java - 插入时出现 Hibernate 异常

Question

我有两个表应用程序，先生。我使用 JPA、Hibernate 进行 ORM 映射。我在插入记录时遇到问题。请帮助我。

* Mr_id in application table is a foreign key

* code in mr table is unique key

* mr_id in MR table is primary key

应用表:

(id，mr_id)

(1，空)

(2，空)

先生表:

(先生 ID、代码、姓名)

(1，代码1，mr1)

(2，代码2，mr2)

I have a jpa repository :   ApplicationRepository

application = Application(1)

application.mr = MR(1,code1,mr1)

when I run  : applicationRepository.save(applications[0])
it causes a problem

Reason: Mr record with (1,code1,mr1) alredy present in mr table. 

How to solve this problem with JPA, Hibernate annotation

---------------------------------
    Application {
       @Id
       var id: Int;

       @ManyToOne(cascade = [(CascadeType.PERSIST)])
       @JoinColumn(name = "mr_id")
       var mr: MR? = null
    }

Answer 1

我认为发生这种情况是因为 JPA 试图在持久化应用程序后持久化 MR(因为它们分离了)，但 mr_id = 1 的 MR 已经存在。尝试找到 mr_id = 1(不是创建)的 mr 并将此 mr 设置为 application.mr