Update MongoDB collection using $toLower

Question

I have an existing MongoDB collection containing user names. The user names contain both lower case and upper case letters.

I want to update all the user names so th

Answer 1

Very similar solution but this worked me in new mongo 3.2 Execute the following in Mongo Shell or equivalent DB tools like MongoChef!

db.tag.find({hashtag :{ $exists:true}}).forEach(
 function(e) {
   e.hashtag = e.hashtag.toLowerCase();
   db.tag.save(e);
});