Model relationships preview in Django - Mini Project: Build & Apply

Model relationships preview

📖 Scenario: You are building a simple Django app to manage books and their authors. Each book has one author, and each author can have multiple books.

🎯 Goal: Create two Django models, Author and Book, with a one-to-many relationship. Then, write a query to get all books by a specific author.

📋 What You'll Learn

Create an Author model with a name field

Create a Book model with a title field and a foreign key to Author

Create a variable author_name with the value 'Jane Austen'

Write a Django ORM query to get all books by the author with name author_name

💡 Why This Matters

🌍 Real World

Managing related data like authors and books is common in library or bookstore apps.

💼 Career

Understanding model relationships and queries is essential for backend Django development.

1

Create the Author model

Create a Django model called Author with a single field name as a CharField with max length 100.

Django

# Your code here

Need a hint?

Use models.CharField(max_length=100) for the name field.

2

Create the Book model with a foreign key

Create a Django model called Book with a title field as CharField max length 200, and a foreign key field called author linking to the Author model with on_delete=models.CASCADE.

Django

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=100)

# Your code here

Need a hint?

Use models.ForeignKey(Author, on_delete=models.CASCADE) for the author field.

3

Create the author_name variable

Create a variable called author_name and set it to the string 'Jane Austen'.

Django

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=100)

class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)

# Your code here

Need a hint?

Set author_name exactly to 'Jane Austen'.

4

Query books by author name

Write a Django ORM query to get all Book objects where the related Author's name matches the variable author_name. Assign the result to a variable called books_by_author.

Django

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=100)

class Book(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)

author_name = 'Jane Austen'

# Your code here

Need a hint?

Use Book.objects.filter(author__name=author_name) to get books by author name.