Automatically displaying date of last page change

Question

I think I remember seeing this a year or so ago, but I can't find it.
Is there a way to grab the date that a page was last modified and display that on the page? It seems like there should be and easy way, since the information shows up in the developer reports.
I have the following query which works in SQL*Plus:
select max(audit_date) from flows_020000.WWV_FLOW_BUILDER_AUDIT_TRAIL
where flow_id = 130
and page_id = 306
but in a page definition I get an 'insufficient privileges' message.
I'd to avoid granting select privileges on the table, as I'd then have to remember to redo it with each new version of ApEx as well. And since I can't get the above to work yet, I'm not sure if I could substitute strings like &APP_ID. and &PAGE_ID. into the where clause, so this could just be a Page 0 item instead of hard coding it onto each page.
Any ideas what I'm missing? (Other than when I purge my logs)
Thanks,
Bill Ferguson

Answer 1

(Almost) a couple of small typos in the first select statement.
First, somehow I wound up with two create table lines. Not sure why, but get rid of one. Next, This bit of code didn't have the other DISTINCT in it (I guess somehow I copied the older version, dunno).
So, here's the correct version:
CREATE TABLE LAST_WEB_APP_CHANGE AS (
SELECT DISTINCT pk_field, short_name workspace, NAME app_name, app_id, page_num, last_change_date, flow_user
FROM (SELECT DISTINCT pk_field, app_id, page_num , lv last_change_date
FROM (SELECT short_name|| LPAD (NVL (flow_id, 0), 6, 0)
|| LPAD (NVL (page_id, 0), 6, 0) pk_field,
flow_id app_id, page_id page_num,
last_value(audit_date) OVER (PARTITION BY flow_id, page_id) AS lv
FROM flows_020000.wwv_flow_builder_audit_trail c,
                              flows_020000.wwv_flow_companies
WHERE c.flow_id = flow_id
AND c.page_id = page_id
AND security_group_id = provisioning_company_id
               GROUP BY short_name, flow_id, page_id, security_group_id, audit_date) a
WHERE page_num IS NOT NULL),
          flows_020000.wwv_flow_builder_audit_trail a,
          flows_020000.wwv_flow_companies c,
          flows_020000.wwv_flow_models m
WHERE a.flow_id = app_id
AND page_id = page_num
AND last_change_date = audit_date
AND a.security_group_id = c.provisioning_company_id
AND a.security_group_id = m.security_group_id
AND short_name = '<your workspace name>'
Just to be sure, I retested again this morning and this one does grab (and create) the last changed record in the audit trail and stores it into whatever table name you chooes (if you edit it).
As Vikas said in an earlier post, it best (probably) to do this on each parsing schema, since each parsing schema can have multiple apps associted with it, and it can become a can of works creating a generic schema accessible to all.
Anyway, after the table is created and populated for each schema, then it's easy to create a page to to handle insert/update/deletes for the future maintainability of the data.
Personally, I'm leaning towards a variation of the above code associated with a button, to update the information, maybe a drop table followed by the above code? I need to experiment some.
But, you can create a Page 0 hidden item, I called mine :P0_LAST_CHANGE_DATE, with a SQL source of :
select TO_CHAR (last_change_date, 'DD-MON-RRRR HH24:MI:SS') last_change_date
from LAST_WEB_APP_CHANGE
where app_id = &APP_ID.
and page_num = &APP_PAGE_ID.
Then, on each page's footer, I have the statement:
Page Last Changed: &P0_LAST_CHANGE_DATE.
Variations of the above can also be used to display who changed it last (the flow_user field).
Now, each page will display the date of last change (almost) painlessly). I just need to periodically go out and maintain the table. Maybe a scheduled job run each night?
Somebody want to supply an example of how to do that?
Bill Ferguson