how to fetch table field in other field - python

I have a cart and subcategory model. I want to fetch the price of the service. How I fetch the price of service in the price field.
I want to fetch price of service in the price field.
Here is my models.py
class SubCategory(models.Model):
name = models.CharField(max_length=254, unique=True)
id_parent = models.ForeignKey(Category, on_delete=models.SET_NULL, null=True)
price = models.IntegerField()
status = models.BooleanField(default=True)
def __str__(self):
return self.name
class Cart(models.Model):
user = models.ForeignKey('accounts.User', related_name="carts", null=True, on_delete=models.SET_NULL)
quantity = models.IntegerField(default=1)
service = models.ForeignKey('accounts.SubCategory',null=True, on_delete=models.SET_NULL)
price = models.ForeignKey('accounts.SubCategory', on_delete=models.CASCADE, default=None, blank=True, related_name='subprice')
date_created = models.DateTimeField(auto_now_add=True)
def __str__(self):
return str(self.price.price)


You would not need to select a value for price since it's derived from the service you selected.
class SubCategory(models.Model):
name = models.CharField(max_length=254, unique=True)
id_parent = models.ForeignKey(Category, on_delete=models.SET_NULL, null=True)
price = models.IntegerField()
status = models.BooleanField(default=True)
def __str__(self):
return self.name
class Cart(models.Model):
user = models.ForeignKey('accounts.User', related_name="carts", null=True, on_delete=models.SET_NULL)
quantity = models.IntegerField(default=1)
service = models.ForeignKey('accounts.SubCategory',null=True, on_delete=models.SET_NULL)
date_created = models.DateTimeField(auto_now_add=True)
def __str__(self):
return str(self.service.price) # if you want just the price of the single service
#property
def total_price(self):
if self.service is not None:
return self.service.price * self.quantity
return 0
service = SubCategory(name="Help with Django", price=5)
aCart = Cart(user=1, quantity=2, service=service)
print(aCart.total_price) # 10


If I understand you clear, you just want to get price of SubCategory attached to Cart. If so, you don't need to add price field to Cart model to get SubCategory price.
You can just define price property on Cart model like this and use it in admin like a regular field:
class Cart(models.Model):
user = models.ForeignKey('accounts.User', related_name="carts", null=True, on_delete=models.SET_NULL)
quantity = models.IntegerField(default=1)
service = models.ForeignKey('accounts.SubCategory',null=True, on_delete=models.SET_NULL)
date_created = models.DateTimeField(auto_now_add=True)
#property
def price(self):
if self.service:
return self.service.price
return None
#property
def total(self):
if self.service:
return self.service.price * self.quantity
return None
def __str__(self):
if self.price:
return str(self.price)
return "Can't show price with no service selected"

Related

AttributeError: 'Order' object has no attribute 'shipping'

