Is the most important thing to be random or to be unique? If you need unique, you can use a timestamp including microseconds. Maybe using something like microtime(): http://us.php.net/manual/en/function.microtime.php The only other way you're probably going to guarentee that you don't repeat numbers is to keep a list of what's been used and compare against it. Otherwise, there's always going to be a slim chance you'll repeat a number. What do you plan on using it for? Maybe someone can give a better recommendation for what you need. And will this number be generated by PHP or the database? Or can it be either? -TG ----- Original Message ----- From: "A. Joseph" <joefazee@xxxxxxxxx> To: "Evert Lammerts" <evert.lammerts@xxxxxxxxx> Cc: "php-db@xxxxxxxxxxxxx" <php-db@xxxxxxxxxxxxx> Date: Thu, 17 Apr 2008 00:00:21 +0100 Subject: Generating random numbers > What is the best way to generating random numbers and you are sure that the > script will never generate the generated ones? > > I`m using mysql database, but this out of SQL AUTO_INCREMENT stuff, I need a > real random generator that will never generate what has been generated. -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php