generate pin numbers for patients

[pradeepjain]

i am creating a a form where in patients are registered and given a unique ID number(serial numbers) . and i need generate a pin number along with this id for him . which is the best way to generate a pin numbers for users (like that of credit cards). so that its unique for each patients.

[Dormilich]

due to not knowing about the constraints of the PIN, I can only tell that you need a random number generator, by which you can fetch a character out of the set of valid characters. then you have to save all PINs, so that you don’t hand out a PIN twice (improbable, but not impossible).

[pradeepjain]

yeah that was ma problem i have !! random number generator should not give same number twice, which is most probable of happening.

[Dormilich]

I happily use a database for storing my PINs. (OK, it’s an email unsubscribing system…)

[pradeepjain]

i know random number generator is gud method for uniqueness but wht if 2 users get the same number ! its not accepted na!!

[Dormilich]

I already told you, that you have to check your newly created PIN against all previously generated PINs…

[pradeepjain]

okie!! sorry i did not make out from the last reply !!

[artov]

You might like to check uniqid() function; it claims to generate unique strings. If you need to put the patients to some categories, the first argument might come in handy (it is a string that is attached to start of the id).

[Dormilich]

it claims to generate unique strings.

at least if the final PIN string is not too short. however, it makes duplicate values only much less probable (although that is tending towards zero).