Call APEX gurus

Question

I am calling APEX gurus and need your help on this. I'm currently developing a page to display some data from an Oracle table.
SSN on the page currently is a "Display Only". SSN data in the table is encrypted. We developed a package to encrypt/decrypt it by using DBS_OBFUSCATION_TOOLKIT.
The package looks like p_info.push(SSN) which means encrypt; p_info.pop(SSN) which means decrypt. On APEX page, in Source section,
Source Used - Only when current value in session state is null; Source Type - SQL Query (return single value); Source value or expression -
select p_info.pop(SSN) from table_A where seqno =:P2_seqno. It works very well.
However, now we need to change SSN on the page from "Display Only" to be able to EDIT. So, I tried to change it "Display Only" to "Text field". Source Used - Always, replacing
any existing value in session state; Source Type and Source value or expression are as same as above. But, when ran the page, after making changes on SSN and hit "Apply Change" button, SSN didn't get changed. Is there anything I'm missing?
Your help will be truly appreciated.

Answer 1

Option 1: The Trigger....this really is better because your data will work no matter how the table is updated, i.e. via APEX or SQL*Plus or whatever...
CREATE OR REPLACE TRIGGER BRIU_MYSSN
BEFORE INSERT OR UPDATE
ON MYSSN
REFERENCING NEW AS new OLD AS old
FOR EACH ROW
DECLARE
   lc_EncryptedSSN CHAR(32);
BEGIN
   lc_EncryptedSSN := pinfo.pop(:new.SSN);
   :new.SSN := lc_EncryptedSSN;
EXCEPTION
   WHEN OTHERS
   THEN
      -- Consider logging the error and then re-raise
      RAISE;
END;
Option 2: APEX
On you page, under Page Processing, right-click on Computations. Pick Item on this Page. Pick the page item corresponding to the SSN. Pick After Submit for you Computation Point. Pick PL/SQL for the function body.
BEGIN
   RETURN info.pop(:P8_SSN);
END;-Joe