Random page item data corruption

Question

I designed an APEX page for a service request processing application with several date page items. Our database is Oracle 10g. The application is in production and the users have reported that data in some date page items become corrupted randomly. For example, the user enters ’07/04/2011’ in the date page item “Planned Start Date” among other values and submits the page. The date somehow winds up ‘07/04/0011’ that is, year 11. (A corrupt date increases the risk that these transactions will not be processed in a timely manner and will negatively impact the level of customer service the user wishes to provide.)
I have identified three possible areas that may hold the key to underlying cause: 1) page item edit mask, 2) page process(es), 3) DB column constraints. Inasmuch as this is a random problem and has affected a handful of rows it may not be possible to trace the logic as the pages are processed. Has anyone encountered this problem and can suggest a possible remedy? For the sake of clarity I placed the setups for the affected page item below.
Selected setups for P14_PLANNED_START_DATE, all unlisted attributes are blank or null:
Settings - Value Required: No; Format Mask: MM/DD/YYYY; Show: on icon click; Show Other Months: No; Navigation List for: None
Source - Source Used: Always, replacing any existing value in session state; Source Type: Database Column; Maintain Session State: Per session; Source Value or Expression: PLANNED_START_DATE
Default - Default Value: to_char(sysdate, ‘MM/DD/YYYY’); Default Value Type: PL/SQL Expression
Sample page processes are:
Validation - Name: P14_PLANNED_START_DATE not null; Type: Item specified is not null; Validation expression: P14_PLANNED_START_DATE; Always execute: No
Conditions – Condition Type: SQL Expression; Expression 1: :REQUEST IN (‘SAVE’, ‘CREATE’)
Validation – Name: P14_PLANNED_STARTEND_OKAY; Type: Function Returning Boolean:
Validation Expression:
IF SIGN(to_date(to_char(to_date(:P14_PLANNED_START_DATE,'MM/DD/YYYY'),'YYYYMMDD-') || :P14_PLANNED_END_TIME,'YYYYMMDD-HH:MI AM')
- to_date(to_char(to_date(:P14_PLANNED_START_DATE,'MM/DD/YYYY'),'YYYYMMDD-') || :P14_PLANNED_START_TIME,'YYYYMMDD-HH:MI AM')) > 0
THEN RETURN TRUE;
ELSE
RETURN FALSE;
END IF;
Conditions – Condition Type: PL/SQL Function body returning Boolean
Expression 1:
IF :REQUEST IN ('SAVE','CREATE') THEN
IF (:P14_PLANNED_START_TIME IS NULL OR :P14_PLANNED_END_TIME IS NULL)
THEN RETURN FALSE;
ELSE RETURN TRUE;
END IF;
ELSE RETURN FALSE;
END IF;
Database: The attributes for the database column are
Column Name: PLANNED_START_DATE
Data Type: DATE
Nullable: No

Answer 1

Ligon,
You're right to think this is pretty laborious stuff. A co-worker wanted to do the same, to make sure users didn't lose a change when clicking Cancel. I suggested he look at calculating the query checksum before and after, which he tried. But it got very cumbersome very fast and he ended up dropping the idea. He's fairly new with Apex, but he's also a quick study, so it's not like he's a novice coder.
I don't have his implementation details anymore to even share with you.
Sorry I couldn't be more help.
Good luck,
Stew