JPA Hibernate级联类型的孩子的孩子

问题描述

我正在寻找文档或回答级联如何对child的child进行工作，例如:

I was looking for documentation or answer how will the cascade work for child of child , example :

public class Parent{
  @OneToMany(fetch = FetchType.EAGER,mappedBy = "parent",cascade = CascadeType.ALL)
  private List<Child> child;
}

public class Child{
     @OneToMany(mappedBy="child")
      private List<AnotherChild> anohterChild;
    }
  @ManyToOne
    private Parent parent;
}

现在的问题是，父类中对子级"应用的级联运算是否会应用于"AnotherChild"?换句话说，如果我坚持父母"对象，它是否坚持"AnotherChild"?

now the question, will the cascade operation applied on "Child" from parent class apply to "AnotherChild" ?in other words if I persist "Parent" Object will it persist "AnotherChild" ?

推荐答案

如果您坚持自己的父母，则只有那些在您父母类的孩子列表中的孩子会被保留，而不是您孩子中的AnotherChilds列表，课.

If you persist your parent, only those childs which are in the child-list of your parent-class get persisted but not the list of AnotherChilds in your child-class.

如果您也想保留它们，也可以级联它:

If you wish to persist them too just cascade it too:

public class Child{
     @OneToMany(mappedBy="child", cascade = CascadeType.PERSIST)
     private List<AnotherChild> anohterChild;

     @ManyToOne
     private Parent parent;
}

并在真正需要时使用CascadeType.ALL，因为这种级联类型不仅包含持久性.如下图所示，CascadeType.ALL包括所有其他级联类型，包括级联类型"remove"，这意味着，当删除父对象时，所有其他子对象也将被删除.

And just use CascadeType.ALLwhen you really need it, because this cascade-type includes more than just persisting. As it is explained in the following picture, CascadeType.ALL includes all other cascade-types including the cascade-type "remove" which means that, when your parent-object gets removed, all other child-objects get removed too.

这篇关于JPA Hibernate级联类型的孩子的孩子的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！