title: Update MongoDB collection with $toLower or $toUpper
body: <p>I would like to convert the 'state' field for all 'Organization' to all UPPER case. So </p>
  
  <p>'Ky' becomes 'KY'
  'tX' becomes 'TX'
  'ca' becomes 'CA'</p>
  
  <p>why this doesn't work</p>
  
  <p><code>db.organizations.update(state:{ $exists : true }},{$set:{state:{ $toUpper : state }}}, false, true)</code></p>