title: Java: I'm not able to use the crud Repository deleteByID() to remove instance from my entity
body: <p>As a beginner in OOP, I'm facing a lot of problems in my exercise.
  I would like to know, how can I remove <code>employe</code> from <code>myrunner.java</code> with the <code>deleteById()</code>.</p>
  
  <p>My Repository </p>
  
  <pre><code>import com.ipiecoles.java.eval2x0.model.Employe;
  
  import org.springframework.data.domain.Page;
  import org.springframework.data.domain.Sort.Direction;
  import org.springframework.data.jpa.repository.Query;
  import org.springframework.data.repository.PagingAndSortingRepository;
  import org.springframework.data.repository.query.Param;
  import org.springframework.stereotype.Repository;
  import java.awt.print.Pageable;
  import java.util.List;
  
  @Repository
  public interface EmployeRepository extends PagingAndSortingRepository&lt;Employe, Long&gt; {
      /**
       * Méthode qui cherche un employé selon son matricule
       * @param matricule
       * @return l'employé de matricule correspondant, null sinon
       */
      Employe findByMatricule(String matricule);
  }
  
  </code></pre>
  
  <p>My runner </p>
  
  <pre><code>private void afficheMenuSupprimerEmploye() {
          System.out.println("=====================================");
          System.out.println("Suppression de l'employé de matricule : ");
          String MatSupprimer = litString(REGEX_MATRICULE); // regex conditions
          System.out.println(MatSupprimer);
  
          Employe deleteEmploye =  employeRepository.findByMatricule(MatSupprimer);
          System.out.println(deleteEmploye); // return null ...
  
          Employe.deleteByID(MatSupprimer);
  
      }
  </code></pre>