title: Model has a field which is an array of strings, how can I find all records that contain a certain string in the array?
body: <p>My model has a field called <code>user_ids</code>, which is an array of strings. How can I find all of the records which include a certain string, <code>string_1</code>, in <code>user_ids</code>?</p>
  
  <p>I'm using Rails 3.0.1 &amp; Ruby 1.9.2p0.</p>