Populate Plain JSON Objects in Mongoose

populate.js

/*
Company Schema
{
	name : String ,
	founded:Number,
	headquaters : {"type":ObjectId, ref:"City"}
}

City Schema 
{
	city_name:String,
	pin :String
}

Employee Schema
{
	name : String,
	age : Number,
	company:{"type":ObjectId , ref: "Company"},
	residence:{"type":ObjectId , ref: "City"}
}

This document shows how to populate JSON object which has Employee data


*/

//doc can be array of documents or single document
var doc =[
	{
		name:'harsha',
		age :21,
		company:'55815115a78e9d7346df81f2',
		residence:'556be5c130a07d9c15337e2d'
	},
	{
		name:'sri',
		age :21,
		company:'559f76303c89d6023677b295',
		residence:'556be5c130a07d9c15337e33'
	}
	];
	
//opts path: id's reference name , model : reference model , select: desire fields if empty it will return all fields .
// http://mongoosejs.com/docs/api.html#model_Model.populate  -----> more opts
var opts =[
	{
		path:company , model:'Company' , select:'name'
	},
	{
		path:residence , model:'City' , select:'city_name'
	}
	];
Employee.populate(doc,opts,function(err,data){
	if(err){
		console.log(err);
		return ;
	}
	console.log(data);
});