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java - Hibernate @embededId 包含具有继承的实体的外键

问题描述

将此作为我的基点：https ://vladmihalcea.com/the-best-way-to-map-a-many-to-many-association-with-extra-columns-when-using-jpa-and-hibernate /

我有一个名为Attendance 的实体，它有一个emebedid AttendacneId，它有两列lectureId（字符串）和studenId（UUID）。出勤实体还具有其他属性，其中包含使用 @MapsId 与学生和讲座实体建立多对一关系。学生扩展了 id 所在的用户实体。现在，当我尝试保存任何内容时，我会收到此错误。

java.util.NoSuchElementException
at java.util.ArrayList$Itr.next(ArrayList.java:860)
at org.hibernate.cfg.annotations.TableBinder.linkJoinColumnWithValueOverridingNameIfImplicit(TableBinder.java:724)
at org.hibernate.cfg.PkDrivenByDefaultMapsIdSecondPass.doSecondPass(PkDrivenByDefaultMapsIdSecondPass.java:37)
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1684)
at org.hibernate.boot.internal.InFlightMetadataCollectorImpl.processSecondPasses(InFlightMetadataCollectorImpl.java:1641)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:286)
at org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:473)
at org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:84)
at utility.Utils.<clinit>(Utils.java:60)
at utility.Testing.main(Testing.java:21)

我的 AttendanceId 班级

@Embeddable
public class AttendanceId implements Serializable {

@Column(name = "lecture_fid")
@Getter
@Setter
private String lectureId;

@Column(name = "student_fid", columnDefinition = "uuid")
@Getter
@Setter
private UUID studentId;

public AttendanceId() {} 
}

我的考勤班

@Entity
@Table(name = "attendance")
public class Attendance implements Serializable {

@EmbeddedId
@Getter
@Setter(AccessLevel.PRIVATE)
private AttendanceId id;
// other fields


@ManyToOne(fetch = FetchType.LAZY)
@MapsId("lectureId")
private Lecture lecture;

@ManyToOne(fetch = FetchType.LAZY)
@MapsId("studentId")
private Student student;
}

我的学生班

@Entity
@PrimaryKeyJoinColumn(name = "id")
public class Student extends User implements Serializable, 
Comparable<Student> {
// other fields

@OneToMany(mappedBy = "student", fetch = FetchType.LAZY)
@Getter
private List<Attendance> attendances = new ArrayList<>();
}

我的用户类

@Entity
@Table(name = "users", uniqueConstraints = {
    @UniqueConstraint(columnNames = {"email", "username"})})
@Inheritance(strategy = InheritanceType.JOINED)
public abstract class User implements Serializable {


@Id
@GeneratedValue(generator = "uuid")
@GenericGenerator(name = "uuid", strategy = "uuid")
@Column(columnDefinition = "UUID")
@Getter(AccessLevel.PUBLIC)
@Setter(AccessLevel.PUBLIC)
private UUID id;
// other fields.
}

我的课堂

@NamedNativeQueries(
    @NamedNativeQuery(name = "getLectureId", query = "select 
       get_lecture_id()")
    )
@Entity
@Table(name = "lecture")
public class Lecture implements Serializable {

@Id
@Column(name = "id")
@GenericGenerator(name = "lectureIdGenerator",
        strategy = "entities.LectureIdGenerator")
@GeneratedValue(generator = "lectureIdGenerator")
@Getter
@Setter
private String id;

@OneToMany(mappedBy = "lecture", fetch = FetchType.LAZY)
@Getter
private List<Attendance> attendances = new ArrayList<>();
// other fields
}

我认为继承引起了问题。还有其他类/实体可以扩展用户实体。如果有人可以帮助我找到问题，那就太好了。谢谢你。

标签： javadatabasehibernatejpa

解决方案

此问题是由HHH-7135休眠问题引起的。

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