CODEWITHSUNDEEP
phplaravelrandomhash
Udders
Udders

Reputation: 6986

create unique 8 digit number

I am creating an application at the moment that needs to give the user a unique 8 digit code (numbers only) that they can enter to access restricted parts of my website, think of it as a rudimentary auth, i.e enter the passcode, the passcode matches a user, the user is returned. What I am having trouble with is creating a unique 8 digit code. I know PHP has uniqid() but that returns a string that is too long.

I have thought about creating a hash of time() and the users IP address, but laravel's Hash::create returns integers and chars.

Can anyone point in the direction of creating a random 8 digit code? I have also tried mt_rand but obvioulsy there is the chance that this could create matching digits, unless of course I check the database for the code before saving and re-generate if it exists?

Upvotes: 1

Views: 5127

Answers (5)

Vaibhavi S.
Vaibhavi S.

Reputation: 1093

Try this function For Laravel it will return 8 digit number with check unique in db also.

In Controller Function

$expense_id = Expense::get_random_string();

Modal

public static function get_random_string()
{
    if (function_exists('com_create_guid') === true)
    {
        return trim(com_create_guid(), '{}');
    }
    $random_unique  =  sprintf('%04X%04X', mt_rand(0, 65535), mt_rand(0, 65535), mt_rand(0, 65535), mt_rand(16384, 20479), mt_rand(32768, 49151), mt_rand(0, 65535), mt_rand(0, 65535), mt_rand(0, 65535));

    $expense = Expense::where('expense_id', '=', $random_unique)->first();
    if ($expense != null) {
        $random_unique = $this->get_random_string();
    }
    return $random_unique;
}

Upvotes: 0

digitalway
digitalway

Reputation: 71

rand(10000000, 99999999);

You have 1/89999999 chance to fall on the same number, so you can check if it has already been used or not ;)

Upvotes: 0

Rishi1000
Rishi1000

Reputation: 344

You need to check-in DB if the number exists or not

$randnum = rand(11111111,99999999);

This will generate a random 8 digit number

Upvotes: 0

Chris Kelker
Chris Kelker

Reputation: 571

My suggestion is a do-while loop, this case if the random string already exists it would generate a new one. Generate the code however you want but Laravel actually has a helper (str_random()) to handle this if you wanted.

/**
* Create a unique code
*
* @return string;
*/
if ( ! function_exists('generateUniqueCode')) {
    function generateUniqueCode()
    {
        do {
            $unique_code = str_random(12);
        } while (\App\User::where('code', $unique_code)->count() > 0);


        return $unique_code;
    }
}

Upvotes: 1

Yasin Patel
Yasin Patel

Reputation: 5731

This is my code to generate random number : 

public function generateRandomNumber($length = 8)
{
  $random = "";
  srand((double) microtime() * 1000000);

  $data = "123456123456789071234567890890";
  // $data .= "aBCdefghijklmn123opq45rs67tuv89wxyz"; // if you need alphabatic also

  for ($i = 0; $i < $length; $i++) {
          $random .= substr($data, (rand() % (strlen($data))), 1);
  }

  return $random;

}

Upvotes: 1

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