CREATE TABLE TBL_TEST (ID NUMBER,NAME VARCHAR2(10),PID NUMBER,QTY NUMBER)；

INSERT INTO TBL_TEST(ID,NAME,PID,QTY) VALUES('1','111','0',1);
INSERT INTO TBL_TEST(ID,NAME,PID,QTY) VALUES('2','222','1', 2);
INSERT INTO TBL_TEST(ID,NAME,PID,QTY) VALUES('4','444','1',4);
INSERT INTO TBL_TEST(ID,NAME,PID,QTY) VALUES('5','555','2',5);
INSERT INTO TBL_TEST(ID,NAME,PID,QTY) VALUES('9','999','2',7);

INSERT INTO TBL_TEST(ID,NAME,PID,QTY) VALUES('10','999-1','9',4);
INSERT INTO TBL_TEST(ID,NAME,PID,QTY) VALUES('11','999-2','9',5);
INSERT INTO TBL_TEST(ID,NAME,PID,QTY) VALUES('12','999-3','9',6);

SELECT ID,
       NAME,
       pid,
       qty,
       dbms_aw.eval_text(ltrim(sys_connect_by_path(qty, '*'), '*'))
       DBMS_XMLGEN.getxmltype
  FROM TBL_TEST
 START WITH ID = 1
CONNECT BY PRIOR ID = pid
 ORDER BY 1

SELECT xmlquery('1*2*3*4' returning content).getnumberval() FROM DUAL;