Node, Express, Sequelize, PostgreSQL, and React App Part 1 — Backend

This blog post will show you my process for creating an app using Node, Express, Sequelize, PostgreSQL, and React. Part 1 is going to focus on the backend using Node, Express, Sequelize, and PostgreSQL. This is the first time that I have used any of these languages for a backend. I will document the basics for getting the backend set up.

I am creating an app called IdeaPad that will help you keep track of any creative ideas that you have. For all of you Mac users out there, it is like combining Notes and Voice Memos together into one convenient app. For example, this will be perfect for songwriters that write lyrics and record demos of the songs that they are working on. Each individual idea will have a space to write notes and record voice memos.

Let’s get started on the backend!

Models
  Ideas table
    subject:string
    category:string

  Contents table
    idea_id:integer
    post:string
    audio:string
Associations
  Ideas has many Contents
  Content belongs to Idea

IdeaPad will be a simple app for only one user. I only need the Ideas and Contents tables with a One-To-Many Association to accomplish this. Each Idea will have many Contents that will consist of either posts or audio files.

You can follow this guide if you need help installing anything or you want more examples and explanations for what you are trying to make:

Node, Express, Sequelize, and PostgreSQL Association Example

Sequelize Commands

sequelize model:create --name Idea --attributes subject:string,category:string
sequelize model:create --name Content --attributes idea_id:integer,content:string,audio:string

Sequelize Models

models/idea.js
'use strict';
module.exports = (sequelize, DataTypes) => {
  const Content = sequelize.define('Content', {
    idea_id: DataTypes.INTEGER,
    post: DataTypes.STRING,
    audio: DataTypes.STRING
  }, {});
  Content.associate = function(models) {
    Content.belongsTo(models.Idea, {
      foreignKey: 'idea_id'
    });
  };
  return Content;
};
models/content.js
'use strict';
module.exports = (sequelize, DataTypes) => {
  const Content = sequelize.define('Content', {
    idea_id: DataTypes.INTEGER,
    post: DataTypes.STRING,
    audio: DataTypes.STRING
  }, {});
  Content.associate = function(models) {
    Content.belongsTo(models.Idea, {
      as: 'idea',
      foreignKey: 'idea_id'
    });
  };
  return Content;
};

