On October 16, 2009 12:29:42 pm Jerry Schwartz wrote: > >-----Original Message----- > >From: Ray [mailto:r...@stilltech.net] > >Sent: Friday, October 16, 2009 1:10 PM > >To: mysql@lists.mysql.com > >Subject: Re: insert random number into table > > > >On October 16, 2009 10:57:48 am Jerry Schwartz wrote: > >> There is a RAND function in MySQL, but if you need to guarantee that the > >> identifiers are unique you should consider using an auto-increment > >> field. > >> > >> If that isn't unique enough, you can use the UUID or UUID_SHORT > >> functions. Theoretically, those should return values that are unique > >> across the Internet (at least). > >> > >> Regards, > >> > >> Jerry Schwartz > >> The Infoshop by Global Information Incorporated > >> 195 Farmington Ave. > >> Farmington, CT 06032 > >> > >> 860.674.8796 / FAX: 860.674.8341 > >> > >> www.the-infoshop.com > >> > >> >-----Original Message----- > >> >From: Ray [mailto:r...@stilltech.net] > >> >Sent: Friday, October 16, 2009 11:43 AM > >> >To: mysql@lists.mysql.com > >> >Subject: insert random number into table > >> > > >> >Hello All, > >> >I am trying to insert a unique random number* with each row when > >> > inserting into a table. I can do it in the application layer (php) but > >> > just wondering if > >> >there is an easier way in the database layer. > >> >Thanks > >> >Ray > >> > > >> >* for example, when registering a person for a contest, I want to give > >> > them a unique, random identifier. > >> > > >> >-- > >> >MySQL General Mailing List > >> >For list archives: http://lists.mysql.com/mysql > >> >To unsubscribe: http://lists.mysql.com/mysql?unsub=jschwa...@the- > >> >infoshop.com > > > >Thanks for the replies. I think I'll use the php solution as it is the > > better match for what I am trying to do. I'l keep the UUID functions in > > mind for future use though. > >Ray > > [JS] Just remember that the pseudo-random numbers that come out of a > computer, regardless of where or how they are generated, are not guaranteed > to be unique. Although the odds of a collision are slim, my philosophy has > always been "if it's possible, it will happen - in the middle of your > vacation". > > If you want to generate UUIDs in PHP, take a look at > http://www.shapeshifter.se/2008/09/29/uuid-generator-for-php/ > > >-- > >MySQL General Mailing List > >For list archives: http://lists.mysql.com/mysql > >To unsubscribe: http://lists.mysql.com/mysql?unsub=jschwa...@the- > >infoshop.com
Thanks for all the suggestions and points. There are definitely some I will keep in mind for future projects. auto increment won't work because I don't want the number to be based on the order of assignment. I probably should have been more clear. What I am trying to do is randomly assign one of a fixed pool of numbers uniquely to each row. What I ended up doing is (in PHP): SELECT all used numbers and put them in an array. create an array of all allowed numbers. combine the two arrays such that all available numbers are left in a third array with index numbers from 1 counting up sequentially. I then randomly choose one of those numbers and write it to the table. Thanks again for all your suggestions. Ray -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
