Node.js – Delete Collection in MongoDB
In this Node.js Tutorial, we shall learn to Delete Collection in MongoDB from Node.js Application, using db.collection.remove() method, with an example.
Following is a step by step guide with an example to delete a collection in MongoDB from Node.js Application.
- Start MongoDB Service. Run the following command to start MongoDB Service sudo service mongod start
- Get the base URL to MongoDB Service. A simple hack to know the base url of MongoDB Service is to Open a Terminal and run Mongo Shell. While the Mongo Shell starts up, it echoes back the base url of MongoDB.arjun@nodejs:~$ mongoMongoDB shell version v3.4.9connecting to: mongodb://127.0.0.1:27017MongoDB server version: 3.4.9Server has startup warnings:2017-10-29T18:15:36.110+0530 I STORAGE [initandlisten]mongodb://127.0.0.1:27017
- Prepare the complete URL. Append the Database name you want to connect to (say newdb), to the base URL. mongodb://127.0.0.1:27017/newdb
- Create a MongoClient. var MongoClient = require('mongodb').MongoClient;
- Make connection from MongoClient to the MongoDB Server with the help of URL. Once the MongoClient is done trying to make a connection, the callback function receives error and db object as arguments.MongoClient.connect(url, <callback_function>);
If the connection is successful, the db object points to the database, newdb.
- Get reference to MongoDB Collection. db.collection(<collection_name>, <callback_function>);
Once you get db object that points to the specified mongodb database, use it to get reference to required collection using the above statement.
- Delete MongoDB Collection. Following is the syntax of remove() method used to delete collection in MongoDB from Node.js. collection.remove({},callback_function)
collection reference to the mongodb collection that we would like to delete callback_function This Node.js Callback Function is called after Node has tried deleting the specified collection, and ready with the result. The callback function receives error and result object as arguments.
Example Node.js program
// example : delete 'users' collection in newdb database var url = "mongodb://localhost:27017/newdb"; // create a client to mongodb var MongoClient = require('mongodb').MongoClient; // make client connect to mongo service MongoClient.connect(url, function(err, db) { if (err) throw err; // db pointing to newdb console.log("Switched to "+db.databaseName+" database"); // get reference to collection db.collection("users", function(err, collection) { // handle the error if any if (err) throw err; // delete the mongodb collection collection.remove({}, function(err, result){ // handle the error if any if (err) throw err; console.log("Collection is deleted! "+result); // close the connection to db when you are done with it db.close(); }); }); }); |
~$ node node-js-mongodb-delete-collection.js Switched to newdb database Collection is deleted! {"n":0,"ok":1} |
Reference
MongoDB Tutorial – Learn MongoDB from basics with Examples.
Conclusion :
In this Node.js MongoDB tutorial : Node.js – Delete Collection in MongoDB, we have learnt to delete a collection from MongoDB Database with Node.js Application using mongodb package. In our next tutorial – Node.js Insert Document to MongoDB Collection, we shall learn to insert one or more documents to a MongoDB collection.