title: How to create a ticket reference number in PHP and mySQL
body: <p>I'm working on a ticketing system in PHP and mySQL.
  I have a table <code>support</code> with <code>id</code> as my primary key and AI.</p>
  
  <p>I want to add <code>ticket_number</code>, so that when a ticket is submitted each ticket is assigned a unique number. I can't use mySQL to AI a second field, right? </p>
  
  <p>If I give the first ticket a number, then write a query to lookup the last <code>ticket_number</code> in the DB, then I was thinking of doing something like:</p>
  
  <pre><code>$ticket = 1;
  $next = $ticket+1;
  echo "ticket number: #".$next;
  </code></pre>
  
  <p>would this work or is there a better way?</p>