Ive been using NHibernate 1.2.0.3001 (which is fantastic BTW) and recently tried to upgrade to the 4000 release - however when I did this I received an error similar to the following

PersistanceUpdate.Tests.UserTests.CreateUser : NHibernate.PropertyAccessException : The type NHibernate.Collection.PersistentBag can not be assigned to a property of type System.Collections.Generic.IList`1[PersistanceUpdate.Country] setter of PersistanceUpdate.User.UserCountries
----> System.ArgumentException : Object of type 'NHibernate.Collection.PersistentBag' cannot be converted to type 'System.Collections.Generic.IList`1[PersistanceUpdate.Country]'.

My mapping class for my test User class is as follows:
<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-cascade="none" default-lazy="false" schema="Test.dbo">
<class
name="PersistanceUpdate.User,PersistanceUpdate"
table="Users">
<id name="Id" column="UserId" type="int" length="4" unsaved-value="0">
<generator class="identity" />
</id>

<property name="Name" column="UserName"/>

<bag name="UserCountries" table="UserCountries">
<key column="UserId"/>
<many-to-many class="PersistanceUpdate.Country,PersistanceUpdate" column="CountryId" />
</bag>



</class>
</hibernate-mapping>

The UserCountries bag maps to an IList<Country> public setter on the User object

I have no problems with 1.2.0.3001 with this code and nothing else has changed expect the new NHibernate dll ( I double checked an re-referenced the 3001 version dll and it works perfectly)

Any ideas on how to fix this as I would really like to use the current version of NHibernate (apologies if this has been addressed before - I did try and find a resolution in the forums but couldn't see anything that applied, and the online help for v1.2.0 says nothing about not being able to map a bag to an IList<>)

many thanks

W

Please post the User class code.

Hi willardspoon!

Don't you have to add generic="true" to your mapping?

Hi guys - the user class originally inherits from an Entity class which provides the Save functionality. Ive stipped this out into the User class (please note I dont normally use the session in this way but it does replicate the error):

User class:

using System;
using System.Collections.Generic;
using System.Text;
using NHibernate.Cfg;
using NHibernate;

namespace PersistanceUpdate
{
public class User
{
private int _id;
private string _name;
private IList<Country> _userCountries = new List<Country>();
private Configuration cfg = new Configuration().Configure();
private ISessionFactory _factory = null;

public User()
{
_factory = cfg.BuildSessionFactory();
}

public int Id
{
get { return this._id; }
set { this._id = value; }
}

public string Name
{
get { return this._name; }
set { this._name = value; }
}

public IList<Country> UserCountries
{
get { return this._userCountries; }
set { this._userCountries = value; }
}

public void Save()
{
ISession session = _factory.OpenSession();
ITransaction trans = session.BeginTransaction();

try
{
session.Save(this);
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
throw ex;
}
finally
{
if(session != null)
session.Close();
}

}
}
}

And the user mapping class is as follows:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-cascade="none" default-lazy="false" schema="Test.dbo">
<class
name="PersistanceUpdate.User,PersistanceUpdate"
table="Users">
<id name="Id" column="UserId" type="int" length="4" unsaved-value="0">
<generator class="identity" />
</id>

<property name="Name" column="UserName"/>

<bag name="UserCountries" table="UserCountries" generic="true">
<key column="UserId"/>
<many-to-many class="PersistanceUpdate.Country,PersistanceUpdate" column="CountryId" />
</bag>



</class>
</hibernate-mapping>


I get the error when I run the following test:

User newUser = new User();
newUser.Name = "User Name";
newUser.Save();

Note - if I remove the bag from the mapping file the user saves correctly

The Country mapping file is as follows

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" default-cascade="none" default-lazy="false" schema="Test.dbo">
<class
name="PersistanceUpdate.Country,PersistanceUpdate"
table="Countries" >
<id name="Id" column="CountryId" type="int" length="4" unsaved-value="0">
<generator class="identity" />
</id>

<property name="Name" column="CountryName"/>



</class>
</hibernate-mapping>

My hibernate.cfg.xml file looks like:

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-configuration xmlns="urn:nhibernate-configuration-2.2" >
<session-factory >
<property name="connection.provider">NHibernate.Connection.DriverConnectionProvider</property>
<property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property>
<property name="connection.connection_string">{My Connection String}</property>
<property name="show_sql">false</property>
<property name="dialect">NHibernate.Dialect.MsSql2000Dialect</property>
<property name="use_outer_join">true</property>
<property name="query.substitutions">true 1, false 0, yes 'Y', no 'N'</property>
</session-factory>
</hibernate-configuration>

As a sanity check I left eveything the same but changed the NHibernate dll back to v1.2.0.3001 and then save worked correctly

Any help would be much appreciated

many thanks

W