How to include a new item in the array of items in an object in MongoDB with C #?

Question

How to include a new item in the array of items in an object in MongoDB with C#?

I tried to use the AddToSet method, but I did not succeed.

I have the following code structure:

1 - Parent object (Revenda):

using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using System.Collections.Generic;

namespace api.mstiDFE.Entidade.api.mstiDFE
{
    public class Revenda : Notificavel, IEntidade
    {

        public Revenda(string Id, long Codigo, string CPF, string CNPJ, List<RevendaCliente> Clientes)
        {
            this.Id = Id;
            this.Codigo = Codigo;
            this.CPF = CPF;
            this.CNPJ = CNPJ;
            this.Clientes = Clientes;
        }

        [BsonId]
        [BsonRepresentation(BsonType.ObjectId)]
        public string Id { get; private set; }

        [BsonElement("Codigo")]
        public long Codigo { get; private set; }

        [BsonElement("Nome")]
        public string Nome { get; private set; }

        [BsonElement("CPF")]
        public string CPF { get; private set; }

        [BsonElement("CNPJ")]
        public string CNPJ { get; private set; }

        [BsonElement("Clientes")]
        public ICollection<RevendaCliente> Clientes { get; private set; }
    }
}

2 - Child object (RevendaCliente):

using MongoDB.Bson;
using MongoDB.Bson.Serialization.Attributes;
using System.Collections.Generic;

namespace api.mstiDFE.Entidade.api.mstiDFE
{
    public class RevendaCliente : Notificavel, IEntidade
    {

        public RevendaCliente(string Codigo, string Nome, string CPF, string CNPJ, ICollection<RevendaClienteToken> Tokens)
        {
            this.Codigo = Codigo;
            this.Nome = Nome;
            this.CPF = CPF;
            this.CNPJ = CNPJ;
            this.Tokens = Tokens;
        }

        [BsonElement("Codigo")]
        public string Codigo { get; private set; }

        [BsonElement("Nome")]
        public string Nome { get; private set; }

        [BsonElement("CPF")]
        public string CPF { get; private set; }

        [BsonElement("CNPJ")]
        public string CNPJ { get; private set; }

        [BsonElement("Tokens")]
        public ICollection<RevendaClienteToken> Tokens { get; private set; }
    }
}

3 - Code used to insert a complete parent object:

public Revenda Add(Revenda revenda)
{
    Database.GetCollection<Revenda>("Revendas").InsertOne(revenda);
    return revenda;
}

4 - Code used to recover a specific reseller:

public Revenda FindById(string id)
{
    return CollRevendas.Find<Revenda>(revenda => revenda.Id == id).FirstOrDefault();
}

Everything works fine.

However, how can I only include a new child object (RevendaCliente) in a parent object (Revenda) already registered in MongoDB?

I am using the following environment: -Microsoft.AspNetCore.App (2.1.1) -MongoDB.Driver (2.8.0)

Answer 1

(as I mentioned in my comment) your problem seems pretty simple, as in MongoDB the related objects in hierarchy are part of the same document, so you need to update your object in-memory and update it.

var parentObject=CollRevendas.Find<Revenda>(revenda => revenda.Id == id).FirstOrDefault();
parentObject.Clientes.Add(newChildObject);
//now update the parent object

Answer 2

Code that worked for me: (Resolved with the support of Aarif)

public bool AddRevendaCliente(string revendaId, RevendaCliente requestRevendaClient)
{
    try
    {
        var filter = Builders<Revenda>.Filter.Eq(s => s.Id, revendaId);

        // Get a reference to the parent parent "Revenda"
        var parentObject = CollRevendas.Find<Revenda>(filter).FirstOrDefault();
        parentObject.Clientes.Add(requestRevendaClient);

        // Update the parent object "Revenda"
        var result = CollRevendas.ReplaceOneAsync(filter, parentObject);
    }
    catch (Exception ex)
    {
        throw;
    }            
    return true;
}