title: how to query below document to find all ev=1
body: <p>I want to query below document to find all ev of email_info subset</p>
  
  <pre><code>{ 
      "_id" : ObjectId("56e13dc9abdb1c233db92dff"), 
      "customer_id" : NumberInt(8383), 
      "customerdetails" : {
          "name" : "Myth 2016", 
          "email_info" : {
              "email" : "myth1926@gmail.com", 
              "ev" : NumberInt(1)
          }, 
          "mobile_userid" : "3#102103293090775998087", 
          "usertype" : "non-anon", 
          "loginmode" : "GooglePlus"
      }
  }
  </code></pre>
  
  <p>i am using </p>
  
  <pre><code>db.customer_detail.find({"email_info.ev":1});
  </code></pre>
  
  <p>but it is not giving me result.</p>