Utilisez des cellules d'information au lieu des têtes de colonne

Essayez-le. Mais d'abord, retirez d'abord l'espace vide de gauche et droit du côté de l'étude.

select isnull([Studying],0)+isnull([Cancel],0)+isnull([Laying off],0)   [All],  Orientation_Name,[Studying],[Cancel],[Laying off] 
from
(
select s.id,o.Name Orientation_Name ,ss.Name  StudyStatus_Name
 from Stu s inner join StudyStatus ss  on s.ID_StudyStatus=ss.ID inner join Orientation O on o.Id=s.ID_Orientation)as st
 pivot
 (
 count(id)
 FOR StudyStatus_Name   IN ([Studying],[Cancel],[laying off])
) as PV

Vous pouvez aller pour la somme conditionnelle et obtenir les résultats.

SELECT o.name,   
       COUNT(*) AS All, 
       SUM(CASE WHEN ss.Name = 'Studying' THEN 1 ELSE 0 END) AS Studying,   
       SUM(CASE WHEN ss.Name = 'Cancel' THEN 1 ELSE 0 END) AS cancel,
       SUM(CASE WHEN ss.Name = 'Laying Off' THEN 1 ELSE 0 END) AS LayingOff
FROM Orientation as o
inner join Stu as s
on s.id_orientation = s.id
inner join StudyStatus AS ss
on ss.id = s.id_StudyStatus
GROUP BY o.name

select isnull([Studying], 0) + isnull([Cancel], 0) + isnull([laying off], 0) [All],
    Orientation_Name,
    [Studying],
    [Cancel],
    [laying off]
from (
        select s.id,
            o.name Orientation_Name,
            ss.name StudyStatus_Name
        from Stu s
            inner join StudyStatus ss on ss.id = s.id_StudyStatus
            inner join Orientation o on o.id = s.id_Orientation
    ) as st pivot (
        count(id) FOR StudyStatus_Name IN ([Studying], [Cancel], [laying off])
    ) as PV

  Pay attention to uppercase and lowercase letters Move Inner Join
  
  Thanks to @LiaqatKundi and @DaleK