Java 从服务发送数据并获取级联="；“全部删除孤立项”；不再被引用

我从服务层（非托管）获取数据

但是

我的代码：

//Parent
@OneToMany(cascade = CascadeType.ALL, fetch = FetchType.LAZY, mappedBy = "parent", orphanRemoval = true)
private Collection<Child> childCollection;

//Child
@JsonIgnore
@ManyToOne(optional = false)
@JoinColumn(name = "ID_PARENT", referencedColumnName = "ID_PARENT")
private Parent parent;

谢谢

find(parent);
parent.child.clear();
flush();