# Express and MongoDB


Hey there, In this article, I would be teaching you how to use **MongoDB** with express.js and perform CRUD operations.

## What is MongoDB?

MongoDB is a no-SQL database. It is a general-purpose, document-based, distributed database built for modern application developers and for the cloud era.

### MongoDB stores the data as form of document inside collections.

For Example: If I have a record of 5 students, So I can say that I have 5 documents inside a collection named as students.

### I hope you got the point. 😄
> Note: In this tutorial, I will be using MongoDB atlas to avoid the complexities faced while installing MongoDB and it would also be easier for beginners to understand too.
> **MongoDB Atlas is a cloud service to use mongoDb.**

## Let’s Begin

## Step 0: Create an account on MongoDB

Head over to [https://www.mongodb.com/](https://www.mongodb.com/) and create your free account to use MongoDB atlas.

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072305584/0bk21t43p.png)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072308087/rhYpGf4m9.png)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072310204/NVQsn51SP.png)

## After creating your account, choose free cluster and click on create a cluster

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072312498/4EbVfkblJ.png)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072314928/ZlTlic--D.png)

## Now, wait for 2–3 minutes for the cluster to get deployed.

## Congrats! You have successfully deployed your cluster and now we are ready to move on to next step. 🎉

## Step1: Configuring MongoDB Atlas

There are a couple of tweaks here and there which we need to follow to get started with MongoDB Atlas.

### **Creating a user role to access the database from our application**

![Navigate to Database Access](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072317300/dQf6HLR8zI.png)*Navigate to Database Access*

![Click add new database user](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072319086/gUkGjayH0g.png)*Click add new database user*

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072321770/4lkjKKcWK.png)

### Now, We have to whitelist the IP’s from where we can access the database.

![Navigate to Network access and click Add IP Address](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072324699/DwPumdvp4.png)*Navigate to Network access and click Add IP Address*

![Select Allow Access from anywhere and select confirm](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072326898/t5TKic-jd.png)*Select Allow Access from anywhere and select confirm*

## Step 2: Project Setup

Now, lets set up our project structure and create boilerplate code.

### Firstly, create a folder. Let's name it as “myProject”.

### Now, Fire-up your terminal or command prompt and run:

```
npm init
```


### Great, Now let's install dependencies.

Run:

```
npm i express mongoose
```


**Great Going, Now let's create some files and folders. For the time bear with me and create these folders. I am going to explain the working of each and file step by step.**

**Our Project Structure:**

```
myProject
|
|- model
     |- user.js
|- index.js
|- package.json
```


![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072328690/xKBUFHfod.png)

In the above project structure, we have created a folder **model, **this is the folder where we are going to keep all our schemas for different collection.

Currently, we have one, the **user.js**

## Step 3: Creating the Boilerplate Code

Head over to index.js and code along with me.

```javascript
const express = require('express');

const app = express()

app.get('/', (req, res) => {
  res.send('Welcome to my API');
})

app.listen(9000, () => console.log('Server Started at PORT 9000'))
```

## Step 4: Connect our node application to MongoDB Atlas

Connecting application to MongoDB is really simple.

1. **Head over to Clusters panel and click connect.**

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072331216/O2UR8VKJI.png)

**2. Click on connect your application.**

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072333318/rQRLRT6rk.png)

**3. Copy the connection string**

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072335514/lCQmlOBDd.png)

Great Now back to our code …..

### Follow the steps below to connect to MongoDB Atlas

1. Import the mongoose package in index.js

```javascript
const express = require('express');
const mongoose = require('mongoose');


const app = express()

app.get('/', (req, res) => {
  res.send('Welcome to my API');
})

app.listen(9000, () => console.log('Server Started at PORT 9000'))
```

2. Use connect function of mongoose to connect to our application and pass the connection string that we copied earlier.

![Replace the original password with <password>](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072337802/iqKxkYvhU.png)*Replace the original password with <password>*

```javascript
const express = require('express');
const mongoose = require('mongoose');

const app = express()

mongoose.connect(
  `mongodb+srv://piyushgarg:hello123@cluster0-2bghc.mongodb.net/test?retryWrites=true&w=majority`
  )
  .then(() => console.log('MongoDB Connect'))
  .catch((err) => console.log(`Error Occured ${err}`))


app.get('/', (req, res) => {
  res.send('Welcome to my API');
})

app.listen(9000, () => console.log('Server Started at PORT 9000'))
```

