hibernate HQL elements error

Question

My HibernateUserImpl mapping look like below

<set name="groups" table="OS_USER_GROUP" inverse="false" cascade="none" lazy="false">
    <key column="user_id"/>
    <many-to-many column="group_id" class="com.opensymphony.user.provider.hibernate3.ahxu.impl.HibernateGroupImpl"/>
</set>

I do HQL query like

select distinct hibuser from HibernateUserImpl hibuser, hibuser.groups.elements  hibgroup where hibuser.name = ? and hibgroup.name = ?

I get error for hibuser.groups.elements . Is there anything I miss out?

error in console

org.hibernate.hql.ast.QuerySyntaxException: hibuser.groups.elements is not mappe
d [select distinct hibuser from com.opensymphony.user.provider.hibernate3.ahxu.i
mpl.HibernateUserImpl hibuser, hibuser.groups.elements  hibgroup where hibuser.n
ame = ? and hibgroup.name = ?]

Answer 1

I think you need to make an explicit join.

    select distinct hibuser 
    from HibernateUserImpl hibuser
    join hibuser.groups hibgroup 
    where hibuser.name = ? and hibgroup.name = ?

Answer 2

hibuser.groups is a collection, thus you cannot access attribut of the element of the collection.

This can be illustrated like :

List groups = ...; groups.elements <- illegal function access.

Thus to access hibuser.groups.elements, you need to do multiple joins :

select element from HibernateUserImpl hibuser join hibuser.groups group join group.elements element where hibuser.name = ? and hibgroup.name = ? and element.whatever = something

But here you only select on hibuser, thus you should not join on other collections. Not joining will first give you a faster query, and avoid usage of distinct. Try to avoid distinct as much as possible.