Spring数据JPA中的saveAndFlush

@Entity
@Table(name = "DISC")
@NoArgsConstructor
@AllArgsConstructor
@Data
@Builder
@ToString
@EqualsAndHashCode(of = { "discId" })
public class Disc implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @ReturnInsert
    @Column(name = "DISC_ID")
    private Long discId;
..
}

和

@Repository
public interface DiscRepository extends JpaRepository<Disc, Long> {
...
}

org.springframework.orm.jpa.JpaSystemException: ids for this class must be manually assigned before calling save():