with t1 (id_mag,fio) as (
select 1,'Иванов' from dual union all
select 2,'Иванов' from dual union all
select 4,'Филипп' from dual union all
select 3,'Смирнов' from dual )
,t2 (id_mag,s) as (
select 1,200 from dual union all
select 2,200 from dual union all
select 3,300 from dual )
select fio,count(distinct(t1.id_mag)) cc_mag,sum(s) ssum
from t1,t2 where t2.id_mag(+)=t1.id_mag
group by fio
order by 1
/

FIO         CC_MAG       SSUM
------- ---------- ----------
Иванов           2        400
Смирнов          1        300
Филипп           1

SQL> ed
Wrote file afiedt.buf

  1  with t1 (id_mag,fio) as (
  2  select 1,'Иванов' from dual union all
  3  select 2,'Иванов' from dual union all
  4  select 4,'Филипп' from dual union all
  5  select 3,'Смирнов' from dual )
  6  ,t2 (id_mag,s) as (
  7  select 1,200 from dual union all
  8  select 2,200 from dual union all
  9  select 3,300 from dual )
 10  select fio,count(distinct(t1.id_mag)) cc_mag,sum(s) ssum
 11  from t1,t2 where t2.id_mag=t1.id_mag
 12  group by fio
 13* order by 1
SQL> /

FIO         CC_MAG       SSUM
------- ---------- ----------
Иванов           2        400
Смирнов          1        300

SQL>

SQL> with t1 (id_mag,fio) as (
  2  select 1,'Иванов' from dual union all
  3  select 2,'Иванов' from dual union all
  4  select 4,'Филипп' from dual union all
  5  select 3,'Смирнов' from dual )
  6  ,t2 (id_mag,s) as (
  7  select 1,200 from dual union all
  8  select 2,200 from dual union all
  9  select 3,300 from dual )
 10  select
 11    fio,count(distinct(t1.id_mag)) cc_mag,sum(s) ssum
 12  from t1 Left Join t2 on (t2.id_mag=t1.id_mag)
 13  group by fio
 14  order by 1
 15  /

FIO         CC_MAG       SSUM
------- ---------- ----------
Иванов           2        400
Смирнов          1        300
Филипп           1