【发布时间】:2019-07-13 16:03:04
【问题描述】:
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
}
我认为继承导致了一个问题。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。
【问题讨论】:
标签: java database hibernate jpa