Check if ID exists in a collection with mongoose

Question

For instance, I have a collection User:

var mongoose = require('mongoose');  var UserSchema = new mongoose.Schema({     email: String,     googleId: String,     facebookId: String,     displayName: String,     active: Boolean });  module.exports = mongoose.model('User', UserSchema); 

And then I have an ID:

var userID = "some-user-id" 

What is the right way to just check if this id exists in the User collection. I don't need it to read the file or return it, I just need the true or false value.

Here is one way to achieve it:

User.findOne({      _id: userID }, function (err, existingUser) { 

But is there faster and more efficient way?

Answer 1

Use count rather than findOne.

This will (under the hood) cause mongoose to use find : http://docs.mongodb.org/manual/reference/method/db.collection.count

findOne() will read + return the document if it exists On the other hand, find() just returns a cursor (or not) and only reads the data if you iterate over the cursor. So in our case, we're not iterating over the cursor, merely counting the results returned.

User.countDocuments({_id: userID}, function (err, count){      if(count>0){         //document exists });     } });