JPA Entity tanpa @Id

Issue

Masalah ini terjadi ketika entity tidak memiliki @Id didalam entity, jadi di JPA mewajibkan dia memiliki @Id.

Solution

Solusinya mengganti @Id dengan @EmbeddedId dan membuat class baru untuk class Idnya yg menyimpan entity relationship dengan tipe data sesuai dengan column di database.

How To

Class Entity Id 

@Embeddable
@Data
public class FilmCategoryId implements Serializable {
    private static final long serialVersionUID = -4161332004787248098L;
    @Column(name = "film_id", nullable = false)
    private Integer filmId;

    @Column(name = "category_id", nullable = false)
    private Integer categoryId;
    
}

Class Entity

@Entity
@Table(name = "film_category")
@Data
public class FilmCategory {
    @EmbeddedId
    private FilmCategoryId id;

    @MapsId("filmId")
    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "film_id", nullable = false)
    private Film film;

    @MapsId("categoryId")
    @ManyToOne(fetch = FetchType.LAZY, optional = false)
    @JoinColumn(name = "category_id", nullable = false)
    private Category category;

    @Column(name = "last_update", nullable = false)
    private Instant lastUpdate;

}

Class Repository

public interface FilmCategoryRepository extends JpaRepository<FilmCategory, FilmCategoryId>, JpaSpecificationExecutor<FilmCategory> {
}