Question

作为Hibernate的新用户，我遇到了一个＆＃34;已分离的实体，在尝试从实体中移除项目时会传递给＃34; 例外{{{ 1}}。我尝试添加List以及以各种组合将级联类型更改为orphanRemoval=true和/或MERGE，但这并没有帮助。我的实体是：

DELETE

在交易中，我尝试有效地执行以下操作：

@Entity
public class User
{   
    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)  // adding "orphanRemoval = true" doesn't help
    @JsonManagedReference
    private List<Application> applications;
}

@Entity
public class Application
{
    @ManyToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL)  // adding "orphanRemoval = true" doesn't help
    @JsonBackReference
    private User user;
}

@Entity
public class ServerApplication extends Application
{
    @OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL)  // adding "orphanRemoval = true" doesn't help
    @JsonManagedReference
    private List<Instance> instances;
}

@Entity
public class Instance
{
    @ManyToOne(fetch = FetchType.EAGER, cascade = CascadeType.ALL) // adding "orphanRemoval = true" doesn't help    
    @JsonBackReference
    private ServerApplication server;
}

这导致：

// For some User's ServerApplication object:
serverAplication.getInstances().remove(0); // Attempt to remove an item from DB.
entityManager.persist(user);

如何正确注释属性以便能够执行持久删除项目，即在org.hibernate.PersistentObjectException: detached entity passed to persist: my.project.User上调用remove？

注意：添加新的List<Instance>个对象并更新列表可正常工作;它只是导致问题的移除。

Answer 1

我认为你应该在删除实例后保留serverAplication，而不是用户：

// For some User's ServerApplication object:
serverAplication.getInstances().remove(0); // Attempt to remove an item from DB.
entityManager.persist(serverAplication);

＆＃34;传递的分离实体持续存在＆＃34;尝试从集合中删除项目时出现异常

1 个答案: