CODEWITHSUNDEEP
javahibernatejpa
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Reputation: 959

JPA mappedBy don't persisting entity with relationship

For example, I have the following entities: Room entity:

@Entity
public class Room extends Base {

@OneToMany(mappedBy = "room")
private List<Person> persons;
//getters and setters
}

And the Person entity:

@Entity
public class Person extends Base {

@ManyToOne
private Room room;

private String name;
//getters and setters
}

If I add person to room's persons list and then persist, the room is added, but person is not. I thought, enough is to add mappedBy parameter to OneToMany annotation, but.. what should I do else?

Upvotes: 1

Views: 945

Answers (2)

Ali Dehghani
Ali Dehghani

Reputation: 48133

Do the opposite, set a Room as the room field of a Person instance:

Room room = ...;
person.setRoom(room);
// persist the person

With the mappedBy, you specify that which entity owns the relationship. Updating the relationship between those two entities is the responsibility of the owning side.

In your example, the Person owns the relationship, so it's his responsibility to update the foreign key, not Room's, so when you add a Person to list of persons in Room and update the Room, Room wouldn't update the foreign key for you.

Upvotes: 2

Madhusudana Reddy Sunnapu
Madhusudana Reddy Sunnapu

Reputation: 8247

You need to set CascadeType=PERSIST or ALL on @OneToMany. And Also set room variable in Person class to populate foreign key in Person table.

Upvotes: 2

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