Mongoose : don't insert if element already stored

Question

I\'m using MongoDB and Mongoose with Express to store tweets that I retrieve via the Twitter API.

I want to avoid saving duplicate tweets. I am doing something like that

Answer 1

You can use an update call with the upsert option to do this:

TweetsModel.update(
    {tweet_id: tweet.tweet_id}, 
    {$setOnInsert: tweet}, 
    {upsert: true}, 
    function(err, numAffected) { .. }
);

If a doc already exists with that tweet id, then this is a no-op. Otherwise it will add the doc.

$setOnInsert requires v2.4+ of MongoDB. If your version is less than 2.4, things get more complicated.