Learning Django with Tutorial.
In the end of lesson I have error:
AttributeError: 'Order' object has no attribute 'shipping'.
I can't understand what's wrong.
Error in PyCharm Terminal
I understand that Order must have shipping attribute, but cant find where exactly looking that.
Sorry for bad english.
My project files:
checkout.html
from django.db import models
from django.contrib.auth.models import User
class Customer(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE, null=True, blank=True)
name = models.CharField(max_length=200, null=True)
email = models.CharField(max_length=200, null=True)
def __str__(self):
return self.name
class Product(models.Model):
name = models.CharField(max_length=200, null=True)
price = models.FloatField()
digital = models.BooleanField(default=False, null=True, blank=False)
image = models.ImageField(null=True, blank=True)
def __str__(self):
return self.name
#property
def imageURL(self):
try:
url = self.image.url
except:
url = ''
return url
class Order(models.Model):
customer = models.ForeignKey(Customer, on_delete=models.SET_NULL, null=True, blank=True)
date_ordered = models.DateTimeField(auto_now_add=True)
complete = models.BooleanField(default=False)
transaction_id = models.CharField(max_length=100, null=True)
def __str__(self):
return str(self.id)
#property
def get_cart_total(self):
orderitems = self.orderitem_set.all()
total = sum([item.get_total for item in orderitems])
return total
#property
def get_cart_items(self):
orderitems = self.orderitem_set.all()
total = sum([item.quantity for item in orderitems])
return total
class OrderItem(models.Model):
product = models.ForeignKey(Product, on_delete=models.SET_NULL, null=True)
order = models.ForeignKey(Order, on_delete=models.SET_NULL, null=True)
quantity = models.IntegerField(default=0, null=True, blank=True)
date_addet = models.DateTimeField(auto_now_add=True)
#property
def get_total(self):
total = self.product.price * self.quantity
return total
class ShippingAddress(models.Model):
customer = models.ForeignKey(Customer, on_delete=models.SET_NULL, null=True)
order = models.ForeignKey(Order, on_delete=models.SET_NULL, null=True)
address = models.CharField(max_length=200, null=False)
city = models.CharField(max_length=200, null=False)
state = models.CharField(max_length=200, null=False)
zipcode = models.CharField(max_length=200, null=False)
date_added = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.address
views.py
from django.shortcuts import render
from django.http import JsonResponse
import json
import datetime
from .models import *
def store(request):
if request.user.is_authenticated:
customer = request.user.customer
order, created = Order.objects.get_or_create(customer=customer, complete=False)
items = order.orderitem_set.all()
cartItems = order.get_cart_items
else:
items = []
order = {'get_cart_total':0, 'get_cart_items':0, 'shipping':False}
cartItems = order['get_cart_items']
products = Product.objects.all()
context = {'products':products, 'cartItems':cartItems}
return render(request, 'store/store.html', context)
def cart(request):
if request.user.is_authenticated:
customer = request.user.customer
order, created = Order.objects.get_or_create(customer=customer, complete=False)
items = order.orderitem_set.all()
cartItems = order.get_cart_items
else:
items = []
order = {'get_cart_total':0, 'get_cart_items':0, 'shipping':False}
cartItems = order['get_cart_items']
context = {'items':items, 'order':order, 'cartItems':cartItems}
return render(request, 'store/cart.html', context)
def checkout(request):
if request.user.is_authenticated:
customer = request.user.customer
order, created = Order.objects.get_or_create(customer=customer, complete=False)
items = order.orderitem_set.all()
cartItems = order.get_cart_items
else:
items = []
order = {'get_cart_total':0, 'get_cart_items':0, 'shipping':False}
cartItems = order['get_cart_items']
context = {'items':items, 'order':order, 'cartItems':cartItems}
return render(request, 'store/checkout.html', context)
def updateItem(request):
data = json.loads(request.body)
productId = data['productId']
action = data['action']
print('Action', action)
print('productId', productId)
customer = request.user.customer
product = Product.objects.get(id=productId)
order, created = Order.objects.get_or_create(customer=customer, complete=False)
orderItem, created = OrderItem.objects.get_or_create(order=order, product=product)
if action == 'add':
orderItem.quantity = (orderItem.quantity + 1)
elif action == 'remove':
orderItem.quantity = (orderItem.quantity - 1)
orderItem.save()
if orderItem.quantity <=0:
orderItem.delete()
return JsonResponse('Item was added', safe=False)
def processOrder(request):
transaction_id = datetime.datetime.now().timestamp()
data = json.loads(request.body)
if request.user.is_authenticated:
customer = request.user.customer
order, created = Order.objects.get_or_create(customer=customer, complete=False)
total = float(data['form']['total'])
order.transaction_id = transaction_id
if total == float(order.get_cart_total):
order.complete = True
order.save()
if order.shipping == True:
ShippingAddress.objects.create(
customer=customer,
order=order,
address=data['shipping']['address'], #порядок как в models
city=data['shipping']['city'],
state=data['shipping']['state'],
zipcode=data['shipping']['zipcode'],
)
else:
print('User is not logged in...')
return JsonResponse('Payment complete!', safe=False)
models.py
from django.db import models
from django.contrib.auth.models import User
class Customer(models.Model):
user = models.OneToOneField(User, on_delete=models.CASCADE, null=True, blank=True)
name = models.CharField(max_length=200, null=True)
email = models.CharField(max_length=200, null=True)
def __str__(self):
return self.name
class Product(models.Model):
name = models.CharField(max_length=200, null=True)
price = models.FloatField()
digital = models.BooleanField(default=False, null=True, blank=False)
image = models.ImageField(null=True, blank=True)
def __str__(self):
return self.name
#property
def imageURL(self):
try:
url = self.image.url
except:
url = ''
return url
class Order(models.Model):
customer = models.ForeignKey(Customer, on_delete=models.SET_NULL, null=True, blank=True)
date_ordered = models.DateTimeField(auto_now_add=True)
complete = models.BooleanField(default=False)
transaction_id = models.CharField(max_length=100, null=True)
def __str__(self):
return str(self.id)
#property
def get_cart_total(self):
orderitems = self.orderitem_set.all()
total = sum([item.get_total for item in orderitems])
return total
#property
def get_cart_items(self):
orderitems = self.orderitem_set.all()
total = sum([item.quantity for item in orderitems])
return total
class OrderItem(models.Model):
product = models.ForeignKey(Product, on_delete=models.SET_NULL, null=True)
order = models.ForeignKey(Order, on_delete=models.SET_NULL, null=True)
quantity = models.IntegerField(default=0, null=True, blank=True)
date_addet = models.DateTimeField(auto_now_add=True)
#property
def get_total(self):
total = self.product.price * self.quantity
return total
class ShippingAddress(models.Model):
customer = models.ForeignKey(Customer, on_delete=models.SET_NULL, null=True)
order = models.ForeignKey(Order, on_delete=models.SET_NULL, null=True)
address = models.CharField(max_length=200, null=False)
city = models.CharField(max_length=200, null=False)
state = models.CharField(max_length=200, null=False)
zipcode = models.CharField(max_length=200, null=False)
date_added = models.DateTimeField(auto_now_add=True)
def __str__(self):
return self.address
urls.py
from django.urls import path
from . import views
urlpatterns = [
path('', views.store, name="store"),
path('cart/', views.cart, name="cart"),
path('checkout/', views.checkout, name="checkout"),
path('update_item/', views.updateItem, name="update_item"),
path('process_order/', views.processOrder, name="process_order"),
]
I reviewed the lesson several times, code seems to be without mistakes.

