title: query for one field doesn't equal another field in elasticsearch
body: <p>How can I query for, or filter for, one field doesn't equal another field?  i.e. where document1.city1.name not equal document1.city2.name.</p>
  
  <p>Some version of this?
  <a href="http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-request-script-fields.html" rel="noreferrer">http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-request-script-fields.html</a> </p>