hibernate - 在实体中找不到@IdClass 的属性

Question

我使用 spring boot 2、jpa 和 hibernate

用这个代码

@Entity
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
public class Samplings {

    @Id
    @GenericGenerator(name = "samplings_id_seq", strategy="com.lcm.model.SamplingSequenceGenerator")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "samplings_id_seq")
    private Integer id;

    @OneToMany(mappedBy = "sampling")
    private List<Samples> samples = new ArrayList<>();

}   

@Entity
@IdClass(SamplesPK.class)
public class Samples  {

    @Id
    private String sampleLetter;

    @Id
    @ManyToOne(optional = false)
    @JoinColumns({
        @JoinColumn(name = "id", referencedColumnName = "id")})
    private Samplings sampling;
}   

public class SamplesPK implements Serializable {

    private Integer id;

    private String sampleLetter;

    public SamplesPK(Integer id, String sampleLetter) {
        this.id = id;
        this.sampleLetter = sampleLetter;
    }

    .... //get / set
}

我收到此错误:

org.hibernate.AnnotationException: Property of @IdClass not found in entity com.lcm.model.Samples:: id

Answer 1

主键类中的字段或属性的名称与实体的主键字段或属性的名称必须对应，并且它们的类型必须相同。来自文档 here .

您的 Samples类的 ID 应该与您的 SamplesPK 的类型相同.

你应该有一个 @Id private Integer id在您的 Samples类(class)