Question

我尝试根据topCategory和middleCategory的外键主键保存项目。

models.py

class MiddleCategory(models.Model):
    title = models.CharField(max_length=50)
    slug = models.SlugField()
    def __str__(self):
        return self.title

class TopCategory(models.Model):
    title = models.CharField(max_length=50)
    slug = models.SlugField()
    middleCategory = models.ManyToManyField(MiddleCategory)
    def __str__(self):
        return self.title


# Item
class Product(models.Model):
    title = models.CharField(max_length=500, db_index=True)
    price = models.DecimalField(max_digits=10, decimal_places=2)
    brand = models.CharField(max_length=100)
#     brand_id = models.IntegerField()
    retailer = models.CharField(max_length=255)
    image = models.CharField(max_length=1000)
    url = models.URLField(max_length=800, unique=True, default='')
    model_numbers = models.BigIntegerField(default=0)
    description = models.CharField(max_length=500)


    featured = models.CharField(max_length=255, db_index=True, default='NO')
    timestamp = models.DateTimeField(auto_now=True)

    topCategory = models.ForeignKey(TopCategory)
    middleCategory = models.ForeignKey(MiddleCategory)

    def __str__(self):
        return self.title

在我的剧本中，我这样保存：

            Product(title=title,
                    price=price,
                    brand=brand,
                    retailer=retailer,
                    image=image, 
                    url=url,
                    description=description, 

                    midCategory=midCategory,
                    topCategory=topCategory
                    ).save()

这是我得到的错误：

ValueError：无法分配＆＃34;＆＃39; 1＆＃39;＆＃34;：＆＃34; Product.topCategory＆＃34;必须是＆＃34; TopCategory＆＃34;实例

Answer 1

您可以获取TopCategory的实例

instance = TopCategory.objects.get(id=topCategory)

然后

Product(title=title,
                    price=price,
                    brand=brand,
                    retailer=retailer,
                    image=image, 
                    url=url,
                    description=description, 
                    midCategory=midCategory,
                    topCategory=instance
                    ).save()

Django保存到外地

1 个答案: