Sorry to dig up an old message, but I don't understand your statement in the case of
"Invoice number reset frequency = Every year".
My problem is that I have set
Invoice Number format = F-{date format="y"}{id size="5"}
Invoice number reset frequency = Every year
and, having orders since 2014, want to apply this only for 2016 orders.
What I did is set, directly with SQL:
#__hikashop_order.order_invoice_id of 2016 only from 1 to 98
#__hikashop_order.order_invoice_number of 2016 only from F-1600001 to F-1600098
(98 if or the example).
The next order posted registered in the database with
#__hikashop_order.order_invoice_id = 1 and #__hikashop_order.order_invoice_number = F-1600001
instead of #__hikashop_order.order_invoice_id = 99 and #__hikashop_order.order_invoice_number = F-1600099
Why?
And according to your statement "The start number for the invoices comes from the biggest value of order_invoice_id in the orders already in the database" what will happen if, let say, the next order is in 2017. Will it be?
#__hikashop_order.order_invoice_id = 1 and #__hikashop_order.order_invoice_number = F-1700001
It looks like that the start rely on some other value coming from another table than #__hikashop_order.
How does it work?