Question

虽然我对此做了一些研究，但我发现在互联网上开了很多威胁，我无法解决我的问题。我附上我的代码：

Triple.java 主键由三个不同概念的3个URI组成，但它是同一列（这是一个问题吗？）

        @Entity
        @IdClass(ConceptPk.class)
        @Table(name = "triple")
        public class TripleDBModel {

            protected List<Annotation> annotations;
            public String conceptUriSubject;
            public String conceptUriObject;
            public String conceptUriPredicate;
            public String id;



            @ManyToMany(
                    cascade={CascadeType.ALL},  
                    fetch=FetchType.LAZY
            )   
            @JoinTable(name = "triple_has_annotation", 
                    joinColumns=@JoinColumn(name="annotation_id"),
                    inverseJoinColumns={@JoinColumn(name="uri_concept_subject", referencedColumnName="triple_id"), @JoinColumn(name="uri_concept_object", referencedColumnName="triple_id"), @JoinColumn(name="uri_concept_predicate", referencedColumnName="triple_id")
         })//EDIT
            public List<Annotation> getAnnotations() {
                return annotations;
            }
            public void setAnnotations(List<Annotation> annotations) {
                this.annotations = annotations;
            }
            @Id 
            @Column(name = "uri_concept_subject", length = 100)
            public String getConceptUriSubject() {
                return conceptUriSubject;
            }
            public void setConceptUriSubject(String conceptUriSubject) {
                this.conceptUriSubject = conceptUriSubject;
            }
            @Id 
            @Column(name = "uri_concept_object", length = 100)
            public String getConceptUriObject() {
                return conceptUriObject;
            }
            public void setConceptUriObject(String conceptUriObject) {
                this.conceptUriObject = conceptUriObject;
            }
            @Id 
            @Column(name = "uri_concept_predicate", length = 100)
            public String getConceptUriPredicate() {
                return conceptUriPredicate;
            }
            public void setConceptUriPredicate(String conceptUriPredicate) {
                this.conceptUriPredicate = conceptUriPredicate;
            }

 @Id
        @Column(name = "triple_id", unique = true, nullable = false)
        public String getId() {
            return id;
        }
        public void setId(String id) {
            this.id = id;
        }
    }

ConceptPk.java

    @Embeddable
    public class ConceptPk implements java.io.Serializable {

        private static final long serialVersionUID = 1L;
        public String conceptUriSubject;
        public String conceptUriObject;
        public String conceptUriPredicate;

        @Id
        @Column(name = "uri", length = 100, unique = true, nullable = false)
        public String getConceptUriSubject() {
            return conceptUriSubject;
        }
        public void setConceptUriSubject(String conceptUriSubject) {
            this.conceptUriSubject = conceptUriSubject;
        }

        @Id
        @Column(name = "uri", length = 100, unique = true, nullable = false)
        public String getConceptUriObject() {
            return conceptUriObject;
        }
        public void setConceptUriObject(String conceptUriObject) {
            this.conceptUriObject = conceptUriObject;
        }

        @Id
        @Column(name = "uri", length = 100, unique = true, nullable = false)
        public String getConceptUriPredicate() {
            return conceptUriPredicate;
        }
        public void setConceptUriPredicate(String conceptUriPredicate) {
            this.conceptUriPredicate = conceptUriPredicate;
        }

Annotation.java

    @Entity
    @Table(name = "annotations")
    public class Annotation {

        private Integer id;
        private List<TripleDBModel> triples;  

    @Id
        @GeneratedValue(strategy = GenerationType.IDENTITY)
        @Column(name = "annotation_id", unique = true, nullable = false)
        public Integer getId() {
            return id;
        }

        public void setId(Integer id) {
            this.id = id;
        }

    @ManyToMany(
                cascade={CascadeType.ALL},
                mappedBy = "annotations", //EDIT
                fetch=FetchType.LAZY
        )   
        public List<TripleDBModel> getTriples() {
            return triples;
        }

        public void setTriples(List<TripleDBModel> triples) {
            this.triples = triples;
        }

但是我收到了这个错误：

Caused by: org.hibernate.AnnotationException: A Foreign key refering TripleDBModel from Annotation has the wrong number of column. should be 3

