JPA ManyToOne Exception

I have the following entities:

@Entity
@Table("table_x")
public class X{

@id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

@ManyToOne
private Y y;
}

@Entity
@Table("table_y")
public class Y{
@id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;

}

@Repository
public interface XRepository extends JpaRepository, JpaSpecificationExecutor{
@Query(value= "select x.* from X x where x.y in :yList")
List getX(List yList);
}

when trying to call getX from XRepository while table_y is empty it throws:
Method threw 'org.springframework.dao.InvalidDataAccessResourceUsageException' exception.

could not extract ResultSet; SQL [n/a]

if table_y has records in the database, everything works fine