java - JPA 单向一对多连接表 - 实体映射不起作用

Question

我尝试为使用以下表设计的数据库创建一些 JPA 实体:PRINCIPALS 和 CREDENTIALS，它们与其他表具有以下关系:

@Entity
@Table(name = "CREDENTIALS")
public class Credentials {

    @Id   
    @Column(name = "CREDENTIAL_ID")
    private Integer credentialID;

    @Id   
    @Column(name = "CREDENTIAL_TYPE_ID")
    private String credentialTypeID;

    @OneToOne
    @JoinColumn(name = "CREDENTIAL_TYPE_ID", insertable = false, updatable = false)
    private CredentialTypes credentialTypes;  
}       

• CREDENTIALS 与 CREDENTIAL_TYPES 具有 oneToOne 关系

  @Entity
  @Table(name = "CREDENTIAL_TYPES")
  public class CredentialTypes {
  
      @Id
      @Column(name = "CREDENTIAL_TYPE_ID")
      private String credentialTypeID;
  
      @Column(name = "DESCRIPTION")
      private String description;
  }   
  

<小时/>

@Entity
@Table(name = "PRINCIPALS")
public class Principals implements Serializable {

    @Id   
    @Column(name = "PRINCIPAL_TYPE_ID", nullable = false)
    private String principalTypeID;

    @Column(name = "PRINCIPAL_ID", nullable = false)
    private String principalID;

    @OneToOne
    @JoinColumn(name = "PRINCIPAL_TYPE_ID", insertable = false, updatable = false)
    private PrincipalTypes principalTypes;

    @OneToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
    @JoinTable(name = "PRINCIPAL_CREDENTIAL",
        joinColumns = @JoinColumn(name = "CREDENTIAL_ID"),
        inverseJoinColumns = @JoinColumn(name = "PRINCIPAL_ID"))
    private List<Credentials> credentials;

• PRINCIPALS 与 PRINCIPAL_TYPES 具有 oneToOne 关系

    @Entity
    @Table(name = "PRINCIPAL_TYPES")
    public class PrincipalTypes implements Serializable {
  
    @Id
    @Column(name = "PRINCIPAL_TYPE_ID", nullable = false)
    private String principalTypeID;
  
    @Column(name = "DESCRIPTION")
    private String description;
  

• 最后，PRINCIPALS 与CREDENTIALS 具有oneToMany 关系，并使用连接表PRINCIPLE_CREDENTIAL

  @Entity
  @Table(name = "PRINCIPAL_CREDENTIAL")
  public class PrincipalCredential implements Serializable {
  
  @Id
  @Column(name = "PRINCIPAL_TYPE_ID", nullable = false)
  private String principalTypeID;
  
  @Id
  @Column(name = "PRINCIPAL_ID", nullable = false)
  private String principalID;
  
  @Id
  @Column(name = "CREDENTIAL_ID")
  private Integer credentialID;
  
  @Id
  @Column(name = "CREDENTIAL_TYPE_ID")
  private String credentialTypeID;
  

在启动时(使用 SpringBoot)，我收到主体和凭证之间的 oneToMany 关系的错误，但不知道如何修复它......尝试了各种其他方法(数据库设计无法更改)。

Caused by: org.hibernate.AnnotationException: A Foreign key refering entities.Principals from entities.Credentials has the wrong number of column. should be 2
        at org.hibernate.cfg.annotations.TableBinder.bindFk(TableBinder.java:502)
        at org.hibernate.cfg.annotations.CollectionBinder.bindCollectionSecondPass(CollectionBinder.java:1467)
        at org.hibernate.cfg.annotations.CollectionBinder.bindManyToManySecondPass(CollectionBinder.java:1233)
        at org.hibernate.cfg.annotations.CollectionBinder.bindStarToManySecondPass(CollectionBinder.java:794)
        at org.hibernate.cfg.annotations.CollectionBinder$1.secondPass(CollectionBinder.java:729)
        at org.hibernate.cfg.CollectionSecondPass.doSecondPass(CollectionSecondPass.java:70)
        at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1697)
        at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1426)
        at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1846)
        at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.perform(EntityManagerFactoryBuilderImpl.java:85  

我发现这个异常很奇怪，因为没有从凭证中引用 Principlas....

Answer 1

joinColumns/inverseJoinColumns 中缺少 PRINCIPLE_TYPE_ID 和 CREDENTIAL_TYPE_ID。我认为你必须使用@JoinColumns注释