Generating XML from SQL queries and saving to a xml file?

Question

Hi there,
I was wondering if somebody could help with regards to the following:
Generating XML from SQL queries and saving to a xml file?
We want to have a stored procedure(PL/SQL) that accepts an order number as an input parameter(the procedure
is accessed by our software on the client machine).
Using this order number we do a couple of SQL queries.
My first question: What would be our best option to convert the result of the
queries to xml?
Second Question: Once the XML has been generated, how do we save that XML to a file?
(The XML file is going to be saved on the file system of the server that
the database is running on.)
Now our procedure will also have a output parameter which returns the filename to us. eg. Order1001.xml
Our software on the client machine will then ftp this XML file(based on the output parameter[filename]) to
the client hard drive.
Any information would be greatly appreciated.
Thanking you,
Francois

Answer 1

Hi
Here is an example of some code that i am using on Oracle 817.
The create_file procedure is the one that creates the file.
The orher procedures are utility procedures that can be used with any XML file.
PROCEDURE create_file_with_root(po_xmldoc OUT xmldom.DOMDocument,
pi_root_tag IN VARCHAR2,
                                        po_root_element OUT xmldom.domelement,
                                        po_root_node OUT xmldom.domnode,
                                        pi_doctype_url IN VARCHAR2) IS
xmldoc xmldom.DOMDocument;
root xmldom.domnode;
root_node xmldom.domnode;
root_element xmldom.domelement;
record_node xmldom.domnode;
newelenode xmldom.DOMNode;
BEGIN
xmldoc := xmldom.newDOMDocument;
xmldom.setVersion(xmldoc, '1.0');
xmldom.setDoctype(xmldoc, pi_root_tag, pi_doctype_url,'');
-- Create the root --
root := xmldom.makeNode(xmldoc);
-- Create the root element in the file --
create_element_and_append(xmldoc, pi_root_tag, root, root_element, root_node);
po_xmldoc := xmldoc;
po_root_node := root_node;
po_root_element := root_element;
END create_file_with_root;
PROCEDURE create_element_and_append(pi_xmldoc IN OUT xmldom.DOMDocument,
pi_element_name IN VARCHAR2,
                                        pi_parent_node IN xmldom.domnode,
                                        po_new_element OUT xmldom.domelement,
                                        po_new_node OUT xmldom.domnode) IS
element xmldom.domelement;
child_node xmldom.domnode;
newelenode xmldom.DOMNode;
BEGIN
element := xmldom.createElement(pi_xmldoc, pi_element_name);
child_node := xmldom.makeNode(element);
-- Append the new node to the parent --
newelenode := xmldom.appendchild(pi_parent_node, child_node);
po_new_node := child_node;
po_new_element := element;
END create_element_and_append;
FUNCTION create_text_element(pio_xmldoc IN OUT xmldom.DOMDocument, pi_element_name IN VARCHAR2,
pi_element_data IN VARCHAR2, pi_parent_node IN xmldom.domnode) RETURN xmldom.domnode IS
parent_node xmldom.domnode;                                   
child_node xmldom.domnode;
child_element xmldom.domelement;
newelenode xmldom.DOMNode;
textele xmldom.DOMText;
compnode xmldom.DOMNode;
BEGIN
create_element_and_append(pio_xmldoc, pi_element_name, pi_parent_node, child_element, child_node);
parent_node := child_node;
-- Create a text node --
textele := xmldom.createTextNode(pio_xmldoc, pi_element_data);
child_node := xmldom.makeNode(textele);
-- Link the text node to the new node --
compnode := xmldom.appendChild(parent_node, child_node);
RETURN newelenode;
END create_text_element;
PROCEDURE create_file IS
xmldoc xmldom.DOMDocument;
root_node xmldom.domnode;
xml_doctype xmldom.DOMDocumentType;
root_element xmldom.domelement;
record_element xmldom.domelement;
record_node xmldom.domnode;
parent_node xmldom.domnode;
child_node xmldom.domnode;
newelenode xmldom.DOMNode;
textele xmldom.DOMText;
compnode xmldom.DOMNode;
BEGIN
xmldoc := xmldom.newDOMDocument;
xmldom.setVersion(xmldoc, '1.0');
create_file_with_root(xmldoc, 'root', root_element, root_node, 'test.dtd');
xmldom.setAttribute(root_element, 'interface_type', 'EXCHANGE_RATES');
-- Create the record element in the file --
create_element_and_append(xmldoc, 'record', root_node, record_element, record_node);
parent_node := create_text_element(xmldoc, 'title', 'Mr', record_node);
parent_node := create_text_element(xmldoc, 'name', 'Joe', record_node);
parent_node := create_text_element(xmldoc,'surname', 'Blogs', record_node);
-- Create the record element in the file --
create_element_and_append(xmldoc, 'record', root_node, record_element, record_node);
parent_node := create_text_element(xmldoc, 'title', 'Mrs', record_node);
parent_node := create_text_element(xmldoc, 'name', 'A', record_node);
parent_node := create_text_element(xmldoc, 'surname', 'B', record_node);
-- write the newly created dom document into the buffer assuming it is less than 32K
xmldom.writeTofile(xmldoc, 'c:\laiki\willow_data\test.xml');
EXCEPTION
WHEN xmldom.INDEX_SIZE_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'Index Size error');
WHEN xmldom.DOMSTRING_SIZE_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'String Size error');
WHEN xmldom.HIERARCHY_REQUEST_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'Hierarchy request error');
WHEN xmldom.WRONG_DOCUMENT_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'Wrong doc error');
WHEN xmldom.INVALID_CHARACTER_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'Invalid Char error');
WHEN xmldom.NO_DATA_ALLOWED_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'Nod data allowed error');
WHEN xmldom.NO_MODIFICATION_ALLOWED_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'No mod allowed error');
WHEN xmldom.NOT_FOUND_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'Not found error');
WHEN xmldom.NOT_SUPPORTED_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'Not supported error');
WHEN xmldom.INUSE_ATTRIBUTE_ERR THEN
RAISE_APPLICATION_ERROR(-20120, 'In use attr error');
WHEN OTHERS THEN
dbms_output.put_line('exception occured' || SQLCODE || SUBSTR(SQLERRM, 1, 100));
END create_file;