Advanced Queuing - Oracle

ecipients DBMS_AQ.aq$_recipient_list_t;
message_handle RAW(16);
message aq.message_typ;
/* Enqueue MESSAGE 1 for subscribers to the queue
i.e. for RED and GREEN: */
BEGIN
message := message_typ(’MESSAGE 1’,
’This message is queued for queue subscribers.’);
DBMS_AQ.ENQUEUE(queue_name => ’msg_queue_multiple’,
enqueue_options => enqueue_options,
message_properties => message_properties,
payload => message,
msgid => message_handle);
Enqueuing and Dequeuing Of Messages
/* Enqueue MESSAGE 2 for specified recipients i.e. for RED and BLUE.*/
message := message_typ(’MESSAGE 2’,
’This message is queued for two recipients.’);
recipients(1) := aq$_agent(’RED’, NULL, NULL);
recipients(2) := aq$_agent(’BLUE’, NULL, NULL);
message_properties.recipient_list := recipients;
DBMS_AQ.ENQUEUE(queue_name => ’msg_queue_multiple’,
enqueue_options => enqueue_options,
message_properties => message_properties,
payload => message,
msgid => message_handle);
COMMIT;
END;
Note that RED is both a subscriber to the queue, as well as being a specified
recipient of MESSAGE 2. By contrast, GREEN is only a subscriber to those messages
in the queue (in this case, MESSAGE) for which no recipients have been specified.
BLUE, while not a subscriber to the queue, is nevertheless specified to receive
MESSAGE 2.
/* Dequeue messages from msg_queue_multiple: */
DECLARE
dequeue_options DBMS_AQ.dequeue_options_t;
message_properties DBMS_AQ.message_properties_t;
message_handle RAW(16);
message aq.message_typ;
no_messages exception;
Oracle Advanced Queuing by Example A-45