在ManyToOne关系上，JPA和EclipseLink的级联持续错误 [英] Cascade persist error with JPA and EclipseLink on ManyToOne relationship

问题描述

将JPA与EclipseLink一起使用我有2个类:用户和地址.

Using JPA with EclipseLink I have 2 classes: User and Address.

简化一下，在同一笔交易中，我创建了一个新用户，一个新地址，并将该地址添加到该用户，因为每个用户可以有许多地址:

Simplifying, in the same transaction I creates a new user, a new address and add that address to the user knowing that each user can have many addresses:

User = new User();
Address address= new Address();
user.addAddress(address);

这是User类中的映射:

This is the mapping in User class:

@OneToMany(mappedBy = "idUser")
private Set<Address> addresses;

这是Address类中的映射:

This is the mapping in Address class:

@ManyToOne(cascade = { javax.persistence.CascadeType.REFRESH, javax.persistence.CascadeType.MERGE })
@JoinColumn(name = "id_user", referencedColumnName = "id", nullable = false)
private User user;

我使用的是Spring Data JPA自定义存储库，其中注入了objectmanager并从服务中调用它:

I am using a Spring Data JPA Custom Repository where I inject the entitymanager and is called from a service:

public void saveUser(TUsuario user) 
{
    em.persist(user);
}

之后，我坚持住地址

address.setDay(1);
address.setMonth(2);
address.setYear(3);
address.setUser(user);

public void saveUserAddress(Address address) 
{
    em.persist(address);
} 

最后，当服务方法完成时，就完成了交易.

And finally, when the service method has finished, the transaction is made.

当我尝试进行thansaction时，会引发错误:

When I try to commit the thansaction an error raises:

'A new object was found through a relationship that was not marked cascade PERSIST'

如果我将用户地址列表标记为层叠PERSIST，则eclipselink尝试将用户保存两次(我认为当我保留用户时一个，而第二次当用户地址保留时).

If I mark the user addresses list as cascade PERSIST, then eclipselink tries to save the user twice (I think one when I persist the user and second when the user address is persisted).

我该怎么做才能使eclipselink不持久化，而是将其检测为现有对象?

How can I do it to eclipselink not to persist it, but detect it as an existing object?

PS:我尝试使用merge而不是persist，但没有用.

PS: I tried to use merge instead of persist and didn't work.

推荐答案

一个错误是:

@OneToMany(mappedBy = "user")//you have idUser

然后添加 请尝试以下操作:

Then add Try the following:

User user = new User();
Address address = new Address();

address.setUser(User);
user.addAddress(address);

em.persist(user);//you can delete this, if you add PERSIST (address.user field) to the @ManyToOne(cascade = { javax.persistence.CascadeType.REFRESH, javax.persistence.CascadeType.MERGE })
em.persist(address);

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