Date format conversion

Question

In one of my receiving form I am storing the exp_date in the format RRRR/MM like 2010/03
And in my irradiation log form the user will enter or scan exp_date in the format 201003. (RRRRMM)
Now I hae to compare this date as validation with my recieving date.
So receiving has **2010/03**
and irradiation log has **201003**
How to use either decode or other function to remove the '/' and compare the dates in both tables
and then save the date in the log table in the format MM/DD/RRRR
Thanks,
Anu

Answer 1

If you're using DATES then they're stored as DATES.
Just compare them rightaway...
Formatting is to be used when the date needs to be queried and presented.
Unless you store them using TRUNC in some bri trigger of something like that.
Then this might be your problem:
MHO%xe> with dates1 as( --simulate data
  2  select to_date('201003', 'yyyymm') dt from dual union all
  3  select to_date('201004', 'yyyymm') from dual union all
  4  select to_date('201005', 'yyyymm') from dual union all
  5  select to_date('201006', 'yyyymm') from dual
  6  )
  7  , dates2 as( --simulate data
  8  select to_date('2010/03', 'yyyy/mm') dt from dual union all
  9  select to_date('2010/04', 'yyyy/mm') from dual union all
10  select to_date('2010/05', 'yyyy/mm') from dual union all
11  select to_date('2010/06', 'yyyy/mm') from dual
12  ) -- actual query here
13  select dt1.dt
14  ,      dt2.dt
15  from   dates1 dt1
16  ,      dates2 dt2
17  where  dt1.dt = dt2.dt;
DT                  DT
01-03-2010 00:00:00 01-03-2010 00:00:00
01-04-2010 00:00:00 01-04-2010 00:00:00
01-05-2010 00:00:00 01-05-2010 00:00:00
01-06-2010 00:00:00 01-06-2010 00:00:00
save the date in the log table in the format MM/DD/RRRRYou might have lost your day and time component probably.