Running multiple Mongodb/mongoose queries - dynamiclly using async.js

dynamicMongooseMultipleQuerie

// working example mongoose
var PersonSchema = new Schema({
	name : String,
	age : Number,
});
var StorySchema = new Schema({
	title : String,
});
var Story = mongoose.model('Story', StorySchema);
var Person = mongoose.model('Person', PersonSchema);
 
// var story1 = new Story({
// 	title: "A man who cooked Nintendo",
// });
 
// var person1 = new Person({
// 	name: "harpreet",
// 	age: "24"
// });

// story1.save(function (err, result) {
// 	if(err) {
// 		console.log(err)
// 	} else {
// 		console.log(result)
// 	}
// }); 
 
// person1.save(function (err, result) {
// 	if(err) {
// 		console.log(err)
// 	} else {
// 		console.log(result)
// 	}
// }); 

// Story.find({}, function(err, result) {
// 	console.log(result);
// });

// Person.find({}, function(err, result) {
// 	console.log(result);
// });


/*
 * Object to store all models
 */
var allRefDatasSchemas = {
	Story : mongoose.model('Story', StorySchema),
	Person : mongoose.model('Person', PersonSchema)
};

/*
 * need an array to run all queries one by one in a definite order
 */
var arr = [];
for(each in allRefDatasSchemas) {
	arr.push(each);
}

/*
 * Callback function for initiation of waterfall
 */
var queue = [
	function(callback) {
		// pass the ref array and run first query by passing starting index - 0
		callback(null, arr, 0)
	}
];

/*
 * Object to store result of all queries
 */
var finalResult = {};

/*
 * Generic Callback function for every dynamic query
 */
var callbackFunc = function(prevModelData, currentIndex, callback) {
	allRefDatasSchemas[arr[currentIndex]].find(function(err, result) {
		if(err) {
			console.log(err)
		} else {
			// console.log(result)
			finalResult[arr[currentIndex]] = result
			callback(null, result, currentIndex + 1)
		}
	})
}

/*
 * Add callback function for every dynamic query
 */
for(each in allRefDatasSchemas) {
	queue.push(callbackFunc);
}

/*
 * Run all dynamic queries one by one using async.js waterfall method
 */
async.waterfall(queue, function (err, result) {
	console.log('finish', finalResult)
});

output

finish {Story:
    [
        {
            title: 'A man who cooked Nintendo',
            _id: 5399d40e0e5605f406e96612,
            __v: 0
        }
    ],
Person:
    [
        {
            name: 'harpreet',
            age: 24,
            _id: 5399d45f365d88e00dad2d81,
            __v: 0
        }
    ]
}

awesome. I was looking something similar to this. thanks a ton! :)
Also wanted to know if we use mongoose function 'FindOne()' for a single schema object then how can I use async with it?