AttributeError：模块“django.db.models”没有属性“ManyToMany”

Question

I am trying to make one of my model objects a ManyToMany Field, so I can access the objects through both models.

I am receiving the following error .

listing = models.ManyToMany(Listings, blank=True, related_name="listing")
AttributeError: module 'django.db.models' has no attribute 'ManyToMany'

models.py :

class WatchList(models.Model):
    listing = models.ManyToMany(Listings, blank=True, related_name="listing")
    user = models.ForeignKey(User, on_delete=models.CASCADE, default="")

Answer 1

The name of the field is a ManyToManyField ^[Django-doc] , so this includes the …Field in ManyToMany :

from django.conf import settings

class WatchList(models.Model):
    listing = models.ManyToManyField(Listings, blank=True, related_name='watchlists')
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)

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Note : It is normally better to make use of the settings.AUTH_USER_MODEL ^[Django-doc] to refer to the user model, than to use the User model ^[Django-doc] directly. For more information you can see the referencing the User model section of the documentation .

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Note : The related_name=… parameter ^[Django-doc] is the name of the relation in reverse , so from the Listings model to the Watchlist model in this case. Therefore it (often) makes not much sense to name it the same as the forward relation. You thus might want to consider renaming the listing relation to watchlists .

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Note : normally a Django model is given a singular name, so listing instead of listings .