From: Anthony Pace
Date: January 20 2011 6:32pm
Subject: best way to have a unique key
List-Archive: http://lists.mysql.com/mysql/224139
Message-Id: <4D387FB8.5010700@utoronto.ca>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Due to certain reasons, the company I am doing business with has decided 
that the primary key, for an orders table, be a unique key; however, I 
don't like the possibility of it conflicting if moved to another machine.

What are some pitfalls of using a unique key, that is generated by a 
server side script, rather than by mysql?
What are the best ways to do this?

Please keep in mind this variable will also be displayed on the 
customer's Receipt, but again, since it's random, it doesn't have to 
mean anything.