Advanced Queuing - Oracle

Dequeue Features
BEGIN
subscriber := aq$_agent('East_Shipping', 'ES.ES_bookedorders_que', null);
dbms_aqadm.add_subscriber(
queue_name => 'OE.OE_bookedorders_que',
subscriber => subscriber,
rule => 'tab.user_data.orderregion = ''EASTERN'' OR
(tab.user_data.ordertype = ''RUSH'' AND
tab.user_data.customer.country = ''USA'') ');
END;
Overseas Shipping defines an agent called Overseas_Shipping with the OS
booked orders queue as the agent address (destination queue to which messages
must be delivered). This agent subscribes to the OE booked orders queue using a
rule specified on the orderregion attribute. Since the representation of orders at
the Overseas Shipping site is different from the representation of orders at the Order
Entry site, a transformation is applied before messages are propagated from the
Order Entry site to the Overseas Shipping site.
/* Add a rule-based subscriber (for Overseas Shipping) to the Booked orders
queues with Transformation. Overseas Shipping handles all non-US orders: */
DECLARE
subscriber aq$_agent;
BEGIN
subscriber := aq$_agent('Overseas_Shipping','OS.OS_bookedorders_que',null);
dbms_aqadm.add_subscriber(
queue_name => 'OE.OE_bookedorders_que',
subscriber => subscriber,
rule => 'tab.user_data.orderregion = ''INTERNATIONAL''',
transformation => 'OS.OE2XML');
END;
See "Message Format Transformation" on page 8-6 for more details on defining
transformations.
Assume that the Overseas Shipping site has a subscriber, Overseas_DHL, for
handling RUSH orders. Since OS_bookedorders_que has the order details
represented as an XMLType, the rule uses XPath syntax.
DECLARE
subscriber aq$_agent;
BEGIN
subscriber := aq$_agent('Overseas_DHL', null, null);
dbms_aqadm.add_subscriber(
8-88 Oracle9i Application Developer’s Guide - Advanced Queuing