Sort the table values in asc or desc

Question

I have a table named date_table contains two columns (Term,multiplier) with values given below
Term Multiplier
1 M
2 M
8 Y
15 D
2 Y
24 M
1800 D
Values given above are term and multipiler.Means 1 M stands 1 month,15 D stands for 15 Days 2 Y stands for 2years. I need a query to select this values in asc or desc order as given below
Term Multiplier
15 D
1 M
2 M
24 M
2 Y
1800 D
8 Y

Answer 1

As others have mentioned, there isn't a fixed number of days in a month or a year so it would be incorrect to assume 28, 30 or 31 days in a month or that there are 365 days in a year (as leap years have 366).
The truest way to determine it is to calculate it using proper date functionality around a base date e.g. you could calculate it from todays date...
SQL> ed
Wrote file afiedt.buf
  1  with t as (select 1 as term, 'M' as multiplier from dual union all
  2             select 2, 'M' from dual union all
  3             select 8, 'Y' from dual union all
  4             select 15, 'D' from dual union all
  5             select 2, 'Y' from dual union all
  6             select 24, 'M' from dual union all
  7             select 1800, 'D' from dual)
  8  --
  9  select term, multiplier
10  from t
11  order by case multiplier when 'D' then sysdate+term
12                           when 'M' then add_months(sysdate,term)
13                           else add_months(sysdate,12*term)
14*          end
SQL> /
      TERM M
        15 D
         1 M
         2 M
         2 Y
        24 M
      1800 D
         8 Y
7 rows selected.
SQL>This way, oracle will accurately work out the date offsets taking into account the number of days in each month and leap years.