I want to take data with two collections.
How to send this data in one response?

This is my code:

```
    //RETURN SINGLE QUERYE
exports.findById = function(req, res) {
    //Get Params
    var querye_id =new BSON.ObjectID(req.params.id); 
    var querye;

    //Get Single Querye
    db.collection('queryes', function(err, collection) {
        collection.findOne({'_id':querye_id}, function(err, item) {
            querye=item;
        });

    });
    //Get Questions and Answers
    db.collection('questions', function(err, collection) {
        collection.find().toArray(function(err, items) {
            querye.questions=items;
        });
    });

    //Send Response
     res.send(querye);

};

```

I have varible querye as undefined. How to solve this?