在Django-Forms中使用外键失败并出现错误

Question

我正在制作一个应用程序，它将接受库存信息，如序列号和每一个其他细节，然后我正在制作另一个表单，将验证从上一个表单的条目。

我尝试了多个解决方案，但在相同的错误上可用，但在这里没有任何帮助。

我在这里粘贴代码。如果还有什么需要，请发表意见

models.py/inventory_app

from django.db import models
#from reservation_app.models import Reserve
class Form1(models.Model):
    item = models.CharField(max_length=125)
    quantity = models.IntegerField(default=0)
    vendor = models.CharField(max_length=125)
    inward = models.IntegerField(default=1234)
    sno = models.ManyToManyField(max_length=100, to='reservation_app.Reserve')
    date = models.DateField()
    date_received = models.DateField()
    

    def __str__(self):
      return self.item

如果我取消对该行的注释：

#from reservation_app.models import Reserve

我收到循环导入错误，因为

ImportError: cannot import name 'Form1' from partially initialized module 'inventory_app.models' (most likely due to a circular import) (C:\Users\satharkar\Desktop\altiostar\inventory\inventory_app\models.py)

Models.py/保留_应用程序

from django.db import models
from inventory_app.models import Form1
# Create your models here.
class Reserve(models.Model):
    company = models.CharField(max_length=125)
    sno = models.ForeignKey(to='inventory_app.Form1', null=True, on_delete= models.SET_NULL)
    date_req = models.DateField()

我的所有更改造成了巨大的混乱，以前我可以从models.py/inventory_app中获取输入，并能够在models.py/reservation_app中看到它，但现在情况并非如此。

每当我尝试输入时，都会收到以下错误：

Environment:


Request Method: POST
Request URL: http://127.0.0.1:8000/form1/

Django Version: 3.1.6
Python Version: 3.9.2
Installed Applications:
['django_filters',
 'inventory_app.apps.InventoryAppConfig',
 'reservation_app.apps.ReservationAppConfig',
 'django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'import_export']
Installed Middleware:
['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']



Traceback (most recent call last):
  File "C:\Users\satharkar\AppData\Local\Programs\Python\Python39\lib\site-packages\django\core\handlers\exception.py", line 47, in inner
    response = get_response(request)
  File "C:\Users\satharkar\AppData\Local\Programs\Python\Python39\lib\site-packages\django\core\handlers\base.py", line 181, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
  File "C:\Users\satharkar\Desktop\altiostar\inventory\inventory_app\views.py", line 28, in form1
    form1 = Form1(item=item, quantity=quantity , inward=inward , sno=sno , vendor=vendor, date=datetime.datetime.now() , date_received=date_received ) #security_stamp_date=security_stamp_date
  File "C:\Users\satharkar\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\base.py", line 496, in __init__
    _setattr(self, prop, kwargs[prop])
  File "C:\Users\satharkar\AppData\Local\Programs\Python\Python39\lib\site-packages\django\db\models\fields\related_descriptors.py", line 545, in __set__
    raise TypeError(

Exception Type: TypeError at /form1/
Exception Value: Direct assignment to the forward side of a many-to-many set is prohibited. Use sno.set() instead.

views.py/reservation_app

from django.shortcuts import render, HttpResponse
from .models import Reserve 
from reservation_app.models import Reserve


# Create your views here.
def reserve(request):
    if request.method == "POST":
        company = request.POST.get('company')
        sno = request.POST.get('sno')
        date_req = request.POST.get('date_req')
        reserve = Reserve(company=company, sno=sno, date_req=date_req ) #security_stamp_date=security_stamp_date 
        reserve.save()

    return render(request, 'home.html')

views.py/inventory_app

from django.shortcuts import render, HttpResponse
from inventory_app.models import Form1
import datetime
from .models import Form1 

def form1(request):
    if request.method == "POST":
        item = request.POST.get('item')
        quantity = request.POST.get('quantity')
        sno = request.POST.get('sno')
        inward = request.POST.get('inward')
        vendor = request.POST.get('vendor')
        date_received = request.POST.get('date_received')
     #   security_stamp_date = request.POST.get('security_stamp_date')
        form1 = Form1(item=item, quantity=quantity , inward=inward , sno=sno , vendor=vendor, date=datetime.datetime.now() , date_received=date_received ) #security_stamp_date=security_stamp_date 
        form1.save()

    return render(request, 'form1.html')

form1.html/inventory_app (如果我粘贴完整的代码，只发布所需的代码，我认为这是不必要的)

<div class="form-group">
  <label for="exampleFormControlInput1">Serial Number</label>
  <input type="text" class="form-control" id="exampleFormControlInput1" name= "sno" placeholder="S/N123ABC123" required >
</div>

home.html/reservation_app

<div class="form-group">
  <label for="exampleFormControlInput1">Radio Serial Number</label>
  <input type="text" class="form-control" id="exampleFormControlInput1" name= "sno" placeholder="S/N123ABC123" required >
</div>

有人能帮我解决这个问题吗？我希望sno的条目应该取自models.py/inventory_app，它应该显示在models.py/reservation_app上，或者你可以说它应该得到验证，然后只需要从reservation_app中完成条目。

我是新来的，所以如果你能帮助我，我会非常感激，因为我被困在这里这么长时间了。

谢谢，Sameer

Answer 1

由于循环导入而导致的错误，您可以这样解决。请使用to=‘’在外键和ManytoMany字段中，在下面的示例中，我们不需要从应用程序咨询中导入模型问题

from django.contrib.auth.models import User 
from django.db import models

class Customer(models.Model): 
    name = models.ForeignKey(User, null=True) 
    gender = models.CharField(max_length=100)
    skin_type = models.CharField(max_length=1000)
    hair_type = models.CharField(max_length=1000)
    bookmarked = models.ManyToManyField(to='consult.Question')

    def __str__(self):
        return str(self.name)