Query MongoDB in C# using LINQ

Question

I have simple class which represents fields in MongoDB document

class Measurement
{
    public ObjectId id { get; set; }
    public int s { get; set; }
    public int[] p { get; set; }
    public int dt { get; set; }
    public int ml { get; set; }
}

I'm trying to get documents matching my conditions using

var collection = database.GetCollection<Measurement>(mongoCollectionName);
    var query = from a in collection.AsQueryable<Measurement>()
                where a.dt > 100
                select a;

When where condition is removed i do receive all documents but with condition none. Response says there's no matching documents but there are (example dt=1538555)

query looks like this {aggregate([{ "$match" : { "dt" : { "$gt" : 100 } } }])}. I build my example using response from this thread and mongodb documentation MongoDB C# Aggregation with LINQ

I would be grateful with solving probably my stupid mistake

Dĵ ΝιΓΞΗΛψΚ · Accepted Answer · 2019-04-24 12:44:10Z

i don't use the c# driver directly anymore so my solution is using MongoDAL.

using System;
using System.Linq;
using MongoDAL;

namespace Example
{
    class Measurement : Entity
    {
        public int s { get; set; }
        public int[] p { get; set; }
        public int dt { get; set; }
        public int ml { get; set; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            new DB("measurements");

            var measurement1 = new Measurement
            {
                s = 10,
                ml = 20,
                dt = 100,
                p = new int[] { 1, 2, 3, 4, 5 }
            };

            var measurement2 = new Measurement
            {
                s = 11,
                ml = 22,
                dt = 200,
                p = new int[] { 1, 2, 3, 4, 5 }
            };

            measurement1.Save();
            measurement2.Save();

            var result = (from m in DB.Collection<Measurement>()
                          where m.dt > 100
                          select m).ToArray();

            Console.ReadKey();

        }
    }
}

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