Re: generating unique id's
| From: | Edward Wong | Date: | Wed, 30 Jun 1999 02:14:09 +0000 |
| Subject: | Re: generating unique id's | ||
| References: | 1 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-769@lists.php.net to get a copy of this message | ||
Hi:
I use the following code:
<?
for ($i = 0; $i < 5; $i++) {
mt_srand((double)microtime()*1000000);
$randval[$i] = mt_rand();
}
for ($i = 0; $i < 5; $i++) {
echo $randval[$i],"<BR>";
}
?>
or
<?
// Method 2
mt_srand((double)microtime()*1000000);
ECHO "<FONT COLOR=RED>";
for ($i = 0; $i < 5; $i++) {
$randval[$i] = mt_rand();
}
for ($i = 0; $i < 5; $i++) {
echo $randval[$i],"<BR>";
}
ECHO "</FONT>";
?>
and the result is:
122653537
849966493
749620674
706811529
86123690
2074739843
1867927643
1706046782
1795463355
1221802180
Any one can meet your needs, you see.
If you can't, maybe your computer is too good. :-)
-------------------------------------
# Edward Wong #
# #
# E-Mail:wyuanzheng@21cn.com #
# Phone: 86-21-63615261 * 207 #
# #
# iSpaceBank Group, Shanghai, China #
# #
-------------------------------------
----- Original Message -----
From: "Cody Caughlan" <codyc@cisco.com>
To: <php-db@lists.php.net>
Sent: Thursday, June 29, 2000 6:10 AM
Subject: [PHP-DB] generating unique id's
> Hello,
>
> I need to generate a unique id. The problem I am running into is this:
> I have a for loop that generates a bunch of id's using the time()
> function, the problem is that since the for loop only takes less than a
> microsecond, and the precision of the time() function is a microsecond,
> all the id's are the same. I looked into using uniqid(), which according
> to the PHP manual generates an INT. However, I tested it out, and in a
> microsecond it DOES generate a series of different, random STRINGS, mix of
> ints and characters, NOT an INT, which like I said is what the PHP manual
> uses. MySQL requires that the primary key be an INT, so I can use uniqid()
> function to generate this id, because its a string.
>
> What can I do?
>
> In summary, generate a whole list of unique INTEGER id's in under a
> microsecond...
>
> Thanks
> /Cody Caughlan
>
>
> --
> PHP Database Mailing List (http://www.php.net/)
> To unsubscribe, e-mail: php-db-unsubscribe@lists.php.net
> For additional commands, e-mail: php-db-help@lists.php.net
> To contact the list administrators, e-mail: php-list-admin@lists.php.net