Question

I have some issue with save object with one to many relationship. In my problem One UserGrop has many UserPermissions. Forthat relation ship I have create my domain class like this:

@Entity
@Table(name = "tbl_usergroup")
public class UserGroup implements Serializable {

    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)    
    @Column(name="userGroupId")
    private long userGroupId;

    @Column(name = "userGroupName")
    private String userGroupName;

    @OneToMany(cascade=CascadeType.ALL,mappedBy="userGroup",fetch=FetchType.EAGER)
    private Set<UserPermissions> userPermissions = new HashSet<UserPermissions>(0);



}

@Entity
@Table(name = "tbl_group_permissions")
public class UserPermissions implements Serializable {

    @Id
    @GeneratedValue
    private Long userPermissionId;

    @ManyToOne(cascade =CascadeType.ALL)     
    @JoinColumn(name="userGroupId",nullable=false)
    @ForeignKey(name = "userGroupId")
    private UserGroup userGroup;


}

But When saving UserGroup, it save hat UserPermisions Objects also. There with the table it does not have any relationship(when retrieving UserGroup object, it doesn’t return Set of UserPermisions objects).

DB:

+------------------+-------------+
--+
| userPermissionId | userGroupId |
e |
+------------------+-------------+
--+
|               33 |        NULL |
  |
|               34 |        NULL |
  |
|               35 |        NULL |
  |
|               36 |        NULL |
  |
|               37 |        NULL |
  |
|               38 |        NULL |
  |
|               39 |        NULL |
  |
|               40 |        NULL |
  |
+------------------+-------------+
--+
8 rows in set (0.00 sec)

Can any body help me to solve this issue?

Answer 1

In the @OneToMany on UserGroup.userPermissions you have mappedBy="userGroup". This means the userGroup property in UserPermisions is responsible for the relation. I guess you don’t set that property and upon saving it’s still null.