Query mongodb database to find all value for a specific field c#

Question

I want to query mongodb database to find all value under a specific field between two dates using c#. Can you help how to query a specific field in a collection?

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this is my collection "Devise" and i try to query all the value of "high"

 public class Devise
{   
    public string parité { get; set; }
    public float low { get; set; }
    public float high { get; set; }
    public DateTime  date_observation { get; set; }

}

---

this is my query code

public class Devisedata
{
    private IMongoDatabase _database;

    public async System.Threading.Tasks.Task<List<Devise>> GetDataDevise(DateTime inputDate1, DateTime inputDate2)
    {

        var collection = _database.GetCollection<Devise>("datafinance");
        var builder = Builders<Devise>.Filter;
        var filter = builder.Gte("date_observation", inputDate1) &
                     builder.Lt("date_observation", inputDate2.AddDays(1));


        var list = await collection.Find(filter).ToListAsync();
        return list;
    }
}

Answer 1

I assumed that by "find all value" you mean all distinct values from field high . If so, you could do this as example below:

var builder = Builders<Devise>.Filter;
var filter = builder.Gte("date_observation", inputDate1) &
                 builder.Lt("date_observation", inputDate2.AddDays(1));

var cursor = await collection.DistinctAsync<double>("high", match);
await cursor.ForEachAsync(doc => Console.WriteLine(doc));

See MongoCollection.Distinct and db.collection.distinct() for more information.

The above snippet is tested in C# Driver v2.2.3 with MongoDB v3.2