.conf

--------------------------------------------------------------------------
hibernate.dialect net.sf.hibernate.dialect.MySQLDialect
hibernate.connection.datasource java:comp/env/jdbc/msp
hibernate.show_sql false
hibernate.use_outer_join true
hibernate.jdbc.batch_size 0
hibernate.jdbc.use_streams_for_binary true
--------------------------------------------------------------------------

Note: without hibernate.use_outer_join true three messages are fetched, parent, child and grandchild.
Thanks for any help

--
Roberto Cosenza

Since the many-to-one object is always outer joined, Hibernate will load parent, gandparent etc... the whole family.

Try

From the doc

No, theres no lazy attribute on a <many-to-one>. Instead you need to map the associated class with a proxy. That will suppress eager fetching.

Hum I sent my older answer (the one I wrote before thinking of it ;-) )
As you can see the end of the post is good and refer to proxy

I found out that the parent & grandparent fetching is performed not during the query but when I access one of the property of the object (not mapped properties of course, a string is enough).

Is this the correct beaviour? I guess not. And the association is mapped with a proxy (it maps to the object itself, which as you can see, uses a proxy).

Testing with outher-join = false/true/auto did not help.

Confused....
/rob

The outer-join setting does not affect HQL queries. If you wish to do outer-join fetching in HQL, you must use LEFT JOIN FETCH.

good.
I'm trying to avoid the fetch join though!
A has a child B which has a child C.

When I access a.getName(), C is fetched....
/roberto

No, you are mistaken.

An proxied object is only fetched when it is first accessed. Are you sure you have mapped it with a proxy?

quite sure gavin, look at the xml file I posted earlier. Can I see in the hibernate log if the "proxy" mapping is seen correctly in some way?

Thanx,
Roberto

Well, the only many-to-one association in the mapping you posted earlier has outer-join="true", so of course the parent will be fetched by outer join when any SimpleMessageResource is first loaded (unless it is loaded by a HQL query).

I use this

query.append("select image from com.nmt.msp.resource.SimpleMessageResource as image");
query.append(" join image.parent as parent");
query.append(" join parent.parent as grandparent");
query.append(" where ");
query.append(" grandparent.id = :rootMessageId");
query.append(" and image.smallContent = :theImageName");

hql query.

This is my current mapping.

<hibernate-mapping>
<class name="com.nmt.msp.resource.SimpleMessageResource" table="message"
proxy ="com.nmt.msp.service.Message">

<id name="id" column="id" type="long" unsaved-value="-1">
<generator class="native"/>
</id>

<many-to-one name="parent" column="parentid" class="com.nmt.msp.resource.SimpleMessageResource" cascade="none" outer-join = "false"/>

<property name="content" column="content" not-null="false" type="binary" length="100000"/>
</class>

</hibernate-mapping>

I do not run load on the message id, I use the object in the session used for the hql query. As soon as I run message.getContent(), the whole hyerarchy is fetched.

I know that is wierd and that there must be some mistake but I cannot find it. Please point me to the right direction.
/roberto

I recommend that you get out your debugger and start stepping through code.