//4c1. UpdateOne row document
public string DocumentFind_UpdateOne(string name = "honda v1",int year=1999)
{
    // Replace the uri string with your MongoDB deployment's connection string.
    var client = new MongoClient(
        "mongodb://localhost:27017/?readPreference=primary&appname=MongoDB%20Compass&directConnection=true&ssl=false"
    );

    string re = "";

    //lấy database
    var database = client.GetDatabase("HvDadabase");
    //Lấy List Collection
    var collection = database.GetCollection<BsonDocument>("HvCars");
               
    //select lấy 1 row Document
    var filter = Builders<BsonDocument>.Filter.Eq("name", name);
               
    re = "dữ liệu trước khi update : <br/> ";
    var documentList = collection.Find(filter).FirstOrDefault();
    foreach (var row in documentList)
    {
        re += row +"<br/>";
    }


    //nội dung sẽ update
    var update = Builders<BsonDocument>.Update.Set("year", year);

    //Update 1 row tìm thấy dầu tiên
    collection.UpdateOne(filter, update);


    re += "<br/> dữ liệu sau khi update : <br/> ";
    documentList = collection.Find(filter).FirstOrDefault();

    foreach (var row in documentList)
    {
        re += row + "<br/>";
    }

    return re;
}