with R2 as
(select distinct A.region_niv1 as ABSCISSE,strate,(count(no_site)*txa) as nb_pieces
from ci.pre_enquete_village A  inner join ci.liste_site  B using(no_enquete) inner join ci.calcul_txa using (strate)
where centre_aquacole_moderne=-1
group by A.region_niv1,txa,strate)
select distinct ABSCISSE,'' as GROUPE,sum(nb_pieces) as TOTAL
from R2
group by ABSCISSE
order by ABSCISSE