Extracting some fields from an object in mongodb - node.js

Question

I am new to mongoDB and I am unable to figure out how to extract only few fields from an object in a collection.I have a collection named recipe which is as follow:-
[
{
"_id": "b44e864d-de8f-4110-b676-bbee13417b2e",
"title": "Fried Eggs",
"ingredients": [
{
"name": "Eggs",
"amount": "10"
},
{
"name": "Olive Oil",
"amount": "2 tbs"
}
],
"steps": [
"1. Heat the pan",
"2.Add Olive Oil",
"3. Add Eggs",
"4. Saute"
],
"comments": [
{
"_id": "8604e67c-2426-4742-bc91-25ee1c4064b5",
"poster": "Ron Swanson",
"comment": "Wrong instructions, Got stuck in Toaster"
},
{
"_id": "040412bc-9046-49ca-9a65-19151b32cd91",
"poster": "Tom Haverford",
"comment": "What are Eggs?"
},
{
"_id": "1034f082-b802-4382-be3e-ef50f07a530a",
"poster": "Andy Dwyer",
"comment": "What came firsst, Eggs or Chicken"
}
]
},
{
"_id": "da6f9798-6547-42f5-85ed-043efabeb196",
"title": "Boiled Eggs",
"ingredients": [
{
"name": "Eggs",
"amount": "5"
},
{
"name": "Water",
"amount": "3 Cups"
}
],
"steps": [
"1.Boil the Water",
"2.Add Eggs",
"3. Keepit for 5 mins",
"4. Let it Cool Down",
"5. Peel off the shell"
],
"comments": [
{
"_id": "cc569ebb-1307-499a-b9ee-7b24e557859f",
"poster": "Ron Swanson",
"comment": "Wrong instructions, Got stuck in Oven"
},
{
"_id": "4f02756a-6e1b-4bda-a928-b3c5e03b55d8",
"poster": "Leslie Knope",
"comment": "What are Eggs?"
},
{
"_id": "0f34a5cc-ebe3-41b5-8f0b-6d1a3c206e6b",
"poster": "Andy Dwyer",
"comment": "Can I remove the shell first and then boil?"
}
]
}]
I want to extract only the title and id of both the recipes when a given route is accessed. Currently,I am using this function, which return all the field of both the recipes.
var recipesCollection = db.collection("recipes");
exports.getAllRecipes = function() {
return recipesCollection.find({}).toArray();
};
What query should I use to extract just the title and id of the two recipes and not all the details?

Answer 1

As per my understanding you are trying to fetch specific fields form the mongo collection. You can achieve this just by using the projection.
var recipesCollection = db.collection("recipes");
exports.getAllRecipes = function() {
return recipesCollection.find({}, {"title": 1}).toArray();
};
For more information follow this:
https://docs.mongodb.com/v3.2/tutorial/project-fields-from-query-results/#return-the-specified-fields-and-the-id-field-only