hibernate - 一对多映射到父类(super class)的属性

Question

我有一个父类(super class) Questions及其子类 MultipleChoiceQuestions

父类(super class)有一个字段 activity

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

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，如果我创建一组父类(super class)实体，它就可以正常工作，

例如

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

有没有办法映射到父类(super class)的属性？

Answer 1

找到了解决方案...:)

我们只需定义 targetEntity = ? 即可实现此目的在 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>();