title: How to use MongoDB find without a hexadecimal _id
body: <p>I am having a lot of trouble finding a record in my database with the <code>_id: "AAE45/0RQfm/VUrywfb1Gw=="</code> 
  (eg. <code>db.collection.find( {_id: new BinData(3, "AAE45/0RQfm/VUrywfb1Gw==") })</code> ).</p>
  
  <p>It works fine using a <code>BinData</code> converter in the mongo console, but refuses to work from inside a javascript file (I am using node.js) even though I have installed the BinData npm and "required" it.</p>
  
  <p>I have also tried the <code>Binary()</code> function, but it keeps telling me it needs to be hexadecimal or 12-byte binary or something. <code>.hex, .str</code> and <code>.toString()</code> don't work either. 
  I found this somewhere:</p>
  
  <pre><code>{"$binary": "AAE45/0RQfm/VUrywfb1Gw==", "$type": "03"}
  </code></pre>
  
  <p>which looks promising, but I have no idea how to implement it.</p>
  
  <p>I hope this makes sense. Any suggestions would be very much appreciated, if anyone has any insight on what process I should follow (eg: convert to binary, then hex, then use ...) that would be fantastic.</p>