title: can terms lookup mechanism query by other field but id?
body: <p>here is elasticsearch official website about terms:
  <a href="https://www.elastic.co/guide/en/elasticsearch/reference/2.1/query-dsl-terms-query.html" rel="nofollow">https://www.elastic.co/guide/en/elasticsearch/reference/2.1/query-dsl-terms-query.html</a></p>
  
  <p>As we can see, if we want to do terms lookup mechanism query, we should use command like this:</p>
  
  <pre><code>curl -XGET localhost:9200/tweets/_search -d '{
    "query" : {
      "terms" : {
        "user" : {
          "index" : "users",
          "type" : "user",
          "id" : "2",
          "path" : "followers"
        }
      }
    }
  }'
  </code></pre>
  
  <p>But what if i want to do query by other field of users.
  Assume that users has some other fields such as name and can i use terms lookup mechanism finding the tweets by giving users name but not id. 
  I have tried to use command like this:</p>
  
  <pre><code>curl -XGET localhost:9200/tweets/_search -d '{
    "query" : {
      "terms" : {
        "user" : {
          "index" : "users",
          "type" : "user",
          "name" : "Jane",
          "path" : "followers"
        }
      }
    }
  }'  
  </code></pre>
  
  <p>but it occurs error. 
  Looking forward to your help. Thank you!</p>