عرض عملي: اصطياد N+1 باختبار يعدّ الاستعلامات

خطوة بخطوة

1. Seed 100 orders with lines in a test.
2. Add a query counter (Hibernate statistics or a datasource-proxy library; verify your choice).
3. Call the order-history endpoint and print the count: 101.
4. Write the assertion queryCount <= 2; the test fails.
5. Planned mistake: add fetch = EAGER and show the count is still high; revert it.
6. Add the join fetch or entity graph; the test passes.