休眠级联操作不起作用

Question

我在休眠时使用级联操作时遇到了一些问题。我有一个实体（TripleDBmodel），实体的主键是使用对三个对象（概念）的引用创建的。它工作的很完美，我也在这些对象上添加了级联操作，我认为TripleDBModel实体的保存操作也会保存数据库中不存在的概念。然而，它不是那样工作的。

@Entity 
@Table(name = "triple") 
public class TripleDBModel implements java.io.Serializable{ 

private Concept subject; 
private Concept object; 
private Concept predicate; 
public TripleDBModel(){ 

} 
@Id 
@ManyToOne(targetEntity=Concept.class) 
@Cascade(org.hibernate.annotations.CascadeType.SAVE_UPDATE) 
@JoinColumn(name="subject_uri") 
public Concept getSubject() { 
    return subject; 
} 
public void setSubject(Concept subject) { 
    this.subject = subject; 
} 
@Id 
@ManyToOne(targetEntity=Concept.class) 
@Cascade(org.hibernate.annotations.CascadeType.SAVE_UPDATE) 
@JoinColumn(name="object_uri") 
public Concept getObject() { 
    return object; 
} 
public void setObject(Concept object) { 
    this.object = object; 
} 
@Id 
@ManyToOne(targetEntity=Concept.class) 
@Cascade(org.hibernate.annotations.CascadeType.SAVE_UPDATE) 
@JoinColumn(name = "predicate_uri") 
public Concept getPredicate() { 
    return predicate; 
} 
public void setPredicate(Concept predicate) { 
    this.predicate = predicate; 
} 

} 


@Entity 
@Table(name = "concept") 
public class Concept implements java.io.Serializable { 

private String uri; 
private String label; 


// private List<TripleDBModel> triple; 

public Concept(String uri, String label) { 
    this.uri = uri; 
    this.label = label; 
    this.ontologies = new ArrayList<Ontology>(); 
} 

public Concept() { 
    super(); 
} 

@Id 
@Column(name = "uri", length = 255, unique = true, nullable = false) 
public String getUri() { 
    return uri; 
} 

public void setUri(String uri) { 
    this.uri = uri; 
} 
.... 

}

Answer 1

级联选项仅适用于关系的@OneToMany侧。

你应该知道什么时候你需要创建一个新的概念，所以单独坚持它不应该是一个问题？