Hi,

I am experiensing a problem using Criteria Queries with a collection of dependent objects.

I have an entity class EmailDialog that contains a collection of UserEmailDialog objects (field participants). UserEmailDialog is an association class that represents properties of an association between Users and EmailDialogs.

Here is my mapping for class EmailDialog:

<class name="EmailDialog" table="EmailDialog">

<id name="id" type="long" column="id" unsaved-value="null" access="property">
<generator class="sequence">
<param name="sequence">emaildialog_sequence</param>
</generator>
</id>

<set name="participants" table="UserEmailDialog">
<key column="emaildialog_id" not-null="true" foreign-key="useremaildialog_emaildialog_fk"/>
<composite-element class="UserEmailDialog">
<many-to-one name="participant" class="com.fa.domain.User" column="user_id" foreign-key="useremaildialog_user_fk" not-null="true"/>
<property name="deleted" type="boolean" column="deleted" not-null="true"/>
<property name="read" type="boolean" column="read" not-null="true"/>
</composite-element>
</set>

<property name="subject" column="subject" type="string" length="300" not-null="true"/>
</class>

I am trying to use the following Criteria Query to find all EmailDialogs in which a particular user participate:
Criteria crit = session.createCriteria(EmailDialog.class).createCriteria("participants").createCriteria("participant").add(Restrictions.eq("id", userId));

I am getting the following exception:
org.hibernate.MappingException: collection was not an association: com.fa.domain.mailbox.EmailDialog.participants.

Can anything be done to get the Criteria Query working without making UserEmailDialog a separate entity class? Is there any way to use such collections of dependent objects in Criteria Queries?

Many thanks.

Try using createAlias instead of createCriteria.By and large, you don't need to use subcriteria unless you want to use each criteria separately. It is usually as effective and more efficient to use just the original Criteria object.