CODEWITHSUNDEEP
phploopsforeach
Clifford Yeti Mapp
Clifford Yeti Mapp

Reputation: 189

Giving a 4 Digit Random Code to all users within Database

I would like to update my users database with a 4 digit random number.

I seem to have got stuck, on the bit for the loop, so that it will give a different random number to each user in the database. So far i have this.

$newpincode = array(sprintf("%04d",mt_rand(0,9999)));

$users_sql = "SELECT * FROM wifi_users";
$result_users = mysql_query($users_sql) or die(mysql_error());
while($row = mysql_fetch_array($result_users)){

foreach ($newpincode as $pin) {

    $sql = "UPDATE wifi_users SET `pincode` = '" . $pin . "' WHERE id = '" . $row['id'] . "'";
    $resultCount = mysql_query($sql) or die(mysql_error());
    $count = mysql_fetch_assoc($resultCount);
    }
}

Upvotes: 0

Views: 876

Answers (4)

Mike Brant
Mike Brant

Reputation: 71384

Why not just run a single query:

UPDATE wifi_users SET `pincode` = LPAD(FLOOR(RAND() * 10000), 4, '0')

Note this doesn't guarantee uniqueness, but then again neither does your current code. 4 digits doesn't give you enough values to provide uniqueness anyways if you plan on having more than 10000 users.

Upvotes: 3

Ja͢ck
Ja͢ck

Reputation: 173572

The problem is that the same pin code is given to all users.

Also, your inner loop would theoretically update the same record multiple times, although in this case that only happens once per record.

To issue a new pin code for each record, you have to move the pin code generation inside the outer loop and remove the inner loop.

As an aside, consider using PDO and prepared statements.

Upvotes: 0

lostphilosopher
lostphilosopher

Reputation: 4511

If you're looking for a unique random number for each user check this out: How to Generate Random number without repeat in database using PHP?

Upvotes: 1

Stefan Dunn
Stefan Dunn

Reputation: 5513

$newpincode = rand(0, 9).rand(0, 9).rand(0, 9).rand(0, 9);

Upvotes: 0

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