Month conversion to number

Question

Need help guys,
i have below query
SELECT (SUBSTR(TO_CHAR(TO_DATE('JAN-2000','MM/YYYY'),'MM-RRRR'),1,9)) FROM DUAL;
this returns the output 01-2000.
If the month is in calender month then it will work correctly.
suppose if the month is not in calender month suppose if i pass ADJ-RRRR,then it should return ADJ-RRRR.How can achieve this using DECODE?

Answer 1

Hi,
user550686 wrote:
you query return invalid month.
The problem is we dont have valid months in that .We have a month name called 'ADJ'.
Thats where the query is failing.Sorry, I don't understand.
Using Sanjay's most recent data, both methods I suggested return what I expect you want.
with d as (
SELECT 'JAN-2000' col1 FROM DUAL union all
SELECT 'JAN-07' col1 FROM DUAL union all
SELECT 'ADJ-RRRR' col1 FROM DUAL union all
SELECT 'ADJ-2006' col1 FROM DUAL union all
SELECT 'FEB-2009' col1 FROM DUAL
SELECT  col1
,     NVL ( TO_CHAR ( to_dt ( col1
                            , 'MON-YYYY'
                 , 'MM-YYYY'
          , col1
          )               AS via_to_dt
,     CASE
          WHEN  UPPER (SUBSTR (col1, 1, 3))  IN ( 'JAN', 'FEB', 'MAR'
                                                         , 'APR', 'MAY', 'JUN'
                                    , 'JUL', 'AUG', 'SEP'
                                    , 'OCT', 'NOV', 'DEC'
          THEN  TO_CHAR ( TO_DATE ( col1
                                     , 'MON-YYYY'
                     , 'MM-YYYY'
          ELSE  col1
     END               AS via_case
FROM     d;Results:
COL1     VIA_TO_D VIA_CASE
JAN-2000 01-2000  01-2000
JAN-07   01-0007  01-0007
ADJ-RRRR ADJ-RRRR ADJ-RRRR
ADJ-2006 ADJ-2006 ADJ-2006
FEB-2009 02-2009  02-2009What results do you want?
If you want to read 'JAN-07' as 'JAN-2007', use 'RRRR' instead of 'YYYY' in the 2nd argument to TO_DATE. There's no point in using 'RRRR' in TO_CHAR.
If you want to equate ADJ with December, then instead of col1, use
REPLACE ( UPPER (col1)
        , 'ADJ'
        , 'DEC'
        )You won't need to use UPPER again, of course.