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@NogDogJun 21.2005 — #I'm not crazy about having to query the database on every loop iteration - that'll definitely slow you down. I think you'd be better off querying once before the loop for a list of all PLrn and save them to an array, then just check to see if your random number is in that array.
If your only concern is to assign a unique number (i.e., you're not trying to set a random order of users), you might want to consider using uniqid() instead and save yourself a lot of trouble. @NogDogJun 21.2005 — #I believe what uniqid() does with no arguments is return what is essentially a hexidecimal number based on the current system time in microseconds, so it's going to be unique as long as you don't call it twice within the same millionth of a second. However, you can use the optional args to make it even more unique (and longer, of course), something like:
Infinite Loop
I seem to be sending a do statement into an infinite loop, and I’m not quite sure why.
Here’s the loop…
do{//create a random number
$rnd = mt_rand();
//check it against existing numbers
$qrr = “SELECT PLrn FROM people WHERE PLrand = ‘$rnd'”;
$rsr = mysql_query($qrr, $link);
$nr = mysql_num_rows($rsr);
if($nr==0)
{
$rchk == “Y”;
}
}while($rchk != “Y”);
The idea is that we create a random number which is assigned to a user when he/she logs on. That random number rotates every 24 hours, but it must be unique.
The do statement is supposed to allocate a random number, and then check it against already stored random numbers to make sure it is unique. If it is, the loop changes the value of $rchk to “Y” and ends the loop. If not, it repeats the loop, generating and checking the random number until it finds one that is unique.
It doesn’t work, and times out after 30 seconds.
Any suggestions?
CTB
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@NogDogJun 21.2005 — #If your only concern is to assign a unique number (i.e., you're not trying to set a random order of users), you might want to consider using uniqid() instead and save yourself a lot of trouble.
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@NogDogJun 21.2005 — #I believe what uniqid() does with no arguments is return what is essentially a hexidecimal number based on the current system time in microseconds, so it's going to be unique as long as you don't call it twice within the same millionth of a second. However, you can use the optional args to make it even more unique (and longer, of course), something like:[code=php]
$id = uniqid(rand(100,999), TRUE);
[/code]