Does any one knows if there must be special consideration when doing Query By Criteria thru a property which is a collection. eg.:

Having a class like next

public class LabeledItem {
private Long id;
private Set<Label> labels;
............
}

correctly mapped; I launch a criteria query like

criteria = session.createCriteria(LabeledItem.class)
.add(Restrictions.eq("labels",theLabels));

being theLabels a Set<Label>. As i want to retrieve only the
LabeledItems with exactly the indicated labels.

My problem is I'm getting the next error when executing the query:

Caused by: org.postgresql.util.PSQLException: No value specified for parameter 1.
at org.postgresql.core.v3.SimpleParameterList.checkAllParametersSet(SimpleParameterList.java:102)
at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:166)
at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:388)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:329)
at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:239)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:139)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1669)
at org.hibernate.loader.Loader.doQuery(Loader.java:662)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:224)
at org.hibernate.loader.Loader.doList(Loader.java:2145)
... 9 more


please help and thanx in advance.

... one thing important i should have remarked: the property labels which
i mean to filter thru, is an association to an another class of many-to-many.

I think you need to add restrictions based on properties of Label.

For eaxample, if Label is defined as:


And you want all Labels starting with an 'A', you would use:


Please rate this reply.

yeah that's what i first tried.....

criteria = session createCriteria(LabeledItem.class)
.createCriteria("labels");
for (Label label : allLabels2match) {
criteria = criteria.add(Restriction.eq("name",label.getName());
}

but that doesn't work as it is equivalent to this SQL:

select id_item from labeleditems li , label l
where li.id_item = l.iditem
AND l.name = 'name1'
AND l.name = 'name2'
AND l.name = 'name3'

.................

AND l.name = 'namen'

and this produces naturally 0 results. That's why i tried directly the property
- labels - without going deep into it.

Rather than ANDs, you want ORs. To do this you need to use Disjunction.


Please don't forget to rate this answer.

Thanx 4 your help but that's not what i want.
Let me explain:

I have for instance next LabeledItems

A -> labeled [fiction, humour]
B -> labeled [fiction]
C -> labeled [history, fiction]

If i seek objects labeled fiction and humour, i expect to get just A, but not A
and B and C as a Disjunction would do; am i wrong?

I guess it rather must have something to do with grouping by items as the Object Model is mapped to tables this way:

LABELED_ITEM (idItem, idLabel) and LABELS (idLabel, name)