如何在Oracle中读写XML文件

Question

老问题了。
现有一张表，内有trainid,startstation,endstation三个字段，如何将数据导出生成XML文件呢？不求工具，只求代码。另求如何读写XML到Oracle中生成表，也是这样个例子。我自己写了点，但不知道如何将字段里的数据导出去，希望高手等告诉我declaredoc xmldom.DOMDocument;
main_node xmldom.DOMNode;traininfo_node xmldom.DOMNode;
traininfo_elemt xmldom.DOMElement;info_node xmldom.DOMNode;
info_elemt xmldom.DOMElement;trainid_node xmldom.DOMNode;
trainid_elemt xmldom.DOMElement;startstation_node xmldom.DOMNode;
startstation_elemt xmldom.DOMElement;endstation_node xmldom.DOMNode;
endstation_elemt xmldom.DOMElement;begindoc:=xmldom.newDOMDocument;
main_node:=xmldom.makeNode(doc);traininfo_elemt:=xmldom.createElement(doc,'traininfo');
traininfo_node:=xmldom.appendChild(main_node,xmldom.makeNode(traininfo_elemt));info_elemt:=xmldom.createElement(doc,'info');
info_node:=xmldom.appendChild(traininfo_node,xmldom.makeNode(info_elemt));trainid_elemt:=xmldom.createElement(doc,'trainid');
trainid_node:=xmldom.appendChild(info_node,xmldom.makeNode(trainid_elemt));
startstation_elemt:=xmldom.createElement(doc,'startstation');
startstation_node:=xmldom.appendChild(info_node,xmldom.makeNode(startstation_elemt));endstation_elemt:=xmldom.createElement(doc,'endstation');
endstation_node:=xmldom.appendChild(info_node,xmldom.makeNode(endstation_elemt));xmldom.writeToFile(doc,'d:\test.xml');end;