Express Sequelize Error - Cannot read property 'findAll' of undefined - postgresql

Question

I have successfully connected Sequelize and Express using Sequelize's github example with a few changes. I am now trying to do a simple Sequelize query to test the connection, but continue to receive an error stating that the model I have queried is not defined.
// ./models/index.js
...
const sequelize = new Sequelize(process.env.DB, process.env.DB_USER, process.env.DB_PASS, {
host: 'localhost',
dialect: 'postgres'
});
// Test SEQUELIZE connection
sequelize
.authenticate()
.then(() => {
console.log('Database connection has been established successfully.');
})
.catch(err => {
console.error('Unable to connect to the database:', err);
});
fs
.readdirSync(__dirname)
.filter(file => {
return (file.indexOf('.') !== 0) && (file !== basename) && (file.slice(-3) === '.js');
})
.forEach(file => {
var model = sequelize['import'](path.join(__dirname, file));
db[model.name] = model;
});
Object.keys(db).forEach(modelName => {
if (db[modelName].associate) {
db[modelName].associate(db);
}
});
db.sequelize = sequelize;
db.Sequelize = Sequelize;
module.exports = db;
// ./routes/index.js
const models = require('../models');
const express = require('express');
const router = express.Router();
router.get('/contacts', (req, res) => {
models.Contact.findAll().then(contacts => {
console.log("All users:", JSON.stringify(contacts, null, 4));
});
});
module.exports = router;
// ./models/contact.js
const Sequelize = require('sequelize');
var Model = Sequelize.Model;
module.exports = (sequelize, DataTypes) => {
class Contact extends Model {}
Contact.init({
// attributes
firstName: {
type: Sequelize.STRING,
allowNull: false
},
lastName: {
type: Sequelize.STRING,
allowNull: false
}
}, {
sequelize,
modelName: 'contact'
// options
});
return Contact;
};
The error I am getting when using postman to hit /contacts with a GET request is:
[nodemon] starting `node server.js`
The server is now running on port 3000!
Executing (default): SELECT 1+1 AS result
Database connection has been established successfully.
TypeError: Cannot read property 'findAll' of undefined
at router.get (C:\Users\username\desktop\metropolis\metropolis-backend\routes\index.js:6:20)

Answer 1

You are not requiring the model properly.
In ./routes/index.js add the next line:
const Contact = require('./models/contact.js');
And then call Contact.findAll()...
Second approach:
You can gather all your models by importing them into a loader.js file which you will store in the models directory. The whole job of this module is to import the modules together to the same place and then export them from a single place.
It will look something like that:
// loader.js
const modelA = require('./modelA');
const modelB = require('./modelB');
const modelC = require('./modelC');
...
module.exports = {
modelA,
modelB,
modelC,
...
}
And then you can require it in the following way:
in router/index.js:
const Models = require('./models');
const contact = Models.Contact;