title: CodeIgniter- active record insert if new or update on duplicate
body: <p>Is it possible to do an <strong>active record</strong> query in CodeIgniter that will update an existing record if one already exists or insert if it doesnt, for the given key?</p>
  
  <p>I understand this could be done by first querying to find an existing record, but I'm seeking the most efficient approach.</p>