On 3/3/06, Murray @ PlanetThoughtful <lists@xxxxxxxxxx> wrote: > > > > >> I have to agree with Anthony - why are you using row order to determine > >> something relating to users? I couldn't follow your brief explanation > >> above, and the fact that you're doing it sets off some soft alarm bells > >> about the design of your application. Why is it important that there > >> shouldn't be any 'gaps' between users? Because you want to know how > many > >> users there are? If so, simply do a SELECT COUNT(*) on the table > >> whenever / wherever you need to know. > >> > >> If you're using it for IDs for the users, it's generally a bad idea to > >> reuse this type of information. If you have some other purpose, I'm > >> extremely curious about what it might be. > >> > > > > > > What I was getting at is you get the unique id for the username (if > > you allow username changes, then you want a unique key to do your > > joins on from other tables). > > > > > > Yep, that's one good reason among many for using unique ids. Thinking a > little about the OP's question, I could understand row order being > relevant in certain situations where you wanted to display something > like, "You were the 432nd person to register at our site!", etc. I'd do this with a timestamp, and then sorting by date and doing a count() on the results. But then again that's just me. I remember the days where i'd clear a database after testing to keep the auto_increment inline, but eventually, you will get out of sync on that, so it's not a reliable way of keeping a numerical sequence. But, too often I've seen people new to database design not liking 'gaps' > because 'user1' will have a unique id of '1', while 'user2' will have a > unique id of '6' because the records associated with unique ids '2' > through '5' were deleted during testing, and so on. So, they feel that > 'user2' should have a unique id of '2', ignoring the fact that that's > not a unique id at all, if you had id '2' associated with another record > at some point. > > I'm not suggesting this is what the OP is doing, just that that's why I > was curious about the purpose. > > Much warmth, > > planetthoughtful > --- > "Lost in thought" > http://www.planetthoughtful.org > > -- Anthony Ettinger Signature: http://chovy.dyndns.org/hcard.html
