Java 删除一对一关系中的持久化对象
我使用openjpa作为映射层,我有两个模型: 用户: 和形象Java 删除一对一关系中的持久化对象,java,openjpa,Java,Openjpa,我使用openjpa作为映射层,我有两个模型: 用户: 和形象 @Entity @Table(name = "IMAGES") public class Image { @Id @GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "images_id_gen") @SequenceGenerator(name = "images_id_gen", sequenceName = "manage.ima
@Entity
@Table(name = "IMAGES")
public class Image
{
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "images_id_gen")
@SequenceGenerator(name = "images_id_gen", sequenceName = "manage.image_id", allocationSize=1)
@Column(name = "id")
private int _id;
这是单向的一对一关系
问题是,我想删除图像而不删除用户,当我删除一个用户时,然后删除与他关联的图像
现在,当我删除一个图像时,它也会删除用户 找到了解决办法。
我将图像字段设置为null,保存用户对象,然后删除图像。只需删除cascade=CascadeType.ALL即可
@Entity
@Table(name = "IMAGES")
public class Image
{
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE,generator = "images_id_gen")
@SequenceGenerator(name = "images_id_gen", sequenceName = "manage.image_id", allocationSize=1)
@Column(name = "id")
private int _id;