Question

我有一个有ID的发票应用。我想按年翻滚。也就是说，它每年都会从001开始。我的返回字符串是2014-001, 2014-002, 2015-001 ...

但是，Django似乎不支持复合键。有没有办法做到这一点？

class Invoice(models.Model):
    description = models.CharField(max_length=200)
    date = models.DateField('Date Issued')
    client = models.ForeignKey('organizations.Contact')
    UNPAID = 'Unpaid'
    PAID = 'Paid'
    STATUS_CHOICES = (
        (UNPAID, 'Unpaid'),
        (PAID, 'Paid'),
    )
    status = models.CharField(max_length=6,
                              choices=STATUS_CHOICES, default=UNPAID)
    notes = models.TextField(blank=True)

    def __str__(self):
        return (self.date.__str__().replace("-", "") +
                "-" + self.id.__str__().zfill(3))

编辑新代码：

def save(self, *args, **kwargs):
    if self.invoice_id is "":
        current_date = self.date.year
        previous_invoice = Invoice.objects.filter(invoice_id__contains=current_date).order_by('-id').first()
        if previous_invoice is not None:
            num = int(previous_invoice.invoice_id[5:])
        else:
            num = 1
        self.invoice_id = '{year}-{num:03d}'.format(year=current_date, num=num)
    super(Invoice, self).save(*args, **kwargs)

Answer 1

您可以使用CharField作为ID，将其设置为主键并在保存时自动生成。

类似于以下内容应该有效：

class Invoice(models.Model):
    id = models.CharField(max_length=8, null=False, primary_key=True)
    ...

def save(self, *args, **kwargs):
    if self.pk is None:
        current_year = datetime.now().year
        previous_invoice = Invoice.objects.filter(id__contains=str(year)).order_by('-id').first()
        if previous_invoice is not None:
            num = int(previous_invoice.id[5:])
        else:
            num = 1
        self.pk = '{year}-{num:03d}'.format(year=current_year, num=num)
    super(Invoice, self).save(*args, **kwargs)

编辑：在primary_key字段定义中添加缺少的id属性。

创建按年滚动的ID

1 个答案: