从 JPA 到Hibernate的单表继承的迁移问题

Question

从标准 JPA （EclipseLink） 迁移到Hibernate时，由于子记录数量不正确和/或子对象的类型无效，测试失败。我认为问题是Hibernate生成的 SQL 没有在InheritanceType.SINGLE_TABLE关系的 where 子句中使用鉴别器列。

关于在映射中更改什么的任何建议？

提前感谢，

蒂莫西

环境

< li>postgres 9.6.17 < li >Spring靴/ JPA 2.4.0 < li>postgres mvn相关性42.2.18

域背景

一个Dc电机最多可以有2组连线。在实体中表示，每个连线都在自己的List中。这些连线是ARM或EQ类型的。由于连线上的属性相同，DBA选择了一个表，其中包含一个名为coil_type的鉴别器列，其值为ARM或EQ。

类定义

父实体

@Entity 
@Table(name = "dc_motor")
public class DcMotor implements Serializable {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    @Version
    private Integer version;
  //other direct fields

    @OneToMany(orphanRemoval = true, cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinColumn(name = "motor_id", referencedColumnName = "id", nullable = false)
    @OrderColumn(name = "idx")
    private List<WireArm> armWires;

    @OneToMany(orphanRemoval = true, cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    @JoinColumn(name = "motor_id", referencedColumnName = "id", nullable = false)
    @OrderColumn(name = "idx")
    private List<WireEq> eqWires;

WireArm 和 WireEq 的抽象基类

@Entity 
@Table(name = "dc_wire")
@Inheritance(strategy = InheritanceType.SINGLE_TABLE)
@DiscriminatorColumn(name = "coil_type", length = 10, discriminatorType = DiscriminatorType.STRING)
public abstract class DcWire implements IDcWire {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    // other direct fields
    // discriminator column coil_type is not explicitly listed as a field

具体子类

@Entity
@DiscriminatorValue(value = "ARM")
public class WireArm extends DcWire implements IDcWire {
    // just constructors
}

@Entity
@DiscriminatorValue(value = "EQ")
public class WireEq extends DcWire implements IDcWire {
    // just constructors
}

生成的 SQL

select /*all fields*/ from dc_motor dcmotor0_ where dcmotor0_.id=1;
select /* all fields EXCEPT coil_type*/ from dc_wire armwires0_ where armwires0_.motor_id=1;
select /* all fields EXCEPT coil_type*/ from dc_wire eqwires0_ where eqwires0_.motor_id=1;

Answer 1

我觉得这个可以用< code > org . hibernate . annotations . discriminator options(force = true)解决。