Field types (CharField, IntegerField, DateField) in Django - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the default max length of a CharField in Django?

Consider the following Django model field:

name = models.CharField()

What will happen when you run migrations?

A It defaults max_length to 255 automatically

B It sets max_length to 100 by default

C It raises a TypeError because max_length is required

D It allows unlimited length strings

💡 Hint

Think about what Django requires for CharField length.

CharField requires max_length to be specified. Omitting it causes a TypeError during migration generation.

❓ state_output

intermediate

What value is stored in the database for this IntegerField?

Given this model field:

age = models.IntegerField(default=18)

What will be the value of age if you create a new instance without specifying age?

A None

B 18

C 0

D Raises an error for missing value

💡 Hint

Check the default parameter behavior.

The default value 18 is used when no value is provided during instance creation.

📝 Syntax

advanced

Which option correctly defines a DateField that allows empty values?

You want a DateField that can be empty in the database and in forms. Which is correct?

A birth_date = models.DateField()

B birth_date = models.DateField(blank=True)

C birth_date = models.DateField(null=True)

D birth_date = models.DateField(blank=True, null=True)

💡 Hint

Remember the difference between blank and null in Django fields.

null=True allows database to store NULL; blank=True allows form to accept empty input. Both are needed for optional DateField.

🔧 Debug

advanced

Why does this model raise an error on migration?

Model code:

class Person(models.Model):
    name = models.CharField(max_length=50)
    age = models.IntegerField(blank=True)

What is the cause of the error?

A IntegerField cannot have blank=True without null=True

B CharField max_length must be greater than 50

C Missing default value for age field

D Models must have a primary key defined explicitly

💡 Hint

Check the meaning of blank and null for IntegerField.

IntegerField with blank=True but without null=True causes validation error because blank affects forms but null affects database storage.

🧠 Conceptual

expert

How does Django handle DateField input from forms when blank=True and null=True are set?

If a DateField has blank=True and null=True, what happens when a user submits an empty date in a form?

A The field stores NULL in the database and passes validation

B The field stores an empty string in the database

C The form raises a validation error for empty input

D The field stores the current date automatically

💡 Hint

Think about how blank and null affect form and database behavior.

blank=True allows empty form input; null=True allows storing NULL in database. So empty input is valid and stored as NULL.