Hi,

I am new to Hibernate and I am creating my first project using ORM tool.
The problem I have now is how to use many to many association.

I couldn't find examples in the internet. the ones I found use XML.

The code is that, but I don't know where to tell NHibernate to use the table Devices_DevicesGroup as associative table. I think it should be straight forward. (I don't and wouldn't like to have to device a class for the associative table as it works just as the LINK for the two real tables).

The tables involved are:

Devices
DevicesGroups
Devices_DevicesGroups (Only the PK for the two tables)

The code for Device DAO is

namespace DAO
{
[NHibernate.Mapping.Attributes.Class(Table = "devices")]
public class Device
{
private string _strImei;
private string _strDescription;
private string _strModel;
private string _strVersion;

//Many to Many relation
private List<DevicesGroup> _collDevicesGroups = null;

[NHibernate.Mapping.Attributes.Id(Name = "Imei")]
[NHibernate.Mapping.Attributes.Generator(1, Class = "assigned")]
public string Imei
{
get
{
return _strImei;
}
set
{
_strImei = value;
}
}

[NHibernate.Mapping.Attributes.Property(Column = "description")]
public string Description
{
get
{
return _strDescription;
}
set
{
_strDescription = value;
}
}

[NHibernate.Mapping.Attributes.Property(Column = "model")]
public string Model
{
get
{
return _strModel;
}
set
{
_strModel = value;
}
}

[NHibernate.Mapping.Attributes.Property(Column = "version")]
public string Version
{
get
{
return _strVersion;
}
set
{
_strVersion = value;
}
}

[NHibernate.Mapping.Attributes.ManyToMany(Class = "DevicesGroup", Column = "id")]
public List<DevicesGroup> DevicesGroups
{
get
{
return _collDevicesGroups;
}
set
{
_collDevicesGroups = value;
}
}

}
}


We are using NHibernate 1.0.3
Using only Attributes (without mapping files).
SQLServer Express 2005

There is a good sample app here:
http://www.theserverside.net/tt/article ... NHibernate

It uses many to many relation. Just think that using nHibernate and attributes instead of hibernate and Xml mapping is nearly the same.

Thanks, I've found the answer here:

http://forum.hibernate.org/viewtopic.ph ... attributes

Cheers