Node Express for file upload management with Postgres and Sequelize

This is demonstartion of developing express node endpoint to accept file as forma data and store the information in Postgres DB using Sequelize ORM.

Source Code can be downloaded from my git hub respository sequelize-fileupload.

Sequelize is a promise-based Node.js ORM for Postgres, MySQL, MariaDB, SQLite and Microsoft SQL Server. It features solid transaction support, relations, eager and lazy loading, read replication and more. For detailed documentation you can check this.

I am using Multer which is a node.js middleware for handling multipart/form-data, which is primarily used for uploading files. The uploaded file is saved to the server and the file information is saved to PostGres Db.

This example assumes PostGreSQL BD is already insatlled. You can use pgAdmin and chec the connection and then create a testdb as below -

I have also included swagger-ui into the project and wrote the documentation manually.

Packages used in this example

"express": "^4.17.1",
"multer": "^1.4.2",
"pg": "^7.12.1",
"sequelize": "^5.15.1",
"swagger-ui-dist": "^3.23.5",
"swagger-ui-express": "^4.0.7"

app.js

var app = express();
const port = process.env.PORT || 3000

global.appRoot = __dirname;

app.use(bodypareser.json()); 
app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));
categoryApi(app,db);

app.listen(port, ()=> console.log(`Application started on Port ${port}.`));

controllers/category

const multer = require('multer');
const fs = require('fs');

const upload = multer({ dest: '/tmp/'});

module.exports = (app, db) => {
    app.get( "/categories", (req, res) =>
        db.Category.findAll({raw: true})
            .then( (result) => res.json(result) )
    );

    app.post('/categories', upload.single('file'), (req,res) => {
        const file = global.appRoot + '/uploads/' + req.file.filename;
        fs.rename(req.file.path, file, function(err) {
            if (err) {
                console.log(err);
                res.send(500);
            } 
            else {
                  db.Category.create({
                        name: req.body.name,
                        description: req.body.description,
                        poster : req.file.filename
                    })
                    .then(r =>  {
                    res.send(r.get({plain:true}));
                    });
            }
          });
    })
}

Configure Sequelize and its model.

models\sequelize.js

const Sequelize = require('sequelize');
const CategoryModel = require('./category');

const sequelize = new Sequelize('testdb', 'postgres', 'Manav2020#', {
    host : 'localhost',
    dialect: 'postgres'
});

const Category = CategoryModel(sequelize, Sequelize);

//Pass { force: true } as option if you want to force delete and recreate.
sequelize.sync() 
  .then(() => {
    console.log(`Database & tables created!`)
});

module.exports = {
    Category
}

models\category.js

module.exports = (sequelize, DataTypes) => {
    return sequelize.define('category', {
        id: {
          type: DataTypes.INTEGER,
          primaryKey: true,
          autoIncrement: true
        },
        name: DataTypes.STRING,
        description: DataTypes.STRING,
        poster: DataTypes.STRING,
      },
      {
        freezeTableName: true // Model tableName will be the same as the model name
      }
    )
}

Test Application using postman:

Add a cateory

Get categories

Thought my swagger documentation is not complete but can also be used to test the rest endpoint as below -