Getting different projection results from same query using mongo and mongoClient

Question

I am having a mongodb database from which I am trying to project some data. When I am using the following query in the mongo command line -

db.gholson.find({}, { "_id": 1 }).skip(85).limit(2).pretty();

I am getting the following output:-

{
    "_id": ObjectId("5abbde863f10ebda405b91f0"),
    "_id": ObjectId("5abbde863f10ebda405b91f1")
}

which is the desired output, but when I set up an express server and use the following query with MongoClient, I am getting all the fields instead of just the ids .

db.collection('gholson').find( {}, { "_id": 1 }).skip(85).limit(2).toArray(( err, result ) => {
        if( err ) throw err;
        console.log( result );
        callback();
    });

The above query returns all the key-value pairs instead of just id. I am unable to figure out, why is this happening.

Answer 1

Since version 3.0 of the driver the second argument of the find function represents options , not the projection. Try the following:

db.collection("gholson").find({}, { "projection": { "_id": 1 } })

or

db.collection("gholson").find({}).project({ "_id": 1 })