django-rest-framework - DRF常用模型和外键

Question

我正在尝试为数据库中的所有对象使用一些通用属性，例如 created_by、updated_by、created_when 和 updated_when。

所以我为公共属性创建了一个类：

class CommonModel(models.Model):
"""Common fields that are shared among all models."""

    created_by = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.PROTECT,
                               editable=False, related_name="+")
    updated_by = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.PROTECT,
                               editable=False, related_name="+")
    created_at = models.DateTimeField(auto_now_add=True,
                                  editable=False)
    updated_at = models.DateTimeField(auto_now=True,
                                  editable=False)

然后我参考我的模型中的通用模型：

class Tag(CommonModel):
"""Tag to be used for products"""
name = models.CharField(max_length=255)

    def __str__(self):
        return self.name


class Vendor(CommonModel):
    """Vendor to be used for products"""
    name = models.CharField(max_length=255, unique=True)

    def __str__(self):
        return self.name

但是，当我将另一个模型中的标签或供应商称为 foreign_key 时，执行迁移时会出错。

class Product(CommonModel):
"""Model for the type of a product"""
    product_id = models.CharField(max_length=255, unique=False)
    description = models.CharField(max_length=255, unique=False, null=True, blank=True, default='')
    vendor = models.ForeignKey(Vendor, blank=False, null=False, on_delete=models.SET_DEFAULT)
    tag = models.ForeignKey(Tag, null=True, blank=True, on_delete=models.SET_NULL)

错误信息：

SystemCheckError: System check identified some issues:

ERRORS:

core.Product.tag: (models.E006) The field 'tag' clashes with the field 'tag' from >model 'core.commonmodel'.
core.Product.vendor: (models.E006) The field 'vendor' clashes with the field 'vendor' from model 'core.commonmodel'.

在我介绍常用模型之前它运行良好。

标签： django-rest-framework

Answer 1

您需要在 Meta 中设置抽象，之后它应该可以正常工作。

class CommonModel(models.Model):
"""Common fields that are shared among all models."""

    created_by = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.PROTECT,
                               editable=False, related_name="+")
    updated_by = models.ForeignKey(settings.AUTH_USER_MODEL,on_delete=models.PROTECT,
                               editable=False, related_name="+")
    created_at = models.DateTimeField(auto_now_add=True,
                                  editable=False)
    updated_at = models.DateTimeField(auto_now=True,
                                  editable=False)

    class Meta:
        abstract = True