Insert element into nested array in Mongodb

Question

I have this :

{
  \"_id\" : ObjectId(\"4fb4fd04b748611ca8da0d48\"),
  \"Name\" : \"Categories\",
  \"categories\" : [{
      \"_id\" : ObjectId(\"4fb4fd04b74         


        

Answer 1

You can do this using FindOneAndUpdateAsync and positional operator

public async Task Add(string productId, string categoryId, SubCategory newSubCategory)
{
    var filter = Builders.Filter.And(
         Builders.Filter.Where(x => x.Id == productId), 
         Builders.Filter.Eq("Categories.Id", categoryId));
    var update = Builders.Update.Push("Categories.$.SubCategories", newSubCategory);
    await collection.FindOneAndUpdateAsync(filter, update);
}