How to perform a complex query in MongoDB
<p>I want to perform a query on this schema:</p>

<pre><code>{ 
   "name" : "xxx",
   "guests" : [ 
       {
            "category" : "category 1",
            "arrived" : false
       },
       {
            "category" : "category 2",
            "arrived" : false
       },
       {
            "category" : "category 1",
            "arrived" : true
       },
       {
            "category" : "category 2",
            "arrived" : true
       }
   ]
}
</code></pre>

<p>I want to get for a certain name, a list with the percentage of guests arrived for each category.</p>

<p>For the document above as example, I want to receive: </p>

<pre><code>{
    name : "xxx",
    results : [
         {
              category : "category 1",
              arrived : 50 (percent)
         },
         {
              category : "category 2",
              arrived : 50 (percent)
         },
    ]
</code></pre>

<p>Is there a way to do this with a single MongoDB query? Also, should I do this computation in the client-side or server-side?</p>