title: mongodb search by multiple tags
body: <p>I am reading the mongoDB manual for searching by tags (elements in arrays); here is the page: <a href="http://docs.mongodb.org/manual/tutorial/model-data-for-keyword-search/" rel="nofollow">http://docs.mongodb.org/manual/tutorial/model-data-for-keyword-search/</a></p>
  
  <p>But, how do I search while using multiple keyworks? Can an array be used like this?</p>
  
  <p>single keyword:</p>
  
  <pre><code>db.volumes.findOne( { topics : "voyage" }, { title: 1 } )
  </code></pre>
  
  <p>many keywords:</p>
  
  <p>db.volumes.findOne( { topics : ['voyage', 'nautical'] }, { title: 1 } )</p>