I want to build a food delivering app, but facing this error. “FieldError: Cannot resolve keyword ‘category_name_contains’ into field. Choices are: catego ry, description, id, image, name, order, price”.
This is the query.py:
try:
model = field.model._meta.concrete_model
except AttributeError:
# QuerySet.annotate() may introduce fields that aren't
# attached to a model.
model = None
else:
# We didn't find the current field, so move position back
# one step.
pos -= 1
if pos == -1 or fail_on_missing:
available = sorted(
[
*get_field_names_from_opts(opts),
*self.annotation_select,
*self._filtered_relations,
]
)
raise FieldError(
"Cannot resolve keyword '%s' into field. "
"Choices are: %s" % (name, ", ".join(available))
)
break
This is the views.py
from ast import Return
from multiprocessing import context
from django.shortcuts import render
from django.views import View
from .models import MenuItem, Category, OrderModel
class Index(View):
def get(self, request, *args, **kwargs):
return render(request, 'customer/index.html')
class About(View):
def get(self, request, *args, **kwargs):
return render(request, 'customer/about.html')
class Order(View):
def get(self, request, *args, **kwargs):
# get every item from each category
appetizers = MenuItem.objects.filter(
category_name_contains='Appetizer')
main_course = MenuItem.objects.filter(
category_name_contains='Main Course')
desserts = MenuItem.objects.filter(category_name_contains='Dessert')
drinks = MenuItem.objects.filter(category_name_contains='Drink')
# pass into context
context = {
'appetizers': appetizers,
'main_course': main_course,
'desserts': desserts,
'drinks': drinks,
}
# render the templates
return render(request, 'custormer/order.html', context)
def post(self, request, *args, **kwargs):
order_items = {
'items': []
}
items = request.POST.getlist('items[]')
for item in items:
menu_item = MenuItem.objects.get(pk=int(item))
item_data = {
'id': menu_item.pk,
'name': menu_item.name,
'price': menu_item.price
}
order_items['items'].append(item_data)
price = 0
item_ids = []
for item in order_items['items']:
price += item['price']
item_ids.append(item['id'])
order = OrderModel.objects.create(price=price)
order.items.add(*item_ids)
context = {
'items': order_items['items'],
'price': price
}
return render(request, 'customer/order_conformation.html', context)
This is my models.py:
from time import strftime
from unicodedata import category, name
from django.db import models
class MenuItem(models.Model):
name = models.CharField(max_length=100)
description = models.TextField()
image = models.ImageField(upload_to='menu_image/')
price = models.DecimalField(max_digits=5, decimal_places=2)
category = models.ManyToManyField('Category', related_name='item')
def __str__(self):
return self.name
class Category(models.Model):
name = models.CharField(max_length=100)
def __str__(self):
return self.name
class OrderModel(models.Model):
created_on = models.DateTimeField(auto_now_add=True)
price = models.DecimalField(max_digits=7, decimal_places=2)
items = models.ManyToManyField(
'MenuItem', related_name='order', blank=True)
def __str__(self):
return f'Order: {self.created_on.strftime("%b %d %I: %M %p")}'
Here’s the traceback:
Traceback (most recent call last): File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangocorehandlersexception.py", line 55, in inner response = get_response(request) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangocorehandlersbase.py", line 197, in _get_response response = wrapped_callback(request, *callback_args, **callback_kwargs) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangoviewsgenericbase.py", line 84, in view return self.dispatch(request, *args, **kwargs) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangoviewsgenericbase.py", line 119, in dispatch return handler(request, *args, **kwargs) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebitescustomerviews.py", line 21, in get appetizers = MenuItem.objects.filter( File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelsmanager.py", line 85, in manager_method return getattr(self.get_queryset(), name)(*args, **kwargs) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelsquery.py", line 1071, in filter return self._filter_or_exclude(False, args, kwargs) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelsquery.py", line 1089, in _filter_or_exclude clone._filter_or_exclude_inplace(negate, args, kwargs) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelsquery.py", line 1096, in _filter_or_exclude_inplace self._query.add_q(Q(*args, **kwargs)) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelssqlquery.py", line 1502, in add_q clause, _ = self._add_q(q_object, self.used_aliases) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelssqlquery.py", line 1532, in _add_q child_clause, needed_inner = self.build_filter( File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelssqlquery.py", line 1377, in build_filter lookups, parts, reffed_expression = self.solve_lookup_type(arg) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelssqlquery.py", line 1187, in solve_lookup_type _, field, _, lookup_parts = self.names_to_path(lookup_splitted, self.get_meta()) File "C:UsersShreyaOneDriveDesktopli'lbiteslittlebites.venvlibsite- packagesdjangodbmodelssqlquery.py", line 1677, in names_to_path raise FieldError( Exception Type: FieldError at /order/ Exception Value: Cannot resolve keyword 'category_name_contains' into field. Choices are: category, description, id, image, name, order, price
So this my problem I have tried many solutions still not getting the problem here. As I can see that there is no problem in my core code but there is some internal issues, but still I can’t run my program without solving them.
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Answer
The error makes complete sense, it is because you have ManyToMany relation with your field category, and you are filtering through filter(category_name_contains) which is not right at all.
Field lookups required __ as a prefix not _. So it must be __contains.
You should use filter(category__name__contains='Appetizer') for every condition.
If you want to filter only through names, so you can simply filter with:
Views.py
class Order(View):
def get(self, request, *args, **kwargs):
# get every item from each category
appetizers = MenuItem.objects.filter(
category__name__contains='Appetizer')
main_course = MenuItem.objects.filter(
category__name__contains='Main Course')
desserts = MenuItem.objects.filter(category__name__contains='Dessert')
drinks = MenuItem.objects.filter(category__name__contains='Drink')
# pass into context
context = {
'appetizers': appetizers,
'main_course': main_course,
'desserts': desserts,
'drinks': drinks,
}
# render the templates
return render(request, 'custormer/order.html', context)
Note:ManyToManyField required its name to be defined astable_namewithsto be the suffix, that means plural of table name. It will be better if you name it ascategoriesinstead ofin yourcategoryMenuItemmodel.
Note:Models doesn’t require model to be the suffix, so it will be better if you name it asOrderinstead of.OrderModel