I have made a feedback form. Now I want to make a user list of those who have given feedback on the particular product. My motive is, that if any user gives feedback on a particular product, he/she won't be able to give another feedback on that particular product and can't see the feedback form. A user can share just one feedback on one product. But he/she will be able to give feedback on other's products. How can I make a user list of those who have given feedback on the particular product? Help me...

models.py:

class Products(models.Model):
    user = models.ForeignKey(User, related_name="merchandise_product_related_name", on_delete=models.CASCADE, blank=True, null=True)
    product_title = models.CharField(blank=True, null=True, max_length = 250)
    on_delete=models.CASCADE, blank=True, null=True)
    
    def __str__(self):
        return str(self.pk)   "."   str(self.product_title)


class ProductREVIEWS(models.Model):

    user = models.ForeignKey(User, related_name='userREVIEW',on_delete=models.CASCADE)
    product = models.ForeignKey(Products, related_name='productREVIEWrelatedNAME',on_delete=models.CASCADE)
   
    def __str__(self):
        return str(self.pk)   "."   str(self.product)   "("   str(self.user)   ")"

views.py:

def quick_view(request, quick_view_id):
    quick_view = get_object_or_404(Products, pk=quick_view_id)
    AllProductFeedback = quick_view.productREVIEWrelatedNAME.all()
    TotalProductsFeedback = AllProductFeedback.count()
    OverallFeedback = ProductREVIEWS.objects.all()

    context = {
        "quick_view":quick_view,
        "TotalProductsFeedback":TotalProductsFeedback,
        "AllProductFeedback":AllProductFeedback,
        "OverallFeedback":OverallFeedback,
    }
    return render(request, 'quickVIEW_item.html', context)

CodePudding user response：

You can .filter(…) ^[Django-doc] with:

User.objects.filter(userREVIEW__product=quick_view)

You can however simply let the database prevent creating two ProductREVIEWS for the same user and product combination with a UniqueConstraint ^[Django-doc]:

from django.conf import settings

class ProductReview(models.Model):
    user = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        related_name='reviews',
        on_delete=models.CASCADE
    )
    product = models.ForeignKey(
        Product,
        related_name='reviews',
        on_delete=models.CASCADE
    )

    class Meta:
        constraints = [
            models.UniqueConstraint(
                fields=('user', 'product'),
                name='review_once'
            )
        ]
   
    def __str__(self):
        return f'{self.pk}.{self.product}({self.user})'

with the modified names, it is:

User.objects.filter(reviews__product=quick_view)

But here the database will thus reject a second review of the same product by the same user.

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.

Note: normally a Django model is given a singular name, so Product instead of Products.

Note: Models in Django are written in PascalCase, not snake_case, so you might want to rename the model from ProductREVIEWS to ProductReview.

Note: The related_name=… ^[Django-doc] is the name of the manager to fetch the related objects in reverse. Therefore normally the related_name of a ForeignKey or ManyToManyField is plural, for example reviews instead of productREVIEWrelatedNAME.