Question

Everytime I use the method save of a JPA Spring data repository it give me back a new object and the Autogenerated PK are not updated in the saved object.

Do I have to update my local object PK with the returned by save method manually?

Code:

private void saveProject(){
        Project savedProject = projectRepository.save(projectModel.getProject());
}

savedProject is not the same as projectModel.getProject

@Entity
@Table(name = "project", schema = "public")
public class Project {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    Integer id;

    @LazyCollection(LazyCollectionOption.FALSE)
    @OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
    List<User> users;
    [...]
}

And:

@Entity
@Table(name = "user", schema = "public")
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    Integer id;

    String name;
}

So, the user PK is gerenated in Mysql, and everytime I save the project a new User is created because the user in the app is still PKless...

Answer 1

每次保存new Project()时，JPA都会在数据库中创建一个新对象。

要更新实体，您需要首先通过首先从数据库中提取该实体，然后将该实体引入JPA上下文。

Project lastProject = projectRepository.findById(PROJECT_ID); //lastProject is now updatable.
lastProject.setName(...);   //update the entity fields
lastProject = projectRepository.save(lastProject); //project will now have the updated name.

Spring data save does not update the PK in the persistence context?

1 个答案: