title: Mongodb $and not working properly
body: <p>I try to find data using mongodb $and in my nodejs app but it not working properly .</p>
  
  <p>my code - </p>
  
  <pre><code>        var brand = req.param('Brand').split(',');
          brand = '"' + brand.join('","') + '"';
          if (query != '')
              query += ','
          query +=  '{"pro.brand": {$in:['+ brand  +']}}'
  
     itemdata.find({$and:[query]}, function(err, product) {
          if (err) {                
              return res.send({info: "Opps sorry"});
          }
          else {                
              res.json({deals: product}); 
          }  
      });
  </code></pre>
  
  <p>When i manually put query ( {"pro.brand": {$in:["Micromax"]}} ) then it work. Otherwise it not working (it return all data).</p>