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MVCC:Snapshot Read vs Current Read MySQL InnoDB存储引擎,实现的是基于多版本的并发控制协议——MVCC (Multi-Version Concurrency Control) (注:与MVCC相对的,是基于锁的并发控制,Lock-Based Concur 阅读全文
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原文: https://stackoverflow.com/questions/1069992/jpa-entitymanager-why-use-persist-over-merge Either way will add an entity to a PersistenceContext, th 阅读全文
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情况一: 不update外键id, update外键关联的实体对象(不允许设置外键实体关联对象的id) RestaurantDto restaurantDto = restaurantDao.getByUserId(userId); restaurantDto.getLocation().setNa 阅读全文