@ManyToOne, @OneToMany delete error

Question

Author class:

@Id
@GeneratedValue(
        strategy = GenerationType.AUTO)
private int id;
private String firstName;
private String lastName;
@OneToMany(
        mappedBy = "author")
private List<Book> bookList;

Book class:

@Id
@GeneratedValue(
        strategy = GenerationType.AUTO)
private int id;
private String name;
private String language;
private int isbn;
@ManyToOne
@JoinColumn(
        name = "author_fk")
private Author author;

I want to delete author and i am getting following error: "update or delete on table "author" violates foreign key constraint "fk_book_author_fk" on table "book"". How can I delete author ? I want to delete author first, not book.

do you want to drop the table? or just delete a record? – ogzd Feb 01 '13 at 13:14 — ogzd, Feb 01 '13 at 13:14

score 1 · Accepted Answer · answered Feb 01 '13 at 13:15

By default, JPA does not cascade operations from parent to child entities. To enable this cascade from Author down to Book, change the following lines:

@OneToMany(mappedBy = "author")
private List<Book> bookList;

To:

@OneToMany(mappedBy = "author", cascade = CascadeType.ALL)
private List<Book> bookList;

score 0 · Answer 2 · answered Feb 01 '13 at 13:02

0

author and book are related in the database and they have properties on delete which in your case can be cascade. You can change that to 'set Null' and perform the delete.

answered Feb 01 '13 at 13:02

altsyset

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@ManyToOne, @OneToMany delete error

2 Answers2