with tab as
 (select 'Andrey' as name, '02' as month, 100 as summa from dual
  union all
  select 'Andrey', '02', 200 from dual
  union all
  select 'Andrey', '03', 50 from dual)
select *
  from tab
pivot (sum(summa) for month in('01' as jan,
                               '02' as feb,
                               '03' as mar/*,
                               '04',
                               '05',
                               '06',
                               '07',
                               '08',
                               '09',
                               '10',
                               '11',
                               '12'*/))