title: SQL delete records in order
body: <p>Given the table structure:</p>
  
  <pre><code>Comment
  -------------
  ID (PK)
  ParentCommentID (FK)
  </code></pre>
  
  <p>I want to run <code>DELETE FROM Comments</code> to remove all records.</p>
  
  <p>However, the relationship with the parent comment record creates a FK conflict if the parent comment is deleted before the child comments.</p>
  
  <p>To solve this, deleting in reverse ID order would work.  How do I delete all records in a table in reverse ID order?</p>