Node Express Controllers

controllers/idea.js
const Idea = require('../models').Idea;
const Content = require('../models').Content;
module.exports = {
  list(req, res) {
    return Idea
      .findAll({
        include: [{
          model: Content,
          as: 'contents'
        }],
      })
      .then((companies) => res.status(200).send(companies))
      .catch((error) => { res.status(400).send(error); });
  },
getById(req, res) {
    return Idea
      .findByPk(req.params.id, {
        include: [{
          model: Content,
          as: 'contents'
        }],
      })
      .then((company) => {
        if (!company) {
          return res.status(404).send({
            message: 'Idea Not Found',
          });
        }
        return res.status(200).send(company);
      })
      .catch((error) => res.status(400).send(error));
  },
add(req, res) {
    return Idea
      .create({
        subject: req.body.subject,
        category: req.body.category,
      })
      .then((company) => res.status(201).send(company))
      .catch((error) => res.status(400).send(error));
  },
addWithContents(req, res) {
    return Idea
      .create({
        subject: req.body.subject,
        category: req.body.category,
        contents: req.body.contents,
      }, {
          include: [{
          model: Content,
          as: 'contents'
        }]
      })
      .then((company) => res.status(201).send(company))
      .catch((error) => res.status(400).send(error));
  },
update(req, res) {
    console.log(req.body);
    return Idea
      .findById(req.params.id, {
        include: [{
          model: Content,
          as: 'contents'
        }],
      })
      .then(company => {
        if (!company) {
          return res.status(404).send({
            message: 'Idea Not Found',
          });
        }
        return company
          .updateAttributes({
            subject: req.body.subject || company.subject,
            category: req.body.category || company.category,
            contents: req.body.contents || company.contents,
          }, {
              include: [{
              model: Content,
              as: 'contents'
            }]
          })
          .then(() => res.status(200).send(company))
          .catch((error) => {console.log(error);res.status(400).send(error);});
      })
      .catch((error) => {console.log(error);res.status(400).send(error);});
  },
delete(req, res) {
    return Idea
      .findByPk(req.params.id)
      .then(company => {
        if (!company) {
          return res.status(400).send({
            message: 'Idea Not Found',
          });
        }
        return company
          .destroy()
          .then(() => res.status(204).send())
          .catch((error) => res.status(400).send(error));
      })
      .catch((error) => res.status(400).send(error));
  },
};
controllers/content.js
const Content = require('../models').Content;
const Idea = require('../models').Idea;
module.exports = {
  list(req, res) {
    return Content
      .findAll({
        include: [{
          model: Idea,
          as: 'idea'
        }],
      })
      .then((contents) => res.status(200).send(contents))
      .catch((error) => { res.status(400).send(error); });
  },
getById(req, res) {
    return Content
      .findByPkv(req.params.id, {
        include: [{
          model: Idea,
          as: 'idea'
        }],
      })
      .then((content) => {
        if (!content) {
          return res.status(404).send({
            message: 'Content Not Found',
          });
        }
        return res.status(200).send(content);
      })
      .catch((error) => res.status(400).send(error));
  },
add(req, res) {
    return Content
      .create({
        idea_id: req.body.idea_id,
        post: req.body.post,
        audio: req.body.audio,
      })
      .then((content) => res.status(201).send(content))
      .catch((error) => res.status(400).send(error));
  },
update(req, res) {
    return Content
      .findById(req.params.id, {
        include: [{
          model: Idea,
          as: 'idea'
        }],
      })
      .then(content => {
        if (!content) {
          return res.status(404).send({
            message: 'Content Not Found',
          });
        }
        return content
          .update({
            post: req.body.post || idea.post,
            audio: req.body.audio || idea.audio,
          })
          .then(() => res.status(200).send(content))
          .catch((error) => res.status(400).send(error));
      })
      .catch((error) => res.status(400).send(error));
  },
delete(req, res) {
    return Content
      .findByPk(req.params.id)
      .then(content => {
        if (!content) {
          return res.status(400).send({
            message: 'Content Not Found',
          });
        }
        return content
          .destroy()
          .then(() => res.status(204).send())
          .catch((error) => res.status(400).send(error));
      })
      .catch((error) => res.status(400).send(error));
  },
};
controllers/index.js
const idea = require('./idea');
const content = require('./content');
module.exports = {
  idea,
  content,
};

Node Express Routes

routes/index.js
var express = require('express');
var router = express.Router();
const ideaController = require('../controllers').idea;
const contentController = require('../controllers').content;
/* GET home page. */
router.get('/', function(req, res, next) {
  res.render('index', { title: 'Express' });
});
/* Company Router */
router.get('/api/idea', ideaController.list);
router.get('/api/idea/:id', ideaController.getById);
router.post('/api/idea', ideaController.add);
router.put('/api/idea/:id', ideaController.update);
router.delete('/api/idea/:id', ideaController.delete);
/* Branch Router */
router.get('/api/content', contentController.list);
router.get('/api/content/:id', contentController.getById);
router.post('/api/content', contentController.add);
router.put('/api/content/:id', contentController.update);
router.delete('/api/content/:id', contentController.delete);
/* Advance Router */
router.post('/api/idea/add_with_contents', ideaController.addWithContents);
module.exports = router;

Wrapping Up

Finally, we can migrate these changes with:

sequelize db:migrate

Start the server up with:

npm run start

Check if it works by going to http://localhost:3000/api/idea and http://localhost:3000/api/content in your browser.

Now we have a backend up and running!

Part 2 will be seeding the backend and creating React frontend.

Thanks for reading!