Seeding atlas database - Cannot read property 'deleteMany' of undefined

Question

After some small changes this code is not seeding the atlas database anymore. Quite sure is a syntax or typo error. Attaching all three relevant files, I really hope someone of you could find a solution as I spent 7 hours on this already. It was working till yesterday, but after trying to use dotenv everything has been messed up.

server.js

const express = require('express');
const connectDB = require('./config/db');
var cors = require('cors');
const path = require('path');
const mongoose = require ('mongoose')
// routes
// const routes = require('./');

const app = express();

// Connect Database
connectDB();

// cors
app.use(cors({ origin: true, credentials: true }));

// Init Middleware
app.use(express.json({ extended: false }));

app.get('/', (req, res) => res.send('Hello world!'));


app.use(express.static(path.join(__dirname, 'client/build')))

// use Routes
// app.use('/api/books', books);

const port = process.env.PORT || 8082;

app.listen(port, () => console.log(`Server running on port ${port}`));

db.js

const db = config.get('mongoURI');
const mongoose = require('mongoose')
// require('dotenv').config()

const connectDB = async () => {
  try {
    await mongoose.connect(db,{ useNewUrlParser: true });

    console.log('MongoDB is Connected...');
  } catch (err) {
    console.error(err.message);
    process.exit(1);
  }
};

module.exports = connectDB;

guests.js

const Schema = mongoose.Schema
const Guest = new Schema
({name : 
    {
        type : String
    }})

const Guests = mongoose.model('Guests', Guest)

module.exports = { Guests };

seed.js

const db = require('./guests')

mongoose.connect("My personal URI", { useNewUrlParser: true, useFindAndModify: false, useUnifiedTopology: true })

const GuestSeed = [{
    name: 'andrea'

}, {
    name: 'harith'
}]

db.guest.deleteMany({})
    .then(() => db.guest.collection.insertMany(GuestSeed))
    .then((data) => {
        console.log(data.lenght + '  records inserted');
        process.exit(0)
    })

    .catch((err) => { console.error(err) })

I receive this error:

TypeError: Cannot read property 'deleteMany' of undefined

Answer 1

From your guests.js file you're exporting an object that looks like this :

{
  Guests : <MongooseModel>
}

However, in your seed.js file you are trying to access a property guest from this object, which doest not exist. The error your are seeing (TypeError: Cannot read property 'deleteMany' of undefined) supports this theory, since db.guest is undefined.

Instead of

db.guest.deleteMany

try this

db.Guests.deleteMany