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vitalik
Unable to use "<field>_id" for FK fields with ModelSchema [BUG]
Bug 1 In an ideal case - one should be able to set the FK of a field directly without a separate query as the Django docs highlights in the following link: https://docs.djangoproject.com/en/4.0/topics/db/optimization/#use-foreign-key-values-directly
However using ModelSchema the field gets validated to the FK model instance and the 'foo_id' shortcut can't be used.
Bug 2 Additionally if one does use "foo_id" in payload (POST or PUT or PATCH) it gets resolved to "foo".
For example:
class City(models.Model):
"""Model with simple info."""
city = models.CharField(_("City"), max_length=3)
def __str__(self):
"""Str Method override."""
return self.city
class Order(models.Model):
"""Model with multiple many to many and fk relations."""
city = models.ForeignKey(City, verbose_name=_("Name"), on_delete=models.CASCADE)
def __str__(self):
"""Str Method override."""
return f"Order {self.pk} for {self.city.name}"
class OrderPostSchema(ModelSchema):
"""Order Post Schema"""
class Config:
"""Config."""
model = Order
model_exclude = ["id"]
@api.post("/order")
def create_order(request, payload: OrderPostSchema):
"""Create Order."""
data = payload.dict()
obj = Order.objects.create(**data)
return {"id": obj.id}
# POSTing to "/order" with payload = {"city_id": 1}
# Throws error: ValueError: Cannot assign "1": "Order.city" must be a "City" instance.
The only workaround (while using ModelSchema):
@api.post("/order")
def create_order(request, payload: OrderPostSchema):
"""Create Order."""
data = payload.dict()
city_id = data.pop('city') #<--- notice not city_id as expected from payload
data["city"] = City.objects.get(pk=city) <--- causes another DB Query
obj = Order.objects.create(**data)
return {"id": obj.id}
I am trying to convert a huge codebase (30+ apps) from DRF and Django Ninja is the best option by far, however being unable to use the ModelSchema with "all" or standard "POST" logic makes it a hard sell given one can use DRF to post the same payload without issue.
Expected Behavior Be able to use "field_id" in ModelSchema.
Versions (please complete the following information):
- Python version: 3.9
- Django version: 4.0.4
- Django-Ninja version: 0.19.1
i think this may helps you
#add manager to modle file
class OrderManager(models.Manager):
def add_city_to_order(self, city_id):
return self.create(city=City.objects.get(pk=city_id))
# and change api endpoint to below
@api.post("/order")
def create_order(request, payload: OrderPostSchema):
"""Create Order."""
data = payload.dict()
obj = Order.objects.add_city_to_order(data["city"])
return {"id": obj.id}
It's pretty weird that this is not done automatically by django-ninja... is there no other way without hacking it?
错误 1在理想情况下 - 应该能够直接设置字段的 FK 而无需单独的查询，因为 Django 文档在以下链接中突出显示：https ://docs.djangoproject.com/en/4.0/topics/db /优化/#use-foreign-key-values-directly
但是，使用 ModelSchema，该字段将被验证到 FK 模型实例，并且不能使用“foo_id”快捷方式。
错误 2 此外，如果确实在有效负载（POST 或 PUT 或 PATCH）中使用了“foo_id”，它会被解析为“foo”。
例如：
class City(models.Model): """Model with simple info.""" city = models.CharField(_("City"), max_length=3) def __str__(self): """Str Method override.""" return self.city class Order(models.Model): """Model with multiple many to many and fk relations.""" city = models.ForeignKey(City, verbose_name=_("Name"), on_delete=models.CASCADE) def __str__(self): """Str Method override.""" return f"Order {self.pk} for {self.city.name}" class OrderPostSchema(ModelSchema): """Order Post Schema""" class Config: """Config.""" model = Order model_exclude = ["id"] @api.post("/order") def create_order(request, payload: OrderPostSchema): """Create Order.""" data = payload.dict() obj = Order.objects.create(**data) return {"id": obj.id} # POSTing to "/order" with payload = {"city_id": 1} # Throws error: ValueError: Cannot assign "1": "Order.city" must be a "City" instance.唯一的解决方法（使用 ModelSchema 时）：
@api.post("/order") def create_order(request, payload: OrderPostSchema): """Create Order.""" data = payload.dict() city_id = data.pop('city') #<--- notice not city_id as expected from payload data["city"] = City.objects.get(pk=city) <--- causes another DB Query obj = Order.objects.create(**data) return {"id": obj.id}我正在尝试从 DRF 转换一个庞大的代码库（30 多个应用程序），而 Django Ninja 是迄今为止最好的选择，但是由于无法将 ModelSchema 与“ all ”或标准“POST”逻辑一起使用，因此很难卖使用 DRF 毫无问题地发布相同的有效负载。
预期行为 能够在 ModelSchema 中使用“field_id”。
版本（请填写以下信息）：
- Python版本：3.9
- Django 版本：4.0.4
- Django-Ninja 版本：0.19.1
i have the same problem! is there other more elegant solution？
@sunboy123 @martinlombana @alirezapla
if more than one foreignkey? i feel this solution is not very well.
I guess the easiest solution for now is to manually write ids in schema:
class OrderPostSchema(ModelSchema):
city_id: int # !
class Config:
model = Order
model_exclude = ["id", "city"] # !
but I'm open to any other suggestions to how to improve this... maybe some connfig flag
class Config:
model = Order
model_fk_use_pks = True # (or model_fk_use_pks = ['city', 'otherfk']
IMO such weird mapping of dropping _id should not happen at all - super confusing. Working with dynamic schemas is supper difficult, because adding such overwrites defeats the whole purpose of dynamic schema. So provided workarounds are not much help here :( Are there any plans to solve this? It's been almost 2 years since this got reported.
