title: Generate unique code from primary key
body: <p>I have a table of orders and I want to give users a unique code for an order whilst hiding the incrementing identity integer primary key because I don't want to give away how many orders have been made.</p>
  
  <p>One easy way of making sure the codes are unique is to use the primary key to determine the code.</p>
  
  <p>So how can I transform an integer into a friendly, say, eight alpha numeric code such that every code is unique?</p>