How to request embedded information in RavenDB?

Question

I have the following document called Reservation:

{ "CustomerId": 1, "Items": [ { "EmployeeId": "employees/1", "StartTime": "2011-08-15T07:20:00.0000000+03:00", "EndTime": "2011-08-15T07:40:00.0000000+03:00" }, { "EmployeeId": "employees/1", "StartTime": "2011-08-15T07:40:00.0000000+03:00", "EndTime": "2011-08-15T09:10:00.0000000+03:00" }, { "EmployeeId": "employees/3", "StartTime": "2011-08-16T07:20:00.0000000+03:00", "EndTime": "2011-08-16T11:35:00.0000000+03:00" } ] "ReservedAt": "2011-10-20T15:28:21.9941878+03:00" } 

In addition, I have the following design class:

 public class ReservationItemProjection { public string ReservationId { get; set; } public string CustomerId { get; set; } public string EmployeeId { get; set; } public DateTime StartTime { get; set; } public DateTime EndTime { get; set; } } 

What index and query do I write if I want to find a ReservationItemProjections match? For instance:.

 // invalid example query: var matches = docs.Query<ReservationItemProjection, ReservationItemProjectionsIndex>() .Where(x => x.EmployeeId == "employees/1" && x.StartTime >= minTime && x.EndTime <= maxTime) .ToList(); 

Please note that I do not want to receive a list of documents for reservation, but a list of ReservationItemProjection objects. The documentation says:

But, while getting documents matching a specific request is helpful, we can do better. Instead of getting the documents myself, I want to get the values ​​directly from the index without getting the full document.

I have already tried using an index like this:

 public class ReservationItemProjectionsIndex : AbstractIndexCreationTask<Reservation, ReservationItemProjection> { public ReservationItemProjectionsIndex() { Map = reservations => from reservation in reservations from item in reservation.Items select new { ReservationId = reservation.Id, CustomerId = reservation.CustomerId, item.EmployeeId, item.StartTime, item.EndTime }; Store(x => x.ReservationId, FieldStorage.Yes); Store(x => x.CustomerId, FieldStorage.Yes); Store(x => x.EmployeeId, FieldStorage.Yes); Store(x => x.StartTime, FieldStorage.Yes); Store(x => x.EndTime, FieldStorage.Yes); } } 

Somehow I can’t get the query and the index to work: it either throws an exception from not being able to throw from the ReservationItemProjection into the reservation or, when I could get the ReservationItemProjection objects, they will have included all the objects in all the reservations that even have one a suitable item, even though there is a Where-where x.EmployeeId == "employees / 1" parameter in my request.

Summary: what is the required index? Does an index require only a Map clause, as well as a Reduce or TransformResults? How to write a query in C #?

Answer 1

Casper, In RavenDB you are requesting documents. Although it is technically possible to do what you want, it is usually meaningless because the projected information does not have the necessary context to do something with it.

What are you trying to do?

For reference, the index will look something like this:

  from doc in docs.Items from reservation in doc.Reservations select new { reservation.EmployeeId, reservation.Start, reservation.End } 

Then check EmployeeId, Start and End as Store.

Now in your request specify:

  session.Query<...,...>().AsProjection<ReservationProjection>().ToList(); 

Calling AsProjection will let the database know that you need the values ​​from the index, not the document