Question

i really can not find enough documentation on hibernate IN keyword, when applied on search within a collection of some object. I have strange problem, I have a hql query:

    FROM Contact co, IN (co.categories)categories WHERE categories.name = ?

In i was expecting list of Contacts ofcourse. But something is wrong with it, because it is not returning list of Contact objects, but list of Object[]????? Is it syntax or this is totally wrong??

Here are mapping parts:

     <set lazy="false" name="categories" table="ContactCategory">
        <key column="id" foreign-key="fk_contact_category" />
        <many-to-many class="Category" column="catid"
            foreign-key="fk_contact_category2" />
    </set>

     <class name="Category">

    <id column="catid" name="Id" type="long">
        <generator class="sequence" />
    </id>
    <property length="50" name="name" type="string" />  
</class>

Important thing to mention: This query is made with the query builder. This is printout of one of generated queries where its failing. Very weird is that – i am getting the correct number of objects in this list, I check the database and number is correct with given parameters, but I dont get Contact objects, but some Object arrays in the List.

Appreciate all the help

Answer 1

You need to add SELECT co

so that your Query is SELECT co FROM Contact co, IN (co.categories)categories WHERE categories.name = ?

The SELECT co is necessary, to tell Hibernate which one item it should return per result set line.

---

SELECT co FROM Contact co LEFT JOIN co.categories cat WHERE cat.name = ?
I have seen the IN keyword only in the Where – clause so far. In Stuff like this,

FROM catagories cat WHERE cat.name IN ('HALLO', 'WORLD')