I want to map a kind of tree structure: only one class, “General”. The class has a iesi.collection called “childs: elements of childs will be “General Object”.
I need to use lazy initialization, (otherwise all the elements of the tree will be loaded when the 'root' element will be loaded).

When I launch my application, I have this error: “Creating a proxy instance failed”.

Those are my class and my mapping xml:


using System;
using System.Collections.Generic;
using System.Text;

namespace CourseRwDb.mapped
{
class General
{

public General()
{
this._childs = new Iesi.Collections.HashedSet();
}


private int _id;
public virtual int id
{
get
{
return _id;
}
set
{
_id = value;
}
}

private int _father;
public virtual int father
{
get
{
return _father;
}
set
{
_father = value;
}
}

private string _kind;
public virtual string kind
{
get
{
return _kind;
}
set
{
_kind = value;
}
}

private int _crw_ord;
public virtual int crw_ord
{
get
{
return _crw_ord;
}
set
{
_crw_ord = value;
}
}
private string _title;
public virtual string title
{
get
{
return _title;
}
set
{
_title = value;
}
}


private Iesi.Collections.ISet _childs;
public virtual Iesi.Collections.ISet childs
{
get
{
return _childs;
}
set
{
_childs = value;
}
}


}
}



<class name="General" table="general" lazy="true" proxy ="General">
<id name="id" column="id" >
<generator class="native" />
</id>
<property name="father" column="father" />
<property name="kind" column="kind" type="String(20)"/>
<property name="title" column="title" type="String"/>
<property name="crw_ord" column="crw_ord" />

<set name="childs" cascade="all-delete-orphan" inverse="true" lazy="true">
<key column="father"/>
<one-to-many class="General"/>
</set>


</class>


I red a lot but I could not find the solution of my problem.

Tanks you
Ciro

well actually, in this situation, you don't need to set the proxy attribute because NH will use the class as a proxy for itself by default. also in your mapping file here, you have a space between "proxy" and the "=".

similarly, i'm not sure of your model, but if General has a one-to-many relationship with a collection of General objects, then it probably needs to have a many-to-one association to itself. something like:


this is the true definition of the Composite Pattern.

-devon

did not work...
I have tried...
...tried to cut 'proxy' attribute
...tried to cut space between "proxy" and the "="
...tried to add the property "father" and to add the many-to-one father

but I always get the same old exception: "Creating a proxy instance failed”.


your answer was anyway useful, for me it is important to have the "true definition of the Composite Pattern"...thanks you

hello,

I got the same message ("Creating a proxy instance failed") and for me it helped to declare my classes as public