Delete one operation in MongoDB using node.js

In this part of the mongodb operations using node.js tutorial series , we will learn about deleting the first occurrence of data matching a certain criteria from a mongodb collection using node.js .

We will start by including mongodb npm package as shown below :

												
var mongo = require('mongodb');
												
											

Establish a connection between the mongoDb database and our node.js app using the following :

												
var new_db = "mongodb://localhost:27017/demo_db"
												
											

• demo_db is the name of the database. You can change it in accordance with your database name.
• 27017 is the port where mongoDb is running.
• Localhost i.e. 127.0.0.1 is the local IP.

deleteOne() is an inbuilt method of mongodb which is used to delete the first occurrence of data obtained using the search query.
The syntax of deleteOne() function is given below :

										
db.collection("NAME_OF_THE_COLLECTION").deleteOne(SEARCH_CONDITION ,(CALLBACK_FUNCTION) => {});
										
									

											
//delete-one.js
var mongo = require('mongodb');
var new_db = "mongodb://localhost:27017/demo_db"
//connecting to the database using nodejs
mongo.connect(new_db ,(error , db) => {
	if (error){
		throw error;
	}
	//query stores the search condition	
	var query = { age : "above 22" };
	
	//Accessing a COLLECTION IN MONGODB USING NODE.JS
	db.collection("details").deleteOne(query , (err , collection) => {
		if(err) throw err;
		console.log(collection.result.n + " Record(s) deleted successfully");
		console.log(collection);
		db.close();
	});
});
											
										

											
>node delete-one.js
1 Record(s) deleted successfully
{ 
	result: 
		{ 
			ok: 1,
			n: 1
		},
	connection: null,
	message: undefined,
	deletedCount: 1 
}											
										

In this article we learned about

1. Including monogdb npm package in your app.
2. Establishing a connection between mongodb database and node.js application.
3. deleteOne() operation in mongodb using node.js