Help! Child-Parent relationship -- Key happens to be a composite key

[THY02K]

Help! Child-Parent relationship -- Key happens to be a composite key

Hi, I'm having a lot of trouble trying to get this work. I have two classes:
1. AppProperty (Parent)
2. AppPropertyValue (Child)

1. AppProperty class' PK column is PropertyUIN (Int32).
2. AppPropertyValue class' composite key column is {PropertyUIN (Int32), PropertyValue (String)}
3. One AppProperty instance can relate to MANY AppPropertyValue instance. The two are related by "PropertyUIN".

Trouble is, when I tried to persist the child class, I get:

SqlException wrapped around by a NHibernate.ADOException :

Message	"Column name 'PropertyUIN' appears more than once in the result column list.
Statement(s) could not be prepared."	String

"PropertyUIN" appears twice because it's part of the composite key AND at the same time it appears for the second time in AppPropertyValue's hbm file for I need to declare "many-to-one" between AppProperty and AppPropertyValue. What should I do to resolve this situation?

Thanks in advance.


Code Fragment:

Public Class AppProperty
		Implements ISerializable

		Protected _propertyUIN As Int32
		...
		...
		Public Property PropertyUIN() As Int32
			Get
				Return _propertyUIN
			End Get
			Set(ByVal Value As Int32)
				_propertyUIN = Value
			End Set
		End Property
		...
End Class

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
	<class name="application.utilities.settings.AppProperty, Utility" table="AppProperty">
		<id name="PropertyUIN" column="PropertyUIN" type="Int32" > 
			<generator class="identity" /> 
		</id> 
		... stuff ...
		<set name="Values" inverse="true" cascade="all" table="AppPropertyValue">
			<key column="PropertyUIN"/>
			<one-to-many class="application.utilities.settings.AppPropertyValue, Utility"/>
		</set>
		... the rest of it ...
	</class>
</hibernate-mapping>


Public Class AppPropertyValue
		Implements ISerializable

		Protected _propertyUIN As Int32
		Protected _propertyValue As String

		Protected _parentProperty As AppProperty
		...
		...
		Public Property PropertyUIN() As Int32
			Get
				Return _propertyUIN
			End Get
			Set(ByVal Value As Int32)
				_propertyUIN = Value
			End Set
		End Property

		Public Property PropertyValue() As String
			Get
				Return _propertyValue
			End Get
			Set(ByVal Value As String)
				_propertyValue = Value
			End Set
		End Property

		Public Property ParentProperty() As AppProperty
			Get
				Return _parentProperty
			End Get
			Set(ByVal Value As AppProperty)
				_parentProperty = Value
			End Set
		End Property
		...
End Class

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
	<class name="application.utilities.settings.AppPropertyValue, Utility" table="AppPropertyValue">
		<composite-id>
			<key-property name="PropertyUIN" column="PropertyUIN" type="Int32"/>
			<key-property name="PropertyValue" column= "PropertyValue" type="String" length="2500"/>
		</composite-id>
		<many-to-one name="ParentProperty" column="PropertyUIN" class="application.utilities.settings.AppProperty, Utility" />
		... stuff ...
	</class>
</hibernate-mapping>

CREATE TABLE AppProperty (
	PropertyUIN INTEGER IDENTITY(1,1),
	...
	PRIMARY KEY  (PropertyUIN)
)

CREATE TABLE AppPropertyValue (
	PropertyUIN INTEGER,
	PropertyValue VARCHAR(2500),
	...
)