Mongodb – In Mongo, If a document I'm saving "Prateek" then I don't want on the next create operation even the "prateek" or "praTEEK", etc is saved

With the help of Apoorva & brainstorming for a bit, I come up with this solution.

// Controller

const { json } = require('express/lib/response');
var Dinosaur = require('../models/dinosaurs');

//addDino
module.exports.addDino = (req, res) => {
    var name = req.body.name;
    var type = req.body.type;
    var height = req.body.height;
    var weight = req.body.weight;
    var Period = req.body.Period;

    req.checkBody('name', 'Name is required').notEmpty();
    var errors = req.validationErrors();
    if (errors)
        return res.status(400).send({
            message: 'Name is Required'
        });
    else {
        let newDino = {
            name: name.toLowerCase(),
            type: type,
            height: height,
            weight: weight,
            Period: Period
        }

        Dinosaur.addDino(newDino, (err, result) => {
            if (err) {
                if (err.name) return res.status(409).send({
                    message: name + ' Already Exist'
                });
                else if (err.url) return res.json({ status: false, error: { url: "Url already exist" }, message: err.url });
                else return res.json(err, "Server Error");
            }
            else {
                return res.status(200).send({
                    message: "Done"
                });
            }
        });
    }
}

//Update
module.exports.updateDino = (req, res) => {
    let _id = req.body.id;
    let name = req.body.name;
    let type = req.body.type;
    let height = req.body.height;
    let weight = req.body.weight;
    let Period = req.body.Period;

    req.checkBody('name', 'Name is required').notEmpty();
    var errors = req.validationErrors();
    if (errors)
        return res.status(400).send({
            message: 'Name is Required'
        });
    else {
        var updateDino = {
            name: name.toLowerCase(),
            type: type,
            height: height,
            weight: weight,
            Period: Period
        }

        Dinosaur.updateDino({ _id: _id }, updateDino, (err, result) => {
            if (err) return res.json({ status: false, message: err });
            else
                return res.status(200).send({
                    message: "Updated"
                });
        });
    }
}

//delete
module.exports.deleteDino = (req, res) => {

    let name = req.body.name;
    req.checkBody('name', 'Name is required').notEmpty();
    var errors = req.validationErrors();
    if (errors)
        return res.status(400).send({
            message: 'Name is Required'
        });
    else {
        Dinosaur.deleteDino(name.toLowerCase(), (err, result) => {
            if (err) {
                return err;
            }
            else if (result.deletedCount == 0) {
                res.status(400).send({
                    message: 'Not Found'
                });
            }
            else
                return res.status(200).send({
                    message: 'Deleted'
                });
        });
    }
}

//GetByName
module.exports.getDino = (req, res) => {
    let query = req.body.name;
    req.checkBody('name', 'Name is required').notEmpty();
    var errors = req.validationErrors();
    if (errors)
        return res.status(400).send({
            message: 'Name is Required'
        });
    else {
        Dinosaur.getDino({ name: query.name.toLowerCase() }, (err, result) => {
            if (err)
                return res.status(400).json("Not Found");
            else if (result == null)
                return res.status(400).json('Not Found');
            else {
                return res.json(uppercase(result.name));
            }
        });
    }
}

module.exports.getAllDino = (req, res) => {
    var query = {};
    Dinosaur.listDino(query, (err, result) => {
        if (err)
            res.json(err);
        else
            return res.status(200).json(result);
    });
}

function uppercase(str) {
    var arr = str.toString().split(' ');
    var newarr = [];

    for (var i = 0; i < arr.length; i++) {
        newarr.push(arr[i].charAt(0).toUpperCase() + arr[i].slice(1));
    }
    return newarr.join(' ');
}

// Model*

var mongoose = require('mongoose');

//dinosaur schema
var DinosaurSchema = mongoose.Schema({
    name: {
        type: String,
        unique: true
    },
    type: {
        type: String
    },
    height: {
        type: Number
    },
    weight: {
        type: Number
    },
    Period: {
        type: String
    }
});

DinosaurSchema.index({ user_id: 1, name: 1, res_type: 1, level: 1 }, { unique: true });

var Dinosaur = mongoose.model('dinosaur', DinosaurSchema);

//add
module.exports.addDino = (query, callback) => {
    Dinosaur.create(query, callback);
}
//updateDino
module.exports.updateDino = (query, data, callback) => {
    Dinosaur.findByIdAndUpdate(query, data, callback);
}
//remove
module.exports.deleteDino = (query, callback) => {
    Dinosaur.deleteOne({ name: query }, callback)
}
//getDino   
module.exports.getDino = (query, callback) => {
    Dinosaur.findOne(query, callback);
}
//getAllDino
module.exports.listDino = (query, callback) => {
    Dinosaur.find(query, callback).sort({ "name": 1 });
}