What about two tables, one would have this: carID carCompany carPayload etc... the second this: position carID This table would be static and if a car was not present in certain conditions they would contain (-1) for the carID. Then finding an empty slot to place an incoming car should be doable (stepping through to find (-1), and when a car is removed from a slot, then you could update the list, just dump out the 'current' order into an array, and then you would be able to sort, order, etc... Hope this makes sense. -Brad > Heh. Sounds like a programming class homework project. > I would say through the clever use of where clauses's, like: > > UPDATE position SET posistion = (position-1) WHERE position > > $idremoved; > > Would work, assuming $idremoved containted the position of the car > removed. > > On Mon, 2003-03-03 at 10:59, Rankin, Randy wrote: > > Hello All, > > This may be a bit off topic. If so, my apololgies. > > A client of mine, a rail car storage company, has asked that I > create a > PHP/MySQL application in which they will maintain and track rail > cars. I am > having a bit of trouble however working through one of thier > requirements. > They need to know in what position the rail car is on each track. > For > example, they might have a track called X which will hold 30 rail > cars. They > would enter the car information for 30 cars and associate each of > them with > track X. If one of the car owners decides to move car 3 out of > storage, then > the remaining 29 cars must be re-numbered ( ie; car 1 and 2 would > remain and > car 4-30 would become car 3-29 ). In the same manner, I need to be > able to > add a car to the track once an empty slot is available. For example, > If the > new car goes at the front of the track then it would become car 1 > and the > remaining cars, originally numbered 1-29 would become 2-30. > > I hope I explained thourougly. Any suggestions would be appreciated. > > Randy > > -- > Adam Voigt (adam@cryptocomm.com) > The Cryptocomm Group > My GPG Key: http://64.238.252.49:8080/adam_at_cryptocomm.asc > -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
