CODEWITHSUNDEEP
javamysqlhibernate
David Antelo
David Antelo

Reputation: 533

"Cannot delete or update a parent row" after removing parent in a OneToMany relationship

I get the error

Cannot delete or update a parent row: a foreign key constraint fails (`gestion_ejercicios_programacion`.`examen`, CONSTRAINT `examen_ibfk_1` FOREIGN KEY (`titulacionID`) REFERENCES `titulacion` (`id`))

when trying to delete an entity with hibernate. Here's what I'm trying to do in my main:

TitulacionDAO tDAO = context.getBean(TitulacionDAO.class);
Titulacion t1 = new Titulacion("titulacion 1");
tDAO.save(t1);

ExamenDAO exDAO = context.getBean(ExamenDAO.class);
Examen ex1 = new Examen(3, 11, "examen 1", t1);
exDAO.save(ex1);

tDAO.delete(t1);

Here's Examen mapping for my Titulacion

@ManyToOne(cascade=CascadeType.PERSIST)
@JoinColumn(name="titulacionID", referencedColumnName="id")
private Titulacion titulacion;

and here's my Titulacion mapping for Examen

@OneToMany(cascade=CascadeType.REMOVE, mappedBy="titulacion", orphanRemoval=true)
private Set<Examen> examenes = new HashSet<>();

This is my database:

CREATE TABLE examen (

    id INT AUTO_INCREMENT PRIMARY KEY,
    mes INT(2),
    ano INT(4),
    descripcion VARCHAR(1000),
    titulacionID INT,

    FOREIGN KEY (titulacionID) REFERENCES titulacion(id)

);

CREATE TABLE titulacion (

    id INT AUTO_INCREMENT PRIMARY KEY PRIMARY KEY,
    nombre VARCHAR(100)

);

I have no idea why this is happening, I've read several posts on this topic and from what I've read this should be working. Thanks for the help

Upvotes: 0

Views: 37

Answers (1)

JB Nizet
JB Nizet

Reputation: 691715

You didn't add the examen to the Titulacion. So when deleting the titulacion, Hibernate doesn't know that the examen need to be deleted too

Upvotes: 1

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