[FIXED] Spring Data JPA - Using @Query with Many to Many Relationships / Join Table

Issue

I have a User entity with a many-to-many relationship with a Role entity.

    @Entity
@Table(name = "auth_user")
public class OAuthUser {

    // @Autowired
    // @Transient
    // private PasswordEncoder passwordEncoder;
    //
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;

    @Column(name = "username")
    private String userName;

    @Column(name = "password")
    @JsonIgnore
    private String password;

    @Column(name = "first_name")
    private String firstName;

    @Column(name = "last_name")
    private String lastName;

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

    @Column(name = "is_enabled")
    private boolean isEnabled;

    /**
     * Reference:
     * https://github.com/nydiarra/springboot-jwt/blob/master/src/main/java/com/nouhoun/springboot/jwt/integration/domain/User.java
     * Roles are being eagerly loaded here because they are a fairly small
     * collection of items for this example.
     */
    @ManyToMany(fetch = FetchType.EAGER)
    @Fetch(value = FetchMode.SUBSELECT)
    @JoinTable(name = "user_role", joinColumns = @JoinColumn(name = "user_id", referencedColumnName = "id"), inverseJoinColumns = @JoinColumn(name = "role_id", referencedColumnName = "id"))
    private List<Role> roles;

    @ManyToMany(fetch = FetchType.EAGER)
    @Fetch(value = FetchMode.SUBSELECT)
    @JoinTable(name = "user_properties", joinColumns = @JoinColumn(name = "AuthID", referencedColumnName = "id"), inverseJoinColumns = @JoinColumn(name = "PropertyID", referencedColumnName = "id"))
    private List<Property> properties;

I am using the Spring Data JPA repositories, and would to be able to create a custom @Query that returns a list of users based upon a particular role id.

    @Query("SELECT u FROM auth_user as u WHERE u.isEnabled AND u.id IN"
        + " (SELECT r.user_id FROM user_role as r WHERE r.role_id = ?1)")
public List<OAuthUser> findByRole(int roleID);

The code above results in the error auth_user is not mapped. I do understand why I am getting the error; the framework is using the entity names (OAuthUser) rather than the table (auth_user) to perform the query. This would ordinarily not be a problem, except for there is no entity for user_role; it is simply a join table with two columns: 'user_id' and 'role_id'.

What is the appropriate way to achieve this?

Thanks.

Solution

The error says:

auth_user is not mapped

It refers to the auth_user used in the query like SELECT u FROM auth_user. It must be OAuthUser instead, in the query.

Answered By - Bhesh Gurung
Answer Checked By - Willingham (JavaFixing Volunteer)