Question

我正在将Kodo JDO项目迁移到EclipseLink，并在尝试将SINGLE_TABLE继承实体映射到另一个实体时陷入困境。我收到“将nvarchar值'Audit'转换为数据类型int时转换失败”，却不知道如何解决。

如何将单表继承映射/联接到另一个实体？
如何获取单表继承子类的集合

请帮助。

这是我的数据库的外观：

审计表：保存有关用户的审计信息。
- Audit_id是PK密钥，并具有一个鉴别符列。
- 如果标识符类型为int。 1用于地址详细信息，2用于电话详细信息。
- 一个用户可以拥有多个审核记录。因此，我需要获取一个集合。
用户表-> user_id为PK。
- 列存储审核ID，而不是字符串。审核ID指向最新更改。

用户ID 100具有2个电话号码审核行。我无法收集结果。 Database - Sample data

基本类别：

@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@Entity
@DiscriminatorColumn(name = "type")
@Table(name = "audit")
@NamedQuery(name = "Audit.findAll", query = "SELECT m FROM Audit m")
public  class Audit implements Serializable
{
  @Id
  @GeneratedValue(strategy = GenerationType.TABLE)
  @Column(name = "audit_id")
  private int auditId;

  @Column(name = "user_id")
  private int userId;

  @OneToMany(mappedBy = "addressAudit1")
  private List<User> User;

  //Getters and Setters are defined.
}

子类1：

@Entity
@DiscriminatorValue("1")
public class Address extends Audit
{
  @Column(name = "street_addr1")
  private String streetAddr1;

  @Column(name = "street_addr2")
  private String streetAddr2;

  //Getters and Setters are defined.
}

子类2：

@Entity
@DiscriminatorValue("2")
public class Phone extends Audit
{
  @Column(name = "home_phone")
  private String homePhone;

  @Column(name = "home_phone_ext")
  private String homePhoneExt;

  @Column(name = "work_phone")
  private String workPhone;

  @Column(name = "work_phone_ext")
  private String workPhoneExt;

  //Getters and Setters are defined.
}

用户类别

@Entity
@Table(name = "user")
@NamedQuery(name = "User.findAll", query = "SELECT m FROM User m")
public class User implements Serializable
{
  @Id
  @GeneratedValue(strategy = GenerationType.TABLE)
  @Column(name = "user_id")
  private int UserId;

*//Below code is causing issue*
  @ManyToOne
  @JoinColumn(name = "CURRENT_STREET")
  private Audit addressAudit1;

  //Getters and Setters are defined.
}

UseCase 1.我需要根据ID搜索用户。这是我的搜索方式

public static User getUserForId(long userID, EntityManagerFactory emf) throws Exception
  {
    User user = null;
    EntityManager em = null;
    try
    {
      em = emf.createEntityManager();
      TypedQuery<User> q = em.createQuery("select u from " + User.class.getName() + " u where u.userId = :userIndex", User.class);
      q.setParameter("userIndex", userID);
      List<User> userList = q.getResultList();
      if (userList.size() > 0)
      {
        Iterator<User> userItr = userList.iterator();
        if (userItr.hasNext())
        {
          user = userItr.next();
        }
      }
    }
    catch (Exception e)
    {
      logger.error(e.getMessage());
      throw new Exception(e.getMessage());
    }
    finally
    {
      em.close();
    }
    return user;
  }

在q.getResultList（）处引发异常。

Internal Exception: com.microsoft.sqlserver.jdbc.SQLServerException: Conversion failed when converting the nvarchar value 'Audit' to data type int.
Error Code: 245
Call: SELECT audit_id, type, JDOVERSION, user_id FROM audit WHERE ((audit_id = ?) AND (type = ?))
    bind => [2 parameters bound]
Query: ReadObjectQuery(name="addressAudit1" referenceClass=Audit )

注意：使用@embedded和@embeddable批注时，其工作原理相同。我放弃了它，因为我无法获取审计集合。

EclipseLink：映射到SINGLE_TABLE继承策略的ManyToOne失败

0 个答案: