Question

我遇到了Django的get_or_create问题，当我创建相同的对象时，弹出相同的日期完整性错误。

我的模型中有字段如下。

class Cart(models.Model):
    created = models.DateTimeField(
        pgettext_lazy('Cart field', 'created'), auto_now_add=True)
    last_status_change = models.DateTimeField(
        pgettext_lazy('Cart field', 'last status change'), auto_now_add=True)
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL, blank=True, null=True, related_name='carts',
        verbose_name=pgettext_lazy('Cart field', 'user'))
    email = models.EmailField(
        pgettext_lazy('Cart field', 'email'), blank=True, null=True)

    def add(self,hoarding, date_from, date_until):
        cart_line, created = self.lines.get_or_create(
            hoarding=hoarding,date_from=date_from,date_until=date_until)



class Meta:
        ordering = ('-last_status_change',)
        verbose_name = pgettext_lazy('Cart model', 'Cart')
        verbose_name_plural = pgettext_lazy('Cart model', 'Carts')

    def __str__(self):
        return smart_str(self.user)


class CartLine(models.Model):
    cart = models.ForeignKey(
        Cart, related_name='lines',
        verbose_name=pgettext_lazy('Cart line field', 'cart'))

    hoarding = models.ForeignKey(
        Hoarding, related_name='+',blank=True, null=True,
        verbose_name=pgettext_lazy('Cart line field', 'hoarding'))

    date_from = models.DateField(blank=True, null=True,
        verbose_name=pgettext_lazy('Cart line field', 'from'))

    date_until = models.DateField(blank=True, null=True,
        verbose_name=pgettext_lazy('Cart line field', 'until'))

    class Meta:
        unique_together = ('cart', 'date_from', 'date_until')
        verbose_name = pgettext_lazy('Cart line model', 'Cart line')
        verbose_name_plural = pgettext_lazy('Cart line model', 'Cart lines')

当我尝试将相同的对象添加到具有相同日期和直到日期的购物车时出现

错误：

IntegrityError at /hoardings/hoardings-demo-2-5/add/
UNIQUE constraint failed: cart_cartline.cart_id, cart_cartline.date_from, cart_cartline.date_until

在创建具有相同日期的对象时，

get_or_create将返回IntegrityError。我在datefield中添加了唯一的功能，但得到了相同的错误。我使用Django 1.11和Python 2.7

我重置数据库几次但它没有帮助，db是Postgres / sqlite。

Answer 1

unique_together约束导致错误。删除相同，一切都会好。

使用DateField的IntegrityError - 使用get_or_create创建对象时

1 个答案: