SELECT
 (T_SAL.MatriculeSalarie || ' ' || NVL(T_SAL.Nom, ' ') || ' '  || NVL(T_SAL.Prenom, ' ') ) as Col1,
 'Date de départ : ' || TO_CHAR(T_HST_INFOSSOCIETE.DateDepart) || '- Motif : ' || TO_CHAR(NVL(T_HST_INFOSSOCIETE.CodeMotifDepart,' ')) as Col2
FROM
  T_PAI,
  T_SAL
  LEFT OUTER JOIN T_HST_INFOSSOCIETE ON T_HST_INFOSSOCIETE.NumSalarie=T_SAL.SA_CompteurNumero
                  AND T_HST_INFOSSOCIETE.InfoEnCours=1
Where    (CURRENT_TIMESTAMP >= NVL(-%NbJoursAvant%,0) + T_HST_INFOSSOCIETE.DateDepart)
      and (CURRENT_TIMESTAMP <= NVL(%NbJoursApres%,0) + T_HST_INFOSSOCIETE.DateDepart)

Order by T_SAL.MatriculeSalarie