Updating a document in MongoDB with Node.js
Updating a document in a collection is easy; simply use the collection's update method and pass the data you want to update.
How to do it...
Here's a simple example:
var mongo = require('mongodb').MongoClient;
var url = 'mongodb://localhost:27017/test';
var update = function(collection, callback) {
  collection.update({ call:'kf6gpe-7' }, 
    { $set: { lat: 39.0, lng: -121.0, another: true } }, 
    function(error, result) {
      console.log('Updated with error ' + error);
      console.log(result);
      callback(result);
    });
};
mongo.connect(url, function(error, db) {
  console.log("mongo.connect returned " + error);
  // Get the documents collection
  var collection = db.collection('documents');
  update(collection, function(result) {
    db.close();
  });
});The pattern of this is identical to the insert method; update is an asynchronous method that invokes a callback with an error code and a result.
How it works…
The update method takes...