Return array of fields from subdocument
<p>can anyone please help I want to query mongo to unwind the array,and i am using mongdb native driver My collection document is as follow,Also please ignore my objectId its just for sample</p>

<pre><code>{  
      "_id":ObjectId(123),
      "name":"Sam",
      "age":20,
      "hobbiesDetail":[  
         {  
            "description":"FootBall",
            "level":"20%"
         },
         {  
            "description":"Cricket",
            "level":"80%"
         }
      ]
   },
   {  
      "_id":ObjectId(124),
      "name":"Ted",
      "age":26,
      "hobbiesDetail":[  
         {  
            "description":"FootBall",
            "level":"20%"
         }
      ]
   }
</code></pre>

<p>And my expected output is </p>

<pre><code>[  
   {  
      "name":"Sam",
      "age":20,
      "hobbies":"Football,Cricket"
   },
   {  
      "name":"Ted",
      "age":26,
      "hobbies":"Football"
   }
]
</code></pre>

<p>I just want to unwind my array and add a comma between hobbies description in one query, Thanx for any help</p>