How to validate text field against PICK_DATE_FORMAT_MASK format ?

Question

Hi Folks,
At application level i've defined a substitution variable PICK_DATE_FORMAT_MASK which stores a date format for all date fields.
On actual page, I have an editable field (Date Picker (use application format mask)) which stores date value.
I would like to add a validation to that field, which would validate value entered by user (if he decide not to use date picker!) - validation if entered value is in PICK_DATE_FORMAT_MASK format mask.
For example:
if PICK_DATE_FORMAT_MASK = 'DD/MM/YYYY'
and on my page if user enters: 01-JAN-2009 then validation error should be raised => "Entered date is in incorrect format!"
Any idea?
Thanks,
Tomas

Answer 1

Hi,
You don't need to manually test the date against the format - SQL will do that for you and generate errors if it can't make a date from the string using the format supplied.
For example:
DECLARE
vDATE DATE;
vLEN NUMBER;
vDATELEN NUMBER;
BEGIN
vLEN := LENGTH(:PICK_DATE_FORMAT_MASK);
vDATELEN := LENGTH(:P1_DATE);
IF vLEN <> vDATELEN THEN
  RETURN 'Invalid date - use ' || :PICK_DATE_FORMAT_MASK || ' formatted dates only!';
ELSE
  vDATE := TO_DATE(:P1_DATE, :PICK_DATE_FORMAT_MASK);
  RETURN NULL;
END IF;
EXCEPTION WHEN OTHERS THEN
RETURN 'Invalid date - use ' || :PICK_DATE_FORMAT_MASK || ' formatted dates only!';
END;This would be for a validation that returns an error message - a NULL return value indicates success - you can change this as required. Note that I am also checking the lengths of the date and the format string as, in some instances, 2-digit years will be accepted even if a 4-digit year is specified in the format string.
Andy