Chapter 4 TestGetsTopTwenty - Format Exception

MongoDB University M220N: MongoDB for .NET Developers
#1

System.FormatException : Element ‘Count’ does not match any field or property of class M220N.Models.Projections.ReportProjection.

Any one getting this same exception?

#2

Hi @Wei_27563,

Are you still facing the issue?

Kanika

#3

Yeah, still not resolved yet.

#4

Oh, this is actually not for Chapter 3 but for the first ticket of Chapter 4, If possible, please update the topic for me, change “Chapter 3” to “Chapter 4”

#5

The eventual solution for this issue is actually adding BsonElement to the Count property of ReportProjection class, a change I suspected since the very beginning.

public class ReportProjection
{
    [BsonElement("_id")]
    public string Id { get; set; }
    [BsonElement("Count")]
    public int Count { get; set; }
}

@kanikasingla , if possible, please add a video with detailed explanation of the serialization of C# classes, what could be the difference with and without these attributes, thanks.

P.S. I suspect ‘Count’ could also be a special property name which caused all those trouble.

#6

Hi @Wei_27563,

Give me some time, I am looking into this.

Kanika

#7

Thank you so much - this had me stumped. Come on MongoDB, get the framework code for mflix sorted!

#8

You are welcome, Mark, I am glad my post helped other students here.

1 Like
#9