Update array specific items

Question

I want only items in list entityParameters will update in x.Params by Id , update all items of entityParameters if entityParameters.Id == x.Params.Id

List<Param> entityParameters

filter = Builders<MachineObj>.Filter.Where(x => x.MachineId == id);

update = Builders<MachineObj>.Update
            .Set(x => x.Params, entityParameters);

Answer 1

        List<ArrayFilterDefinition> arrayFilters = new();
        int i = 0;
        foreach (var item in entityParameters)
        {
            var updateItem = Builders<MachineObj>.Update.Set($"Params.$[elem{i}]", item);

            arrayFilters.Add(new BsonDocumentArrayFilterDefinition<BsonDocument>(
               new BsonDocument($"elem{i}.ParamId", item.ParamId)
            ));

            update = Builders<MachineObj>.Update.Combine(update, updateItem);

            i++;
        }

        updateOptions = new UpdateOptions
        {
            ArrayFilters = arrayFilters
        };

    await machinesDB.Machines.UpdateOneAsync(filter, update, updateOptions);