Dynamic Action on tabular form: to auto set value for all changes rows

Question

Hi All:
I am using APEX4.2.3 and I am not very familar with JQUERY or Javascript.
I am having a tabular form to support Update and Delete action. The tabular form has 4 columns:
Column A: ID                      (Number)     : Read-only column
column B: Name                 (Varchar2)   : Editable
Column C: Age                    (Number)     : Editable
Column D: ChangeFlag      (Varchar2)   : Read-only column                             ==> however, I want this column been automatically upldated by my APEX application
Here is the requirement: First user update Column B, or C or both for # of rows; then user click "Save Change" button. For ALL updated rows, I need to automatically update Column D with below logic:
For a given row,
               IF Column D IS NULL  THEN
                     set value = 'M'                           -- M means modified
               ELSE --- column D has a value already
                    IF last character of Column D is 'M', THEN
                           don't do anything;
                    ELSE
                          set value of D = existing value + 'M'                       (here + means concatenate
                   END IF;
            END IF;
I thought this can be done by creating dynamic action on tabular form ... I have researched this on this forum and can't find a good match example ..
I know I can implement this using a DB trigger; however, I want to learn if this can be achived via Dynamic Action.
Thanks!
Kevin

Answer 1

Hi Expert:
Anyone can offer any direction or help on this?
Thanks!
Kevin