title: Postgres hstore, how to query for arrays containing values?
body: <p>[All codes here are samples] I have the Book model with the info field as hstore.</p>
  
  <pre><code>class Book &lt; ActiveRecord::Base
    serialize :info, ActiveRecord::Coders::NestedHstore
  end
  </code></pre>
  
  <p>and the info field is filled like this:</p>
  
  <pre><code>info: {"tags" =&gt; ["tag one", "tag two"]}
  </code></pre>
  
  <p>I need a query that I can find the books that contains the tag "tag one". How can I accomplish this? </p>