Nhibernate self join read join field value - nhibernate

Question

I intend to read the referencing field (ParentMenu) value for my self join mapping. The class and mappings are as follows;
public class MenuSetup
{
public virtual int MenuId { get; set; }
public virtual string DisplayText { get; set; }
public virtual int MenuOrder { get; set; }
public virtual bool MenuStatus { get; set; }
public virtual bool HasKids { get; set; }
public virtual MenuSetup Parent { get; set; }
public virtual ICollection<MenuSetup> SubMenu { get; set; }
}
Mappings below;
public MenuSetupMap()
{
Id(x => x.MenuId).GeneratedBy.Identity();
Map(x => x.DisplayText);
Map(x => x.MenuStatus);
Map(x => x.MenuOrder);
Map(x => x.HasKids);
HasMany(x => x.SubMenu).KeyColumn("ParentMenu");
References(x => x.Parent).Column("ParentMenu");
.Cascade.AllDeleteOrphan()
.Fetch.Join().Inverse().KeyColumn("MenuId");
}
There is ParentMenu field that i want to read like this into my view model HomeMenuViewModel.
var session = MvcApplication.SessionFactory.GetCurrentSession();
string qry = #"select p.MenuId,p.DisplayText,p.MenuStatus,p.MenuOrder,
m from MenuSetup as p left join p.Parent m";
var vm=session.CreateQuery(qry).List<object[]>()
.Select(x=>new HomeMenuViewModel()
{
MenuId=(int)x[0],
DisplayText=(string)x[1],
MenuStatus=(Boolean)x[2],
MenuOrder=(int)x[3],
ParentMenu = x[10] == null ? 0 : (int)x[10]
}).ToList();
throws an error "System.IndexOutOfRangeException was unhandled by user code". I am stuck really need help.
The query generated from NHProf is shown below;
select menusetup0_.MenuId as col_0_0_,
menusetup0_.DisplayText as col_1_0_,
menusetup0_.MenuStatus as col_2_0_,
menusetup0_.MenuOrder as col_3_0_,
menusetup1_.MenuId as col_4_0_,
menusetup1_.MenuId as MenuId10_,
menusetup1_.DisplayText as DisplayT2_10_,
menusetup1_.MenuStatus as MenuStatus10_,
menusetup1_.MenuOrder as MenuOrder10_,
menusetup1_.HasKids as HasKids10_,
menusetup1_.ParentMenu as ParentMenu10_
from [MenuSetup] menusetup0_
left outer join [MenuSetup] menusetup1_
on menusetup0_.ParentMenu = menusetup1_.MenuId
Waiting for help in earnest.
Thank you
UPDATE SOLUION
I found the solution after much tinkering
I needed to declare the field in the MenuSetup class as below
public class MenuSetup
{
.
.
public virtual int ParentMenu { get; set; }
.
}
In the Mapping class, i declared the column as well.
My retrieval code changed to
var session = MvcApplication.SessionFactory.GetCurrentSession();
string qry = #"select p.MenuId,p.DisplayText,p.MenuStatus,p.MenuOrder,
p.ParentMenu from MenuSetup as p";
var vm=session.CreateQuery(qry).List<object[]>()
.Select(x=>new HomeMenuViewModel()
{
MenuId=(int)x[0],
DisplayText=(string)x[1],
MenuStatus=(Boolean)x[2],
MenuOrder=(int)x[3],
ParentMenu = x[4] == null ? 0 : (int)x[4]
}).ToList();

Answer 1

The amount of object[] items is related to the HQL query, not to the generated SQL query. I.e. the above query will return object[] having 5 elements:
// the HQL Snippet
select
p.MenuId, // object[0]
p.DisplayText, // object[1]
p.MenuStatus, // object[2]
p.MenuOrder, // object[3]
m // object[4]
from MenuSetup ....
So, there is no object[10] ... and that's why we do have System.IndexOutOfRangeException
The 5th element is complete parent. The solution should be like this:
ParentMenu = x[4] == null ? null : (MenuSetup)x[4]
NOTE: it could be better if we would use only one property from parent, e.g. change HQL to ...m.DisplayText...