FluentNHibernate: Nested component mapping results in NHiberate QueryException - fluent-nhibernate

Question

Hi i have a problem with mapping in Nhibernate. When I run a linq query referring to one of the component classes of my entity, I get a QueryException as below:
could not resolve property: ClosedCases of: Project.Entities.Headline
I have one table with records which i want to map into multiple objects of my headline entity.
Question:
Is there something wrongly set up in my mapping?
My Headline entity is separated into multiple logical classes as you can see below
public class Headline:Entity
{
public virtual DateTime Date { get; set; }
public virtual TeamTarget Teamtarget { get; set; }
}
public class TeamTarget : Entity
{
public virtual DateTime FromDate { get; set; }
public virtual DateTime ToDate { get; set; }
public virtual TargetItem AchievedTarget { get; set; }
public virtual Team Team { get; set; }
}
public class TargetItem : Entity
{
public virtual decimal ClosedCases { get; set; }
public virtual decimal Invoicing { get; set; }
}
Mapping file:
public class HeadlineMap: ClassMap<Headline>
{
public HeadlineMap()
{
Table("Headlines.Headlines");
Id(x => x.Id).Column("HeadlinesId");
Map(x => x.Date);
Component(x => x.Teamtarget, t =>
{
t.References(x => x.Team).Column("TeamId").Cascade.None();
t.Component(x => x.AchievedTarget, ti =>
{
ti.Map(x => x.Invoicing).Column("TeamInvoicing");
ti.Map(x => x.ClosedCases).Column("TeamClosedCases");
});
});
The Linq query I am running looks like this:
decimal closedCases = _headlineRepository.All
.Where(x =>
x.Date >= DateTimeExtensionMethods.FirstDayOfMonthFromDateTime(selectMonthFromDate)
&& x.Date <= DateTimeExtensionMethods.LastDayOfMonthFromDateTime(selectMonthFromDate)
&& x.Teamtarget.Team.Id == teamId
).Average(x => x.Teamtarget.AchievedTarget.ClosedCases);
I know that i can access headline item by using team entity by team id and this works, just have problem with the mapping of achieved target.
any ideas?

Answer 1

I think your mapping is fine. But as far as I know, it isn't possible to query a nested component with Linq to NHibernate. It can't understand what joins to do, it becomes too complex.
I think it is possible using NHibernate 3's QueryOver API using JoinQueryOver or JoinAlias. You should read this: QueryOver in NH 3.0
Maybe something like this would work:
Headline headlineAlias = null;
TeamTarget targetAlias = null;
Team teamAlias = null;
TargetItem targetItemAlias = null;
var query = session.QueryOver<Headline>(() => headlineAlias)
.JoinAlias(() => headlineAlias.Teamtarget, () => targetAlias)
.JoinAlias(() => targetAlias.Team, () => teamAlias)
.JoinAlias(() => targetAlias.AchievedTarget, () => targetItemAlias)
.Where(x => x.Date >= DateTimeExtensionMethods.FirstDayOfMonthFromDateTime(selectMonthFromDate) && x.Date <= DateTimeExtensionMethods.LastDayOfMonthFromDateTime(selectMonthFromDate))
.And(() => teamAlias.Id == teamId)
.Select(Projections.Avg(() => targetItemAlias.ClosedCases))
.SingleOrDefault<decimal>();