java - Hibernate 父类(super class)中带有 @OneToOne 注释的字段

Question

我有类Document，其中包含带有@OneToOne注释的字段Ad ad。 类 ResultDocument 扩展了 Document，应用了 JOINED 继承策略。当我启动我的应用程序时，出现错误: org.hibernate.MappingException:在实体 [ua.translate.model.ad.ResultDocument] 上找不到属性 [ad]

请解释一下此错误的原因。

类文档:

@Entity
@Table(name = "INIT_DOCUMENT_TEST")
@Inheritance(strategy = InheritanceType.JOINED)
public class Document {


@Id
@SequenceGenerator(name = "standart",initialValue = 1)
@GeneratedValue(generator = "standart",strategy =GenerationType.SEQUENCE)
@Column(name = "DOCUMENT_ID")
private long id;

@Lob
@Column(name = "DOCUMENT_FILE",nullable = false)
private byte[] file;

@Column(name = "DOCUMENT_FILE_NAME",nullable = false)
private String fileName;

@Column(name = "DOCUMENT_CONTENT_TYPE",nullable = false)
private String contentType;

@OneToOne(fetch = FetchType.LAZY)
@JoinColumn(name = "DOCUMENT_AD_ID")
private Ad ad;
.....
}

类结果文档:

@Entity
@Table(name = "RESULT_DOCUMENT_TEST")
@PrimaryKeyJoinColumn(name= "result_document_id")
public class ResultDocument extends Document{

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "TRANSLATOR",nullable = false)
    private Translator downloader;
    .....
}

Answer 1

我认为您不应该从 Document 扩展，因为如果您使用 hibernate 或 JPA，该技术将使用关系而不执行继承。