@PersistenceContext
PersistenceAnnotationBeanPostProcessor
SharedEntityManagerInvocationHandler
@OneToOne
mappyedBy:拥有关系的字段。此元素仅在关联的反向(非拥有)端指定。
eg:
User:
id
name
@OneToOne(mappedBy="user")
Config config
Config:
key
value
@OneToOne
User user
config 表里会有个user_id的字段
|
@OntToMany
eg:
User:
id
name
@OneToMany(mappedBy="user")
List<Order> orders;
Order:
id:
@ManyToOne
User user;
order 表到时候会有一个user_id的外键
|