Saumya

Happy new year! I am late about the post. But can not miss it. The reflection about the past year.

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Working with databases from Node is easy. But then working with a support from ORM/ODM makes it more interesting. Last time we saw how we can work with SQL servers?, this post is about NoSQL servers, specifically MongoDB. There is a nice ODM for MongoDB known as mongoose.

This mongoose makes the database calls as simple as it could be. The concepts here are

• Define a schema
• Get the Model from the Schema
• Do the database operations on the Model

The sample project is here in Github.

The first call to mongoose is a connection to MongoDB.

var mongoose = require('mongoose');
mongoose.connect( mongoURL , {useUnifiedTopology: true,useNewUrlParser: true},function(error){
        if(error){
            throw error
        }
        console.log('Connection : SUCCESS : ');

        // Go ahead with Database modifications
        //
    });

There are two ways to call connect function. The way it is shown above will give error object if there is an error in connection. One has to check for the availability of this object and do things accordingly. If not present, then we have a successful connection. Once that is done, one can call the CRUD methods of the model for modifying the database.

A model file(example: dog.model.js) will look as below.

const mongoose = require('mongoose');
const DogSchema = mongoose.Schema({
    name: String,
    description: String
});
const DogModel = mongoose.model('MyDog', DogSchema);
module.exports = DogModel;

This is how to get the model and from there on, you can use the mongoose API to modify the database through the model Object.

Happy Coding.

Finished a project having database, Node and web UI. While connecting the database from Node server is easy, there are as usual a lot of options here. First I used mysql but soon after realised there is an updated package to it called mysql2. So I have shifted to mysql2. Once its installed, it is straight forward to connect to any database. The docs are very helpful to get going.

Once database connection is done and one get used to the workflow, the need for an ORM arises. There are many options for this in Node land. After looking into different options, I started using Sequelize. It is as nice as Node itself and the docs of this library is very helpful and welcoming.

These two things makes life a lot easier, while working with database from a Node server. Next comes the time to write APIs for the frontend. I used Express to get things done for the APIs. There is one thing to keep in mind while working with JSON for the APIs in Express. The thing is one has to initialise Express application like below.

    const express = require('express');
    const app = express();
    const port = 3000;
    app.use(express.json());
    app.use(express.urlencoded({ extended: false }));

Once this is done, we are ready to take/give JSON from/to UI. If you are trying to host it on Heroku, then the following line is important.

 app.listen( process.env.PORT || port , () => console.log(`My App listening!`) );

This is required because, Heroku does not listen on port 3000 as we are trying to make it. But Heroku port is available for us at process.env.PORT. So we are using it here.

Next is making the APIs CORS enabled. Which is done as below.

    app.use(function (req, res, next) {
        res.setHeader('Access-Control-Allow-Origin', 'http://localhost:1234');
        res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
        res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type, Accept');
        res.setHeader('Access-Control-Allow-Credentials', true);
        next();
    });

Now we are ready to write the APIs.

Front End

The frontend I have done, is using bulma for CSS and jQuery for DOM manipulation. Well yes, I hava avoided all the frameworks and new toys of today. And still could do the project and finish it. I have iterated it a lot and it is all fun to see how time could be saved even if one does not use a framework!

Here are the code repositories to have a look for frontend and backend.

• Frontend
• Backend

It is a very nice experience to see Javascript in all sides and almost no framework on frontend and still having a decent project running.