F expressions for field comparisons in Django - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import F expressions from Django.

Django

from django.db.models import [1]

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AF

BValue

CQ

DCase

Attempts:

3 left

💡 Hint

Common Mistakes

Importing Q instead of F

Forgetting to import F

Importing unrelated classes like Value or Case

The F class is imported from django.db.models to allow field comparisons in queries.

2fill in blank

medium

Complete the code to filter objects where 'price' is greater than 'cost' using F expressions.

Django

Product.objects.filter(price__[1]=F('cost'))

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Agt

Blt

Clte

Dgte

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'lt' which means less than

Using 'gte' or 'lte' which include equality

Using exact which means equal

The lookup gt means 'greater than'. This filters products where price is greater than cost.

3fill in blank

hard

Fix the error in the code to compare 'quantity' with 'minimum_quantity' using F expressions.

Django

Inventory.objects.filter(quantity__[1]=F('minimum_quantity'))

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Aequals

Beq

Cis

Dexact

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'eq' or 'equals' which are not valid lookups

Using 'is' which is a Python keyword, not a lookup

The correct lookup for equality in Django queries is exact. 'eq', 'equals', and 'is' are invalid lookups.

4fill in blank

hard

Fill both blanks to update 'stock' by subtracting 'sold' using F expressions.

Django

Product.objects.update(stock=F('stock') [1] F('[2]'))

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A-

B+

Csold

Dprice

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' instead of '-' causing stock to increase

Using wrong field name like 'price' instead of 'sold'

To reduce stock by the sold amount, subtract 'sold' from 'stock' using the '-' operator and the field name 'sold'.

5fill in blank

hard

Fill all three blanks to filter orders where 'total' is at least twice the 'cost'.

Django

Order.objects.filter(total__[1]=F('cost') [2] [3])

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Agte

B*

C2

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using '+' instead of '*' for multiplication

Using 'gt' instead of 'gte' to exclude equal values

Using wrong number instead of 2

Use 'gte' for 'greater than or equal', multiply 'cost' by 2 using '* 2' to compare with 'total'.