如果您模拟
level以
connect by下列，则可以使用DBMS_XMLGEN.newcontextfromhierarchy和CTE完成此操作：
SELECt DBMS_XMLGEN.getXML(DBMS_XMLGEN.newcontextfromhierarchy('with employee as ( select 1 id, ''A'' name, 2 managerid from dual union all select 2 id, ''B'' name, 4 managerid from dual union all select 3 id, ''C'' name, 4 managerid from dual union all select 4 id, ''D'' name, null managerid from dual ), t1(lvl,id,name,managerid) AS ( -- Anchor member. SELECt 1 as lvl, id, name, managerid FROM employee WHERe managerid IS NULL UNIOn ALL -- Recursive member. SELECt t1.lvl+1 as lvl, t2.id, t2.name, t2.managerid FROM employee t2, t1 WHERe t2.managerid = t1.id)SEARCH DEPTH FIRST BY id SET order1SELECt lvl, xmlelement("Node", xmlattributes(name AS "name", id AS "id"))FROM t1ORDER BY order1')) FROM dual输出
<?xml version="1.0"?><Node name="D" id="4"> <Node name="B" id="2"> <Node name="A" id="1"/> </Node> <Node name="C" id="3"/></Node>
