Nhibernate filter on a property inside reference property using query over

Question

I am using NHibernate with fluent mapping. I have the following scenario:

public class A
{
     public virtual int ID{get; set;}
     public virtual B BReference {get; set;}
     public virtual string aProperty {get; set;}
}

public class B
{
    public virtual int ID {get;set;}
    public virtual string Name {get; set;}
}

public class MapA: Map<A>
{
    Id(x=> x.ID);
    Map (x=> x.aProperty);
    References(x => x.BReference);
}

public class MapB : Map<B>
{
    Id(x=>x.ID);
    Map(x=>x.Name);
}

What i want to do is to filter A objects on the property A.BReference.Name. I am using the queryover to do my queries:

public object GetResult(ISession session)
{
   var result = session.QueryOver<A>.Where(a=> a.BReference.Name=="Value").List();
   return result;
}

Currently NHibernate is throwing an exception Could not resolve property BReference.Name of: A.

Is there some way to overcome this propblem? I can't change the queryover pattern now because we have dependence on it. Thanks for your help.

score 1 · Accepted Answer · answered Jun 11 '12 at 08:11

1

Hi you have to use JoinAlias to load the related table before you write a criteria.

B bReference = null;
var result = session.QueryOver<A>()
.JoinAlias(x => x.BReference, () => bReference, NHibernate.SqlCommand.JoinType.LeftOuterJoin)
.Where(x => bReference.Name == "Value").List<A>();

answered Jun 11 '12 at 08:11

Marian Ban

8,158
1
32
45

Is there any other solutions without using Aliases? – Manar Husrieh Jun 11 '12 at 09:16
@Manar Husrieh Yes. You you can use Linq to NHibernate. Why are Aliases bad for you? – Marian Ban Jun 11 '12 at 11:10
Cause we are working with dynamic code and we already implemented without aliases and with queryover. – Manar Husrieh Jun 11 '12 at 12:00

Nhibernate filter on a property inside reference property using query over

1 Answers1