عرض عملي: حالات الكيان في المُنقّح (Debugger)

خطوة بخطوة

1. Put breakpoints in a transactional test around new, persist, a setter, and the end of the method.
2. Inspect the entity: id null while transient; use entityManager.contains(p) to show managed.
3. Change a field and show that the SQL log stays silent until flush() or commit.
4. Planned mistake: modify an entity after the transaction ended (detached); show nothing is saved, then fix with merge inside a transaction.
5. Call remove and show the DELETE is sent at flush.