Question

I’m allowing users to register on my site for a ‘game’; as is normal, they all receive unique IDs. At a given point in time, registration will cease. At that time, I would like to run code to assign partners, but not pairs.

So, if I had the following:

+——–+——-+
| user_id | partner |
+——–+——-+
| 1 | |
| 3 | |
| 7 | |
| 11 | |
| 12 | |
| 18 | |
+——–+——-+

what would I do to end up with something like this:

+——–+——–+
| user_id | partnr |
+——–+——–+
| 1 | 7 |
| 3 | 12 |
| 7 | 18 |
| 11 | 1 |
| 12 | 11 |
| 18 | 3 |
+——–+——–+

1,7,18,3,12,11;1,7,18,3,12,11

$query = "SELECT users FROM tabl";
$result = mysql_query ($query)
    or die ("Query '$query' failed with error message: \"" . mysql_error () . '"');

while ($row = mysql_fetch_array($result)) {
    $users[] = $row[0];
}

$current = end($users);
$partners = array();
foreach ($users as $user)
{
        $partners[$user] = $current;
        $current = $user;
}
print_r($partners);

This seems to work, thanks to Sjoerd, but I need to write it back to the partner column.

Answer 1

• Retrieve the list of users.
• Shuffle this list (optional).
• Assign each user the next one in the list as partner, where the last user gets the first user as partner.

Code to loop through the array and assign partners:

$users = array('john', 'jack', 'jones', 'joelle', 'jesica');

$current = end($users);
$partners = array();
foreach ($users as $user)
{
        $partners[$user] = $current;
        $current = $user;
}
print_r($partners);