How do I index for a nested date in RavenDB

Question

I may be barking up entirely the wrong tree here but... I have a RavenDB with lots of objects of type RavenPerson stored.

Each RavenPerson has a list of mailing bodies each of which has a date associated.

{
  "Bodies": [
    {
      "RenewalRunDate": "2011-11-30T00:00:00.0000000+00:00",
      "BodyText": "A bunch of text"
    }
  ]
}

I want to take a given date and get a list of the person's id and the related body text.

So...

    public class MailingsByDate : AbstractIndexCreationTask<RavenPerson, PersonMailingModel>
    {
        public MailingsByDate()
        {
            Map = people =>
                  people.SelectMany(person => person.Bodies,
                                    (person, body) =>
                                    new PersonMailingModel
                                        {
                                            MembershipNumber = person.MembershipNumber,
                                            MailingBody = body.BodyText,
                                            MailingDate = body.RenewalRunDate
                                        });
        }
    }

but when I call this

        var mailings = DocumentSession.Query<PersonMailingModel, MvcApplication.MailingsByDate>()
                                      .Where(pmm => pmm.MailingDate == date.Value);

I get an exception

Unable to cast object of type 'IntegraRenewalMailLibrary.RavenPerson' to type 'RenewalLogs.Models.PersonMailingModel'.

Thanks in advance!

---

Update: Altering the call to the index as below doesn't resolve the exception

        var mailings = DocumentSession.Query<PersonMailingModel, MvcApplication.MailingsByDate>()
                                      .Where(pmm => pmm.MailingDate == date.Value)
                                      .As<PersonMailingModel>()
                                      .ToList();

---

Update to Update: I've created a visual studio solution with example test cases here: https://github.com/pauldambra/IndexExploration

using version 1.0.888

I definitely haven't wrapped my head around what is happening in the indexes so I'm guessing this is me either not doing it right or trying to do the wrong thing...

---

Ayende pointed me to the solution on twitter which was to take the SelectMany call out the index and replace it with a call using the linq query form

    public class RecipientsByDate : AbstractIndexCreationTask<Person, PersonMailing>
    {
        public RecipientsByDate()
        {
            Map = people => from person in people
                            from body in person.Bodies
                            select new PersonMailing
                                       {
                                           MembershipNumber = person.MembershipNumber,
                                           MailingBody = body.BodyText,
                                           MailingDate = body.MailingDate
                                       };

        }
    }

Answer 1

Call As() in the end of this call