Re: Re: Unique Object Instance ID..?

On Sun, 2009-01-11 at 00:07 +0000, Nathan Rixham wrote: > Colin Guthrie wrote: > > 'Twas brillig, and Nathan Rixham at 10/01/09 23:31 did gyre and gimble: > >> all I need is a completely unique id for each object instance that can > >> never be repeated at any time, even in a multiserver environment (and > >> without using any kind of incremented value from a db table or third > >> party app) > >> > >> thoughts, ideas, recommendations? > > > > While it's not guaranteed to be unique the general technique used in > > these situations is to use a UUID. The chances of a clash are slim > > (2x10^38 ish combinations). > > > > You can generate a uuid via mysql "SELECT UUID()" or via the PHP Pecl > > extension php-uuid. > > > > The other way of doing it would be to insert a row into a database row > > with an auto-increment field and use the value of that auto-incrment > > field as your identifier (SELECT LAST_INSERT_ID() in mysql or via the db > > layers API). > > > > HTHs > > > > Col > > > > > > cheers for the input; uuid it has to be I guess; don't want it reliant > on any third party software or db so pecl is out, as is mysql - looks > like I'm going to have to (and probably enjoy) making a uuid function to > generate type 4 random uuids. > > only other thought is to combine all the instance variables, hash the > combination of them and save that together with a timestamp.. Use microtime for your timestamp... much less likely to have a collision than using seconds. Cheers, Rob. -- http://www.interjinn.com Application and Templating Framework for PHP