LINQ中实现对象Many-To-Many(多对多)的关系映射

前段时间,大概用了一下LINQ to SQL, 发觉O/Rdesigner似乎没有Many-To-Many(多对多)关系的支持,只有自己写代码实现.
:(

提供一下俺的解决办法:
例如User和UserGroup的关系,假设保存在UserInGroups表中,这里记录了User和Group的对应关系,那么,需要手动在User/Group类中添加对应的partial属性:

public partial class User{
    piblic IEnumerable<Groups> Groups
    {
        var groups = from g in db.UserInGroups
                            where g.UserId = this.UserId
                            select {g.Groups};
        return groups;
    }
}


public partial class Group{
    piblic IEnumerable<Users> Users
    {
        var users = from u in db.UserInGroups
                            where u.GroupId = this.GroupId
                            select {u.Users};
        return users;
    }
}