如何在JPA中使用子类中的两个组合键和父类中的一个PK进行OneTONE映射

Question

我有以下错误说明

异常[EclipseLink-7220]（EclipsePersistenceServices-2.6.3.v20160428-59c81c5）：org。日食坚持不懈例外情况。ValidationException异常描述：实体类[class com.jlr.vista.business.rule.model.rule]中带注释元素[field specificationSubset]上的@JoinColumns不完整。当源实体类使用复合主键时，必须使用@JoinColumns为每个联接列指定@JoinColumn。必须在每个这样的@JoinColumn中指定name和referencedColumnName元素。

我已经找到了许多解决方案关于这个错误但他们都没有解决这种问题在每种情况下两个类都有相同数量的复合键但在我的情况下我有一个PK在实体类和FK在子类但孩子类还有一个PK，这使它们成为复合键。

在这种情况下，应如何实现@OneToOne映射？我使用的是EclipseLink版本2.6

规则JAVA

 public class Rule
    {
        private static final long serialVersionUID = 1L;


        @Id
        @Column(name="RULE_ID")
        @GeneratedValue(strategy=GenerationType.SEQUENCE,generator="RUL_SEQ1")
        @SequenceGenerator(name="_RUL_SEQ1",sequenceName="RUL_SEQ1",allocationSize=1)
        protected Integer ruleId;

        @Column(name="PARENT_RULE_ID")
        protected Integer parentRuleId;

        @Column(name="RULE_TYPE_CODE")
        protected String ruleTypeCode;

        @Column(name="BRAND")
        protected String brand;

        @Column(name="RULE_DESCRIPTION")
        protected String ruleDesscription;

        @Column(name="RULE_REFERENCE")
        protected String ruleReference;

        @Column(name="CONSTRAINT_TYPE")
        protected String constraintType;

        @Column(name="ARCHIVE_STATUS")
        protected String archiveStatus;

        @ManyToMany(targetEntity=VistaRulePartner.class, fetch=FetchType.LAZY)
        @JoinColumns({
            @JoinColumn(name="RULE_ID", referencedColumnName="RULE_ID")
        })
        protected List<VistaRulePartner> partners;

        @OneToMany(targetEntity=OrderTypeSubset.class,fetch=FetchType.LAZY,cascade=CascadeType.ALL)
        @JoinColumn(name="RULE_ID", referencedColumnName="RULE_ID",insertable=false,updatable=false)
        protected List orderTypeSubsets;
                    @OneToOne(targetEntity=SpecificationSubset.class,cascade=CascadeType.ALL,fetch=FetchType.LAZY,optional=false)
        @JoinColumn(name="RULE_ID",referencedColumnName="RULE_ID",insertable=false,updatable=false, nullable=false)
private SpecificationSubset specificationSubset;
}

规格子集。JAVA

@IdClass(SpecificationSubsetPK.class)
@Entity
@Table(name="RULE_SPECIFICATION")
@InstantiationCopyPolicy
@Cache( refreshOnlyIfNewer=true,
        coordinationType = CacheCoordinationType.SEND_NEW_OBJECTS_WITH_CHANGES)
public class SpecificationSubset extends ModelArchivable
{
    @Id
    @Column(name="RULE_ID")
    private Integer ruleId;

    @Id
    @Column(name="RULE_SPEC_ID")
    private Integer ruleSpecId = 1;

    @Column(name="SPEC_MARKET")
    private String specMarket;

    @Column(name="DESC_GROUP_ID")
    private String descGroupId;

    @OneToMany(targetEntity=FeatureSubset.class, fetch=FetchType.LAZY)
    @JoinColumns({
        @JoinColumn(name="RULE_ID", referencedColumnName="RULE_ID", insertable=false, updatable=false),
        @JoinColumn(name="RULE_SPEC_ID", referencedColumnName="RULE_SPEC_ID", insertable=false, updatable=false)
    })
    private List featureSubsets;

    @OneToOne(targetEntity=Rule.class, fetch=FetchType.LAZY)
    @JoinColumn(name="RULE_ID", referencedColumnName="RULE_ID")
    private Rule ruleHolder;
}

特点ubset.java

@Entity
@Table(name="RULE_FEATURE")
@NamedQuery(
        name="GetFeatureCodesForVehicleConfig",
        query="SELECT f FROM FeatureSubset f WHERE f.ruleId = :ruleId AND f.featureType = 'YEAR'")
@InstantiationCopyPolicy
@Cache( coordinationType = CacheCoordinationType.SEND_NEW_OBJECTS_WITH_CHANGES)
public class FeatureSubset
{
    @Id
    @Column(name="FEATURE_TYPE_NO")
    @GeneratedValue(strategy=GenerationType.SEQUENCE,generator="VISTA_RUF_SEQ1")
    @SequenceGenerator(name="RUF_SEQ1",sequenceName="RUF_SEQ1",allocationSize=1)
    private Integer featureTypeNo; //Sequence no for the vista_rule_feature table

    @Column(name="RULE_SPEC_ID")
    private Integer ruleSpecId = 1;

    @Column(name="RULE_ID")
    private Integer ruleId;

    @Column(name="FEATURE_TYPE_ID")
    private String featureType;

    @Column(name="FEATURE_CODE")
    private String featureCode;

    @OneToOne(targetEntity=SpecificationSubset.class, fetch=FetchType.LAZY)
    /*@JoinColumns({
        @JoinColumn(name="RULE_ID", referencedColumnName="RULE_ID"),
        @JoinColumn(name="RULE_SPEC_ID", referencedColumnName="RULE_SPEC_ID")
    })*/
    private SpecificationSubset specificationSubset;
}

Answer 1

您不需要在关系的两侧定义映射信息——一个就足够了，通常是关联的所有者。

因此，由于您的规范子集包含到规则的映射信息，因此在规则中，您可以引用此关系：

@OneToOne(targetEntity=SpecificationSubset.class,
          cascade=CascadeType.ALL,
          fetch=FetchType.LAZY,
          optional=false,
          mappedBy="ruleHolder")  // name of the property in an owning class
private SpecificationSubset specificationSubset;

似乎你也需要修复拥有方，因为你已经有了一个@列与RULE_ID名称：

@OneToOne(targetEntity=Rule.class, fetch=FetchType.LAZY)
@JoinColumn(name="RULE_ID", referencedColumnName="RULE_ID", insertable=false, updatable=false)
private Rule ruleHolder;