Thanks everyone. Makes sense. Now I got another issue. When I try to see if an error exists I get this: Warning: mysql_error(): supplied argument is not a valid MySQL-Link resource in /home/********/public_html/Store/test.php on line 14 Is there a setting somewhere that I need to set to make sure this is available? Thanks and sorry is these are dumb-ass questions :) Aaron > Yes I believe that is what Richard was saying about "Trap the INSERT > error", you should get an error back from the database about having a > problem with the insert instead of showing that error you will want to > add some logic that when that error occurs you simply generate another > number. > > On 10/11/05, aaronjw@xxxxxxxxxxxxx <aaronjw@xxxxxxxxxxxxx> wrote: >> Hi Richard, >> >> Ok... I do already have a Unique index on the column but this process is >> something that I cannot echo out the error code to the user. The code is >> generated on the fly when an order an is placed so you can see... I >> can't >> echo out the error to the customer. >> >> Can I do an if statement IF an error is returned to try generatre >> another >> randon code and keep going until one is available? I can do this all >> intenrally without the customer knowing/seeing anything? >> >> Hope I am making some sense. Not trying to confuse the issue. >> >> Thanks. Appreciate your thoughts. >> >> Aaron >> >> > On Mon, October 10, 2005 3:24 pm, Dan McCullough wrote: >> >> create a function to check if the rndnumber=couponcode row count = 0 >> >> if not then redo rndnumber if it does = 0 then insert rndnumber >> > >> > Noooooooooooooooooooooooooooo! >> > >> > You are creating a RACE CONDITION in which ONE user might generate a >> > 'valid' code, and ANOTHER user might generate a 'valid' code AT THE >> > SAME TIME, and then they BOTH get the same coupon code. >> > >> > The probability of this is very very very low, but still NOT zero. >> > >> > And it's the kind of thing that won't show up in testing, but sure as >> > God made little green apples, it WILL happen at the worst possible >> > time after you "go live" >> > >> > The database engine has a *TON* of code in it to avoid this kind of >> > Bad Thing happening. >> > >> > Use it. >> > >> > create a UNIQUE INDEX on the column that needs to be unique. >> > >> > Trap the INSERT error. >> > >> > -- >> > Like Music? >> > http://l-i-e.com/artists.htm >> > >> > -- >> > PHP General Mailing List (http://www.php.net/) >> > To unsubscribe, visit: http://www.php.net/unsub.php >> > >> > >> >> > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
