Learning Node.js MongoDB: Part 5: Deleting

On By Dan CoxIn code, JavaScript

Learning Node.js MongoDB

MongoDB is a popular NoSQL document-oriented database system. The Node.js driver allows for connecting to an existing MongoDB installation or system.

Deleting

As with all other operations, MongoDB supports the “one” and “many” functions for deleting as well. These are deleteOne() and deleteMany().

deleteOne()

The function deleteOne() works on existing collections.

Like with updating, a document must be found in order to be deleted. The first argument to the function deleteOne() is a query to find a single document.

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://127.0.0.1:27017/";

MongoClient.connect(url, function(err, db) {
  
    if (err) throw err;
  
    var dbo = db.db("example");
  
    var myquery = { name: "Dan Cox" };
  
    dbo.collection("users").deleteOne(myquery, function(err, res) {
    
        if (err) throw err;
    
        db.close();
  });

});

deleteMany()

The function deleteMany() works on existing collections.

Similar to updating, a query can use regular expressions to search across documents for deletion.

var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://127.0.0.1:27017/";

MongoClient.connect(url, function(err, db) {
  
    if (err) throw err;
  
    var dbo = db.db("example");
  
    var myquery = { name: /a/ };
  
    dbo.collection("users").deleteMany(myquery, function(err, res) {
    
        if (err) throw err;
    
        db.close();
  });

});