title: How to safely modify in memory mongoid model?
body: <p>I'm using mongoid gem on rail project and I'm quite puzzled by trying to modify the model in memory but never saving it so I do not modify the db. I'm trying to modify an attribute from a model loaded in memory but it does not work as shown bellow:</p>
  
  <pre><code>mymodel = MyModel.where('some criteria')
  mymodel.first.some_attribute = 0
  mymodel.first.some_attribute == 0 -&gt; is false
  </code></pre>
  
  <p>So I guess mongo reloads from the db each time we do first or even looping on each entry and setting some attribute has no effect, if I loop again all attributes I set are still set to the original value. Is there a way to commit the transaction and force mymodel to stay loaded in memory? It's hard for me to use proper terminology so I hope you get what I'm saying.</p>