6

我想自动增加 3 位字符和 4 位数字的发票编号。

class Invoice:
    invoice_no = models.CharField(max_length=500, null=True, blank=True, validators=[RegexValidator(regex='^[a-zA-Z0-9]*$',message='Invoice must be Alphanumeric',code='invalid_invoice number'),])

我在后端注册了这个模型。但是现在当我在管理员中点击创建发票时，发票应该会自动填写。当我再次在管理员中单击创建新发票时，invoice_number 应该增加一并且应该是自动字段。

例如发票编号 MAG0001、MAG0002、MAG0003 等，当我单击创建新发票时，这应该是管理员中的自动字段。

4

5 回答 5

15

定义一个函数来生成发票编号。

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
    invoice_int = int(invoice_no.split('MAG')[-1])
    new_invoice_int = invoice_int + 1
    new_invoice_no = 'MAG' + str(new_invoice_int)
    return new_invoice_no

现在将此函数用作模型字段中的默认值。

invoice_no = models.CharField(max_length=500, default=increment_invoice_number, null=True, blank=True)

这只是一个想法。修改函数以匹配您首选的发票编号格式。

于 2015-01-28T18:10:53.737 回答
3 
def invoiceIncrement():
    get_last_invoice_number
    incremente_last_invoice_number
    return next_invoice_number

class Invoice:
    invoice_no = models.CharField(max_length=500, null=True, blank=True, 
        validators=[RegexValidator(regex='^[a-zA-Z0-9]*$',
        message='Invoice must be Alphanumeric',code='invalid_invoice number'),], 
        default=invoiceIncrement)

试试这个：有一些明显的问题：

  1. 如果多人同时添加发票，可能会发生冲突

  2. 每次创建新发票时都需要进行额外的数据库调用。

另外：您可能只想考虑使用 auto_increment 或 UUID。

于 2015-01-28T17:56:42.127 回答
3

在上面的 arulmr 答案中，只需编辑 char 字段

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
    invoice_int = int(invoice_no.split('MAG')[-1])
    width = 4
    new_invoice_int = invoice_int + 1
    formatted = (width - len(str(new_invoice_int))) * "0" + str(new_invoice_int)
    new_invoice_no = 'MAG' + str(formatted)
    return new_invoice_no  

class Invoice(models.Model):
    invoice_no = models.CharField(max_length = 500, default = increment_invoice_number, null = True, blank = True)

这将正常工作。

于 2015-01-29T04:54:23.597 回答
1

也许这段代码可以提供帮助

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
于 2015-12-26T09:54:31.973 回答
0 
def invoice_number_gen():
   last_invoice = Invoice.objects.all().order_by('id').last()
   last_invoice_number = last_invoice.invoice_no
   #invoice number format is 'customer_name_short + number' eg: CS003 
   last_invoice_digits =int(last_invoice_number[2:]) 
   #comment: slicing CS003 to get the number 003 and converting to int.
   last_invoice_initials = last_invoice_number[:2]              
   new_invoice_digits = last_invoice_digits + 1
   new_invoice_number = last_invoice_initials + str(new_invoice_digits)
   return (new_invoice_number)
于 2021-11-11T04:10:50.853 回答