Hi,

I am new to the Nhibernate.

I have two tables, created with the constraints.

User
Id (Primary Key)
Name

and

Video
VideoId
UserId (FK_User_Id)
Description

and the following is the mapping file

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.0">
<class name="business.User, business" table="User" >
<id name="Id" type="Int32" unsaved-value="0">
<generator class="identity" />
</id>
<set name="Video" inverse="true" lazy="true">
<key column="UserId"/>
<one-to-many class="business.Video, business"/>
</set>
<property name="Name" column="Name" type="String" length="50" />
</class>
<class name="business.Video, business" table="Video" >
<id name="VideoId" column="VideoId" type="Int32" unsaved-value="0">
<generator class="identity" />
</id>
<property name="UserId" column="UserId" type="Int32" length="4" />
<many-to-one name="User" column="Id" not-null="true"/>
<property name="Description" column="Description" type="String" />
</class>
</hibernate-mapping>


My class files contain the code

using System;
namespace business
{
public class User
{
private int _Id;
private string _Name;

public int Id
{
get { return _Id; }
set { _Id = value; }
}
public int Name
{
get { return _Name; }
set { _Name = value; }
}
}
}


using System;
namespace com.zvdeo.business
{
public class Video
{
private int _VideoId;
private int _UserId;
private string _Description;

public int VideoId
{
get { return _VideoId; }
set { _VideoId = value; }
}
public int UserId
{
get { return _UserId; }
set { _UserId = value; }
}
public string Description
{
get { return _Description; }
set { _Description = value; }
}
}
}


I just wanted to retrieve the records of the table Video by executing..

session.CreateQuery("select V.VideoId, V.UserId, V.Description from video V");

and i am getting the Nhibernate.MappingException as
{"Problem trying to set association type by reflection"}

and InnerException as

{"Could not find a getter for property User in class business.Video"}


Is the mapping file which I created wrong?

What should I do to get the correct results?

Thanks in advance,
Ali

The error message you got gives you the hint what to do. In your mapping files you have defined a bidirectional relation between User and Video. But in your class definition this relation is missing. In your User class you have to define a Video property and in your video class you have to define a User collection.



Your Query should look llike



I have found a nice article about object relational mapping sometimes ago. Here is the link:

http://www.agiledata.org/essays/mappingObjects.html

Regards
Klaus

Hi Klaus,

Thanks so much for the solution..