QuerySyntaxException with enum - spring

Question

I have a UserAssignmentRole class like this :
#Data
#Entity
public class UserAssignmentRole {
...
#Enumerated(EnumType.STRING)
public Role role;
}
And the Role is enum, it looks like this:
public enum Role{
admin,
member,
pending
}
Now when in my repository I try to query to select all with role of admin, it gives me error:
#Query("select uar from UserAssignmentRole uar where uar.role=Role.admin")
public List<UserAssignmentRole> listAdmin(Long userID, Long assignmentID);
How this can be solved?
Error : org.hibernate.hql.internal.ast.QuerySyntaxException: Invalid path: 'Role.admin'
Full error : https://pastebin.com/tk9r3wDg

Answer 1

It is a strange but intended behaviour of Hibernate since 5.2.x
An enum value is a constant and you're using a non-conventional naming (lowercase)
Take a look at this issue and Vlad Mihalcea's long explanation of the performance penalty.
If you’re using non-conventional Java constants, then you’ll have to set the hibernate.query.conventional_java_constants configuration property to false. This way, Hibernate will fall back to the previous behavior, treating any expression as a possible candidate for a Java constant.

Answer 2

You can try not to write this sql by yourself but with repository create code like this:
#Repository
public interface UserAssignmentRolelRepository extends JpaRepository<UserModel, Long>{
public List<UserAssignmentRole> findByRole(Role role);
}
And then:
#Autowired
UserAssignmentRolelRepository repository ;
public void someMethod(){
List<UserAssignmentRole> userAssignmentRoles = repository.findByRole(Role.admin);
}
UPDATE 1
As it was point out in this answer: non-conventional naming. You can change labels in your enum to uppercase.
public enum Role{
Admin,
Member,
Pending
}
and then:
#Query("select uar from UserAssignmentRole uar where uar.role=com.example.package.Role.Admin")
public List<UserAssignmentRole> listAdmin(Long userID, Long assignmentID);
UPDATE 2
But if you really want to have lowercase in DB.
It requires more code to change. Enum change to:
public enum Role{
Admin("admin"),
Member("member"),
Pending("pending");
private String name;
Role(String name) {
this.name = name;
}
public String getName() { return name; }
public static Role parse(String id) {
Role role = null; // Default
for (Role item : Role.values()) {
if (item.name.equals(id)) {
role = item;
break;
}
}
return role;
}
}
In UserAssignmentRole
// #Enumerated(EnumType.STRING)
#Convert(converter = RoleConverter.class)
private Role role;
And additional class:
import javax.persistence.AttributeConverter;
import javax.persistence.Converter;
#Converter(autoApply = true)
public class RoleConverter implements AttributeConverter<Role, String> {
#Override
public String convertToDatabaseColumn(Role role) {
return role.getName();
}
#Override
public Role convertToEntityAttribute(String dbData) {
return Role.parse(dbData);
}
}