一对多映射到超类的属性

Question

我有一个超类Questions及其子类MultipleChoiceQuestions

超类有一个领域 activity

我想创建一个Set<MultipleChoiceQuestions>并使用OneToMany注释mappedBy = "activity"

例如

@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "activity" )
private Set<NQIMultipleChoiceQuestions> mcqQuestions = new HashSet<NQIMultipleChoiceQuestions>();

我收到此错误:

org.hibernate.AnnotationException: mappedBy reference an unknown target entity property 

但是,如果我创建一组超类实体,它工作正常,

例如

@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "activity")
private Set<NQIQuestions> questions = new HashSet<NQIQuestions>();

有没有办法映射到超类的属性？

Answer 1

找到了解决方案...... :)

我们可以通过定义targetEntity =来实现这一目的.在OneToMany定义中..

例如..

@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.ALL, mappedBy = "activity" , targetEntity=NQIQuestions.class)    
private Set<NQIMultipleChoiceQuestions> mcqQuestions = new HashSet<NQIMultipleChoiceQuestions>();