RavenDB - How to merge related docs of same type into an index projection - indexing

Question

Assuming the following class:
public class Thing
{
public string Id { get; set; }
public string Title{ get; set; }
public string KeyId { get; set; }
public CultureInfo Culture { get; set; }
}
and the following result class:
public class ProjectedThing
{
public string Id { get; set; }
public string Title{ get; set; }
public string KeyId { get; set; }
public CultureInfo Culture { get; set; }
public IEnumerable<Thing> Things { get; set; }
}
How can I build an index that holds the result class?
The closest I've come is with the following index definition:
public class ProjectedThings : AbstractIndexCreationTask<Thing,ProjectedThing>
{
public ProjectedThings()
{
Map = docs => from doc in docs
select new
{
Title = doc.Title,
KeyId = doc.KeyId,
Culture = doc.Culture,
Things = new[] {
new Thing{
Id = doc.Id,
Title = doc.Title,
KeyId = doc.KeyId,
Culture = doc.Culture,
TitlePluralized = doc.TitlePluralized
}
}
};
Reduce = results => from r in results
group r by r.KeyId into g
select new
{
Title = g.FirstOrDefault(x => x.Id == x.KeyId).Title,
KeyId = g.Key,
Culture = g.FirstOrDefault(x => x.Id == x.KeyId).Culture,
Things = from thing in g.SelectMany(x => x.Things).Where(x => x.Id != x.KeyId)
select new
{
Id = thing.Id,
Title = thing.Title,
KeyId = thing.Key,
Culture = thing.Culture
}
};
}
}
That's almost doing the trick, but I can't collect the Title, KeyId, and Culture in the reduction. Only the Things property is being populated.

Answer 1

Look at your code:
g.FirstOrDefault(x => x.Id == x.KeyId)
I don't understand this, but this is likely to be always false.
You probably want:
g.FirstOrDefault().Title,