我正在为数据库建模
有TRIPLE
,其中包含三个CONCEPT
。因此,类TRIPLE
的主键一起是三个uri
。 (一个概念可能在不同的TRIPLE
)
此外,TRIPLE
与另一个类ANNOTATION
相关,这是一个问题,如何识别triple_id
?但首先,如果构建此Id复合词是正确的。
为此建模:
Concept.java
@Entity
@Table(name = "concept")
public class Concept implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private String id;
private List<TripleDBModel> triples;
@ManyToMany(
cascade={CascadeType.ALL},
fetch=FetchType.LAZY,
mappedBy = "concepts"
)
public List<TripleDBModel> getTriples() {
return triples;
}
public void setTriples(List<TripleDBModel> triples) {
this.triples = triples;
}
ConceptPk.java
@Embeddable
public class ConceptPk implements java.io.Serializable {
private static final long serialVersionUID = 1L;
private String uri;
public ConceptPk(String uri, String label){
this.uri = uri;
}
public ConceptPk(){
super();
}
@Id
@Column(name = "uri", length = 100, unique = true, nullable = false)
public String getUri() {
return uri;
}
public void setUri(String uri) {
this.uri = uri;
}
}
Triple.java
@Entity
@IdClass(ConceptPk.class)
@Table(name = "triple")
public class TripleDBModel {
protected List<Annotation> annotations;
protected String conceptUriSubject;
protected String conceptUriObject;
protected String conceptUriPredicate;
@ManyToMany(
cascade={CascadeType.ALL},
fetch=FetchType.LAZY
)
@JoinTable(name = "triple_has_concept",
joinColumns=@JoinColumn(name="uri"),
inverseJoinColumns=@JoinColumn(name="triple_id")) //What shoul I write here???
public List<Annotation> getAnnotations() {
return annotations;
}
public void setAnnotations(List<Annotation> annotations) {
this.annotations = annotations;
}
@Id public String getConceptUriSubject() {
return conceptUriSubject;
}
public void setConceptUriSubject(String conceptUriSubject) {
this.conceptUriSubject = conceptUriSubject;
}
@Id public String getConceptUriObject() {
return conceptUriObject;
}
public void setConceptUriObject(String conceptUriObject) {
this.conceptUriObject = conceptUriObject;
}
@Id public String getConceptUriPredicate() {
return conceptUriPredicate;
}
public void setConceptUriPredicate(String conceptUriPredicate) {
this.conceptUriPredicate = conceptUriPredicate;
}
}
提前致谢!!
答案 0 :(得分:2)
你可以使用这样的Id类:
class TripleId implements Serializable {
@Column(...)
private String conceptUriSubject;
@Column(...)
private String conceptUriObject;
}
并在Triple中使用它:
@Entity
@Table(name = "triple")
public class TripleDBModel {
@EmbeddedId
private TripleId id;
...
}
另请注意,您可以提供多个连接列:
inverseJoinColumns= {@JoinColumn(name="subjectUri"), @JoinColumn(name="objectUri"), ... }