Re: Re: Create unique non-autoincrement key for700,000records?

On Tue, 2008-12-16 at 09:56 +0100, Ondrej Kulaty wrote: > Sorry you are right. He said he wants each row to have an unique ID so > AutoIncId+timestamp will satisfy it, But still i think that adding > microseconds timestamp is better because it will be harder for potential > hacker to guess. > -- > > > S pozdravem > Ondej Kulat > --------------------- > Winternet s.r.o. > odd. vvoje aplikac > tel. 585 209 132 > www.winternet.cz > > "Robert Cummings" <robert@interjinn.com> pe v diskusnm pspvku > news:1229416450.9173.46.camel@localhost... > > On Tue, 2008-12-16 at 09:21 +0100, Ondrej Kulaty wrote: > >> I think he knows how to use it, he didn't show us a certain example where > >> and how he wants to use it, i just posted the way how i do generate an > >> unique identifier, if he use the first mentioned way - > >> AutoIncID+unix_timestamp - there can be a collision, when two users will > >> attempt to perform this task on the same id at the same time. yes, it's > >> not > >> very probable but if you have system with many users it can happen > > > > No it's impossible. Auto increment guarantees a unique auto incremented > > ID. Adding the value returned by unix_timestamp() to this unique ID can > > only create unique sums since both the auto increment ID and the time > > are increasing. There cannot be a collision. > > > > Cheers, > > Rob. > > -- > > http://www.interjinn.com > > Application and Templating Framework for PHP > > > > > Surely better than creating some complex method by which to reference the row, is to use methods of sanitising input that would prevent a hacker from manipulating your queries? Ash www.ashleysheridan.co.uk