Xtykutl

I'm creating a rest API for my android app and I'm stuck at the cart portion of the API and I want this kinda output data:

{

"userEmail": adbd@xyz.com,

"items": [

    {

        "item_id": "d3e9d433-bf54-4567-b070-cb033cc27c63",

        "quantity": 1

    },

    {

        "item_id": "1a3d7141-1676-422d-bcd1-dbe7eb3a561c",

        "quantity": 1

    },

    {

        "item_id": "0f768f63-3953-4f7d-b30b-c61fc2b07cc1",

        "quantity": 2

    }

]

}

But I don't know how to implement this I have used MongoDB and node js.
Schema of my cart looks like this

var mongoose = require("mongoose");



var Cart = mongoose.Schema({



userEmailId: {

    type: String,

    default: "",

    required: true

},

items :[{

    itemIds: {

        type: String,

        default: "",

        required: true

    },

    itemQuantity: {

        type: String,

        default: "1",

        required: false

    }

}]

});



module.exports = mongoose.model("Cart", Cart);

Here is the controller of the cart:

const cart = require('../models/Cart_Model');



exports.showCart = (req,res) =>{



cart.find({

    userEmailId : req.params.userEmailId

},

function(err,Cart){



    if(err){

        res.send(err);

    }else{

        res.send(Cart);

    }

});

}



exports.updateItem = (req,res)=>{



var fieldsForUpdate = {};



res.send(req.body.itemIds);



cart.updateOne({

    userEmailId : req.body.userEmailId

},fieldsForUpdate,

function(err,num,raw){



});



}

But now I don't know how to proceed to add and update data to this cart and is this schema is okay?
Thank you in advance! :)