Let’s have a look at how actual filters that match only some of our documents look like. We are going to rewrite our script because we need some more documents to play with

Node MongoClient.js

'use strict';

var MongoClient = require('mongodb').MongoClient;
 
MongoClient.connect( 'mongodb://127.0.0.1:27017/accounting', function (err, connection) {

var collection = connection.collection('customers');

var doFind = function (callback) { collection.find().toArray(function (err, documents) {
        console.dir(documents);
        callback();
      });

};
var doInsert = function (i) { if (i < 20) {
var value = Math.floor(Math.random() * 10); collection.insert(
{'n': '#' + i, 'v': value}, function (err, count) {
        doInsert(i + 1);
      });
} else {
console.log();
console.log('Inserted', i, 'documents:'); doFind(function () {
      doUpdate();
    });
} };
var doUpdate = function () { 

collection.update(

{'v': {'$gt': 5}},
{'$set': {'valuable': true}}, {'multi': true},

function (err, count) {

console.log();
console.log('Updated', count, 'documents:'); 

doFind(function () {
collection.remove({}, function () { connection.close();
}); 
});
}); 
};
    doInsert(0);
  });