title: group by all enum values without specifying enum values
body: <p>Given an <code>ENUM</code> column with some values like <code>a, b, c</code>, I wish to query the table, <code>GROUP BY</code> the column such that a default number (0) is returned even if no rows are found.</p>
  
  <p>I've seen answers that use <code>CASE column WHEN 'a' THEN count = 0</code> (<a href="https://stackoverflow.com/a/12348380/1097483">https://stackoverflow.com/a/12348380/1097483</a>), but that requires me to specify all the ENUM values.</p>
  
  <p>Is it possible to do so without specifying the column's ENUM values?</p>
  
  <p>For example with the following data:</p>
  
  <p>3 rows with 'a', 2 rows with 'b', 0 rows in 'c',</p>
  
  <pre><code>SELECT COUNT(*), enum FROM
  `table`
  GROUP BY enum
  </code></pre>
  
  <p>Will return results for 'a' and 'b', but not 'c'. How do I get it for all possible ENUM values?</p>