Edit length of increment_id in sales_order table on Magento 2 - magento2

Question

I want to decrease length of order increment #00000000001 to #00001.
I found some tutorials for magento 1 but not for Magento 2.
Please help if someone is aware how to perform this task.
Thanks

Answer 1

In the etc directory of your module, add a di.xml file with this content:
<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
<type name="Magento\SalesSequence\Model\Sequence">
<arguments>
<argument name="pattern" xsi:type="string"><![CDATA[%s%'.05d%s]]></argument>
</arguments>
</type>
</config>
This way Magento will pass a 5 digit pattern instead of its default pattern made by 9 digits.
This is because the first and the last %s symbol are replaced respectively with the prefix and the suffix values stored in the sales_sequence_profile table. The matching is done with the meta_id of your store (you can check yours by reading from the sales_sequence_meta table). The %'.05d pattern means that you want an integer with 5 padding digits on its left which is replaced with the next order number calculated by Magento.
For example, assuming that you have:
Prefix: PX
Suffix: SX
with the above pattern, the first order number will be PX00001SX

Answer 2

you can decrease length of order increment #00000000001 to #00001.
Try this: https://store.emizentech.com/magento2/custom-order-and-invoice-number-magento-2-0.html

Answer 3

Solved with a custom developed plugin:
I already had an observer to save the customer as new customer automatically after placing an order and before rendering the success page:
On the events.xml (already existing observer i've previously made)
<event name="sales_order_place_after">
<observer name="customcheckout_customer" instance="Dufry\CustomCheckout\Model\Observer\SaveCustomer"/>
</event>
On the observer SaveCustomer.php (already existing observer i've previously made):
$order = $observer->getOrder();
$increment = $order->getIncrementId();
if(strlen($increment) > 9){
$newIncrement = substr($increment, -8);
$newIncrement = substr($increment,0,1).$newIncrement;
$order->setIncrementId($newIncrement);
}
...
$order->save()
And worked like a charm.
I did the second "substr" part to keep the prefix the was previously configured.