title: Ruby on Rails find_by case insensitive
body: <p>I need to find a record from 2 parameters but I need one of them to be case insensitive. The current case sensitive line is</p>
  
  <pre><code>  c = Course.find_by(subject_area: area, cat_number: cat)
  </code></pre>
  
  <p>But I need subject_area to be case insensitive. How would I achieve that?</p>