鎖定機制(悲觀/樂觀)如何與數據庫事務隔離級別相關? [英]How are locking mechanisms (Pessimistic/Optimistic) related to database transaction isolation levels?
Django - 有沒有辦法在事務提交之前使用其相關模型驗證模型? [英]Django - Is there a way to validate a model with its related models before transaction commit?