Missing Eager Load (ARCH2051)

Key python.orm.missing-eager-load · Severity warning · Category orm

Iterating over related navigation data without select_related / prefetch_related triggers N+1 queries at runtime. Eager loading is the canonical prevention.

Incorrect

orders = Order.objects.filter(status="paid")
for order in orders:
    total = sum(item.price for item in order.items.all())  # a SELECT per order

Correct

orders = Order.objects.filter(status="paid").prefetch_related("items")
for order in orders:
    total = sum(item.price for item in order.items.all())  # loaded up front

Fix

Add prefetch_related or select_related to the query before iterating over the relation.