title: I want to access parent model fields using child model object in django
body: <p>Hello guys I have one query in my Django project.
  First of all, You can see that I have two Django models named BookSeller and Book</p>
  
  <p>Bookseller model</p>
  
  <pre><code>class BookSeller(models.Model):
      user_name = models.CharField(max_length=200)
      user_email = models.CharField(max_length=200)
      user_password = models.CharField(max_length=200)
      user_phone = models.CharField(max_length=100)
      user_photo = models.ImageField(upload_to='book/seller_photos/%Y/%m/%d/', blank=True)
      user_address = models.CharField(max_length=300)
      user_state = models.CharField(max_length=100)
      user_city = models.CharField(max_length=100)
  
      def __str__(self):
          return self.user_name
  </code></pre>
  
  <p>Book Model</p>
  
  <pre><code>class Book(models.Model):
      book_owner = models.ForeignKey(BookSeller, related_name='book_seller', on_delete=models.CASCADE)
      book_category = models.CharField(max_length=200) 
      book_title = models.CharField(max_length=200)
      book_price = models.IntegerField()
      book_edition = models.CharField(max_length=200)
      book_author = models.CharField(max_length=200)
      book_old = models.IntegerField()
      book_page = models.IntegerField()
      book_description = models.TextField(max_length=200)
      book_image_1 = models.ImageField(upload_to='book/book_photos/%Y/%m/%d', blank=True)
      book_image_2 = models.ImageField(upload_to='book/book_photos/%Y/%m/%d', blank=True)
      book_image_3 = models.ImageField(upload_to='book/book_photos/%Y/%m/%d', blank=True)
      book_image_4 = models.ImageField(upload_to='book/book_photos/%Y/%m/%d', blank=True)
  
      def __str__(self):
          return self.book_title
  </code></pre>
  
  <p>Want to DO: In my project I want to find books by that book seller's city.
  For example, if I write city name 'Silicon Valley' in my search field then it should show me all "Books" that's Sellers(BookSeller) belonging to Silicon Valley.</p>
  
  <p>Query: So my query is how can I do that Django Query set, because I can't find out any query which can do this task.</p>
  
  <p>If you guys have any other solution then please suggest me!!!   </p>