我正在使用JPA，并具有如下所示的类层次结构。

@Entity
    public class Stage {
        @Id
        @Column(name="ID")
        @GeneratedValue(generator = "Stage_IDGenerator", strategy = GenerationType.SEQUENCE)
        private long id;

        @Enumerated(EnumType.STRING)
        @Basic(optional=false)
        private StageStatus status;
    }

    @Entity
    @Inheritance(strategy = InheritanceType.JOINED)
    public class TravelStage extends Stage {
        @Basic(optional=false)
        @Column(nullable = false)
        private String source;

        @Basic(optional=false)
        @Column(nullable = false)
        private String destination;
    }

    @Entity
    @Inheritance(strategy = InheritanceType.JOINED)
    public class WorkStage extends Stage {
        @Basic(optional=false)
        @Column(nullable = false)
        private String workPlace;
    }

使用以下代码创建并尝试保存“WorkStage”实体时

WorkStage ws = new WorkStage();
    ws.setStatus(StageStatus.OPEN);
    ws.setWorkPlace("POSTCODE");
    workStageRepository.save(ws);

我收到错误

SQL Error: 1364, SQLState: HY000
    Field 'destination' doesn't have a default value

为什么会发生这种情况？字段目的地不在WorkStage实体中。如何更正这种情况？