fluent nhibernate circular dependencies

Question

I have 2 entities and everything works fine except NHibernate won't load the FieldGroupItems property in the second entity on an object. I suspect it's because there is a circular dependency between the 2 entities. I really need both ChildGroups and FieldGroupItems. If I remove ChildGroups than FieldGroupItems is loaded fine. Is there a way to have what I want. The only way I can think of is to use Guid collections instead of object collections to store only the Ids and fetch data manually from code. Any help is appreciated.

public class FieldGroupItemInstance : TenantBaseEntity
{
    public virtual Guid ItemId { get; set; }  //ID from the database to update actual object later
    public virtual bool IsTemporaryId { get; set; }  //true if field group is new (doesn't exist in system)
    public virtual IList<QuestionnaireInstanceField> Fields { get; set; }
    public virtual IList<QuestionnaireFieldGroupInstance> ChildGroups { get; set; }

    public FieldGroupItemInstance()
    {
        Fields = new List<QuestionnaireInstanceField>();
        ChildGroups = new List<QuestionnaireFieldGroupInstance>();
    }
}

public class QuestionnaireFieldGroupInstance : TenantBaseEntity
{
    public virtual Guid FieldGroupTemplateId { get; set; }
    public virtual IList<FieldGroupItemInstance> FieldGroupItems { get; set; } //Each repeated group of instances
    //public virtual FieldGroupItemInstance Parent { get; set; }

    public QuestionnaireFieldGroupInstance()
    {
        FieldGroupItems = new List<FieldGroupItemInstance>();
    }
}

Answer 1

If you are using fluentnhibernate to map your entities, this should work. Just pay attention to the Cascade options.

public class FieldGroupItemInstanceMap() 
{
        public FieldGroupItemInstanceMap()
        {
                Table("FieldGroupItemInstance");

                HasManyToMany(x => x.ChildGroups)
                        .Table("FieldGroupItemInstance_QuestionnaireFieldGroupInstance")
                        .ParentKeyColumn("IdFieldGroupItemInstance")
                        .ChildKeyColumn("IdQuestionnaireFieldGroupInstance")
                        .Cascade.None();
        }
}

public class QuestionnaireFieldGroupInstanceMap() 
{
        public QuestionnaireFieldGroupInstanceMap()
        {
                Table("QuestionnaireFieldGroupInstance");

                HasManyToMany(x => x.FieldGroupItems)
                        .Table("FieldGroupItemInstance_QuestionnaireFieldGroupInstance")
                        .ParentKeyColumn("IdQuestionnaireFieldGroupInstance")
                        .ChildKeyColumn("IdFieldGroupItemInstance")
                        .Cascade.None();
        }
}