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

With the accepted solution I know its very trivial to do the same for an array of elements, just in case

db.myCollection.find().forEach(
   function(e) {
      for(var i = 0; i < e.articles.length; i++) { 
          e.articles[i] = e.articles[i].toLowerCase(); 
      }
      db.myCollection.save(e); 
   }
)