How to split amount to months using query?

Question

I have, for example simplified, this result from query (select... from... where...):

id months amount
1  2     120
1  6      180
2  2     120
2  6      180

Now I need to get, from first table above, ANOTHER table and it should look like this:

id months month_name amount
   2                 120
1  2      2013-04    60
1  2      2013-05    60
   6      180
1  6      2013-04     30
1  6      2013-05     30
1  6      2013-06     30
1  6      2013-07     30
1  6      2013-08     30
1  6      2013-09     30
   2      120
2  2      2013-04     60
2  2      2013-05     60
   6      180
2  6      2013-04     30
2  6      2013-05     30
2  6      2013-06     30
2  6      2013-07     30
2  6      2013-08     30
2  6      2013-09     30

No idea how to get this result by query? Should I use procedure? If so - any examples?

EDITED: It seems I need now: If given date is more than a month (lets say two months) before sysdate then the first amount should be doubled and all split should be done in 1 month less. Hard to explain. For example ....add_months(to_date('2013-03','yyyy-mm'), N.l-1) as month_name... taking sysdate is 2013-04, then result should appear:

id months month_name amount
   2                 120
1  2      2013-03    120
   6      180
1  6      2013-03     60
1  6      2013-04     30
1  6      2013-05     30
1  6      2013-06     30
1  6      2013-07     30
   2      120
2  2      2013-03     60
   6      180
2  6      2013-03     60
2  6      2013-04     30
2  6      2013-05     30
2  6      2013-06     30
2  6      2013-07     30

Answer 1

In 9i and higher versions you can:

select decode(flag, 'original', null, id), months, amount
from(
    select id, 
           months, 
           add_months(to_date('2013-04','yyyy-mm'), N.l-1) as month_name,
           amount/months as amount, 
           'splitted' as flag
    from your_table t
    join (select level l from dual connect by level < 1000) N
    on (t.months >= N.l)

    union all

    select id, months, amount, null, 'original'
    from your_table
)
order by id, months;

Answer 2

with Oracle 11 you can do a recursive query to get it.

with base_Query as (select * from test),
data (id, months, amount, iter, month_amount) 
  as (select id, months, amount, 0, amount/months
        from base_Query
      union all
      select id, months, amount, iter+1, month_amount
        from data
       where iter+1 <= months)
select case when iter = 0 then to_number(null) else id end id, 
       months, 
       case when iter = 0 then amount else month_amount end amount
  from data d
 order by d.id, months;

eg http://sqlfiddle.com/#!4/27edc/1

10g modelling variant too:

with base_query as (select rownum r, t.*, amount/months monthly_amount from test t)
select case i when 0 then to_number(null) else id end id,
       months, amount
  from base_query
model
partition by (r)
dimension by (0 as i)
measures (months, amount, monthly_amount, id)
rules (
  id[for i from 0 to months[0] increment 1] = id[0],
  amount[any] = case cv(i) when 0 then amount[0] else monthly_amount[0] end,
  months[any] = months[0]
);

http://sqlfiddle.com/#!4/27edc/4

i added rownum to get a unique addresssing system, as your data had non-unique id's!

Answer 3

Your question seems incomplete. I think you just wanted the data from table by removing the Where condition. So please try with "SELECT * FROM YOUR_TABLE_NAME"

This should give you the result you were searching for if I am correct with your incomplete question