How can I save multiple documents concurrently in Mongoose/Node.js?

Question

At the moment I use save to add a single document. Suppose I have an array of documents that I wish to store as single objects. Is there a way of adding them all with a si

Answer 1

You can use the promise returned by mongoose save, Promise in mongoose does not have all, but you can add the feature with this module.

Create a module that enhance mongoose promise with all.

var Promise = require("mongoose").Promise;

Promise.all = function(promises) {
  var mainPromise = new Promise();
  if (promises.length == 0) {
    mainPromise.resolve(null, promises);
  }

  var pending = 0;
  promises.forEach(function(p, i) {
    pending++;
    p.then(function(val) {
      promises[i] = val;
      if (--pending === 0) {
        mainPromise.resolve(null, promises);
      }
    }, function(err) {
      mainPromise.reject(err);
    });
  });

  return mainPromise;
}

module.exports = Promise;

Then use it with mongoose:

var Promise = require('./promise')

...

var tasks = [];

for (var i=0; i < docs.length; i++) {
  tasks.push(docs[i].save());
}

Promise.all(tasks)
  .then(function(results) {
    console.log(results);
  }, function (err) {
    console.log(err);
  })