JPA OneToOne关联,其中2个实体使用复合主键但使用不同的列名？

Question

我们正在尝试将Hibernate与一个使用大量复合键的数据库一起使用,这让我们感到非常头疼.不幸的是,我们无法更改架构,因此我们必须在字段之间进行大量额外的映射.我们仅限于使用JPA 1.0和Hibernate 3.3.

到目前为止,我们遇到的最大问题是使用2个值的复合键在两个实体之间进行一对一关联,其中表对这些列具有不同的名称(DB具有命名约定每列的特定于表的前缀.)

每当我们执行查询时,都会遇到以下异常:

Caused by: org.hibernate.TypeMismatchException Provided id of the wrong type for class com.business.entity.InvestorIssuerEmailEntity.  
Expected: class com.business.entity.InvestorIssuerEmailEntityPK, got class com.business.entity.InvestorIssuerEntityPK; 

这些表的两个类InvestorIssuerEntity和InvestorIssuerEmailEntity具有可选的@OneToOne关联(在某些情况下,InvestorIssuer在InvestorIssuerEmail中没有匹配的记录):

@IdClass(InvestorIssuerEntityPK.class)
@Table(name = "T090_INVESTOR_ISSUER")
@Entity
InvestorIssuerEntity
    @Column(name = "T090_091_INVESTOR_ID", nullable = false, insertable = true, 
updatable = true, length = 18, precision = 0)
    @Id
    private Long investorId;

    @Column(name = "T090_102_ISSUER_ID", nullable = false, insertable = true, 
updatable = true, length = 18, precision = 0)
    @Id
    private Long issuerId;

(other fields omitted)

    @OneToOne(optional = true)
    @JoinColumns(value = {
            @JoinColumn(name="T090_091_INVESTOR_ID", referencedColumnName = "T284_INVESTOR_ID", nullable = false, insertable = false, updatable = false),
            @JoinColumn(name = "T090_102_ISSUER_ID", referencedColumnName = "T284_ISSUER_ID", nullable = false, insertable = false, updatable = false)
    })
    @NotFound(action = NotFoundAction.IGNORE)
    private InvestorIssuerEmailEntity investorIssuerEmail;

... 

InvestorIssuerEntityPK 
    @Id
    @Column(name = "T090_091_INVESTOR_ID", nullable = false, insertable = true, 
updatable = true, length = 18, precision = 0)
    private Long investorId;

    @Id
    @Column(name = "T090_102_ISSUER_ID", nullable = false, insertable = true, 
updatable = true, length = 18, precision = 0)
    private Long issuerId;

...

@IdClass(InvestorIssuerEmailEntityPK.class)
@Table(name = "T284_INVESTOR_ISSUER_EMAIL")
@Entity
InvestorIssuerEmailEntity
    @Column(name = "T284_INVESTOR_ID", nullable = false, insertable = true, 
updatable = true, length = 18, precision = 0)
    @Id
    private Long investorId;

    @Column(name = "T284_ISSUER_ID", nullable = false, insertable = true, 
updatable = true, length = 18, precision = 0)
    @Id
    private Long issuerId;

...

InvestorIssuerEmailEntityPK 

    @Column(name = "T284_INVESTOR_ID", nullable = false, insertable = true, 
updatable = true, length = 18, precision = 0)
    @Id
    private Long investorId;

    @Column(name = "T284_ISSUER_ID", nullable = false, insertable = true, 
updatable = true, length = 18, precision = 0)
    @Id
    private Long issuerId;  

我试图通过对两个实体使用与@EmbeddableId相同的类来解决Type Mismatch问题,然后使用@AttributeOverrides,如下所示:

@Id
@EmbeddedId
@AttributeOverrides({
        @AttributeOverride(name = "investorId",
                column = @Column(name = "T284_INVESTOR_ID", nullable = false, insertable = true, updatable = true, length = 18, precision = 0)),
        @AttributeOverride(name = "issuerId",
                column = @Column(name = "T284_ISSUER_ID", nullable = false, insertable = true, updatable = true, length = 18, precision = 0))
})
private InvestorIssuerId investorIssuerId;

我只对这两个实体进行了更改,仍然对其他实体使用@IdClass方法(是否仅为您的实体使用@IdClass或@EmbeddableId,而不是两者？)

我们最终得到了其他问题,例如"实体映射中的重复列",所以我们已经恢复了这种方法,看看是否还有其他解决方法.

有没有人有任何解决方案来解决这个问题？我查看了StackOverflow,但没有遇到协会中使用的复合键具有不同名称的任何情况.

注意: 即使在尝试下面的建议之后,我们仍会收到此错误:org.hibernate.MappingException:实体映射中的重复列:com.business.entity.InvestorIssuerEntity列:T090_091_INVESTOR_ID(应使用insert ="false"update = "假")

我甚至从InvestorIssuerEntity删除了所有关联,但仍然遇到了同样的问题.当我删除复合键类中的@Column注释时,错误才消失.当然,查询不起作用,因为没有映射到投资者ID!我不明白Hibernate在哪里找到"映射中的重复列",因为除了复合键之外,我已经删除了除T090_091_INVESTOR_ID之外的所有其他内容.

我们在InvestorIssuerEntity中有其他关联,它们在相同的主键上进行连接,但关联的实体在其组合键中也有其他列.一旦你使用@EmbeddedId,你应该将它们用于所有实体吗？我们仍然将@IdClass用于其他类.但那又如何在任何地方引起"重复列"呢？

Answer 1

看来我为你的案子找到了一个有效的解决方案:

@Entity
public class InvestorIssuerEntity {
    @EmbeddedId 
    private InvestorIssuerEntityPK investorIssuerEntityPK;

    @OneToOne(optional=true, mappedBy="investorIssuerEntity")
    private InvestorIssuerEmailEntity investorIssuerEmailEntity;
}

@Entity
public class InvestorIssuerEmailEntity {
    @EmbeddedId @AttributeOverrides({
        @AttributeOverride(name="investorId", column=@Column(name="T02_INV_ID")),
        @AttributeOverride(name="issuerId", column=@Column(name="T02_ISS_ID"))
    })
    private InvestorIssuerEntityPK investorIssuerEntityPK;

    @OneToOne(optional=true) @PrimaryKeyJoinColumns({
        @PrimaryKeyJoinColumn(name="T02_ISS_ID", referencedColumnName="T01_ISS_ID"), 
        @PrimaryKeyJoinColumn(name="T02_INV_ID", referencedColumnName="T01_INV_ID")
    })
    private InvestorIssuerEntity investorIssuerEntity;
}

@Embeddable
public class InvestorIssuerEntityPK implements Serializable {
    private static final long serialVersionUID = -1176248537673293674L;

    @Column(name="T01_INV_ID")
    private Long investorId;

    @Column(name="T01_ISS_ID")
    private Long issuerId;
}

它生成以下DDL,这似乎是您正在寻找的:

create table InvestorIssuerEmailEntity (
    T02_INV_ID bigint not null,
    T02_ISS_ID bigint not null,
    primary key (T02_INV_ID, T02_ISS_ID)
)

create table InvestorIssuerEntity (
    T01_INV_ID bigint not null,
    T01_ISS_ID bigint not null,
    primary key (T01_INV_ID, T01_ISS_ID)
)

alter table InvestorIssuerEmailEntity 
    add constraint FKC2FBCC4E1E26612E 
    foreign key (T02_INV_ID, T02_ISS_ID) 
    references InvestorIssuerEntity