CONNECT aq_admin/aq_admin@tsh9i

EXECUTE DBMS_AQADM.grant_queue_privilege ( -
   privilege     =>     'ALL', -
   queue_name    =>     'aq_admin.event_queue', -
   grantee       =>     'aq_user', -
   grant_option  =>      FALSE);

At this point the queue can be used for enqueue and dequeue operations by the AQ_USER user.
 

Enqueue Message

Messages can be written to the queue using the DBMS_AQ.ENQUEUE procedure:
 

CONNECT aq_user/aq_user@tsh9i

DECLARE
  l_enqueue_options     DBMS_AQ.enqueue_options_t;
  l_message_properties  DBMS_AQ.message_properties_t;
  l_message_handle      RAW(16);
  l_event_msg           AQ_ADMIN.event_msg_type;
BEGIN
  l_event_msg := AQ_ADMIN.event_msg_type('REPORTER', 1, 2);

  DBMS_AQ.enqueue(queue_name          => 'aq_admin.event_queue',        
                  enqueue_options     => l_enqueue_options,     
                  message_properties  => l_message_properties,   
                  payload             => l_event_msg,             
                  msgid               => l_message_handle);

  COMMIT;
END;
/

Dequeue Message

Messages can be read from the queue using the DBMS_AQ.DEQUEUE procedure:
 

CONNECT aq_user/aq_user@tsh9i

SET SERVEROUTPUT ON

DECLARE
  l_dequeue_options     DBMS_AQ.dequeue_options_t;
  l_message_properties  DBMS_AQ.message_properties_t;
  l_message_handle      RAW(16);
  l_event_msg           AQ_ADMIN.event_msg_type;
BEGIN
  DBMS_AQ.dequeue(queue_name          => 'aq_admin.event_queue',
                  dequeue_options     => l_dequeue_options,
                  message_properties  => l_message_properties,
                  payload             => l_event_msg,
                  msgid               => l_message_handle);

  DBMS_OUTPUT.put_line ('Event Name          : ' || 
l_event_msg.name);
  DBMS_OUTPUT.put_line ('Event Current Status: ' || 
l_event_msg.current_status);
  DBMS_OUTPUT.put_line ('Event Next Status   : ' || 
l_event_msg.next_status);
  COMMIT;
END;
/

Variations

The DEQUEUE_OPTIONS_T, DEQUEUE_OPTIONS_T and MESSAGE_PROPERTIES_T types can be used to vary the way messages are enqueued and dequeued. This is where the real flexibility of advanced queuing becomes evident. The discussion of these options is beyond the scope of this article.