Help convert date please

Question

I have 3 possible length Dates stored in a VARCHAR2 field type, I am trying to convert that for a friend:
we are looking for this in the End as either a Date or a Number field or both (that's what is needed)
20110829 YYYYMMDD
what I have is these distinct length type on the field:
8
07/13/13
9
6/30/2012
10
10/13/2011
Can someone help me convert this field to either number: 20120512 or Date YYYYMMDD ? both examples would help too :- ) learning

Answer 1

You can use the below to find the problem date(s) in your table. The SELECT obviously needs to be updated with your table/column names
CREATE OR REPLACE FUNCTION dateconvert(p_chardate  VARCHAR2)
RETURN VARCHAR2
AS
  v_date  DATE;
BEGIN
  v_date := TO_DATE(p_chardate, 'MM/DD/RR');
  RETURN 'OK';
EXCEPTION
  WHEN OTHERS THEN
    RETURN   p_chardate;
END;
SELECT datecol
FROM   datetable
WHERE dateconvert(datecol) != 'OK';