删除孤儿数据

//获得set，清空

umpActivity.getUmpActivityTypeSet().clear();

//设置新值，会将新的数据加进去，原来的全部会被删掉，因为?@Cascade(org.hibernate.annotations.CascadeType.ALL)
umpActivity.getUmpActivityTypeSet().addAll(newUmpActivityTypeSet);

?

?

@OneToMany(cascade = { CascadeType.ALL }, mappedBy = "umpActivity", fetch = FetchType.EAGER)
?@Cascade(org.hibernate.annotations.CascadeType.ALL)
?@JoinColumn(name = "activity_id")
?@OrderBy("umpType")
?public Set<UmpActivityType> getUmpActivityTypeSet() {
??return umpActivityTypeSet;
?}