title: Ruby, pluck on hashes
body: <p>s is hashes of array</p>
  
  <pre><code>relativebase = s.pluck(:base_point).inject(:+) + s.pluck(:distance_point).inject(:+) + s.pluck(:speed_point).inject(:+) + s.pluck(:frequency_point).inject(:+) + s.pluck(:quality_point).inject(:+)
  </code></pre>
  
  <p>This is calling the database four times which I want to do in one single query. How can i get this.</p>