JPA Cascade Persistence

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I'm trying to perform a cascading persistence using JPA.

I have the entity: Course and Module

  • 1 Course can have multiple Module 

    @Entity(name = "course")

public class Course extends BaseEntity {

private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id_course")
private Long idCourse;

@SerializedName("Modules")
@OneToMany(mappedBy = "course", cascade = CascadeType.ALL, orphanRemoval = false)
private List<Module> modules;

  • 1 Module can have only one Course 

    @Entity(name = "module")
public class Module extends BaseEntity {

private static final long serialVersionUID = 1L;

@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Column(name = "id_module")
private Long idModule;

@OneToOne
@JoinColumn(name = "id_course")
private Course course;

I want the Course to be saved when it saves all "children - Module". As you are today, you are persistently persisting. However in the module table the id_course field is getting null.

    
asked by anonymous 09.05.2018 / 18:51

1 answer

2

Probably because the course is null 

@OneToOne(cascade= {{CascadeType.DETACH})
@JoinColumn(name = "id_course")
private Course course;

Fill it out before saving 

for (Module  m : course.getModules()) {
    m.setCourse(course);
}
    
09.05.2018 / 19:38
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