Why is my discriminator being returned as a proxy?

Question

I have a Status property in one of my POCO's that acts as a discriminator (very similar to using an enum).

Here is part of the HBM that has the Status column.

<many-to-one class="Locate.Common.Domain.Statuses.Status, Locate.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" name="Status">
  <column name="Status_id" not-null="true" />
</many-to-one>

And here is my HBM for the Status table.

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
  <class xmlns="urn:nhibernate-mapping-2.2" name="Locate.Common.Domain.Statuses.Status, Locate.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" table="`Status`">
    <id access="nosetter.lowercase-underscore" name="Id" type="System.Int32, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Status_id" />
      <generator class="assigned" />
    </id>
    <discriminator type="String">
      <column name="Status_id" />
    </discriminator>
    <property access="nosetter.lowercase-underscore" name="Name" type="System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="Name" not-null="true" />
    </property>
    <property access="nosetter.camelcase-underscore" name="IsUserSelectable" type="System.Boolean, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
      <column name="IsUserSelectable" not-null="true" />
    </property>
    <subclass name="Locate.Common.Domain.Statuses.CallbackStatus, Locate.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" discriminator-value="3" />
    <subclass name="Locate.Common.Domain.Statuses.EmergencyStatus, Locate.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" discriminator-value="5" />
    <subclass name="Locate.Common.Domain.Statuses.FirstCheckerStatus, Locate.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" discriminator-value="1" />
    <subclass name="Locate.Common.Domain.Statuses.PleaseAdviseStatus, Locate.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" discriminator-value="4" />
    <subclass name="Locate.Common.Domain.Statuses.SecondCheckerStatus, Locate.Common, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" discriminator-value="2" />
  </class>
</hibernate-mapping>

Lastly, here is my QueryOver.

var locates =
    session.QueryOver(() => locateAlias)
    .SelectList(x => x
        .Select(xx => xx.WorkToBeginDateTime).WithAlias(() => sentTo.DueDate)
        .Select(xx => xx.SendTo).WithAlias(() => sentTo.SentTo)
        .Select(xx => xx.TicketNo).WithAlias(() => sentTo.TicketNo)
        .Select(xx => xx.Status).WithAlias(() => sentTo.Status)
    )
    .JoinAlias(() => locateAlias.Status, () => statusAlias)
    .Where(() => locateAlias.IsComplete == false)
    .TransformUsing(Transformers.AliasToBean<SentToDto>()).List<SentToDto>();

This query runs without error however the Status property isn't getting initialized properly. When I go to use the Status value I receive this exception.

Initializing[Locate.Common.Domain.Statuses.Status#2]-Could not initialize proxy - no Session.

Looking at the NHibernate Profiler I can see that it is in fact selecting the proper Status_id.

What's wrong with me HBM or query?

Note that I am successfully able to query for all statuses and receive a list of all status discriminator objects. I can also see that the proxy object generated contains the correct values of the Status object so NHibernate is properly returning the correct values.

Answer 1

your Query doesnt Eeger-fetch the Status property and later, when you access Status the session, with which you loaded the locates is already closed. So instead of .JoinAlias(() => locateAlias.Status, () => statusAlias) use .Fetch(locate => locate.Status).Eager

Edit: i verified, its because of the Selects that Status is not eagerly fetched. Its only eager fetching if a locate-object is returned. you could do:

var locates =
    session.QueryOver(() => locateAlias)
    .Where(() => locateAlias.IsComplete == false)
    .Fetch(locate => locate.Status).Eager
    .ToEnumerable()
    .Select(locate => new SentToDto
    {
        DueDate = locate.WorkToBeginDateTime,
        SendTo = locate.SendTo,
        TicketNo = locate.TicketNo,
        Status = locate.Status,
    }.ToList();