Additionally, pass the following parameters to the connect function:
> Refer to [https://mongoosejs.com/docs/deprecations.html](https://mongoosejs.com/docs/deprecations.html) for more info

```
{

useNewUrlParser: true,

useUnifiedTopology: true

}
```


```javascript
const express = require('express');
const mongoose = require('mongoose');

const app = express()

mongoose.connect(
  `mongodb+srv://piyushgarg:hello123@cluster0-2bghc.mongodb.net/test?retryWrites=true&w=majority`,
  {
    useNewUrlParser: true,
    useUnifiedTopology: true
  }
  )
  .then(() => console.log('MongoDB Connect'))
  .catch((err) => console.log(`Error Occured ${err}`))


app.get('/', (req, res) => {
  res.send('Welcome to my API');
})

app.listen(9000, () => console.log('Server Started at PORT 9000'))
```

## Congrats! 🎉… try running the server and you would see MongoDB connected on the console.

## Step 4: Creating user schema

In this step, we would be working with the **user.js** inside our **models** folder and create a user schema.

```javascript
const mongoose = require('mongoose');

const userSchema = mongoose.Schema({
  name: {
    type: String,
    required: true,
  },
  email:{
    type: String,
    required: true,
    unique: true,
  },
  password:{
    type: String,
    required: true,
  },
  age: {
    type: Number
  }
})

const user = mongoose.model('users', userSchema);

module.exports = user;
```

In this file, we, first of all, require the mongoose package and then use the . Schema method to create the schema. In the Schema method, we pass an object specifying our schema of the user with various properties like type, unique and required.

Finally, we create a model using mongoose. model which requires two parameters:

First: The name of the model as a string. [ users ]

Second: The user schema we created above.

## Hooray! User Schema Ready! Now we are ready to perform CRUD operations

## Step 5: API and CRUD operations

In this step, we would be creating API's to perform crud operation on our DB.

Back to index.js

### Import the user.js and start coding along with me.

```javascript
const express = require('express');
const mongoose = require('mongoose');

const app = express()

const User = require('./model/user');

mongoose.connect(
  `mongodb+srv://piyushgarg:hello123@cluster0-2bghc.mongodb.net/test?retryWrites=true&w=majority`,
  {
    useNewUrlParser: true,
    useUnifiedTopology: true
  }
  )
  .then(() => console.log('MongoDB Connect'))
  .catch((err) => console.log(`Error Occured ${err}`))


app.get('/', (req, res) => {
  res.send('Welcome to my API');
})

app.get('/users/all', (req, res) => {

  User.find({}, (err, users) => {
    if(err) return res.json(err);
    return res.json(users)
  })

})


app.get('/users/:id', (req, res) => {

  const id = req.params.id;
  User.findById(id, (err, user) => {
    if(err) return res.json(err);

    return res.json(user);
  })
})

app.post('/user/new', (req, res) => {
  const {name, email, password, age} = req.body;
  const myUser = new User();
  myUser.name = name;
  myUser.email = email;
  myUser.password = password; // Make sure you hash the passowrd;
  myUser.age = age;

  myUser.save()
    .then(() => res.send('User inserted into db'))
    .catch(err => res.send(err))
})

app.listen(9000, () => console.log('Server Started at PORT 9000'))
```

There is one error in code and that is we have not implemented the express.json() middleware.

Well, that’s your task.

## **And Done! 😍**

## Let's test our implementation in Postman

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072339920/r0pkkEO2h.png)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072341953/4aPOTziEg.png)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072344189/VOzghI2VFZ.png)

### In your MongoDB Atlas go to collections and see your newly created user document there.

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072346131/NmjTVu1jzz.png)

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1621072348299/GJy50SUWK.png)

## Great! 😍 Our API is working great.
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## Social Links:

Github: [https://github.com/piyushgarg195](https://github.com/piyushgarg195)

Linkedin: [https://www.linkedin.com/in/piyushgarg195/](https://www.linkedin.com/in/piyushgarg195/)

Website: [https://www.piyushgarg.dev/](https://www.piyushgarg.dev/)