Model relationships preview in Django - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a one-to-many relationship where each Book belongs to one Author.

Django

class Book(models.Model):
    title = models.CharField(max_length=100)
    author = models.[1](Author, on_delete=models.CASCADE)

Drag options to blanks, or click blank then click option'

AForeignKey

BManyToManyField

COneToOneField

DCharField

Attempts:

3 left

💡 Hint

Common Mistakes

Using ManyToManyField instead of ForeignKey for one-to-many

Using CharField for relationships

The ForeignKey field creates a one-to-many relationship where each Book is linked to one Author.

2fill in blank

medium

Complete the code to define a many-to-many relationship between Student and Course.

Django

class Student(models.Model):
    name = models.CharField(max_length=50)
    courses = models.[1](Course)

Drag options to blanks, or click blank then click option'

AManyToManyField

BForeignKey

COneToOneField

DTextField

Attempts:

3 left

💡 Hint

Common Mistakes

Using ForeignKey which only allows one side to have many

Using OneToOneField which restricts to one-to-one

The ManyToManyField allows each Student to enroll in multiple Courses and each Course to have many Students.

3fill in blank

hard

Fix the error in the code to correctly link Profile to User with a one-to-one relationship.

Django

class Profile(models.Model):
    user = models.[1](User, on_delete=models.CASCADE)

Drag options to blanks, or click blank then click option'

AForeignKey

BOneToOneField

CManyToManyField

DCharField

Attempts:

3 left

💡 Hint

Common Mistakes

Using ForeignKey which allows multiple Profiles per User

Using ManyToManyField which allows many Profiles per User and vice versa

OneToOneField is used to link Profile to User so each Profile belongs to exactly one User.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps each Author's name to the count of their books.

Django

book_counts = {author.name: [1] for author in authors if [2] > 0}

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Aauthor.book_set.count()

Bauthor.books.count()

Clen(author.book_set.all())

Dauthor.book_count

Attempts:

3 left

💡 Hint

Common Mistakes

Using a non-existent attribute like author.books

Using len() on a queryset without calling all()

Use author.book_set.count() to count books related to each author. The same expression checks if the count is greater than zero.

5fill in blank

hard

Fill all three blanks to create a dictionary comprehension mapping each Course's title to the number of enrolled students for courses with more than 2 students.

Django

course_students = {course.[1]: [2] for course in courses if course.students.[3] > 2}

Drag options to blanks, or click blank then click option'

Atitle

Bcourse.students.count()

Ccount()

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using course.name instead of course.title

Forgetting to call count() on the related manager

Use course.title for the course name, course.students.count() to count enrolled students, and count() to check if the number is greater than 2.