我做错了什么？提前致谢

Answer 1

最终的解决方案是：

ConceptPk.java

@Embeddable
public class ConceptPk implements java.io.Serializable {

    private static final long serialVersionUID = 1L;
    public Concept conceptUriSubject;
    public Concept conceptUriObject;
    public Concept conceptUriPredicate;

    @Id 
    @ManyToOne(cascade=CascadeType.MERGE)
    @JoinColumn(name="uri_concept_subject")
    public Concept getConceptUriSubject() {
        return conceptUriSubject;
    }
    public void setConceptUriSubject(Concept conceptUriSubject) {
        this.conceptUriSubject = conceptUriSubject;
    }

    @Id 
    @ManyToOne(cascade=CascadeType.MERGE)
    @JoinColumn(name="uri_concept_object")
    public Concept getConceptUriObject() {
        return conceptUriObject;
    }
    public void setConceptUriObject(Concept conceptUriObject) {
        this.conceptUriObject = conceptUriObject;
    }

    @Id 
    @ManyToOne(cascade=CascadeType.MERGE)
    @JoinColumn(name="uri_concept_predicate")
    public Concept getConceptUriPredicate() {
        return conceptUriPredicate;
    }
    public void setConceptUriPredicate(Concept conceptUriPredicate) {
        this.conceptUriPredicate = conceptUriPredicate;
    }

Triple.java

@Entity
@IdClass(ConceptPk.class)
@Table(name = "triple")
public class TripleDBModel {

    protected List<Annotation> annotations;
    public Concept conceptUriSubject;
    public Concept conceptUriObject;
    public Concept conceptUriPredicate;



    @ManyToMany(
            cascade={CascadeType.ALL }, 
            fetch=FetchType.LAZY
    )   
    @JoinTable(name = "triple_has_annotation", 
            joinColumns={@JoinColumn(name="uri_concept_subject"), @JoinColumn(name="uri_concept_object"), @JoinColumn(name="uri_concept_predicate") },          
            inverseJoinColumns=@JoinColumn(name="annotation_id") )
    public List<Annotation> getAnnotations() {
        return annotations;
    }
    public void setAnnotations(List<Annotation> annotations) {
        this.annotations = annotations;
    }
    @Id 
    @Column(name = "uri_concept_subject", length = 100)
    public Concept getConceptUriSubject() {
        return conceptUriSubject;
    }
    public void setConceptUriSubject(Concept conceptUriSubject) {
        this.conceptUriSubject = conceptUriSubject;
    }
    @Id 
    @Column(name = "uri_concept_object", length = 100)
    public Concept getConceptUriObject() {
        return conceptUriObject;
    }
    public void setConceptUriObject(Concept conceptUriObject) {
        this.conceptUriObject = conceptUriObject;
    }
    @Id 
    @Column(name = "uri_concept_predicate", length = 100)
    public Concept getConceptUriPredicate() {
        return conceptUriPredicate;
    }
    public void setConceptUriPredicate(Concept conceptUriPredicate) {
        this.conceptUriPredicate = conceptUriPredicate;
    }

}

Answer 2

我不确定这是您收到的错误消息的原因，但您的映射有几个错误：

@JoinColumn属性中的每个inverseJoinColumns都应指定其referencedColumnName属性。
应切换joinColumns和inverseJoinColumns属性的值。 joinColumns用于引用源实体。 inverseJoinColumns用于引用目标实体。
mappedBy属性应为annotations，而不是annotation
（无关，但可能不正确）：cascade=CascadeType.ALL可能不是你想要的多对多。删除此三元组时，您不希望删除三元组的所有注释，因为这些注释会被其他三元组引用。

Answer 3

@ManyToMany(
        cascade={CascadeType.ALL},
        mappedBy = "annotation",
        fetch=FetchType.LAZY
)   
public List<TripleDBModel> getTriples() {
    return triples;
}

mappedBy应为“注释 s ”

编辑：查看this wikibook，尤其是底部。这是关联映射等的非常好的参考。

从Annotation引用Triple的外键具有错误的列数。

3 个答案: