title: rails store array in to database field
body: <p>I want to store an array into a database field.
  I tried the following method:</p>
  
  <pre><code>class MyStuff &lt; ActiveRecord::Base  
    serialize :things
  end
  
  stuff = MyStuff.new 
  stuff.things &lt;&lt; "pen" 
  stuff.things &lt;&lt; "paper"
  stuff.save
  </code></pre>
  
  <p>I get an error: "The error occurred while evaluating nil.&lt;&lt;"</p>
  
  <p>Is there any other approach?</p>