RavenDB ID getting messed up in code created index - ravendb

Question

First off I'm just getting started with RavenDB so please be patient as I explain the issue. I'm trying to create my first map, map, reduce, transform index. Yeah I know I'm trying to do a lot but I have most of it working.
So first off I do this in my global.asax to make sure that all "ID" properties are used as the identifier on documents.
_documentStore.Conventions.FindIdentityProperty = p => p.Name == "ID";
OK now lets take a look at the index.
public class ProblemListViewIndex : AbstractMultiMapIndexCreationTask<ProblemListView>
{
public ProblemListViewIndex()
{
AddMap<Problem>(problems => from problem in problems
select new
{
ID = problem.ID,
SolutionCount = 0,
});
AddMap<Solution>(solutions => from solution in solutions
select new
{
ID = solution.ProblemID,
SolutionCount = 1,
});
Reduce = results => from result in results
group result by result.ID
into g
select new
{
ID = g.Key,
SolutionCount = g.Sum(x => x.SolutionCount),
};
Indexes.Add(x => x.ID, FieldIndexing.Analyzed);
TransformResults = (database, results) => from result in results
let problem = database.Load<Problem>("problems/" + result.ID.ToString())
let user = database.Load<User>("users/" + problem.PostedByID.ToString())
select new
{
ID = result.ID,
PostedByID = problem.PostedByID,
PostedByName = user.DisplayName,
SolutionCount = result.SolutionCount,
};
}
}
So everything looks good and when I test the index in the RavenDB website I get mixed results. I have duplicate projections. I have the two projections that I expect but two copies of them. Here are what the "ID" looks like on the projection results.
problems/194
problems/195
194
195
I'm confused but then I went back and looked at the "maps". My code translated into something different in the created index. Here is what the first map looks like when created initially.
docs.Problems
.Select(problem => new {ID = problem.__document_id, SolutionCount = 0})
Even being new to RavenDB I see the problem. It's using the "__document_id" field when I want to use the "ID" field. I change the map in then save the index to the following.
docs.Problems
.Select(problem => new {ID = problem.ID, SolutionCount = 0})
Once I do that my projection looks exactly as I expected and as I want it.
194
195
My question is what do I need to do in my code to get my index to create using "ID" over "__document_id"?

Answer 1

I don't see what's wrong here. I#ve put together a test using your code and I get what I have expected:
public class MultiMapWithTransformAndCustomId
{
public class Problem
{
public string ID { get; set; }
public string PostedByID { get; set; }
public string Foo { get; set; }
}
public class Solution
{
public string ID { get; set; }
public string ProblemID { get; set; }
public string Foo { get; set; }
}
public class User
{
public string ID { get; set; }
public string DisplayName { get; set; }
}
public class ProblemListViewIndex : AbstractMultiMapIndexCreationTask<ProblemListViewIndex.ReduceResult>
{
public class ReduceResult
{
public string ID { get; set; }
public int SolutionCount { get; set; }
public string PostedByID { get; set; }
public string PostedByName { get; set; }
}
public ProblemListViewIndex()
{
AddMap<Problem>(problems => from problem in problems
select new
{
ID = problem.ID,
SolutionCount = 0,
});
AddMap<Solution>(solutions => from solution in solutions
select new
{
ID = solution.ProblemID,
SolutionCount = 1,
});
Reduce = results => from result in results
group result by result.ID
into g
select new
{
ID = g.Key,
SolutionCount = g.Sum(x => x.SolutionCount),
};
Indexes.Add(x => x.ID, FieldIndexing.Analyzed);
TransformResults = (database, results) => from result in results
let problem = database.Load<Problem>(result.ID.ToString())
let user = database.Load<User>(problem.PostedByID.ToString())
select new
{
ID = result.ID,
PostedByID = problem.PostedByID,
PostedByName = user.DisplayName,
SolutionCount = result.SolutionCount,
};
}
}
[Fact]
public void Can_do_simple_query()
{
using (var documentStore = new EmbeddableDocumentStore
{
RunInMemory = true
})
{
documentStore.Conventions.FindIdentityProperty = p => p.Name == "ID";
documentStore.Initialize();
using (var documentSession = documentStore.OpenSession())
{
documentSession.Store(new User {ID = "users/1", DisplayName = "Daniel"});
documentSession.Store(new User {ID = "users/2", DisplayName = "Lang"});
documentSession.Store(new Problem {ID = "problems/194", PostedByID = "users/1"});
documentSession.Store(new Problem {ID = "problems/195", PostedByID = "users/2"});
documentSession.Store(new Solution {ID = "solutions/1", ProblemID = "problems/194"});
documentSession.Store(new Solution {ID = "solutions/2", ProblemID = "problems/194"});
documentSession.Store(new Solution {ID = "solutions/3", ProblemID = "problems/195"});
documentSession.SaveChanges();
}
new ProblemListViewIndex().Execute(documentStore);
using (var documentSession = documentStore.OpenSession())
{
var results = documentSession.Query<ProblemListViewIndex.ReduceResult, ProblemListViewIndex>()
.Customize(x => x.WaitForNonStaleResultsAsOfLastWrite())
.ToList();
Assert.Equal(2, results.Count);
var daniel = results.First(x => x.PostedByName == "Daniel");
var lang = results.First(x => x.PostedByName == "Lang");
Assert.Equal("problems/194", daniel.ID);
Assert.Equal("problems/195", lang.ID);
}
}
}
}

Answer 2

I found this problem too, I found a work around by adding another field to my Index, for example SolutionId, and set it's value to the same as the Id.
You should then be able to run queries against this value without any issues.
I asked the same question on here before, and apparently this is by design.

Answer 3

Adding to what Daniel said, solution.ProblemID is an integer field.
The simplest solution is to change the solution map to be:
ID = "problems/" + solution.ProblemID,
But I would strong suggest that you will use string references, instead of integer references, it will make everything simpler.