title: coalesce count equals 0 group by
body: <p>Good evening! How do I <code>COALESCE</code> a grouped by <code>COUNT(*)</code> query?</p>
  
  <pre><code>SELECT categories.name, COALESCE(COUNT(*), 0) as total FROM questions
    INNER JOIN categories
      ON questions.categoryid = categories.categoryid
  GROUP BY name
  ORDER BY total DESC;
  </code></pre>
  
  <p>I read the docs and this is the main solution to do it, but it is not returning the categories with <code>total = 0</code>.</p>
  
  <p>Kind regards</p>