Accessing DBMS_AQ from Apex screen gives an error

Question

Hi,
I have created an Advanced queue (DBMS_AQ) in my schema and i can successfully enqueue and dequeue messages through a stored proc.
But when i call the same stored proc from an APEX screen, i get the following error.
"ORA-24010: QUEUE APEX_PUBLIC_USER.<Q_name> does not exist."
As AQ admin and even as SYSDBA, the following permissions were given, but still
no luck.
1) DBMS_AQADM.grant_queue_privilege (
privilege => 'ENQUEUE_ANY',
queue_name => 'Q_name',
grantee => 'APEX_PUBLIC_USER',
grant_option => FALSE);
2) DBMS_AQADM.grant_queue_privilege (
privilege => 'DEQUEUE_ANY',
queue_name => 'Q_name',
grantee => 'APEX_PUBLIC_USER',
grant_option => FALSE);
3) DBMS_AQADM.grant_queue_privilege (
privilege => 'ALL',
queue_name => 'Q_name',
grantee => 'PUBLIC',
grant_option => FALSE);
4) Created a public synonym for the queue and tried to access the queue from the screen.
Can you please help me to access the Queue from APEX screens ?

Answer 1

Hi Scott,
First to answer your questions based on the error i was getting
All 1 , 2 and 3 are the same.
1) The schema assigned to the application is 'XYZ'
2) 'XYZ' is the AQ_administrator
3) Permission was granted to APEX_PUBLIC_USER by connecting as 'XYZ'.
Also in my local XE DB, i tried the same and i am able to access Q from the APEX application created in that Schema.
I did not grant any privilege except that the schema (foo) is the AQ_ADMIN.
schema: foo
workspace: foo (automatically created when i create an app in the schema)
parsing schema: foo
Please find the steps below
Connect As Sysdba
AQ_ADMIN PRIVELEGES
1) GRANT aq_administrator_role TO foo;
2) GRANT execute ON dbms_aq TO foo;
3) GRANT execute ON dbms_aqadm TO foo;
Connect As foo
1) create type image_uploaded_ot as object
sheet_id NUMBER(15));
2) GRANT EXECUTE ON IMAGE_UPLOADED_OT TO PUBLIC;
-- create QT and Q
3) begin
DBMS_AQADM.CREATE_QUEUE_TABLE (
     queue_table => 'image_uploaded_qt',
queue_payload_type => 'image_uploaded_ot'
DBMS_AQADM.CREATE_QUEUE (
queue_name => 'image_uploaded_q',
queue_table => 'image_uploaded_qt'
DBMS_AQADM.START_QUEUE (
queue_name => 'image_uploaded_q'
end;
-- verify if queue exists
4) SELECT name, enqueue_enabled, dequeue_enabled
FROM user_queues;
SELECT name, enqueue_enabled, dequeue_enabled
FROM user_queues;
5) TESTING - ENQUEUE/DEQUEUE
CREATE OR REPLACE PROCEDURE demo_enqueue ( OT_I image_uploaded_ot)
IS
enq_msgid RAW(16);
eopt dbms_aq.enqueue_options_t;
mprop dbms_aq.message_properties_t;
aprop sys.aq$_agent;
pragma autonomous_transaction;
BEGIN
aprop := sys.aq$_agent(NULL, 'foo.image_uploaded_q', 0);
mprop.sender_id := aprop;
dbms_aq.enqueue('foo.image_uploaded_q', eopt, mprop, OT_I, enq_msgid);
COMMIT;
END demo_enqueue;
CREATE OR REPLACE PROCEDURE demo_dequeue IS
deq_msgid RAW(16);
dopt dbms_aq.dequeue_options_t;
mprop dbms_aq.message_properties_t;
payload_t image_uploaded_ot;
q_on_hand PLS_INTEGER;
no_messages EXCEPTION;
pragma exception_init(no_messages, -25228);
pragma autonomous_transaction;
BEGIN
dopt.dequeue_mode := dbms_aq.remove;
dopt.navigation := dbms_aq.first_message;
dopt.visibility := dbms_aq.immediate;
-- add functionality with mprop.attempts and mprop.enqueue_time
dbms_aq.dequeue('foo.image_uploaded_q', dopt, mprop, payload_t, deq_msgid);
UPDATE OFFICE
SET OFFICE_NAME = 'TEST'
WHERE OFFICE_ID = payload_t.SHEET_ID;
COMMIT;
EXCEPTION
WHEN others THEN
RAISE;
END;
6) TESTING FROM APEX
created a pl/sql process
declare
test_ot image_uploaded_ot;
begin
test_ot := image_uploaded_ot(1);
demo_enqueue(test_ot);
demo_dequeue();
end;
By looking at the test program above and the answer to the questions. The test prgm satisfies criteria 1 and 2 above and as you had mentioned and confirmed by test prgm, 3 is not required.
I am not sure what privilege is missing in the actual schema.
But atleast a hope that a AQ is accessible from APEX :)
Thanks,
Rakesh