old_contents: from django.db import models
  
  
  # Product Model
  class Product(models.Model):
      create_date = models.DateTimeField(auto_now_add=True)
      update_date = models.DateTimeField(auto_now=True)
      product_name = models.CharField(max_length=200)
      product_desc = models.CharField(max_length=2000)
      colors = models.ManyToManyField('Color', through='ProductColor')
  
      class Meta:
          ordering  = ('-create_date',)
  
      def __str__(self):
          return str(self.id) + ' ' + self.product_name + ': ' + self.product_desc
  
  # Color Model
  class Color(models.Model):
      create_date = models.DateTimeField(auto_now_add=True)
      update_date = models.DateTimeField(auto_now=True)
      color_name = models.CharField(max_length=200)
  
      class Meta:
          ordering = ('-color_name',)
  
      def __str__(self):
          return str(self.id) + ' ' + self.color_name
  
  # Product And Color Transaction
  class ProductColor(models.Model):
      product = models.ForeignKey(
          'Product',
          on_delete=models.CASCADE,
      )
      color = models.ForeignKey(
          'Color',
          on_delete=models.CASCADE,
      )
  
      def __str__(self):
          return str(self.product.product_name) + ' - ' + str(self.color.color_name)
  
  # Model Order (Parent for OrderDetail)
  class Order(models.Model):
      create_date = models.DateTimeField(auto_now_add=True)
      update_date = models.DateTimeField(auto_now=True)
      orderdetails = models.ManyToManyField('OrderDetail', related_name='+')
      order_desc = models.CharField(max_length=2000)
  
      class Meta:
          ordering  = ('-create_date',)
  
      def __str__(self):
          return str(self.order_desc)
  
  # Model OrderDetail
  class OrderDetail(models.Model):
      create_date = models.DateTimeField(auto_now_add=True)
      update_date = models.DateTimeField(auto_now=True)
      order = models.ForeignKey(
          'Order',
          on_delete=models.CASCADE,
      )
      product_color = models.ForeignKey(
          'ProductColor',
          on_delete=models.CASCADE,
      )
  
      class Meta:
          ordering  = ('-create_date',)
  
      def __str__(self):
          return str(self.order.order_desc) + ' details'
  
  # Model Stock
  class Stock(models.Model):
      product_color = models.ForeignKey(
          'ProductColor',
          on_delete=models.CASCADE,
      )
      ammount = models.IntegerField()
  
new_contents: from django.db import models
  
  
  # Product Model
  class Product(models.Model):
      create_date = models.DateTimeField(auto_now_add=True)
      update_date = models.DateTimeField(auto_now=True)
      product_name = models.CharField(max_length=200)
      product_desc = models.CharField(max_length=2000)
      colors = models.ManyToManyField('Color', through='ProductColor')
  
      class Meta:
          ordering  = ('-create_date',)
  
      def __str__(self):
          return str(self.id) + ' ' + self.product_name + ': ' + self.product_desc
  
  # Color Model
  class Color(models.Model):
      create_date = models.DateTimeField(auto_now_add=True)
      update_date = models.DateTimeField(auto_now=True)
      color_name = models.CharField(max_length=200)
  
      class Meta:
          ordering = ('-color_name',)
  
      def __str__(self):
          return str(self.id) + ' ' + self.color_name
  
  # Product And Color Transaction
  class ProductColor(models.Model):
      product = models.ForeignKey(
          'Product',
          on_delete=models.CASCADE,
      )
      color = models.ForeignKey(
          'Color',
          on_delete=models.CASCADE,
      )
  
      def __str__(self):
          return str(self.product.product_name) + ' - ' + str(self.color.color_name)
  
  # Model Order (Parent for OrderDetail)
  class Order(models.Model):
      create_date = models.DateTimeField(auto_now_add=True)
      update_date = models.DateTimeField(auto_now=True)
      orderdetails = models.ManyToManyField('OrderDetail', related_name='+')
      order_desc = models.CharField(max_length=2000)
  
      class Meta:
          ordering  = ('-create_date',)
  
      def __str__(self):
          return str(self.order_desc)
  
  # Model OrderDetail
  class OrderDetail(models.Model):
      create_date = models.DateTimeField(auto_now_add=True)
      update_date = models.DateTimeField(auto_now=True)
      order = models.ForeignKey(
          'Order',
          on_delete=models.CASCADE,
      )
      product_color = models.ForeignKey(
          'ProductColor',
          on_delete=models.CASCADE,
      )
  
      class Meta:
          ordering  = ('-create_date',)
  
      def __str__(self):
          return str(self.order.order_desc) + ' details'
  
  # Model Stock
  class Stock(models.Model):
      product_color = models.ForeignKey(
          'ProductColor',
          on_delete=models.CASCADE,
      )
      ammount = models.IntegerField()
  
      def __str__(self):
          return str(self.product_color) + ' (' + str(self.ammount) + ')'
  
subject: Add str representation to model.Stock