Server side error
The error is because you didn't declared shipping variable in your Orders model.
class Order(models.Model):
customer = models.ForeignKey(Customer, on_delete=models.SET_NULL, null=True, blank=True)
date_ordered = models.DateTimeField(auto_now_add=True)
complete = models.BooleanField(default=False)
transaction_id = models.CharField(max_length=100, null=True)
shipping = models.CharField(max_length=200, null=True)
def __str__(self):
return str(self.id)
#property
def get_cart_total(self):
orderitems = self.orderitem_set.all()
total = sum([item.get_total for item in orderitems])
return total
#property
def get_cart_items(self):
orderitems = self.orderitem_set.all()
total = sum([item.quantity for item in orderitems])
return total
Go to models file and update the Order class with above code.
client side
While making API request set the header Content-Type to text/html.
Because the API is responding HTML file not json.
That's why you have an error in browser.

in Order model there should be a field named shipping which is require in the processorder view.
just add below field in Order model
shipping = models.BooleanField(default=False)
since you want ot hide it , then a property need to be added not the db field
so your model should look like this
class Order(models.Model):
customer = models.ForeignKey(Customer, on_delete=models.SET_NULL, null=True, blank=True)
date_ordered = models.DateTimeField(auto_now_add=True)
complete = models.BooleanField(default=False)
transaction_id = models.CharField(max_length=100, null=True)
#property
def shipping(self):
shipping = False
# add shipping logic here
return shipping
def __str__(self):
return str(self.id)
#property
def get_cart_total(self):
orderitems = self.orderitem_set.all()
total = sum([item.get_total for item in orderitems])
return total
#property
def get_cart_items(self):
orderitems = self.orderitem_set.all()
total = sum([item.quantity for item in orderitems])
return total
follow the tutorial a little more, you will be able to grasp the solution.

