title: Return SOLR result which has "x" field with value "v"
body: <p>I am using SOLR 4.9 Version.Following are my indexed document.</p>
  
  <pre>
  <code>
  
      {
         "id": "1",
         "index_id": "index",
         "tm_title":"Avenger"
         "category":"1"
         "type":"movie"
         "article_type":"Hollywood"
      },
      {
         "id": "2",
         "index_id": "index",
         "tm_title":"Avenger 2: Age of ultron"
         "category":"1",
         "type":"movie"
         "article_type":"Hollywood"
      },
      {
         "id": "3",
         "index_id": "index",
         "tm_title":"Spiderman"
         "category":"2"
         "type":"movie"
         "article_type":"Hollywood"
      },
      {
         "id": "4",
         "index_id": "index",
         "tm_title":"Emy Jackson"
         "type":"celebrity"
         "article_type":"Hollywood"
      },
      {
         "id": "5",
         "index_id": "index",
         "tm_title":"Jim Watson"
         "type":"celebrity"
         "article_type":"Hollywood"
      }
  
  </code>
  </pre>
  
  <p><strong>Now requirement is like combination of movie and celebrity result like this.<br></strong></p>
  
  <ol>
  <li>Query 1: If searching for <b>"Hollywood"</b> which have <b>"category":"2"</b> and also include celebrities. Then result will be ids of <b>3,4,5</b>.</li>
  <li>Query 1: If searching for <b>"Hollywood"</b> which have <b>"category":"1"</b> and also include celebrities. Then result will be ids of <b>1,2,4,5</b>.</li>
  </ol>
  
  <p>I searched a lot for this but not find out the solution for this.
  I am trying following query.</p>
  
  <p>FOR Query 1: <pre><code>localhost:8983/solr/collection1/select?q=Hollywood&amp;fq=if(exist(category),category:2,'');</code></pre></p>
  
  <p>FOR Query 2: <pre><code>localhost:8983/solr/collection1/select?q=Hollywood&amp;fq=if(exist(category),category:1,'');</code></pre></p>