I think having a table for each site would be sufficent -----Original Message----- From: Ethan Rosenberg [mailto:ethros@xxxxxxxxxxxxx] Sent: Wednesday, October 27, 2010 9:11 AM To: php-db-lists.php.net Subject: Incrementing Primary Key Dear List - Thanks for all your excellent help. I am setting up a database for medical research, which will be conducted at various sites. The sites will be identified by a letter {A,B,C ....}. The medical record number [primary key] will start at 1001 and increment by one(1) for each patient at each site; ie, A 1001, A1002, B1001, B1002 ...... How do I do this? Do I need a separate database for each site? Ethan -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php