title: Facing issue while converting blank ('') to toDouble in mongodb
body: <p>I am facing issue while converting blank ('') to toDouble in mongodb</p>
  <p>my query is as</p>
  <pre><code>{$expr: {$gte: [{$toDouble: &quot;$rating&quot;}, 1.5]}}
  </code></pre>
  <p>For getting result which has rating <strong>GreaterthanOREqual</strong> to 1.5, but some rows has <strong>rating:''</strong>
  So getting error- Failed to parse number '' in $convert with no onError value: Empty string<a href="https://i.stack.imgur.com/OTIQ7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/OTIQ7.png" alt="enter image description here" /></a></p>