NHibernate - need help with ICriteria query

Question

I am having trouble getting my query by criteria to work.

I want to filter the UserPublications collection by userId but it is not filtering. The ClientPublications collection has filtered correctly though.

Any advice?

Thanks in advance.

public IList<ClientReport> GetAvailableClientReports(int userId)
    {
        ICriteria criteria = NHibernateSession.CreateCriteria(typeof(ClientReport))
            .CreateCriteria("ClientPublications")                
            .Add(Expression.Eq("IsDownloaded", true))
            .SetResultTransformer(CriteriaUtil.DistinctRootEntity)
            .AddOrder(Order.Asc("Name"))
            .CreateCriteria("UserPublications")                    
            .CreateAlias("ClientUser", "user")
            .Add(Expression.Eq("user.UserId", userId));

        return GetByCriteria(criteria);
    }

Answer 1

If you mapped the UserId property as "Id" in your mapping file (which you probably do if you used the same conventions as in this question), it should be:

.Add(Expression.Eq("user.Id", userId))

The Id property is a special case in NHibernate

Answer 2

why don't you create an alias for UserPublications and add the expression there? like

.CreateCriteria("UserPublications", "up")                    
.Add(Expression.Eq("up.ClientUser.UserId", userId));

or maybe

.CreateCriteria("UserPublications", "up")                    
.CreateAlias("up.ClientUser", "user")
.Add(Expression.Eq("user.UserId", userId));

as far as i can see calling

.CreateAlias("ClientUser", "user")

depends on NH's ability to detect where ClientUser exists and create the join which may not be working (bug or otherwise)

Answer 3

For future ref, I got it working by adding a filter in the mapping file

First define the filter in the parent class mapping:

<filter-def name="userFilter">
  <filter-param name="userId" type="System.Int32"/>
</filter-def>

Then define filter further in the mapping to the collection

<bag name="UserPublications" access="property" lazy="true" cascade="all-delete-orphan">      
  <key column="ClientPublicationID"/>
  <one-to-many class="ReportMgr.Model.ClientUserPublication, ReportMgr.Model" />
  <filter name="userFilter" condition="ClientUserID = :userId"></filter>
</bag>

Then enable the filter and specify the parameter value just before executing the ICriteria query:

NHibernateSession.EnableFilter("userFilter").SetParameter("userId", userId);
ICriteria criteria = NHibernateSession.CreateCriteria(typeof(ClientReport))
            .CreateCriteria("ClientPublications")
            blah blah blah                   
return GetByCriteria(criteria);