休眠JPA值删除OneToMany关系 [英] Hibernate JPA value removing OneToMany relation

问题描述

当我将AlarmnotifyEmailEntity的实例添加到alarmnotifyEmailEntityList对象并更新AlarmnotifyEmailConfEntity的实例时，值为save正确地进入数据库。

Bu当删除alarmnotifyEmailEntityList的一项时，我无法做同样的事情。
我相信这个值会从alarmnotifyEmailEntityList中移除，但并不会反映到数据库中的这些变化。 =alarmnotify_email_conf）
@Table（name =alarmnotify_email_conf）
public class AlarmnotifyEmailConfEntity implements Serializable {

@OneToMany（mappedBy =alarmnotifyEmailConfRef，cascade = CascadeType.ALL ）
私人列表< AlarmnotifyEmailEntity> alarmnotifyEmailEntityList;

$ //
$ b @Entity（name =alarmnotify_email）
@Table（name =alarmnotify_email）
public class AlarmnotifyEmailEntity实现了Serializable {
@JoinColumn（name =alarmnotify_email_conf_ref，referencedColumnName =id）
@ManyToOne
private AlarmnotifyEmailConfEntity alarmnotifyEmailConfRef;
}类的结尾

我只调用以下语句来更新。

JPAManager.getJPAManagerInstance（）。update（alarmnotifyemailconf）;

  public Object update（对象o）{
 
尝试{
 tx.begin（）; 
 EntityManager em = getEntityManager（）; 
 System.out.println（更新对象：+ o）; 
 o = em.merge（o）; 
 em.close（）; 
 tx.commit（）; 
 System.out.println（关闭并提交合并操作）; 
 return o; 
} 
 catch（Exception e）{
 e.printStackTrace（）; 
} 
 return o; 
  

}

解决方案我已经找到答案在 jpa从集合中删除孩子。
作为结果加入 orphanRemoval = true 解决了这个问题。

@Entity（name = alarmnotify_email_conf）
@Table（name =alarmnotify_email_conf）
public class AlarmnotifyEmailConfEntity implements Serializable {

@OneToMany（mappedBy =
alarmnotifyEmailConfRef，cascade = CascadeType.ALL， orphanRemoval = true ）
private列表alarmnotifyEmailEntityList;

 <$ c 
  

I have two tables where there is a OneToMany, MnatToOne relation.

When I have added instance of AlarmnotifyEmailEntity into alarmnotifyEmailEntityList object and update instance of AlarmnotifyEmailConfEntity, value is save properly into Database.

Bu I could not do the same thing when deleting one of the item of alarmnotifyEmailEntityList. I am sure that value is removed from alarmnotifyEmailEntityList but it does not reflect this changes into Database

    @Entity(name ="alarmnotify_email_conf")
    @Table(name = "alarmnotify_email_conf")
    public class AlarmnotifyEmailConfEntity implements Serializable {

    @OneToMany(mappedBy = "alarmnotifyEmailConfRef",cascade=CascadeType.ALL)
        private List<AlarmnotifyEmailEntity> alarmnotifyEmailEntityList;

    }//end of Class

    @Entity (name ="alarmnotify_email")
    @Table(name = "alarmnotify_email")
    public class AlarmnotifyEmailEntity implements Serializable {
     @JoinColumn(name = "alarmnotify_email_conf_ref", referencedColumnName = "id")
        @ManyToOne
        private AlarmnotifyEmailConfEntity alarmnotifyEmailConfRef;
    }end of Class

I am only invoking following statement to update.

JPAManager.getJPAManagerInstance().update(alarmnotifyemailconf);

 public Object update(Object o) {

  try {
     tx.begin();
     EntityManager em = getEntityManager();          
     System.out.println("updating object:" + o);
     o = em.merge(o);
     em.close();
     tx.commit();
     System.out.println("closed and commited merge operation");
     return o;
  }
  catch (Exception e) {
     e.printStackTrace();
  }
  return o;

}

解决方案

I have found out the answer in jpa removing child from collection. as a result adding orphanRemoval=true solved the problem.

@Entity(name ="alarmnotify_email_conf") @Table(name = "alarmnotify_email_conf") public class AlarmnotifyEmailConfEntity implements Serializable {

@OneToMany(mappedBy = "alarmnotifyEmailConfRef",cascade=CascadeType.ALL ,orphanRemoval=true) private List alarmnotifyEmailEntityList;

}//end of Class

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