Mapping Problem With Composite Ids

hybris · **Joined:** Tue May 26, 2009 8:26 am **Posts:** 1

Hey guys,

I recently managed to convince my colleagues to use NHibernate for persistence. So now I have to deal with it, without knowing very much about using Hibernate. At the moment I've got a problem with my mapping. I want to attach several arguments to a monitor. The arguments have got a composite-id, which I think must have something to do with the problem as all other one-to-manys are working fine.

ARGUMENT

Code:

<?xml version="1.0" encoding="utf-8" ?> 
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
    <class name="Foo.Model.HArgument, SelmaDb" table="argument">
        <composite-id name="HArgumentPK" class="Foo.Model.HArgumentPK">
          <key-property name="MonitorId" column="monitor_id" type="integer"/>
          <key-property name="Position" column="position" type="integer"/>
        </composite-id>
        <many-to-one name="Monitor" column="monitor_id" class="Foo.Model.HMonitor"/>
        <property name="Value" column="value" type="String" length="255"/> 
    </class>
</hibernate-mapping>

MONITOR

Code:

<?xml version="1.0" encoding="utf-8" ?> 
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
    <class name="Foo.Model.HMonitor, SelmaDb" table="monitor">
        <id name="Id" column="id" type="Int32"> 
            <generator class="identity" /> 
        </id> 
        <many-to-one name="Client" column="client_id" class="Foo.Model.HClient"/>
        <many-to-one name="Command" column="command_id" class="Foo.Model.HCommand"/>
        <property name="Interval" column="interval" type="Int32"/>
        <bag name="Arguments" cascade="none" lazy="true">
          <key column="monitor_id"/>
          <one-to-many class="Foo.Model.HArgument"/>
        </bag>
    </class>
</hibernate-mapping>

Skeleton classes

Code:

public class HArgument
    {
        #region orm specific
        public virtual HMonitor Monitor { get; set; }
        public virtual int Position { get; set; }
        public virtual string Value { get; set; }
        #endregion
....

Code:

public class HMonitor
    {
        #region orm specific
        public virtual int Id { get; set; }
        public virtual HClient Client { get; set; }
        public virtual HCommand Command { get; set; }
        public virtual int Interval { get; set; }
        public virtual IList<HArgument> Arguments { get; set; }
        #endregion
.....

When i build the session factory I get the following error: "Association references unmapped class: Foo.Model.HArgument". If I don't use the <bag> Tag in the HMonitor.hbm.xml it seems to work fine (at least I get the app to run as it should).

I think the solution must be really easy, I just don't seem to get it right...
Thanks for your help in advance,
peace
Hybris

wolli · **Posted:** Wed May 27, 2009 4:19 am

Which way do you use to "register" classes for hibernate ? If you use AddAssembly, check if the mapping file is set to build action "Embedded Resource".