Is there a problem with APEX Application Processes and VPD?

Question

I have a table that has a policy function. When I select from the table straight from the page it seems to be only returning the appropriate rows for the user.
But, when I select from the same table using an application process (On-Demand), PL/SQL Block.
BEGIN
OWA_UTIL.mime_header ('text/xml', FALSE);
HTP.p ('Cache-Control: no-cache');
HTP.p ('Pragma: no-cache');
OWA_UTIL.http_header_close;
HTP.prn ('<select>');
FOR c IN (SELECT '1' o,
name || ' (' || school || ')' d,
pk_id r
FROM sch_base
WHERE pk_id = nvl(:REFRESH_LOV_PK_ID,'null')
UNION
SELECT '2' o,
'%' d,
'%null%' r
FROM dual
UNION
SELECT '3' o,
name || ' (' || school || ')' d,
pk_id r
FROM sch_base
WHERE pk_id <> nvl(:REFRESH_LOV_PK_ID,'null')
ORDER BY 1,2)
LOOP
HTP.prn ('<option value="' || c.r || '">' ||
c.d || '</option>');
END LOOP;
HTP.prn ('</select>');
END;
It returns all rows in the table.

Answer 1

This is the policy on my table:
begin
dbms_rls.add_policy(
object_schema => 'SIS_EXPRESS',
object_name => 'SCH_BASE',
policy_name => 'SCH_BASE Policy',
function_schema => 'SIS_EXPRESS',
policy_function => 'VPD_SCH_BASE',
statement_types => 'select');
end;
I have a function VPD_SCH_BASE which set the where condition for the SCH_BASE table.
It works for a simple list values select, but not when this Application Process is run.
BEGIN
OWA_UTIL.mime_header ('text/xml', FALSE);
HTP.p ('Cache-Control: no-cache');
HTP.p ('Pragma: no-cache');
OWA_UTIL.http_header_close;
HTP.prn ('<select>');
FOR c IN (SELECT '1' o,
name || ' (' || school || ')' d,
pk_id r
FROM sch_base
WHERE pk_id = nvl(:REFRESH_LOV_PK_ID,'null')
UNION
SELECT '2' o,
'%' d,
'%null%' r
FROM dual
UNION
SELECT '3' o,
name || ' (' || school || ')' d,
pk_id r
FROM sch_base
WHERE pk_id <> nvl(:REFRESH_LOV_PK_ID,'null')
ORDER BY 1,2)
LOOP
HTP.prn ('<option value="' || c.r || '">' ||
c.d || '</option>');
END LOOP;
HTP.prn ('</select>');
END;