CODEWITHSUNDEEP
mysqlhibernatejpaspring-dataspring-data-jpa
AA_PV
AA_PV

Reputation: 1359

Spring data with hibernate: multiple row insert in one-to-many entity without cascade

I’m using spring data and hibernate as JPA implementation with spring boot. I’m new to this. I have an entity where I’m maintaining the mapping between two entities which already exist and entries into this mapping only come in at the time of a specific update.

@Entity
@Table(name = "song_genres")
public class SongGenres {

    public SongGenres(Song song, List<Genre> genres) {
        this.genres = genres;
        this.song = song;
    }

    public SongGenres() {
//        Empty constructor as required by hibernate
    }

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    @OneToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "song_id")
    private Song song;

    @OneToMany(fetch = FetchType.LAZY)
    @JoinColumn(name = "genre_id")
    private List<Genre> genres;

    public List<Genre> getGenres() {
        return genres;
    }
}

I’m trying to insert all the genre values associated with a song at once, using

SongGenres songGenres = new SongGenres(song, genres);
songGenresRepository.save(songGenres);

but this is giving an error that

java.sql.SQLException: Field 'genre_id' doesn't have a default value

and the sql logs show a single row insert

Hibernate: insert into song_genres (song_id) values (?)

How is multiple row insert in one-to-many achieved without cascade?

Upvotes: 0

Views: 3088

Answers (2)

MyTwoCents
MyTwoCents

Reputation: 7622

Just define CASCADE type for your List here "List genres" Add No of Items in list and persist main entity. You can read more about it here

Eg:

@OneToMany(cascade = CascadeType.ALL, mappedBy = "visitId")
private Collection<SampleData> lstSampleData;

Upvotes: 0

AA_PV
AA_PV

Reputation: 1359

For now, I changed the entity definition since there isn't much difference between the two

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
private Long id;

@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "chapter_id")
private Chapter chapter;

@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "genre_id", nullable = false)
private Genre genre;

and the save operation becomes

    List<ChapterGenre> chapterGenres = new ArrayList<>();
    for (Genre genre : genres) {
        chapterGenres.add(new ChapterGenre(chapter, genre));
    }
    chapterGenreRepository.save(chapterGenres);

From this one, concluded there isn't much of a difference from spring's implementation point of view.

Although this ain't best performance mysql-wise. Would be interesting if spring data comes up with a simple single insert API.

Upvotes: 0

Related Questions