create table #temp2 (idprat int, idfil int, nomefil varchar(200), nprat int, nlinee int, tipo int, importo decimal(10,2))
insert into #temp2 (idprat, idfil, nomefil, nprat, nlinee,tipo, importo)
select
pr.Id_prat,
pr.Id_fil,
fil.Fil_Denominazione,
1 as nr_pratiche,
case when pl.ID_linea is null then null else 1 end as nr_linee,
pr.prat_atip_banca, --1 pratica banca, 0 pratica 
pl.prlin_importo
from Pratiche as pr
full join Pratiche_Linee as pl
on  pl.Id_prat = pr.Id_prat
join Filiali as fil
on pr.Id_fil = fil.ID_Fil
where 
pr.Id_ist=1 and 
pr.prat_data between '01/01/2017' and '31/01/2017'
select 
idfil, 
nomefil,
nprat, 
case when count(idprat) > 1 then sum(nlinee) else sum(isnull(nlinee,'0')) end as nlinee,
tipo, 
sum(importo)as imp
from #temp2
group by idprat,idfil,nomefil,nprat,tipo
order by idfil