JPA: Issue with loading One To Many relation

Question

Hi All,
I have a One to Many relation mapped as below
@Entity
@Table(name="ACCOUNT_TABLE")
public class UserAccount {
     // Attributes
     @Id
     @GeneratedValue(strategy=GenerationType.SEQUENCE,generator="USER_SEQ")
     @SequenceGenerator(name="USER_SEQ", sequenceName="USERS_SEQ",allocationSize=1)
     @Column(name="CLIENT_ID")
     private Long clientId;
     @Column(name="USER_ID")
     private String userId;
     @OneToMany(fetch=FetchType.LAZY, mappedBy="userAccount")
     @JoinColumn(name="USER_ID", referencedColumnName="USER_ID", insertable=false, updatable=false)
     private List<UserRole> assignedRoles;
@Entity
@Table(name = "ROLE_TABLE")
public class UserRole extends BaseEntity implements Serializable {
     private static final long serialVersionUID = -1651953276532642312L;
     @Id
     @Column(name = "USER_ID", length = 30, nullable=false, insertable=false, updatable=false)
     private String userId;
     @Column(name = "BUSINESS_CODE", length = 10, nullable=false, insertable=false, updatable=false)
     private String businessCode;
     @Column(name = "ROLE_NAME", length = 30, nullable=false, insertable=false, updatable=false)
     private String roleName;
     @ManyToOne()
     @JoinColumn(name="USER_ID", referencedColumnName="USER_ID", insertable=false, updatable=false)
     private UserAccount userAccount;
As you may have noticed, the tables are not joined on the Primary key of parent. This is legacy schema and I have to work with it.
Account and Role are joined by the USER_ID column. This I specified by providing JoinColumn.
Then I have a DAO to retrieve the relation based on user id.
public class UserAccountDAOJPAImpl UserAccountDAO{
     private static final String USER_ACCOUNT_BY_USERID = "select distinct ua " +
     "from UserAccount ua " +
     "left outer join fetch ua.assignedRoles ar " +
     "where ua.userId = ?1 ";
     public UserAccount findByUserName(String userName){          
          UserAccount userAccount=null;
          List<UserAccount> userAccounts =null;
     Query query = this.entityManager.createQuery(USER_ACCOUNT_BY_USERID);
     query.setParameter(1, userName.toUpperCase());
     userAccounts = query.getResultList();
     if(!userAccounts.isEmpty()) {
          userAccount=userAccounts.get(0);
          return userAccount;
When I test this code ( for the user Id I used in test there are 11 roles )
The SQL generated is correct, when I run the SQL in PL/SQL Developer, it returns the results as expected.
But the DAO method above returns one UserAccount object with List of 11 UserRole objects as expected. But all of these 11 UserRole objects are same, where as the query returns 11 different roles.
I couldn't figure out what I was doing wrong.
Any help is appreciated.
thanks,
Raghavan

Answer 1

@OneToMany(fetch=FetchType.LAZY, mappedBy="userAccount")
@JoinColumn(name="USER_ID", referencedColumnName="USER_ID", insertable=false, updatable=false)
private List<UserRole> assignedRoles;
}What do you get when you remove this @JoinColumn annotation? It shouldn't be necessary. (user_id seems a little suspect as the join column name by the way, I would have expected role_id here...)