Converting dayperiods? Is it possible?

Question

Hey everyone...
I have a question relating to creating a SQL query. I am not pro by any means, but rather a beginner-intermediate, so bear with me...
I am creating a query to find all the actions that took place on a particular account yesterday that was over a certain amount. The only problem is, in my companies database, the date is listed as a dayperiod and not an actual date. Is there any function or any way to translate dayperiods into standard formated date (08/09/2007) or something similar? If that is not possible, is there any way to do something like...
where cd.DAYPERIOD > SYSDATE-2
Any ideas?
Thanks,
Scott

Answer 1

And,
you could create a function that allows you to convert to a date without typing it each time.
FUNCTION get_real_date(p$_dayperiod IN NUMBER)
  RETURN DATE
IS
BEGIN
  RETURN TO_DATE(TO_NUMBER(TO_CHAR(TO_DATE('01011970', 'MMDDYYYY'), 'J')) + p$_dayperiod, 'J');
END;
WITH cc AS (
SELECT 1 id, 13734 dayperiod FROM DUAL UNION ALL
SELECT 2, 13733 FROM DUAL UNION ALL
SELECT 3, 13732 FROM DUAL)
--end test data
SELECT dayperiod
      ,get_real_date(dayperiod)
  FROM cc; 
DAYPERIOD              GET_REAL_DATE(DAYPERIOD) 
13734                  09-AUG-07                
13733                  08-AUG-07                
13732                  07-AUG-07                
3 rows selected
WITH cc AS (
SELECT 1 id, 13734 dayperiod FROM DUAL UNION ALL
SELECT 2, 13733 FROM DUAL UNION ALL
SELECT 3, 13732 FROM DUAL)
--end test data
SELECT id
      ,dayperiod
      ,get_real_date(dayperiod)
  FROM cc
WHERE get_real_date(cc.dayperiod) = TRUNC(SYSDATE, 'DD') - 1; 
ID                     DAYPERIOD              GET_REAL_DATE(DAYPERIOD) 
2                      13733                  08-AUG-07                
1 rows selected