Question

        $q = "SELECT user_id FROM users WHERE partner='$qpartner' AND group_id='$gi' AND status='1'";
        $r = mysqli_query ($dbc, $q) or trigger_error("Query: $q\n<br />MySQL Error: " . mysqli_error($dbc));
            while ($row = mysqli_fetch_array($r)) {
                $usinneed[] = $row[0];
            }
        $affected = mysqli_affected_rows($dbc);
        $q2 = "SELECT user_id FROM users WHERE partner<>'$qpartner' AND group_id='$gi' AND status='1' ORDER BY RAND() LIMIT $affected";
        $r2 = mysqli_query ($dbc, $q2) or trigger_error("Query: $q\n<br />MySQL Error: " . mysqli_error($dbc));
            while ($row = mysqli_fetch_array($r2)) {
                $potent_partners[] = $row[0];
            }

            $current = end($usinneed);
            $partners = array();
            foreach ($usinneed as $user)
            {
                $partners[$user] = $current;
                $current = $user;
                $q = "UPDATE users SET partner = '{$partners[$user]}' WHERE user_id = '{$user}'";
                mysqli_query ($dbc, $q) or trigger_error("Query: $q\n<br />MySQL Error: " . mysqli_error($dbc));
            }

        print_r($partners);

I’m lost as soon as I come to the $current; that’s where the changes are needed and I need help.
$usinneed is an array of all of the users who need a partner, and $potent_partners is an array of potential partners to pair with the Users In Need ($usinneed).
The arrays have an equal number of rows. How do I update the users table so that each $usinneed has their partner field set to one of the $potent_partners?

Answer 1

Would array_combine be of any help perhaps?

EDIT

Given the comments below, here’s the new details (formatted correctly):

We start with the queries that populate two arrays: $usersInNeed (an array of those without partners) and $newPartners (an array of people that need to be paired up with $usersInNeed)

We pair them up in PHP using array_combine. So

$usersInNeed = Array(2,4); // Keys
$newPartners = Array(8,5); // values
$combined = array_combine($usersInNeed,$newPartners); // result: Array(2 => 8, 4 => 5);

Now, we go back through the database and update those users with their partner. You can do this a bunch of ways, but a foreach seems simplest:

// take each entry in $combined and break it out so the key is "$userInNeed" and the
// value is "$newPartner" (illustrate what array_combine did)
foreach ($combined as $userInNeed => $newPartner) 
{
  $sql = "UPDATE users SET partner='{$newPartner}' WHERE user_id='{$userInNeed}';";
  // execute the statement
}