CODEWITHSUNDEEP
javamysqlspringspring-bootjpa
ABpositive
ABpositive

Reputation: 303

JPA Spring boot remove reference on delete?

Im using JPA, MySQL and Spring boot

I cant for the life of me figure out how to apply cascades, the documentation doesnt seem to apply what I intend:

eg. https://hellokoding.com/deleting-data-with-jpa-hibernate/ Use CascadeType.ALL or CascadeType.REMOVE attributes to delete the child entities when the parent entity is deleted. They may be used on @OneToOne, @OneToMany, @ManyToOne, and @ManyToMany

^ I don't want to remove child entities I want to ONLY remove reference

my guess is this relationship is many-to-many?

many users can have many modules
many modules can have many users

How do I get it to apply this via cascade annotation?

when a user is deleted the module is not

when a module is deleted its reference is removed from user

when a user is added a module is not

when a module is added a user is not

Current entity:

@Entity
@Table(name = "module")
public class Module {
    @Id
    @GeneratedValue( strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;
    @ManyToMany(fetch = FetchType.LAZY, cascade = CascadeType.ALL, mappedBy = "modules")
    private Set<User> users;

Upvotes: 0

Views: 1672

Answers (1)

Gannebal Barka
Gannebal Barka

Reputation: 83

You can specify orphanRemoval if true - remove from db, if false - not remove

For ManyToMany

@ManyToMany
@Cascade(value = org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
private Set<User> users;

For OneToMany

@OneToMany(mappedBy = "topic", cascade = CascadeType.ALL, orphanRemoval = true)
private Set<User> users;

Upvotes: 0

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