Custom Sequence Number Generation for Order

@mstnorris This is a 6 year old answer, but for others that wonder the same thing and finds this thread via google, in some countries (Ex: Most of Scandinavia), orders and invoices by law have to have sequential numbers (within the company).

@bobbybouwmann Even if this post is 7 Years old, this snippet is very usefull. In order to add a prefix - e.g. the current year - and to reset incrementation on year-change here is a update for that snippet:

public function getNextOrderNumber()
{
  // Get the last created order
  $lastOrder = Order::orderBy('created_at', 'desc')->first();

  // Set Prefix
  $prefix = date('Y');

  // Set db-field
  $field = 'order_id';

  // Set length of incrementing number
  $length = 6;

  if (!$lastOrder) {
    // We get here if there is no order at all
    // If there is no number set it to 0, which will be 1 at the end.

    $number = 0;
  } else {
    // If we have ORD2023000001 in the database then we only want the number
    // So the substr returns this 000001
    $number = substr($lastOrder->{$field}, strlen($prefix));
  }

  // Reset incrementing no if prefix has changed (e.g. in new year)
  if (substr($lastOrder->order_no, 0, strlen($prefix)) !== $prefix) {
    $number = 0;
  }

  // Add the string in front and higher up the number.
  // the %05d part makes sure that there are always 6 numbers in the string.
  // so it adds the missing zero's when needed.

  return sprintf('%s%0' . $length . 'd', $prefix, intval($number) + 1);
}

@vanderb by the time you have got half way through your function, some other thread is running and preparing the same number and prefix - ie, your code is not atomic and therefore NOT recommended.

@Snapey Thanks for response. You're totally right and could end in bad conflicts on bigger projects.

This is only an updated version of the code by @bobbybouwmann that helped me out in smaller projects, without high traffic or multiple threads at same time. For bigger projects with high traffic/expected multiple threads I am using complete shopping solutions like aimeos etc.

@vanderb I tackled this problem before and wrote it up on my site at https://talltips.novate.co.uk/laravel/create-guaranteed-unique-invoice-number-in-laravel

@Snapey Great, thank you for sharing your experience!