title: Delete document from mongoDB
body: <p>This might be a really stupid question, but I'm new to MongoDB, so bear with me. I've created a stand alone ruby class:</p>
  
  <pre><code>require 'rubygems'
  require 'mongo'
  
  require 'bson'
  require 'mongo_mapper'
  
  MongoMapper.database = "testing"
  
  class Twit
    include MongoMapper::Document
  
    key :id,          Integer, :unique =&gt; true
    key :screen_name, String,  :unique =&gt; true
  
  ...
  </code></pre>
  
  <p>Then I do the following with irb</p>
  
  <pre><code>&gt;&gt; twit = Twit.all.first
   =&gt; #&lt;Twit _id: BSON::ObjectId('4df2d4a0c251b2754c000001'), id: 21070755, screen_name: "bguestSB"&gt; 
  &gt;&gt; twit.destroy
   =&gt; true 
  &gt;&gt; Twit.all
   =&gt; [#&lt;Twit _id: BSON::ObjectId('4df2d4a0c251b2754c000001'), id: 21070755, screen_name: "bguestSB"&gt;] 
  </code></pre>
  
  <p>So how do I destroy documents in MongoDB? What am I doing wrong?</p>