Solved

unique random number generation

Posted on 2010-11-21
4
647 Views
Last Modified: 2012-05-10
I'm looking for a php script that generates unique random numbers may be up to 16 digits then insert them in a table.

0
Comment
Question by:a0k0a7
  • 2
4 Comments
 
LVL 1

Accepted Solution

by:
thalueng earned 250 total points
ID: 34185208
Not sure I fully understand your requirement. The following code generates a random number "$rand" and inserts it into table "rand_table" together with an "$id". If the $id already exists in the table, then the previous random number is replaced with the new one. This example works as is for Joomla 1.5, for any other context just replace the last 2 lines of code with your query function.

$rand = mt_rand();
$query =      'INSERT INTO rand_table (id, rand_field)'.
            ' VALUES ('.$id.','.$rand.
            ') ON DUPLICATE KEY UPDATE uid='.$uid.',last_rand='.$rand;
// the following 2 lines are Joomla specific
$this->_db->setQuery($query);
return $this->_db->query();
0
 
LVL 13

Assisted Solution

by:dsmile
dsmile earned 250 total points
ID: 34185234
Here's the script

1. a function to generate 16 digits number uniquely & randomly
2. sample code to insert / select from DB
<?php
/*
* create a random number uniquely base on input
*/
function createNumber($lastNumber) {
	$number = rand(0, 99999999) . rand(0, 99999999);
	while ($number == $lastNumber) {
		$number = rand(0, 99999999) . rand(0, 99999999);
	}

	return $number;
}

session_start();
if (!isset($_SESSION['number'])) {
	$_SESSION['number'] = 0;
}

$number = createNumber($_SESSION['number']);
$_SESSION['number'] = $number;

//init
$host = 'localhost'; $db_user = 'root'; $db_password = '';
$database = 'test';
$connect = mysql_connect ( $host, $db_user, $db_password );
mysql_select_db ( $database );

//insert new number
if ($number) {
	$result = mysql_query("INSERT INTO test_r (number) VALUES ('". $number ."')");
	if (!$result) {
	   echo 'Could not run query: ' . mysql_error();
	   exit;
	}
}

//list generated numbers
$result = mysql_query('SELECT number FROM test_r');
if (!$result) {
   echo 'Could not run query: ' . mysql_error();
   exit;
}

echo 'Generated Numbers: <br />';
while ($row = mysql_fetch_array($result)) {
   echo $row['number'] .'<br />';
}
?>

Open in new window

0
 
LVL 8

Author Comment

by:a0k0a7
ID: 34185568
Thanks a lot for the suggestion really help me figure out a couple things, what I would need to do if I want to check if my random number is in a specific table before making the insert.

If the random number is in the table then I would like to keep generating a random number until the number is not available in the table so i can do the insert.

@Dsmile, @thalueng I appreciate your help.

0
 
LVL 1

Expert Comment

by:thalueng
ID: 34186178
Make rand_field a primary key and change the query to $query = 'INSERT INTO rand_table (rand_field) VALUES ('.$rand.')';

If the value exists in the table, the query will abort with an error. Loop through several mt_rand() and queries until it returns without error.

BTW: use mt_rand(), not rand(), which is faster and better randomizer.
0

Featured Post

Free learning courses: Active Directory Deep Dive

Get a firm grasp on your IT environment when you learn Active Directory best practices with Veeam! Watch all, or choose any amount, of this three-part webinar series to improve your skills. From the basics to virtualization and backup, we got you covered.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Creating and Managing Databases with phpMyAdmin in cPanel.
Load balancing is the method of dividing the total amount of work performed by one computer between two or more computers. Its aim is to get more work done in the same amount of time, ensuring that all the users get served faster.
The viewer will learn how to count occurrences of each item in an array.
The viewer will learn how to look for a specific file type in a local or remote server directory using PHP.

685 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question