MapReduce with GUID in Map function

[kYann]

Hi,

Seems that there is a bug with using Guid in the map function when doing MapReduce.

If I try to do this.query.Where(c => c.RessourceIdentifier = myGuid).Average(c => c.Value) I get no result if RessourceIdentifier is a Guid.
It works if RessourceIdentifier is a numeric.
Maybe it's because a Guid is stored as binary data in mongodb and in the map function you try to match the Guid as a string.

public class TestGuidIssue
{
public Guid RessourceIdentifier { get; set; }
public int Value { get; set; }
}

[schotime]

You are correct. If it has to do a map/reduce function (eg.avg, max, min, sum) then it uses javascript, which can't compare a guid because it is binary. This is the same issue if you are doing a (or, ||) comparison in which a guid is also involved.

[Salutoo]

Hi,

How about comparing the BinData- fields ".base64()" (and optionally ".subtype()") in the query? These fields should be available from inside the javascript expressions; something like:

db.TestGuidIssue.find(function() { return this.RessourceIdentifier.base64() == "6hALHeupAkqdKI+R3k945g==" || this.Value > 1}, {Value:1})

works in my mongodb shell without problems. The base64 could be created by c# using

string.Format(""{0}"", Convert.ToBase64String(((Guid)value).ToByteArray()));

I've taken a short look at the NoRM code, but not compiled it or applied any changes myself cause I'm missing both compiler and coding tools other then notepad (^^) at the moment; but I might be able to look into this soon. Why is the Code for Guid's doing "string.Format(""{0}"", value);" anyway? Especially with the if-branch "value is ObjectId || value is Guid". Are there cases which work that way that I miss?