title: Using mongodb driver how to do not in $regex query
body: <p>From searching the internet i am not sure if this is possible so i figured i would ask you smart people.</p>
  
  <p>I am trying to allow a admin users of a site free range to do more advanced search queries. The db is mongo. Whatever is inputed into the search input gets put into a <code>{"$regex": "{user input}"}</code>.</p>
  
  <p>I know i can use <code>$not</code> operator, but i am wondering if a NOT could be applied in the $regex field. This would save me from having to parse the input and fill in the <code>$not</code> and just let the <code>$regex</code> handle it.</p>
  
  <p>This would only be available to admins who knew how to put the regex into the search input so i don't need to worry about complexity for simple users.</p>
  
  <p>Thanks for any help.</p>
  
  <p>EDIT:
  Also, i figured out later what i was really meaning with $not was $ne. Something where a user could type <code>"someFieldName" $ne "someId"</code> which would be put in the $regex query to mongo and get results for all documents where <code>someFieldName</code> doesn't have `someId'.</p>