title: Can you query MongoDB for any properties with a given value?
body: <p>I'm beginning to play around with MongoDB and I'm wondering if it's possible to query the datastore for any property with a particular value.</p>
  
  <p>So instead of:</p>
  
  <pre><code>db.foo.find({'color':'red'})
  </code></pre>
  
  <p>I'm looking to see if you can do something like:</p>
  
  <pre><code>db.foo.find({'%':'red'})
  </code></pre>
  
  <p>Is that possible? Is there a syntax for wildcarding the property slot? I tried using a regular expression but that gave me an error.</p>