Auto increament the invoice number in django backend for new invoice

Question

I want to auto increament the invoice number which is 3 digits char and 4 digits number.

class Invoice:
    invoice_no = models.CharField(max_length=500, null=Tr         


        

Answer 1

Maybe this code can help

def increment_invoice_number():
    last_invoice = Invoice.objects.all().order_by('id').last()
    if not last_invoice:
        return 'MAG0001'
    invoice_no = last_invoice.invoice_no
    new_invoice_no = str(int(invoice_no[4:]) + 1)
    new_invoice_no = invoice_no[0:-(len(new_invoice_no))] + new_invoice_no
    return new_invoice_no