title: Get particular element from mongoDB array
body: <p>I have mongo collection like below</p>
  
  <pre class="lang-js prettyprint-override"><code>{
    "auther" : "xyz" , 
    "location" : "zzz" , 
    "books" : 
      [
        {"book1" : "b1" , "date" : 2-3-00} ,
        {"book1" : "b2" , "date" : 4-9-00}
      ]
  }
  
  {
    "auther" : "pqr",
    "location" : "zzz" , 
    "books" : 
      [
        {"book1" : "b1" , "date" : 2-4-00}
      ]
  }
  </code></pre>
  
  <p>I want to get the only the date of book b1 and author xyz . </p>
  
  <p>i have make  query like below</p>
  
  <pre class="lang-js prettyprint-override"><code>db.coll.find({"auther" : "xyz" , "books.book1" : "b1"} , {"books.date" : 1})
  </code></pre>
  
  <p>but it's gives output as follows</p>
  
  <pre class="lang-js prettyprint-override"><code>"books" : {"date" : 2-4-00} , "books" : {"date" : 4-9-00}
  </code></pre>
  
  <p>I want to get the only the date of book b1 and other xyz .means only  <code>"books" : {"date" : 2-4-00}</code></p>
  
  <p>is it possible in mongo or am I doing something wrong?</p>