__str__ returned non-string (type Product)

I'm getting __ str __ returned non-string (type Product) when I try to add OrderItem in my Django project
models.py:
class Order(models.Model):
customer = models.ForeignKey(Customer, on_delete=models.CASCADE)
date_ordered = models.DateField(auto_now_add=True, blank=True, null=True)
complete = models.BooleanField(default=False)
transaction_id = models.CharField(max_length=100, null=True)
def __str__(self):
return self.transaction_id
class OrderItem(models.Model):
product = models.ForeignKey(Product, on_delete=models.CASCADE)
quantity = models.PositiveIntegerField(default=1)
order = models.ForeignKey(Order, on_delete=models.CASCADE)
def __str__(self):
return self.product
class Product(models.Model):
name = models.CharField(max_length=200, null=True)
price = models.FloatField()
image = models.ImageField(null=True, blank=True)
tag = models.ForeignKey(Tag, on_delete=models.CASCADE, blank=True, null=True)
def __str__(self):
return str(self.name)
#property
def imageUrl(self):
try:
url = self.image.url
except:
url =''
return url
admin.py:
admin.site.register(Customer)
admin.site.register(Product)
admin.site.register(Order)
admin.site.register(Tag)
admin.site.register(OrderItem)
I get the same error when I try this:
class Product(models.Model):
name = models.CharField(max_length=200, null=True)
price = models.FloatField()
image = models.ImageField(null=True, blank=True)
tag = models.ForeignKey(Tag, on_delete=models.CASCADE, blank=True, null=True)
def __str__(self):
return 'test'
Sometimes I get this error when I try to add/delete items (in Orders, OrderItems, Products)

The problem is not the __str__ method of the Product class, but the __str__ method of the OrderItem class. self.product is not a string, but a Product object, so you can not return this in the __str__ method. You can for example return the str(…) of the product:
class OrderItem(models.Model):
product = models.ForeignKey(Product, on_delete=models.CASCADE)
quantity = models.PositiveIntegerField(default=1)
order = models.ForeignKey(Order, on_delete=models.CASCADE)
def __str__(self):
return str(self.product)

Find the difference between two model field

I want to find the difference between quantity of Product class and sold_quantity of Stock class. How do I do that
models.py
from django.db import models
class Category(models.Model):
name = models.CharField(max_length=100, blank=True, null=True)
def __str__(self):
return self.name
class Product(models.Model):
name = models.CharField(max_length=100)
slug = models.CharField(max_length=100)
price = models.DecimalField(max_digits=6, decimal_places=2)
quantity = models.IntegerField(null=True, blank=True)
category = models.ForeignKey(
Category, on_delete=models.CASCADE, blank=True, null=True)
def __str__(self):
return self.name
class Stock(models.Model):
sold_quantity = models.IntegerField(null=True, blank=True)
product = models.ForeignKey(Product, on_delete=models.CASCADE, null=True)
def __str__(self):
return self.product.name

For one instance you can do this by:
Example: id=1
product_instance = Product.objects.get(id=1)
quantity_difference = product_instance.quantity - product_instance.stock.sold_quantity
Note: This assumes the relationship is coupled between models.

