Ordering QuerySets

Why Order Matters

Without order_by(), Django doesn't promise any particular order — the database can return rows in whatever order is fastest for it, which can change between calls.

Note: Always add order_by() when the display order matters to users.

Example: Why Order Matters

The first call may return chapters in any sequence; the second always returns them sorted by their order field, ascending.

from core.models import Chapter

# Order is not guaranteed
Chapter.objects.all()

# Order is now guaranteed by 'order' field
Chapter.objects.order_by('order')

Ascending and Descending Order

A plain field name like title sorts smallest/earliest first (ascending); putting a minus sign in front, like '-title', reverses it to descending.

Example: Ascending and Descending Order

The second query returns the exact same tutorials as the first, just in reverse alphabetical order.

from core.models import Tutorial

# A to Z
Tutorial.objects.order_by('title')

# Z to A
Tutorial.objects.order_by('-title')

Ordering by Multiple Fields

You can pass several field names to order_by(); Django sorts by the first field, and uses the next fields to break ties.

Note: List the most important sort key first.

Example: Ordering by Multiple Fields

Tutorials are grouped by category alphabetically, and within each category they're sorted by their order field.

from core.models import Tutorial

# Sort by category, then by order within each category
Tutorial.objects.order_by('category', 'order')