title: MongoDB Query : Find where key's value from list of values
body: <p>This may be really basic but I can't figure out how to do it.</p>
  
  <p>I would like to query if key == value1 'OR' key == value2 in the collection.</p>
  
  <p>Now, the list of values is long. So although</p>
  
  <pre><code>db.collection.find({
    "$or": [{
      "key": "value1"
    }, {
      "key": "value2"
    }]
  });
  </code></pre>
  
  <p>will work but I would like to pass a list of values rather.</p>
  
  <p>Is there any syntax in MongoDB that allows me to do so? I would be using Mongoid so if such a thing exists in Mongoid, that would be great.</p>