Fetch JPA entities by discriminator column - spring

Question

I'm using single table inheritance and trying to fetch entities by their discriminator column but I'm getting errors ...
I don't have the discriminator value as a field in the class.
Here's my code :
User Class
#Entity
#Table(name = "MT_User")
#Inheritance(strategy = InheritanceType.SINGLE_TABLE)
#DiscriminatorColumn(name = "userType", discriminatorType = DiscriminatorType.STRING)
#DiscriminatorValue("CLASSIC")
public class User {
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private int uid;
public String imageFileName;
private String pseudo;
private String email;
private String password;
#ManyToMany(cascade = CascadeType.ALL)
#JoinTable(name = "MT_User_Playlist", joinColumns = #JoinColumn(name = "uid"), inverseJoinColumns = #JoinColumn(name = "tlid"))
private List<Playlist> playlists;
...
}
Admin Class
#Entity
#DiscriminatorValue("ADMIN")
public class Admin extends User implements SuperUser {
//no fields
...
}
User Repository
public interface UserRepository extends CrudRepository<User, Integer> {
User findByPseudo(String pseudo);
User findByEmail(String email);
void deleteByPseudo(String pseudo);
void deleteByEmail(String email);
List<User> findByUserType(String userType);
#Query("from mt_user where user_type=ADMIN")
List<User> findAdmins();
#Query("from mt_user where user_type=ADMIN and pseudo=?1")
User findAdminByPseudo(String pseudo);
}
Here are the errors I get :
Caused by: java.lang.IllegalArgumentException: org.hibernate.hql.internal.ast.QuerySyntaxException: mt_user is not mapped [from mt_user where user_type=ADMIN and pseudo=?1]
Caused by: java.lang.IllegalArgumentException: org.hibernate.hql.internal.ast.QuerySyntaxException: mt_user is not mapped [from mt_user where user_type=ADMIN]
Caused by: java.lang.IllegalArgumentException: Failed to create query for method public abstract java.util.List org.ThePouil.projects.mytunes.DAO.UserRepository.findByUserType(java.lang.String)! No property userType found for type User!
Thanks for your help !
:: EDIT ::
This solved my problems :
#Query("from User")
List<User> findUsers();
#Query("from Admin")
List<User> findAdmins();
#Query("from Admin where pseudo=?1")
User findAdminByPseudo(String pseudo);

Answer 1

You should use class name of your #Entity and not tables names in your queries. It should be from Admin or from User.