Orm 未在数据库中插入外键值：无法在列中插入Null

我正在将客户端应用程序从Hibernate迁移到EclipseLink。但在对学生实体调用persist方法时，它并没有为外键插入值。数据库是oracle。地址和学生之间存在多对一的关系

在生成的SQL中，外键列也不存在

*

---

*正确的映射如下所示：

@Entity
@Table(name = "Student", schema = "Student_DB")
@SequenceGenerator(name = "studentSeq", sequenceName = "Student_SEQ", schema = "Student_DB", allocationSize = 1)
public class StudentEntity implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "studentSeq")
    @Column(name = "S_ID")
    private BigDecimal studentID;

    @OneToMany(mappedBy = "studentEntity", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    private List<AddressEntity> addresses;

}


@Entity
@Table(name = "Address", schema = "Student_DB")
@SequenceGenerator(name = "AddressSeq", sequenceName = "Address_SEQ", schema = "Student_DB", allocationSize = 1)
public class AddressEntity implements Serializable {

    @Id
    @Column(name = "A_ID")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "AddressSeq")
    private long addressID;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "S_ID", referencedColumnName = "S_ID", nullable = false)
    private StudentEntity studentEntity;
}

---

它不是精确的代码，但类似于你有私人列表地址；使用OneToManymappedBy=studentEntity映射，并指定@JoinColumnname=S_ID注释。MappedBy用于指示另一方控制外键（定义和字段），而JoinColumn与此冲突，用于单向映射。不能两者都是，因此您在部署期间忽略了一些警告，并且由于AddressEntity.studentEntity引用是只读的，因此未设置该字段。嗨，Chris，谢谢您的输入，我尝试了两个选项，第一个是删除@join column，第二个是从student类中删除mappedby，但结果是相同的错误代码：1400 Call:INSERT INTO student_DB.Address S_ID，DGFH，SGFFD，GHJG，GHJGH VALUES？bind=>[5个参数绑定]在insert语句中，它还应该包括S_ID，但我不知道为什么这里缺少它：如果您保留insertable=false、updatable=false，但删除了join列，则表示从未从该映射中设置外键。如果保留joinColumn注释，Eclipselink将在初始插入后在单独的语句中更新外键。您不能使用联接列单向映射，并且对EclipseLink具有NOTNULL约束。嗨，Simon，谢谢！！！谢谢你的努力。建议的更改是有效的，但只是一个问题，因为它是客户端的现有代码，只是想知道地址实体中insertable=false、updateable=false的目的是什么。正如我所知，它们应该在那里，这样我的地址实体就不会创建或更新student，或者我对这个概念的理解有误吗？它们表明此列是只读的。出了什么问题。我很乐意帮忙。如果你能接受我的回答，我将不胜感激

@Entity
@Table(name = "Address", schema = "Student_DB")
@SequenceGenerator(name = "AddressSeq", sequenceName = "Address_SEQ", schema = "Student_DB", allocationSize = 1)
public class AddressEntity implements Serializable {

    @Id
    @Column(name = "A_ID")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "AddressSeq")
    private long addressID;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "S_ID", referencedColumnName = "S_ID", insertable = false, updatable = false, nullable = false)
    private StudentEntity studentEntity;
}

> [EL Fine]: sql: 2019-06-25
> 18:39:00.895--ClientSession(1656550367)--Connection(-872205654)--INSERT
> INTO Student_DB.Student (S_ID, ...) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?,
> ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)  bind => [24 parameters
> bound] [EL Fine]: sql: 2019-06-25
> 18:39:00.946--ClientSession(1656550367)--Connection(-872205654)--INSERT
> INTO Student_DB.Address (A_ID, CO...) VALUES (?, ?, ?, ?, ?)  bind =>
> [5 parameters bound] [EL Fine]: sql: 2019-06-25
> 18:39:00.954--ClientSession(1656550367)--SELECT 1 FROM DUAL [EL
> Warning]: 2019-06-25 18:39:00.955--UnitOfWork(-922357549)--Exception
> [EclipseLink-4002] (Eclipse Persistence Services -
> 2.5.0.v20130507-3faac2b): org.eclipse.persistence.exceptions.DatabaseException Internal
> Exception: java.sql.SQLIntegrityConstraintViolationException:
> ORA-01400: cannot insert NULL into ("Student_DB"."Address"."S_ID")

@Entity
@Table(name = "Student", schema = "Student_DB")
@SequenceGenerator(name = "studentSeq", sequenceName = "Student_SEQ", schema = "Student_DB", allocationSize = 1)
public class StudentEntity implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "studentSeq")
    @Column(name = "S_ID")
    private BigDecimal studentID;

    @OneToMany(mappedBy = "studentEntity", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    private List<AddressEntity> addresses;

}


@Entity
@Table(name = "Address", schema = "Student_DB")
@SequenceGenerator(name = "AddressSeq", sequenceName = "Address_SEQ", schema = "Student_DB", allocationSize = 1)
public class AddressEntity implements Serializable {

    @Id
    @Column(name = "A_ID")
    @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "AddressSeq")
    private long addressID;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "S_ID", referencedColumnName = "S_ID", nullable = false)
    private StudentEntity studentEntity;
}