Advanced Queuing - Oracle

queue_name => ’AQ_book_orders’,
queue_table => ‘book_order_qtab’);
-- start the queue
dbms_aqadm.start_queue(‘AQ_book_orders’);
END;
/
Converting Messages
The message system link called fqlink, which connects to a third-party messaging
system, should be created by calling dbms_mgwadm.create_msgsystem_link(
). The foreign queue, FQ_book_orders, of the third-party messaging system
should be registered by calling dbms_mgwadm.register_foreign_queue( ).
Propagating Outbound XML Messages: Example
This example sets up propagation to move book order messages from the AQ
queue, AQ_book_orders, to the foreign queue, FQ_book_orders, in the form of
XML documents. Users can use the package DBMS_XMLSCHEMA to generate an XML
schema from the ADT book_order_typ to parse and process the XML messages
at the third-party messaging system side.
The following script defines a function and a transformation to convert an AQ book
order message to an XML document that is stored in an object of the canonical type
sys.mgw_basic_msg_t. Run the script as user mgwuser.
-- create a transformation function
CREATE OR REPLACE FUNCTION fnc_order2basic (book_order IN book_order_typ)
RETURN sys.mgw_basic_msg_t
IS
v_xml XMLType;
v_text varchar(2000); -- assume book orders in XML document
-- are less than 2000 char long.
v_basic sys.mgw_basic_msg_t;
BEGIN
-- create a XMLType object from the book_order
v_xml := XMLType.createXML(book_order, null, null);
-- convert the XMLType object to XML document (text)
v_text := v_xml.getStringVal();
-- store the XML document in a mgw_basic_msg_t obejct
v_basic := sys.mgw_basic_msg_t.construct;
v_basic.text_body := sys.mgw_text_value_t(v_text, null);
Messaging Gateway 18-41