Fix N+1 queries

An N+1 query happens when code loads a list with one query and then runs one more query per item, usually through lazy-loaded relations inside a loop or a serializer. It looks fine with test data and collapses with real data. The fix must be proven by counting queries, not by reading the code.

Find and fix N+1 queries in: [TARGET] Only if [QUERY_LOG] is given: Start from this log or trace: [QUERY_LOG]

1. Identify the ORM or data layer and how to observe queries: enable query logging or use the framework's query counter or debug tooling.
2. Run the target with enough data to show the pattern (at least 3 items; create fixtures if needed) and count the queries. Record the count and, if available, the time.
3. Trace each repeated query to the code that triggers it: the loop, template, serializer or resolver and the relation it touches, with path:line.
4. Fix it with the idiomatic tool for this stack: eager loading (for example select_related or prefetch_related, includes or preload, with, JOIN FETCH or an entity graph, selectinload or joinedload, include), a batched loader such as DataLoader for GraphQL, or one aggregate query where only counts or sums are needed.
5. Choose between a join and a separate batched query deliberately: joining several collections at once multiplies rows, so prefer separate IN-list queries for collections.
6. Re-run and count again. Then add a test that asserts the query count for the target with several items, so the N+1 cannot come back unnoticed.

• Load only the relations the code actually uses; do not over-fetch whole object graphs.
• Keep the response shape and ordering identical.
• Do not add caching as the fix for an N+1.
• Report real query counts from runs, not from reading the code.
• Before saying the work is done, run the check that proves it (tests, build, type check or the command the user gave) and report the real result.
• If you could not run a check, say so plainly and say which one.
• Do only what was asked. If you notice something else worth changing, mention it in one line at the end instead of changing it.
• Keep the change as small as it can be while still being correct.

Result

One line: queries before and after for N items, and time if measured.

Cause

Each N+1: path:line — the loop or serializer — the relation loaded per item.

Fix

The diff, then one sentence per change on why it removes the extra queries.

Regression guard

The test added and its result.

Other N+1 patterns spotted

Bullets with path:line, not fixed. Or "None".