Sum per month

Question

Hi
my oracle version 10g
With testdata as (select 1 trade_id, 110 trade_size, to_date('01/02/11',' dd/mm/yy') trade_date, ’AA’ source from dual union all
select 2 trade_id, 80 trade_size, to_date('25/01/11',' dd/mm/yy') trade_date, ’AB’ source from dual union all
select 3 trade_id, 210 trade_size, to_date('17/01/11',' dd/mm/yy') trade_date, ’BB’ source from dual union all
select 4 trade_id, 150 trade_size, to_date('15/02/11',' dd/mm/yy') trade_date, ’AA’ source from dual union all
select 5 trade_id, 260 trade_size, to_date('20/12/10',' dd/mm/yy') trade_date, ’AB’ source from dual union all
select 6 trade_id, 320 trade_size, to_date('15/12/10',' dd/mm/yy') trade_date, ’BB’ source from dual union all
select 7 trade_id, 100 trade_size, to_date('25/01/11',' dd/mm/yy') trade_date, ’CC’ source from dual union all
select 8 trade_id, 260 trade_size, to_date('10/01/11',' dd/mm/yy') trade_date, ’CC’ source from dual union all
select 9 trade_id, 200 trade_size, to_date('25/11/10',' dd/mm/yy') trade_date, ’AB’ source from dual union all
select 10 trade_id, 200 trade_size, to_date('05/01/11',' dd/mm/yy') trade_date, ’AB’ source from dual union all)
result would be
Sum of trade_size by source per month
Source—Feb.11—Jan.11—Dec.10—Nov.10
AA---------260-----------0----------0---------0
AB--------0-----------280---------260-------200
BB--------0-----------210---------320---------0
CC--------0-----------360----------0---------0

Answer 1

If it's for rolling previous 4 months, something like:
SQL> ed
Wrote file afiedt.buf
  1  With testdata as (select 1 trade_id, 110 trade_size, to_date('01/02/11',' dd/mm/yy') trade_date, 'AA' source from dual union all
  2                    select 2 trade_id, 80 trade_size, to_date('25/01/11',' dd/mm/yy') trade_date, 'AB' source from dual union all
  3                    select 3 trade_id, 210 trade_size, to_date('17/01/11',' dd/mm/yy') trade_date, 'BB' source from dual union all
  4                    select 4 trade_id, 150 trade_size, to_date('15/02/11',' dd/mm/yy') trade_date, 'AA' source from dual union all
  5                    select 5 trade_id, 260 trade_size, to_date('20/12/10',' dd/mm/yy') trade_date, 'AB' source from dual union all
  6                    select 6 trade_id, 320 trade_size, to_date('15/12/10',' dd/mm/yy') trade_date, 'BB' source from dual union all
  7                    select 7 trade_id, 100 trade_size, to_date('25/01/11',' dd/mm/yy') trade_date, 'CC' source from dual union all
  8                    select 8 trade_id, 260 trade_size, to_date('10/01/11',' dd/mm/yy') trade_date, 'CC' source from dual union all
  9                    select 9 trade_id, 200 trade_size, to_date('25/11/10',' dd/mm/yy') trade_date, 'AB' source from dual union all
10                    select 10 trade_id, 200 trade_size, to_date('05/01/11',' dd/mm/yy') trade_date, 'AB' source from dual
11                   )
12  --
13  -- end of test data
14  --
15  select source
16        ,max(mnth1) as mnth1
17        ,max(mnth2) as mnth2
18        ,max(mnth3) as mnth3
19        ,max(mnth4) as mnth4
20  from (
21        select source
22              ,case when trunc(trade_date,'MM') = trunc(sysdate,'MM') then sum(trade_size) else null end as mnth1
23              ,case when trunc(trade_date,'MM') = trunc(add_months(sysdate,-1),'MM') then sum(trade_size) else null end as mnth2
24              ,case when trunc(trade_date,'MM') = trunc(add_months(sysdate,-2),'MM') then sum(trade_size) else null end as mnth3
25              ,case when trunc(trade_date,'MM') = trunc(add_months(sysdate,-3),'MM') then sum(trade_size) else null end as mnth4
26        from testdata
27        group by source, trunc(trade_date,'MM')
28       )
29  group by source
30* order by source
SQL> /
SO      MNTH1      MNTH2      MNTH3      MNTH4
AA        260
AB                   280        260        200
BB                   210        320
CC                   360
SQL>