title: Mysql use parsed column from SELECT in WHERE condition
body: <p>How can I do something like this:</p>
  
  <pre><code>SELECT DID, DNumbers, CONCAT(SUBSTRING_INDEX(DNumbers, " - ", 1), ", ") AS DNumbers_Parsed
  FROM Test
  WHERE DNumbers_Parsed LIKE '%, 1,%' AND DNumbers_Parsed LIKE '%, 5,%'
  </code></pre>
  
  <p>This gives an error saying column <code>DNumbers_Parsed</code> not found. I know I can just use the same parsing thing for each condition but is it possible to only do it once and then use it in conditions?</p>