title: How to query mongo db lowercase in array using $all and $regex
body: <pre><code>dbo.collection("intent").find({ input: { $all : [ { $regex: new RegExp("^" + message.toLowerCase(), "i") } ] } }).toArray(function(err, result) {
  
  
        });
  </code></pre>
  
  <p>It showed eror</p>
  
  <blockquote>
    <p>MongoError: no $ expressions in $all,</p>
  </blockquote>