how to set a key,value in a mongo array - arrays

Question

I have a collection of students where they can have other students as friends
{name:'someone', email:'st', friends[ObjectId,ObjectId]}
To access the list of friends I'll have to populate that object and search inside all the objects of the array friends
this will take mutch time
What I would like to do is this:
collection.find({name:'someone'},function(err,obj){
if(obj['user1'])
//do st
else
//do st
})
this will reuire that i insert objects like this:
collection.find({name:'st'},function(err,obj){
obj.friends['some one']=ObjectId(of an other student)
})
but this last one is not working

Answer 1

You can easily accomplish this if you use Mongoose in addition to Mongo. In your students schema you need an Array of friends which will be just the ID's of other students:
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var StudentSchema = new Schema({
name: String,
friends: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Student' }]
});
module.exports = mongoose.model('Student', StudentSchema);
Then when adding a friend all you need to do is push the ID of that friend into the array of friends.
Once the collection stores the relationship properly you can use mongoose's populate method to actual fill in the data in your API end point.. Something like this:
app.get('/student/:id, function(req, res){
Student.find({_id: req.params.id})
.populate('friends')
.exec(function(err, student){
if(err){
// handle error
} else {
res.json(student)
}
})
});