Question

以下情况：当我尝试使用@EmbeddedId字段保存实体时，hibernate会使字段＆＃34; mandant＆＃34;从基类到＆＃34; contact_mandant＆＃34;抛出无效的标识符错误。表格中的列名称＆＃34;联系人＆＃34;是＆＃34; mandant＆＃34;而不是＆＃34; contact_mandat＆＃34;。我只是不明白为什么会自动更改字段名称。这里有一些代码：

    @MappedSuperclass
    public abstract class BaseId implements Serializable {

      @Column(name = "Mandant", precision = 2, nullable = false)
      protected Byte mandant;

      ...getter, setter...
    }

    @Embeddable
    public class ContactId extends BaseId implements Serializable {

       @Column(name = "Id_Contact", precision = 9)
       private Long id;

      ...getter, setter...
    }

    @Entity
    public class Contact extends Base {

      @EmbeddedId
      private ContactId contactId;

      ...getter, setter...
    }

   @Entity(name = "Employee")
   public class Employee extends Base {

    @EmbeddedId
    private EmployeeId id;

    @MapsId("contactId")
    @JoinColumns(value = {
            @JoinColumn(referencedColumnName = "Mandant"),
            @JoinColumn(referencedColumnName = "Id_Contact")
    })
    @OneToOne(fetch = FetchType.LAZY)
    private Contact contact;

       ...getter, setter...
    }

   @Embeddable
   public class EmployeeId extends BaseId implements Serializable {

     @Column(name = "Id_Employee", precision = 9)
     private Long id;

     private ContactId contactId;

      ...getter, setter...
    }

我来自.Net世界，我对JPA还不太熟悉。有人可以给我一个友好的提示，说明我做错了什么，或者我的实施问题出在哪里，拜托？

祝你好运新闻记者

P.s。：Spring 4和Hibernate 5

Answer 1

使用共享组合密钥的解决方案：

没有＆＃34; id＆＃34;在@MapsId框架中生成以下查询：

＆＃34;插入EMPLOYEE_DETAILS（AEN_DATUM，SACHB_KZ，DETAILS，employee_id_employee，employee_MANDANT）值（？，？，？，？，？）＆＃34;

添加＆＃34; id＆＃34;到@MapsId查询是：

＆＃34;插入EMPLOYEE_DETAILS（AEN_DATUM，SACHB_KZ，DETAILS，id_employee，MANDANT）值（？，？，？，？，？）＆＃34;

@Entity(name = "Employee")
@Table(name = "EMPLOYEE")
public class Employee extends Base {

    @EmbeddedId
    private EmployeeId id;

    @Column(name = "FIRST_NAME", length = 100, nullable = false)
    private String firstName;

    @Column(name = "SUR_NAME", length = 100, nullable = false)
    private String surName;
...
}

@Embeddable
public class EmployeeId extends BaseId implements Serializable {

    @Column(name = "id_employee", precision = 9)
    private Long employeeId;
...
}

@Entity(name = "EmployeeDetails")
@Table(name = "EMPLOYEE_DETAILS")
public class EmployeeDetails extends Base {

    @EmbeddedId
    private EmployeeId id;

    @Column(name = "DETAILS", nullable = false)
    private String details;

    @MapsId("id")
    @OneToOne
    private Employee employee;
...
}

它与上面的实现不一样，但问题是一样的。该查询是使用CONTACT_MANDANT而非MANDANT生成的。

和平

JPA /休眠。如何自动阻止继承字段获取类前缀

1 个答案: