title: How do I reset sequence numbers to become consecutive?
body: <p>I've got a mysql table where each row has its own sequence number in a "sequence" column. However, when a row gets deleted, it leaves a gap. So... </p>
  
  <pre><code>1
  2
  3
  4
  </code></pre>
  
  <p>...becomes... </p>
  
  <pre><code>1
  2
  4
  </code></pre>
  
  <p>Is there a neat way to "reset" the sequencing, so it becomes consecutive again in one SQL query?</p>
  
  <p>Incidentally, I'm sure there is a technical term for this process. Anyone?</p>
  
  <p>UPDATED: The "sequence" column is not a primary key.  It is only used for determining the order that records are displayed within the app.</p>