Django access to product total price through order model

I want to get each product's total price in all orders which I mean how much each product sold in all orders. What Query should I write in views.py to display this matter in html?
this is my models.py:
class Product(models.Model):
name = models.CharField(max_length=200, null=True)
price = models.FloatField(null=True)
description = models.CharField(max_length=200, null=True, blank=True)
date_created = models.DateTimeField(auto_now_add=True, null=True)
def __str__(self):
return self.name
class Order(models.Model):
STATUS = (
('Pending', 'Pending'),
('Shipping', 'Shipping'),
('Delivered', 'Delivered'),
)
# order will remain after customer deleted
customer = models.ForeignKey(Customer, null=True, on_delete=models.SET_NULL)
product = models.ForeignKey(Product, null=True, on_delete=models.SET_NULL)
date_created = models.DateTimeField(auto_now_add=True, null=True)
status = models.CharField(max_length=200, null=True, choices=STATUS)
note = models.CharField(max_length=200, null=True)
def __str__(self):
return self.product.name
and this is my views.py:
def home(request):
products = Product.objects.all()
orders = Order.objects.all()
total_order_prices = Order.objects.aggregate(Sum('price'))
orders.products = Product.objects.all().aggregate(Sum('price'))
context = {'orders':orders, 'products':products,'total_order_prices': total_order_prices }
return render(request, 'account/home.html', context)

Morez!
What I recommend is defining a foreign key to Order() in the Product(). Doing so would allow you to get related objects much more easily, as shown here.
All you would have to do is products = order.product_set.
Hope it helps!

Shopping cart DB not showing number of Individual Items Ordered

I'm trying to create a shopping cart model, I've created the Order Model, OrderItem model and Also the Item model. Although I find it difficult to link the order it model to the order in the API view.
here's the Model
class Pizza(models.Model):
id = models.AutoField(primary_key=True)
name = models.CharField(max_length=60)
desc = models.CharField(max_length=150)
price = models.IntegerField()
url = models.CharField(max_length=250)
def __str__(self):
return self.name
class OrderItem(models.Model):
id = models.AutoField(primary_key=True)
product = models.ForeignKey("Pizza", on_delete=models.CASCADE, null=True)
date_added = models.DateTimeField(auto_now=True)
date_ordered = models.DateTimeField(null=True)
amount = models.IntegerField(null=True)
def __str__(self):
return self.product.name
class Order(models.Model):
id = models.AutoField(primary_key=True)
name = models.CharField(max_length=60)
email = models.CharField(max_length=150)
address = models.CharField(max_length=150)
total = models.IntegerField()
created_at = models.DateTimeField(default=timezone.now)
items = models.ManyToManyField(OrderItem)
def __str__(self):
return self.name
//The viewset
class OrderViewSet(viewsets.HyperlinkedModelSerializer):
# permission_classes = [IsPostOrIsAuthenticated,]
serializer_class = OrderSerializer
queryset = Order.objects.all().order_by('-created_at')
Currently, I cant display the amount attribute of the order item in my API, It just shows the id and Also the link to the individual orderitem in an order

I think for cart you can use external fields on relations between Order and Pizza. Documentation about this here
Your models looks like:
class Pizza(models.Model):
name = models.CharField(max_length=60)
desc = models.CharField(max_length=150)
price = models.IntegerField()
url = models.CharField(max_length=250)
def __str__(self):
return self.name
class Order(models.Model):
name = models.CharField(max_length=60)
email = models.CharField(max_length=150)
address = models.CharField(max_length=150)
total = models.IntegerField()
created_at = models.DateTimeField(auto_now=True)
items = models.ManyToManyField(Pizza, through='OrderItem')
def __str__(self):
return self.name
class OrderItem(models.Model):
product = models.ForeignKey('Pizza', on_delete=models.CASCADE, null=True)
order = models.ForeignKey('Order', on_delete=models.CASCADE, null=True)
date_added = models.DateTimeField(auto_now=True)
date_ordered = models.DateTimeField(null=True)
amount = models.IntegerField(null=True)
def __str__(self):
return self.product.name
Example, how you can get dict of items amount in order:
order = Order.objects.filter('-created_at').first() // get last order
cart = {item.pk: item.amount for item in order.items}

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