I have a big but maybe simple problem with my web page. I don't seem to get one-to-one mapping to work. The ProductItem member in the Product object
is always null after I'm loading it from my database. I'm using Billy McCafferty's design described in this article:

http://www.codeproject.com/KB/architect ... tices.aspx.

I have probably made a very simple mistake but I can't seem to find out what I have been doing wrong. All the needed data seems to be saved in the database but when I load

object from the database it fails. If you need more info or code, I'll post it.

I would be very grateful if someone could help me with this.

Best regards

/Ingo

////////////////////////////////////////////////////////////////////////////////////
//
// Mapping
//
////////////////////////////////////////////////////////////////////////////////////
//
// Product.hbm.xml
//
////////////////////////////////////////////////////////////////////////////////////
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
<class name="MyProject.Core.Product, MyProject.Core" table="Products">
<id name="ID" column="ProductID">
<generator class="identity" />
</id>


<one-to-one name="ProductItem"
class="MyProject.Core.ProductItem, MyProject.Core" />

</class>
</hibernate-mapping>

////////////////////////////////////////////////////////////////////////////////////
//
// ProductItem.hbm.xml
//
////////////////////////////////////////////////////////////////////////////////////
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2">
<class name="MyProject.Core.ProductItem, MyProject.Core" table="ProductItems" lazy="false">
<id name="ID" column="ProductItemID">
<generator class="identity" />
</id>

<property name="Quantity" column="Quantity" />

<many-to-one name="Product"
class="MyProject.Core.Product, MyProject.Core"
column="ProductID"
cascade="all" />

</class>
</hibernate-mapping>


////////////////////////////////////////////////////////////////////////////////////
//
// Database tables
//
////////////////////////////////////////////////////////////////////////////////////
//
// Products table

//
////////////////////////////////////////////////////////////////////////////////////
CREATE TABLE [dbo].[Products](
[ProductID] [int] IDENTITY(1,1) NOT NULL,
CONSTRAINT [PK_Products] PRIMARY KEY CLUSTERED

////////////////////////////////////////////////////////////////////////////////////
//
// ProductItems table
//
////////////////////////////////////////////////////////////////////////////////////
CREATE TABLE [dbo].[ProductItems](
[ProductItemID] [int] IDENTITY(1,1) NOT NULL,
[ProductID] [int] NOT NULL,
[Quantity] [int] NOT NULL,
CONSTRAINT [PK_ProductItems] PRIMARY KEY CLUSTERED

////////////////////////////////////////////////////////////////////////////////////
//
// Code
//
////////////////////////////////////////////////////////////////////////////////////
//
// Product.cs

//
////////////////////////////////////////////////////////////////////////////////////
using System;
using System.Collections.Generic;
using MyProject.Core.DataInterfaces;
using ProjectBase.Utils;

namespace MyProject.Core
{
public class Product : DomainObject<int>
{
#region Constructors

/// <summary>
/// Needed by ORM for reflective creation.
/// </summary>
protected Product() { }

#endregion

#region Properties

/// <summary>
/// Gets or sets the the product items associated to this product
/// </summary>
public virtual ProductItem Item
{
get { return _Item; }
set
{
_Item = value;
}
}

#endregion

#region Members

private ProductItem _Item;

#endregion
}
}

////////////////////////////////////////////////////////////////////////////////////
//
// ProjectItem.cs
//
////////////////////////////////////////////////////////////////////////////////////
using System;
using System.Collections.Generic;
using MyProject.Core.DataInterfaces;
using ProjectBase.Utils;

namespace MyProject.Core
{
public class ProductItem : DomainObject<int>
{
#region Constructors

/// <summary>
/// Needed by ORM for reflective creation.
/// </summary>
protected ProductItem() { }

#endregion

#region Properties

/// <summary>
/// Gets or sets the quantity of the products in this item
/// </summary>
public virtual int Quantity
{
get { return _Quantity; }
set
{
_Quantity = value;
}
}

/// <summary>
/// Gets or sets the ID for the product associated with this items entry
/// </summary>
public virtual Product Product
{
get { return _Product; }
set
{
_Product = value;
}
}

#endregion

#region Members

private int _Quantity;
private Product _Product;

#endregion
}
}