I am trying to reference some child entities with part of the parents composite key not all of it, why cant I? This happens when I use the following mapping instead of that which is commented.

I get the following error

Foreign key in table VolatileEventContent must have same number of columns as referenced primary key in table LocationSearchView

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="JeanieMaster.Domain.Entities" assembly="JeanieMaster.Domain">
  <class name="LocationSearchView" table="LocationSearchView">

    <composite-id>
      <key-property name="LocationId" type="Int32"></key-property>
      <key-property name="ContentProviderId" type="Int32"></key-property>
      <key-property name="CategoryId" type="Int32"></key-property>
    </composite-id>

    <property name="CompanyName" type="String" not-null="true" update="false" insert="false"/>
    <property name="Description" type="String" not-null="true" update="false" insert="false"/>
    <property name="CategoryId" type="Int32" not-null="true" update="false" insert="false"/>
    <property name="ContentProviderId" type="Int32" not-null="true" update="false" insert="false"/>
    <property name="LocationId" type="Int32" not-null="true" update="false" insert="false"/>
    <property name="Latitude" type="Double"  update="false" insert="false" />
    <property name="Longitude" type="Double"  update="false" insert="false" />

    <bag name="Events" table="VolatileEventContent" where="DeactivatedOn IS NULL" order-by="StartDate DESC" lazy="false" cascade="none">
      <key>
        <column name="LocationId"></column>
        <column name="ContentProviderId"></column>
        <!--<column name="LocationId"></column>
        <column name="ContentProviderId"></column>
        <column name="CategoryId"></column>-->
      </key>
      <one-to-many class="Event" column="VolatileEventContentId"></one-to-many>
    </bag>

  </class>
</hibernate-mapping>

And VolatileEventContent mapping file

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" namespace="JeanieMaster.Domain.Entities" assembly="JeanieMaster.Domain">
  <class name="Event" table="VolatileEventContent" select-before-update="false" optimistic-lock="none">
    <composite-id>
      <key-property name="LocationId" type="Int32"></key-property>
      <key-property name="ContentProviderId" type="Int32"></key-property>
    </composite-id>

    <property name="Description" type="String" not-null="true" update="false" insert="false"/>

    <property name="StartDate" type="DateTime" not-null="true" update="false" insert="false" />
    <property name="EndDate" type="DateTime" not-null="true" update="false" insert="false" />

    <property name="CreatedOn" type="DateTime" not-null="true" update="false" insert="false" />
    <property name="ModifiedOn" type="DateTime" not-null="false" update="false" insert="false" />

    <many-to-one name="Location" class="Location" column="LocationId" />

    <bag name="Artistes" table="EventArtiste" lazy="false" cascade="none">
      <key name="VolatileEventContentId" />
      <many-to-many class="Artiste" column="ArtisteId" ></many-to-many>
    </bag>
  </class>
</hibernate-mapping>