JPA - does not work cascada type all

Question

I have a problem with saving the list of entities in the database.

I have entity

@Entity
@Table(name = "movies")
@Data
public class MovieEntity {

    @Id
    @Column(unique = true, updatable = false)
    @GeneratedValue
    private Long id;

    @OneToMany(mappedBy = "movie", cascade = CascadeType.ALL)
    private Set<MovieDescription> descriptions;
}

with classes

@Entity
@Data
@EqualsAndHashCode(callSuper = true)
@DiscriminatorValue(value = MovieField.Values.DESCRIPTION)
public class MovieDescription extends MovieInfo {

    private String description;
}

which inherits from

@Entity
@Table(name = "movies_info")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "dtype")
@Data
public class MovieInfo {

    @Id
    @Column(unique = true, updatable = false)
    @GeneratedValue
    private Long id;

    @ManyToOne
    private MovieEntity movie;
}

Although I am using cascade = CascadeType.ALL when using such a code

final MovieEntity movie = new MovieEntity();
    movie.setStatus(EditStatus.WAITING);
    movie.setTitle(movieDTO.getTitle());
    movie.setType(movieDTO.getType());
    movieDTO.getDescription().ifPresent(description -> {
        MovieDescription movieDescription = new MovieDescription();
        movieDescription.setDescription(description);
        movie.getDescriptions().add(movieDescription);
    });
this.movieRepository.save(movie);

is saved to the database the object itself MovieEntitywithout MovieDescription. The mapped list does not save to the database. Why?

Answer 1

In your case MovieDescription class is the relation owner. This is implied by

@OneToMany(*mappedBy = "movie"*, cascade = CascadeType.ALL)
private Set<MovieDescription> descriptions;

JPA persists relations only with owner sides but you are not setting a MovieEntity link in your description

    MovieDescription movieDescription = new MovieDescription();
    movieDescription.setDescription(description);
    movie.getDescriptions().add(movieDescription);

Add the next line for it to work:

    movieDescription.setMovie(movie);