broken models relationship in admin. please look at the erd.png

django/didgeridoo/webshop/admin.py

@@ -3,7 +3,7 @@ from django.contrib.auth.admin import UserAdmin as BaseUserAdmin
 from django.contrib.auth.models import User
 
 # Register your models here.
-from webshop.models import (Article, Order, OrderPosition,
+from webshop.models import (Article, Order, CartOfGoods,
                             Person, City, Picture, OrderOfGoods,
                             Category, Option)
 
@@ -57,10 +57,10 @@ class ArticleAdmin(admin.ModelAdmin):
     inlines = (PictureInline,)
 
 
-class OrderPositionInline(admin.StackedInline):
-    model = OrderPosition
+class CartOfGoodsInline(admin.StackedInline):
+    model = CartOfGoods
     can_delete = False
-    verbose_name_plural = 'Order Positions'
+    verbose_name_plural = 'Cart Items'
 
 
 class OrderAdmin(admin.ModelAdmin):
@@ -68,7 +68,7 @@ class OrderAdmin(admin.ModelAdmin):
     list_filter = ('date',)
     date_hierarchy = 'date'
     ordering = ('-date',)
-    inlines = (OrderPositionInline,)
+    inlines = (CartOfGoodsInline,)
 
 
 class OrderOfGoodsAdmin(admin.ModelAdmin):

django/didgeridoo/webshop/models.py

@@ -3,7 +3,7 @@ from django.core.validators import MinValueValidator
 from django.db import models
 from django.contrib.auth.models import User
 from django.utils import timezone
-
+from currencies.models import ExchangeRate
 
 class Option(models.Model):
     name = models.CharField(max_length=200, unique=True)
@@ -56,12 +56,23 @@ class OrderStatus(models.Model):
         return self.name
 
 
+class Order(models.Model):
+    """ purchase  """
+    user = models.ForeignKey(User, on_delete=models.CASCADE)
+    article = models.ManyToManyField(Article, through='OrderPosition')
+    status = models.ForeignKey(OrderStatus)
+    date = models.DateTimeField(default=timezone.now)
+
+
 class OrderOfGoods(models.Model):
+    """  articles of purchase """
     article = models.ForeignKey(Article)
-    amount = models.FloatField(max_length=5)
+    amount = models.FloatField(max_length=3)
     delivery_date = models.DateField()
+    order = models.ForeignKey(Order)
     order_date = models.DateTimeField(auto_now_add=True)
     order_status = models.ForeignKey(OrderStatus)
+    exchange_rate = models.ForeignKey(ExchangeRate)
 
     class Meta:
         verbose_name_plural = "Order of Goods"
@@ -76,32 +87,22 @@ class Picture(models.Model):
         return self.name
 
 
-class Order(models.Model):
-    user = models.ForeignKey(User, on_delete=models.CASCADE)
-    article = models.ManyToManyField(Article, through='OrderPosition')
-    status = models.ForeignKey(OrderStatus)
-    date = models.DateTimeField(default=timezone.now)
-
-
-class OrderPosition(models.Model):
-    article = models.ForeignKey(Article, on_delete=models.CASCADE)
-    order = models.ForeignKey(Order, on_delete=models.CASCADE)
-    amount = models.FloatField(max_length=5)
-    price_in_chf = models.DecimalField(max_digits=19,
-                                       decimal_places=2,
-                                       validators=[MinValueValidator(
-                                            Decimal('0.00'))])
-
-
 class ShoppingCart(models.Model):
+    """ cart of user """
     name = models.CharField(max_length=200)
     user = models.ForeignKey(User, on_delete=models.CASCADE)
-    article = models.ManyToManyField(Article)
 
     def __str__(self):
         return self.name
 
 
+class CartOfGoods(models.Model):
+    """ cart items """
+    article = models.ForeignKey(Article, on_delete=models.CASCADE)
+    amount = models.FloatField(max_length=5)
+    cart = models.ForeignKey(ShoppingCart)
+
+
 class City(models.Model):
     name = models.CharField(max_length=200)
     zip_code = models.PositiveSmallIntegerField()

django/didgeridoo/webshop/views.py

@@ -4,7 +4,7 @@ from django.contrib.auth.decorators import login_required
 from django.contrib.auth.models import User
 from django.contrib.auth.forms import UserCreationForm
 from webshop.models import (Article, Category, ArticleStatus, Person,
-                            City, Picture)
+                            City, Picture, CartOfGoods)
 from webshop.forms import RegistrationForm, AddToCartForm
 
 from currencies.models import ExchangeRate, ExchangeRate_name
@@ -144,7 +144,12 @@ def article_details(request, article_id):
             if amount.is_valid():
                 print("is valid")
                 amount = amount.cleaned_data['amount']
-                print("amount:", amount, "article_id:", article_id)
+                cart = CartOfGoods.objects.create(
+                    article=article_id,
+                    amount=amount,
+                    cart="",
+                    )
+                cart.save()
                 amount = AddToCartForm()
         else:
             amount = AddToCartForm()