1. Install the necessary packages:
First, you will need to install the necessary packages for this tutorial. You will need the MongoDB Node.js driver, as well as the Express web framework. To install these packages, run the following command in your terminal:
npm install mongodb express
2. Connect to the MongoDB database:
Next, you will need to connect to the MongoDB database. To do this, you will need to create a MongoClient instance and connect to the database. The following code snippet shows how to do this:
const MongoClient = require(‘mongodb’).MongoClient;
const url = ‘mongodb://localhost:27017’;
const dbName = ‘mydb’;
const client = new MongoClient(url);
client.connect(function(err) {
if (err) throw err;
console.log(“Connected successfully to server”);
const db = client.db(dbName);
});
3. Delete data by id:
Once you have connected to the database, you can delete data by id. To do this, you will need to use the deleteOne() method. This method takes two parameters: a filter object and an options object. The filter object is used to specify the document to delete, and the options object is used to specify any additional options.
For example, the following code snippet shows how to delete a document with an id of “123”:
db.collection(‘mycollection’).deleteOne({ _id: ‘123’ }, function(err, result) {
if (err) throw err;
console.log(“Document deleted”);
});
4. Close the connection:
Finally, you will need to close the connection to the database. To do this, you can use the close() method. The following code snippet shows how to do this:
client.close();
Delete data by _id into mongoDB database with mongoose in node js express app; This tutorial will guide you on how delete data from mongodb database using mongoose module in node js express.
This tutorial will create a html table using bootstrap 4 library and display a list with the delete button. Then create a route and import in app.js file to delete data from mongodb mongoose in node js express app.
How to Delete Data From Mongodb Mongoose Using Node js
- Step 1 – Create Node Express js App
- Step 2 – Install express flash validator ejs body-parser mongoose dependencies
- Step 3 – Connect App to MongoDB
- Step 4 – Create Model
- Step 5 – Create List and Delete Routes
- Step 6 – Create Views
- Create List Page and Delete Button
- Step 7 – Import Modules in App.js
- Step 8 – Start App Server
Step 1 – Create Node Express js App
Execute the following command on terminal to create node js app:
mkdir my-app cd my-app npm init -y
Step 2 – Install express flash ejs body-parser mongoose Modules
Execute the following command on the terminal to express flash ejs body-parser mysql dependencies :
npm install -g express-generator npx express --view=ejs npm install npm install express-flash --save npm install express-session --save npm install body-parser --save npm install mongoose npm install express-validator cors --save
body-parser – Node.js request body parsing middleware which parses the incoming request body before your handlers, and make it available under req.body property. In other words, it simplifies the incoming request.
Express-Flash – Flash Messages for your Express Application. Flash is an extension of connect-flash with the ability to define a flash message and render it without redirecting the request.
Express-Session– Express-session – an HTTP server-side framework used to create and manage a session middleware.
Express-EJS– EJS is a simple templating language which is used to generate HTML markup with plain JavaScript. It also helps to embed JavaScript to HTML pages
Mongoose – Mongoose is a MongoDB object modeling tool designed to work in an asynchronous environment. Mongoose supports both promises and callbacks.
Step 3 – Connect App to MongoDB
Create database.js file into your app root directory and add the following code into it to connect your app to the mongodb database:
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost:27017/users', {useNewUrlParser: true});
var conn = mongoose.connection;
conn.on('connected', function() {
console.log('database is connected successfully');
});
conn.on('disconnected',function(){
console.log('database is disconnected successfully');
})
conn.on('error', console.error.bind(console, 'connection error:'));
module.exports = conn;
Step 4 – Create Model
Create Models directory and inside this directory create userModel.js file; Then add following code into it:
const mongoose = require("../database");
// create an schema
var userSchema = new mongoose.Schema({
name: String,
email:String
});
var userModel=mongoose.model('users',userSchema);
module.exports = mongoose.model("Users", userModel);
Step 5 – Create List and Delete Routes
Create routes; so visit routes directory and open users.js route file; Then add the following routes into it:
var express = require('express');
var router = express.Router();
var mongoose = require('mongoose');
var userModel = require('../models/userModel');
/* GET home page. */
router.get('/', function(req, res, next) {
userModel.find((err, docs) => {
if (!err) {
res.render("users/list", {
data: docs
});
} else {
console.log('Failed to retrieve the Users List: ' + err);
}
});
});
// DELETE USER
router.get('/delete/(:id)', function(req, res, next) {
userModel.findByIdAndRemove(req.params.id, (err, doc) => {
if (!err) {
res.redirect('/users/list');
} else {
console.log('Failed to Delete user Details: ' + err);
}
});
})
module.exports = router;
Step 6 – Create Views
Create some views; so visit views directory of your app and create list.ejs into it.
Create List Page and Delete Button
Create html markup for display list from mongodb database; So visit views directory and create list.ejs file inside it. Then add the following code into it:
<!DOCTYPE html>
<html>
<head>
<title>node js mongodb delete by _id</title>
<link rel='stylesheet' href='/stylesheets/style.css' />
<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/js/bootstrap.min.js" integrity="sha384-ChfqqxuZUCnJSK3+MXmPNIyE6ZbWh2IMqE241rYiqJxyMiZ6OW/JmZQ5stwEULTy" crossorigin="anonymous"></script>
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.3/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-MCw98/SFnGE8fJT3GXwEOngsV7Zt27NXFoaoApmYm81iuXoPkFOJwJ8ERdknLPMO" crossorigin="anonymous"> </head>
<body>
<div> <a href="/" class="btn btn-primary ml-3">Home</a> </div>
<!-- <% if (messages.error) { %>
<p style="color:red"><%- messages.error %></p>
<% } %> -->
<% if (messages.success) { %>
<p class="alert alert-success mt-4">
<%- messages.success %>
</p>
<% } %>
<br>
<table class="table">
<thead>
<tr>
<th scope="col">#</th>
<th scope="col">Name</th>
<th scope="col">Email</th>
<th width="200px">Action</th>
</tr>
</thead>
<tbody>
<% if(data.length){
for(var i = 0; i< data.length; i++) {%>
<tr>
<th scope="row">
<%= (i+1) %>
</th>
<td>
<%= data[i].name%>
</td>
<td>
<%= data[i].email%>
</td>
<td> <a class="btn btn-success delete" href="../users/delete/<%= data[i]._id%>">Delete</a> </td>
</tr>
<% }
}else{ %>
<tr>
<td colspan="3">No user</td>
</tr>
<% } %>
</tbody>
</table>
</body>
</html>
Step 5 – Import Modules in App.js
Import express flash session body-parser mongoose dependencies in app.js; as shown below:
var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
var bodyParser = require('body-parser');
var flash = require('express-flash');
var session = require('express-session');
var usersRouter = require('./routes/users');
var app = express();
// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use(session({
secret: '123456catr',
resave: false,
saveUninitialized: true,
cookie: { maxAge: 60000 }
}))
app.use(flash());
app.use('/list', usersRouter);
// catch 404 and forward to error handler
app.use(function(req, res, next) {
next(createError(404));
});
// error handler
app.use(function(err, req, res, next) {
// set locals, only providing error in development
res.locals.message = err.message;
res.locals.error = req.app.get('env') === 'development' ? err : {};
// render the error page
res.status(err.status || 500);
res.render('error');
});
module.exports = app;
Step 7 – Start App Server
You can use the following command to start node js app server:
//run the below command npm start after run this command open your browser and hit http://127.0.0.1:3000/list
Conclusion
Node js mongodb delete by _id using mongoose; In this tutorial, you have learned how to how delete data from mongodb database by _id using mongoose in node js express app.
