mongoose populate naming and structure - node.js

Question

I have this "User" model where I store friends, this friends have some option
// Prepare schema
var schema = new db.Schema({
friends: [{
active : Boolean,
user : { type: db.Schema.ObjectId, ref: 'user' },
options : [{ type: db.Schema.ObjectId, ref: 'friend_option' }],
}],
image: { type: db.Schema.ObjectId, ref: 'file' },
password: {
type: String,
select: false
},
email: String,
name: String,
udid: [{
device: String,
udid: String
}],
created_on: Date
});
here I get one user with his friends
var friendQuery = User.find( {_id:req.params.id});
friendQuery.select('friends');
friendQuery.populate({ path: 'friends._id', model: 'user', select:'_id name' });
friendQuery.exec(
function(err, user) {
if (err)
res.send(err);
res.send(user);
});
my question is, why the result have a different name from my model? why friends->_id->_id instead go friends->user->_id?
friends": [
{
"_id": {
"_id": "58025664c154929d3207b232",
"name": "User 1"
},
"options": [
],
"active": false
},
{
"_id": {
"_id": "580257e1e3cd4fc7326fa97b",
"name": "User 2"
},
"options": [
],
"active": false
}
]
another option, this solution is good for an hypothetical big app?

Answer 1

The way You are using this in incorrect just make a simple change in your query
var friendQuery = User.find( {_id:req.params.id});
friendQuery.select('friends');
friendQuery.populate({ path: 'friends.user', model: 'user', select:'_id name' });
friendQuery.exec(
function(err, user) {
if (err)
res.send(err);
res.send(user);
});
as you are taking reference of your user in friends array simply replace _id from query to user that will definitely work for you