title: I create a One to One realtionship in django Multitable-Inheritance but it not show Book-id in my child class Table and also show Integrity Error Why?
body: <p>This is my models.py :</p>
  <pre><code>class Book(models.Model):
      Book_Name = models.CharField(max_length=100, default=&quot;Don Quixote&quot;)
      Author_Name = models.CharField(max_length=100, blank=True, default=&quot;Miguel de Cervantes&quot;)
      Price = models.FloatField(default=175.00)
  
      created = models.DateTimeField(auto_now_add=True)
      update = models.DateTimeField(auto_now=True)
  
      def __str__(self):
          return self.Book_Name
  
  class ISBN(models.Model):
      book = models.OneToOneField(Book, on_delete=models.CASCADE, parent_link=True, primary_key=True)
      Isbn = models.CharField(max_length=100)
  
      def __str__(self):
          return self.Book_Name
  </code></pre>
  <p>in according to my code every Book has one isbn number but in admin panel ISBN table don't show book attributes or don't show any book-id. it show only Isbn column and after i give input in this column it show me error &quot;IntegrityError at /admin/inheritance/isbn/add/&quot; and &quot;NOT NULL constraint failed: inheritance_isbn.book_id&quot;</p>
  <p>This is my admin.py :</p>
  <pre><code>@admin.register(Book)
  class PostAdmin(admin.ModelAdmin):
      list_display = ['Book_Name', 'Author_Name', 'Price']
  
  @admin.register(ISBN)
  class PostAdmin(admin.ModelAdmin):
      list_display = ['book', 'Isbn']
  </code></pre>
  <p>I'm a noob to python and Django so any help would be greatly appreciated.</p>